BROMPTON BICYCLE - OWNER'S MANUAL INTRODUCTION A Brompton used and maintained correctly will give reliable service. These instructions deal comprehensively with looking after and making the most of your machine. Before using your Brompton, we particularly recommend that as a minimum, you read the sections on safety and folding. You should also be aware of the importance of maintaining adequate tyre pressures: soft tyres not only make for a lot more pedalling effort (which takes much of the fun out of riding), but also wear out quickly and have an adverse effect on handling. We cannot overemphasise, therefore, the need to keep tyres well inflated (section C 1). If you take delivery of your Brompton still in its packing, you will a) have to fit the left hand pedal (unless it has a folding pedal fitted); note that it has a left hand thread; b) have to back off the hinge clamp handles a few turns before unfolding. If you carry out any adjustments or maintenance work yourself, read the relevant section of these instructions first; it is possible inadvertently to impair the folding process or, if reassembly is carried out incorrectly, to damage the machine. If you take your machine to a dealer for any servicing work, we advise you wherever possible to use an authorised Brompton stockist. Once familiar with the Brompton. you will find that it comes into its own as a package of personal transport you can always keep to hand. There are countless uses for it. especially if you take it with you when travelling about, and we hope that you discover the extraordinary mobility and freedom that your Brompton can give. Serial Number: This is marked on the back of the main frame by the rear suspension pivot. You are advised to keep a record of this. CONTENTS Page 2 ........Section A................. Safety Page 2 ........Section B ................ Folding and unfolding Page 7 ........Section C ................ Using the Brompton Page 10 .......Section D ............... Saddle position Page 11 .......Section E ................ Handlebar and control lever position Page 11 .......Section F ................ Removing and refitting the wheels Page 15 .......Section G ................ Other design points to do with folding Page 18 .......Section H ................ Running adjustments and checks Page 20 .......Section J ................. Lubrication Page 22 .......Section K ................ Routine replacements Page 23 ...... Section L ................ Specification of spares
SECTION A: SAFETY. 1. Before riding off, get into the habit of checking that the seat pillar clamp is properly secured, and that the hinge clamp levers are firmly screwed up. 2. Carrying the Brompton: it is obviously less critical that the bike is correctly folded than assembled, but bear in mind that, if the machine has not been properly locked together, unexpected unfolding of the folded package, for instance on a staircase or lifting it off a luggage rack, could cause injury. 3. Do NOT try to alter the height of the handlebar stem where it enters the front forks. 4. Keep the gears properly adjusted, and brakes and control cables in good condition. Ensure that all running adjustments are carried out as described in section H. 5. During folding and unfolding, avoid putting your hands anywhere that they may be trapped. 6. Hard riding and high mileage use: follow the recommendations in section K regarding routine replacements of ALLOY frame components. 7. If you (end your Brompton to anyone else, make sure that they are familiar with it, and, if you let children use it, it is a good idea to tie the rear frame to the seat pillar to prevent it from unwanted folding. 8. In the wet, braking performance can be slightly impaired, and you should make allowance for this. 9. Always use lights, front and rear, when riding after dark.
SECTION B: FOLDING AND UNFOLDING. If you have not had the Brompton demonstrated and explained to you, you should read all of this section before attempting to unfold or fold the bike. For those who are already familiar with the Brompton, part 3 is valuable as a source cf tips.
Part 1: Basic order of unfolding and folding. a) UNFOLDING: Stage 1: SADDLE, HANDLEBAR and (if a folding pedal is fitted) PEDAL; these items can be dealt with in any order, but they must be unfolded before moving on to stage 2. Stage 2: FRONT WHEEL. The bicycle is now in its "parked" position and ready for use.
b) FOLDING: Always "park" the bike by swinging the rear wheel under before folding; Stage 1: FRONT WHEEL (right hand pedal should be moved out of the way if necessary). Stage 2: HANDLEBAR, SADDLE and, if fitted, folding PEDAL; again, these items can be dealt with in any order once the front wheel has been folded back and latched onto the rear frame.
Part 2: Other points to remember. 1. The seat pillar, when folded, is what locks the folded package together: it projects down from the main frame, so preventing the rear frame from rotating. DON'T therefore try to park or unpark the Brompton if any part of the seat pillar is projecting below the main frame, and DON'T try to latch or unlatch the front wheel from the rear frame if the saddle is folded (as this latching and unlatching requires that the rear frame rotates slightly relative the main frame). Remember also that when you pick the bike up the folded package may fail apart if the saddle is not fully down. 2. The folded bicycle can be picked up by the main tube. A useful alternative is to grip the forward part of the saddle, but to do this you must a) reclamp the seat pillar after folding (the saddle pointing slightly rightwards so as to be over the centre of gravity), and b) avoid pulling the padding away from the saddle frame. 3. Turning the cranks/pedals when the bicycle is parked: a) the left hand pedal should not be folded when this is being done, as it can catch on parts of the rear frame; b) during folding, the right hand pedal may have to be moved: to do this, the cranks can be rotated forwards or backwards. However when new, particularly on the 5-speed in top gear, turning the cranks quickly backwards can cause the chain to go slack or even come off. If this happens, turn the pedals forward instead, or alternatively keep the bike in middle gear when folding.
Part 3: Unfolding and folding explained in detail. If you have not seen the Brompton being folded, you may get the impression on reading this section that the process is difficult: it involves in practice only a few easy movements to which you will quickly become accustomed.
Unfolding: Stage 1 - Saddle and handlebars (and folding pedal): Saddle, figure 1: Undo the quick release lever, QR, under the saddle by swinging it outwards and backwards. Grasp the saddle at the rear end, and, resting one hand on the main frame tube at or near M, draw the saddle upwards until it comes to a firm stop: twist the saddle so that it points straight ahead, and secure the lever OR by moving it forward so as to lie alongside the main frame. In order to obtain a smooth action when moving the saddle up or down, you should pull or push along the line of the seat pillar itself. Adjusting the saddle position to suit your own preference is dealt with in section D. Handlebar, figure 2: The handlebar assembly is retained in position when folded by dint of the nipple, HBNIP, being trapped in the clip, HBC. To release, pull the handlebar outwards and forwards and swing the assembly upwards. To secure, make sure that the hinge clamp plate, HCPL, straddles both hinge plates, and screw up the lever at HH, firmly.
Left Hand pedal, figure 3: If this is fitted, unfold it by swinging the pedal body, PB, outwards. When in the correct position, the latch plate, LP, will snap into position to lock the pedal in place.
Stage 2 - Front wheel, figures 4 & 5: Do not attempt to unfold the front wheel assembly if either the saddle or the handlebar is still folded. Unfolding or folding the front wheel assembly requires only a single action, described below. First however, you should understand what goes on: the front wheel assembly is held in place when folded by means of the hook, H. passing over the tube, CHS, on the rear frame. To release, the
CHS
whole bicycle must be tipped slightly back relative to the rear wheel underneath it, so that the hook clears the tube, fig. 4. The front wheel is then moved out and forward into position; during this action there is no need to turn the front wheel - it should be kept pointing forward and slightly leftwards (fig. 5). Also you should note that during this action the top of the handlebar assembly remains roughly in the same position, with the bottom moving round a small half circle. You will find that there is a variety of methods for carrying out this action, but to begin with we suggest you use the following way: grasp the handlebar support, HBS, lift it slightly (maybe lifting the main frame or pushing back on the saddle at the same time), and then, using a "stirring" action move the front wheel out and round to its unfolded position. No strength is needed for this, but if you find the the action awkward to begin with, take hold of the front mudguard with your other hand and help the wheel round and forward. Finally, do up the hinge clamp on the main frame at MM, securing the lever firmly (leaning the bike to the right helps keep the locking plate in place whilst doing this). The bicycle is now parked, in effect ready for use: to unpark (figure 6), lift the bike by the saddle (keeping the front wheel turned slightly leftwards) and allow the rear wheel assembly to rotate down and back into its unfolded position. By controlling the way in which you raise and lower the saddle, this can be done in a single smooth movement, the momentum of the wheel assembly carrying it through: if to begin with you find the wheel hanging in the halfway position, help the wheel round by hand or with your foot. There is no need to lock the rear wheel assembly, as your weight, when you are on the bike, keeps it in place.
Folding: Always start by parking the bike, figure 6: to do this, turn the front wheel slightly leftwards (if you don't, no harm would result but the rear wheel would clash with the front wheel) and then raise the bike by the saddle, so allowing the rear wheel assembly to swing down and forward to lie under the main frame. The bike is now parked, and providing it is on reasonably level ground will stand up unsupported.
It is tempting to start folding with the "easy" items, the seat or handlebars. The bike cannot be folded properly if you do start with these: you must fold the front wheel assembly back first. Stage 1 - Front wheel, figure 5: First make sure that the right hand pedal is out of the way of the front wheel. It is best if the right hand pedal ends up pointing backwards and downwards.
Unscrew the hinge clamp at MH on the main frame until the locking plate is free (three or four turns of the handle normally suffice). Grasp the handlebar support, HBS, lift slightly (maybe pushing back on the saddle at the same time) and, keeping the front wheel pointing forwards, use a "stirring" action to move it out and back round till it lies alongside the rear wheel (again no strength is needed for this, but if it helps, take hold of the front mudguard with your other hand and guide the wheel round). Make sure that the hook, H, has passed over the tube, CHS, on the rear frame, and allow the front wheel assembly to drop (the whole bike actually rotating relative the rear frame). The front wheel is now in its folded position, and you can proceed with folding the remaining items. Stage 2 - Handlebars and saddle (and folding pedal): Handlebar, figure 2: Undo the hinge clamp at HH, the base of the handlebar stem; swing the handlebars down to lie alongside the front wheel and push home so that the nipple, HBNIP, engages in the clip, HBC. Alternatively, simply let the handlebars drop into position on their own. Saddle, figure 1: Undo the lever, QR, and push the saddle down. During this action, the lower end of the seat pillar passes behind the plastic disc, LSD, on the rear frame, and it is because of this that the rear frame remains folded, in turn retaining the front wheel in its folded position. So if you do not push the saddle down fully, it is possible for the folded package to come apart when you pick the bike up. You may wish to use the saddle as a handle to carry the bike, and in this case, you should reclamp the seat pillar using the lever, QR.
Folding pedal, figure 3: It is best to fold this with the left hand crank as high as possible (i.e. with the cranks turned so that the right hand pedal touches the front wheel). Rotate the pedal so that the ridged side of the latch plate is pointing upwards; next press the outer part of the latch plate downwards, so that the inner part clears the top of the bearing housing, BH. Lift the pedal body and stow the pedal. Front wheel assembly, other methods for folding and unfolding: the method described above, viz. holding the handlebar support and using a stirring action to move the front wheel assembly, is perfectly satisfactory. If you frequently fold and unfold your Brompton, you should be aware that there are other methods. These involve gripping the handlebar itself, holding the clamp handle, HH, pressing gently backwards on the saddle, or a combination of these. It is not appropriate to describe all the alternatives here, but you may find, after a few trials, a method that is more convenient for you.
SECTION C: USING THE BROMPTON. 1. Tyre pressures: Front: 50 - 70 psi. With Brompton rims you may exceed the pressure marked on the Rear: 60 - 70 psi. tyre wall. However do NOT exceed 75 psi: the tyre may distort or burst. If you are to use the bike on rough roads, then the ride will be more comfortable if you keep the pressures near the lower end of the ranges given. But to obtain the minimum pedalling effort, use the higher pressure. The pump supplied (optional on the single speed) is intended principally for emergency roadside use: when fitting and removing the connector from the tyre, you should do so as fast as possible to minimise the inevitable escape of air while the valve is open. For normal topping up of pressure, it is easier to use a car-type hand or foot pump. If you choose to use a compressed air line to inflate the tyre, for instance at a garage, you should be aware that the pressure in the tyre will rise very quickly; allow the air to enter in very short bursts, checking the pressure all the time; alternatively make sure that the pressure regulator on the air line is set to an acceptable value. With lower tyre pressures, the pedalling effort rapidly increases: KEEP YOUR TYRES WELL INFLATED.
2. Gears: When changing gear, either take the pressure off the pedals or stop pedalling. If stationary, it is usually necessary to back pedal a little, (o allow the new ratio to engage. If, when pulling the lever on the trigger control down, you encounter unusual resistance, do not force the control: instead, back pedal and try again. On 5-speed models, when the gear change system is correctly set up and adjusted, gear changing is straightforward, much the same as on a 3-speed. However, it is vital that the gear change system is so maintained and used that gears are accurately selected Inside the hub itself: if a gear is not correctly selected while you are pedalling, damage is likely. Attention must be given to the following three elements of the control system; a) adjustment: the screw-adjustor provided at the cable end next to the rear axle must be set so that the indicator rod is at the correct position (see section H) b) the gear-control trigger: make sure, when you are changing gear that the lever clicks positively into place and that it is not left in an "in-between" position. c) there must be MINIMUM friction in the cable run: the cable itself must be in good condition and free of kinks or sharp radii (e.g. near ends): the guide pulleys must roll freely and be properly aligned. If transmission is not smooth in any gear (e.g. if the hub "hunts" between gears), then take immediate action to remedy this. 3. Fitting luggage to the front carrier block. Fitting and removing front luggage is most easily carried out with the bicycle parked. The front carrier frame available for the Brompton has a tapered latch plate built into it. To attach the frame, slide this down onto the front of the carrier block: you will hear a distinct click as the frame approaches its rest position, an indication that the sprung latch lever in the carrier block has engaged. To remove luggage, pull the bottom of the latch lever backwards (this projects out of the bottom of the carrier block, just above the front brake), and then draw the frame upwards and off: a slight side to side rocking action may be needed to free the luggage from the block. 4. Using the cover. The cover is supplied with a saddle bag for storage when not in use. Attach the saddle bag, if you wish to use it, to the lugs at the rear of the saddle in the normal way. If you do not use the saddle bag for the cover, you may find it useful as a container for other small items. To fit the cover, make sure that the pull-cord around the base is relaxed; then, with the opening in the top of the cover towards the rear, draw the cover down over the folded bike. If you wish to make a neater package and also partially to cover the base of the bike as well, pull the lower edge of the cover right down, and draw the pull cord tight.
With the cover on, you can carry the bike by putting your hand through the slot in the top and gripping the frame or saddle in the normal way.
5. The Brompton's parking feature. When you first start using the Brompton, you may find it difficult to accustom yourself to the way the rear wheel falls away whenever you pick the bike up. However, you will soon come to appreciate that this characteristic, insofar as it allows you to park the bike instantly, can be a great convenience. When you wish to wheel the bike up on to a curb, the rear wheel assembly may tend to start folding, particularly with the type T when you have a load on the rear carrier. You will find that you can normally prevent this by lightly applying the rear brake as you pull the rear wheel up onto the curb. If you wish to do without the Brompton's parking feature, preferring the rear wheel assembly to stay put, tie an elasticated cord round the base of the seat pillar. It is often desirable to do this when carrying loads on the carrier (however with some items, typically a case well tied on to the carrier, you will find that the bike can be parked with the rear end folded only "half way").
6. Carrying the unfolded bike. Now and again, for instance to climb a set of steps, you may wish to carry the Brompton without folding it up. To prevent the rear frame from folding, you need to use two hands, one holding the rear end, but if you have no luggage at the rear, you can pick the bike up with one hand by the main frame and let the rear end hang down.
7. Wheeling the folded bike around. The folded package (unless it is a C-type) may be wheeled around on its castors. Unclip the handlebar assembly and raise it: the bicycle may now be drawn along on its castors using the handlebar as a handle; there is no need to do up the handlebar clamp. This feature is useful over relatively short distances, for instance along a station platform: it is not practical for longer distances (when it pays to unfold the machine and wheel it along) or on uneven ground.
8. Operating the dynamo on the T-type. To engage the dynamo against the tyre, either, if the dynamo is fitted with a lever, depress the lever, or, if there is no lever, push the body of the dynamo down relative to its bracket. To release the dynamo, pull the body of the dynamo away from the tyre until a click is felt.
SECTION D: SADDLE POSITION. You should bear in mind that repositioning the saddle (except when using the saddle adaptor pin pointing downwards) will cause it to project further from the folded package. BASIC ADJUSTMENTS: The height of the saddle on the Brompton can be adjusted in the normal way. For the maximum height, draw the seat pillar up until it reaches a positive stop, and for lower positions slide it down. If you wish to select a very Sow position, note that the bottom of the seat pillar may project below the main frame so preventing the rear frame from swinging between parked and unparked positions. The angle is also adjusted in the normal way: slacken the nut securing the saddle clip, choose a suitable angle and re-tighten the nut: torque 13NM. The saddle can be moved 30mm back by reversing its clip so that the seat pillar passes forward of the bolt. Gaining additional height: riding with a saddle even slightly too low is no fun. There are 3 remedies: a) set the saddle as high as possible on the standard pillar, b) use another design of saddle, with greater depth, or c) fit one of the non-standard options listed below. With b) and c) you will incur a slight weight penalty. NON-STANDARD SEAT PILLAR OPTIONS Saddle adaptor pin: There are two ways of using the optional saddle adaptor pin (SAPP). If you are looking for the most compact folded configuration or wish to have the saddle further forward, then mount the SAPP inclined "downwards", and attach the saddle at the appropriate position on the SAPP. If you wish for extra height (up to 30mm), mount the SAPP inclined upwards. The correct torque for the nut on the SAPP's clip bolt is 13-14NM. Under no circumstances fit the SAPP projecting backwards from the seat pillar: this could produce stresses for which the bicycle is not designed. Extended seat pillar: If you require further reach to the pedals than can be obtained with the standard seat pillar, and if you can live with the saddle projecting that much further from the folded package, then you should consider fitting an extended seat pillar: this gives an extra 60mm of height. The SAPP can be used with this as well. Telescopic seat pillar: This provides sufficient height for the very tallest users, yet for those occasions when the bike must be fully collapsed, a quick release allows the saddle to be virtually fully lowered down.
SECTION E: HANDLEBAR AND CONTROL LEVER POSITION. The handlebars and control levers on the Brompton are factory set so as to provide a sensible compromise between compactness and riding comfort, and for most users, particularly those who regularly need to fold the machine, the riding position offered by the handlebars is satisfactory. There is no vertical adjustment (see below), but there is some adjustment available in the fore/aft direction. You should be aware that if you do choose to make such an adjustment, then the folded handlebar will not lie as close to the front wheel as normal. Handlebars or levers moved FORWARD: these will hit against the front wheel on folding, and so prevent the handlebar catch from functioning properly; adjust the handlebar nipple as described in section G. 5-speed gear control lever: it is possible to select a variety of mounting positions. If you do choose to move it, you should be aware that, because of the need for precise gear-selection on the 5-speed hub, changes in the position of the gear-control which introduce any bending or strain in the control cable must be avoided. UNDER NO CIRCUMSTANCES should you attempt to set the handlebar at a higher position by withdrawing the lower part of the handlebar stem from the steerer tube on the front forks. If the handlebar stem assembly has to be moved for any reason, then, on reassembly, a) leave a gap of 0.5mm-1.5mm between the top of the steering locknut and the step in the stem under the hinge, b) use a tightening torque of 20NM for the expander bolt (whose 6mm AF socket head is visible when the handlebar is folded), and c) make sure to align the handlebar catch (section G).
SECTION F: REMOVING AND REFITTING THE WHEELS. If the brakes are properly adjusted and the tyre is well inflated when removing or fitting a wheel, you will find it difficult to move the tyre past the brake blocks; one way round this is to deflate the tyre. Front wheel. To remove, undo and remove the nut and washer on the left hand end of the axle and swing the mudguard stay out of the way. Slacken the other nut retaining the axle in place and remove the wheel (see note below). To replace, follow the above in reverse, making sure that each tab washer engages the hole near the fork end, and that the axle remains seated against the end of each slot while you tighten the wheel nuts: torque 15NM. Note: If the front wheel has not been removed for some time, you may find, when you come to undo the second of the two nuts that the axle starts to turn with the nut so that the nut cannot be slackened off sufficiently to remove the wheel:
if this happens, retighten both nuts, then slacken and retighten the left hand nut until it turns easily on the axle; re-tighten this nut and then undo the right hand nut, and finally slacken the LH nut again. Rear wheel. Park the bike, with the gear trigger in top gear and top gear engaged (i.e. back pedal and forward pedal to make it engaged). Removing the chain tensioner Gear controls: slacken off the knurled locknut N and unscrew the barrel B (fig T1); the indicator chain GICH will be left hanging loose from the end of the ax!e and should be unscrewed from the hub and withdrawn. On a 5-speed, the guide roller assembly, GRA, must also be withdrawn from the end of the axle. Move the sprung arm, CTARM, anti clockwise and lift the chain off; allow the CTARM to move back clockwise until it comes to a stop; undo the securing nut CTN (on a 3-speed this is a special nut, and on a 5-speed it is a standard wheel nut) and remove it together with its washer(s); the chain tensioner assembly may now be removed by drawing it sideways, off the end of the axle. Removing the wheel. Slacken the axle mounting nuts and lift the wheel clear: if the axle tends to stick in its slots, push the wheel rim slightly sideways, first one way then the other, until the axle works loose. Fitting the wheel. First make sure that the chain passes round the rear axle or sprocket. On geared models the axle carries a serrated washer each end with projecting tabs TA (fig W1): these tabs must enter the slot SL when doing up the axle nut, and furthermore, to obtain correct wheel alignment, the tab TA1 must abutt the end of the slot, SL1: a simple way to achieve this is to do up the axle nut so that the tabs TA start to enter the slot and, before fully tightening the nuts, move the axle down the slots (e.g. by tapping) until the tabs touch the end of the slots at SL1. Torque for wheel nuts 22NM.
Fitting the chain tensioner: First arrange the chain so that it is running true over both chainwheel and rear sprocket; next note that the chain tensioner body has two flanges on its inner face - these should pass either side of the axle plate when fitting the chain tensioner; address the chain tensioner to the axle plate and press home, making sure that the chain passes between the fixed idler sprocket CTIDL and the rear sprocket: next secure the chain tensioner using:1-speed, a standard wheel nut and the 22mm diam washer: 3-speed (fig W4), the chain tensioner nut CTN and washer -this nut should NOT be done up too a little more than hand tight suffices (max
its
tightly, torque
5NM): 5-speed (fig W4), a standard wheel nut (CTN), an anti-rotation washer (ARW) under this nut, and the tab washer (TBW). It is essential that the TBW, which provides location for the guide roller assy, is at the correct angle, such that the guide roller (GRA) aligns with the indicator chain when that is connected to the control cable (fig W7). To obtain the correct position, screw on the CTN, just tight enough to prevent the TBW from moving: fit the GRA (temporarily) and turn it (and the TBW) until it points accurately towards the cable pulley assy., CPULA. Finally, secure the CTN: this nut should be done up firmly, but not too tight (torque approx. 10NM): take care not to knock the tab washer whilst doing this. Misalignment can cause poor gear selection and damage to the hub.
Now draw up the slack in the chain and feed it over the idler wheel on the sprung arm CTARM - check that the chain is flowing correctly by turning the cranks
Next, screw the indicator chain GICH into the hub, and make sure it is fully screwed home, then unwind through not more than half a turn so that it points towards the gear cable. On a 5-speed, fit the GRA and push it home firmly. Finally connect the gear cable anchorage to the indicator chain and, with the bike unfolded, make sure that it is correctly adjusted (see section H). SECTION G: OTHER DESIGN POINTS TO DO WITH FOLDING HOOK Correct function of the hook is important for satisfactory folding; it retains the front wheel in place when the bike is folded. It comprises part of the front mudguard stay, or, if there are no mudguards, a special wire form (not illustrated). If it is knocked or damaged, the design allows it to be bent back to position. For both types of hook, the function is the same, and, for this to be correct1. the chainwheel must not be too far from the centre line of the bike. Part of the stay, B (fig H1), acts as a buffer against the chain wheel during folding, and also steadies the folded front wheel. If the chainwheel lies too far out (the gap G (fig H3) between inside of chain and hinge plate RHPL when the bike is parked should be 0-3mm, not more), then the hook will be a tight fit over the chainstay CHS, and may stick when trying to unfold the front wheel. 2. the hook must not be bent wrong (fig H2): if it is bent up too far, as shown dotted, then a) it may catch on the rear spokes, and b) it may easily slide off the tube CHS, causing the bike to unfold inadvertently. If it is bent down too far, then the hook will contact the tube CHS at C before the front wheel (and the rest of the bike) has dropped to its fully folded position. The hook may also tend to stick on the tube CHS during unfolding if it is bent fore/aft, or if it is "crushed" in so that the distance "E" is less than the distance "D".
If the hook is ineffective, and/or sticks during unfolding, then, bearing the above in mind, judicious bending of the hook will cure the problem. HANDLEBAR CATCH AND NIPPLE: The body of the handlebar catch acts as a stop to align the front wheel correctly during folding. There is a bulge B on the body of the catch: this should, on a 5-speed, be directed forwards and to the left (fig J1), and, on a single-speed or 3-speed, rearwards and to the right (fig J2). The correct torque for the securing screw is 9NM. Operation of catch and nipple: these must be set correctly, for, if wrong, the handlebar catch will loose its spring effect, with the result that the handlebars can become unlatched too easily from the folded package. a) Alignment of the catch, HBC: the catch itself must be aligned so that the nipple enters centrally (fig J3 rather than J4). b) Alignment of the nipple, HBNIP: this must be in line with the catch HBC as it enters it during folding (fig J5 rather than J6). Bear this in mind if making adjustments as described at c) below. c) Offset of the nipple HBNIP: if the handlebar itself, or the control levers/cables, are set too far forward, they may, on folding, foul against the front wheel and so prevent the nipple from fully entering the catch (i.e. as per fig J8). To remedy, either reset the handlebar or levers further back (i.e further out when folded), or unscrew the nipple so that it is further from the support tube, HBS: the nipple must be able to enter the catch HBC fully, as per fig J7.
If the set up is correct and the catch remains ineffective, either replace the h'bar catch, or you may obtain a temporary cure by twisting the nipple slightly (i.e. as not normally recommended, fig J6).
FIG J3
FIG J4
LOWER STOP DISC: When you pick up the folded bike, the rear frame cannot unfold because the lower stop disc, LSD, butts against the "folded" seat pillar, SP. The LSD, which is an eccentric, can be adjusted to give the correct gap between itself and the SP: if the gap is too small, then the SP may foul, irritatingly, against the LSD during folding; if the gap is too large, then the rear wheel will drop away too far when the bike is picked up, so that the hook retaining the front wheel slips off the tube CHS on the rear frame. The correct gap is 2-3mm (fig L1). To set the lower stop correctly, partially slacken off the retaining screw so that the LSD is not loose, but can be moved by hand: fold the bike completely, and move the LSD to give the correct gap (the LSD should be disposed to lie towards the LH side of the bike (fig L2), not towards the right). Finally, re-tighten the retaining screw firmly.
CABLE ROUTING, figure N1: Although the routing of the cables looks straightforward, it is in fact carefully worked out: correct assembly is vital if these are not to be damaged during folding. Also, when replacing cables, the outers must be exactly the same length (+/-3mm) as the existing cables, and also have ferrules fitted the same as on the original cables: always use lined, low friction cables. All cables MUST pass in front of the handlebar, to the left of the handlebar stem and to the right of the main frame tube. The FRONT brake cable must pass through the forward cable guide CGF (though note that if a wire loop is brazed to the LH front fork blade, the cable must pass outside this). The REAR cable(s) must pass through the cable gatherer CABGATH on the front brake cable, the centre cable guide CGC and the rear cable guide CCR as shown: they should also pass inside the tube TT and the tube SS. The gear cable GCAB should lie below the brake cable BRCABR.
REAR HINGE SCREWS: These are factory set with a torque of 10NM, using thread-locking fluid, and (unless there is a problem) should NEVER be checked or moved. SECTION H: RUNNING ADJUSTMENTS AND CHECKS. It is VITAL that certain of the jobs listed here are carried out at least once, if not two or three times, during the first few hundred miles of use when parts are bedding in (see chart on centre page). Thereafter, except for brake adjustment, they need to be carried out less and less frequently. If you are not confident about carrying out these jobs yourself, your dealer will be pleased to help. Gear cable adjustment Adjustment of the gear control must be carried out with the bike fully unfolded (i.e NOT parked), and with the indicator rod screwed fully home into the hub (and backed off not more than half a turn to obtain correct alignment with the cable). Adjustment is carried out by slackening the lock nut N (fig W5), turning the barrel B until the correct setting is obtained, and relocking the nut N. During adjustment, you must ensure that the gear you select by moving the control trigger has indeed engaged in the hub, and to this end, each time you are moving the trigger, keep the wheel spinning forwards, and pedal back and forwards, to ensure the gear engages. If satisfactory operation of the gears cannot be obtained, then more than likely there is a fault with the cable run. 3-speed (fig W8). Engage top gear, then move the control trigger to the middle position: the step, S, towards the end of the indicator rod, IR, should be level with the end of the axle, visible through the hole in the CTN. Next, select bottom gear, then middle, then top, and check that all three are engaging correctly. 5-speed (fig W9). Engage top gear, then move the control trigger to position 2 (2nd bottom gear): the annular groove, SR, coloured red, towards the end of the indicator rod, should lie level with the end of the axle. Next change down and then up through all the gears, and check that all gears engage cleanly, fine tuning the setting if needed. In practice, you may find that, with the gears functioning correctly, the groove SR lies (when in 2nd gear) somewhere between the end of the axle and 1.5mm out from the end of the axle (i.e. a slightly tighter setting):
FOR CORRECT SETTING SR TO BE LEVEL WITH, OR JUST OUT FROM AXLE END
SR
FIGW9
but bear in mind that, when in top, the indicator chain, GICH, should be just slack. Next, test the gear selection under load by riding the bike, again changing down and up through all the gears. Crank axle bolts and pedals: The crank axle bolts MUST be torqued down (32NM, use a 14mm AF socket) after the first few hours of use, and should be checked thereafter. Check also that the pedals are secure (torque 30NM): note that the i-H pedal has I_H thread. Spokes: These tend to bed in during early use, and to lose some of their initial tension. which can cause rapid spoke failure: this is particularly true for heavier riders. See that these are re-tensioned correctly after initial use, and check thereafter. Seat clamp: The quick release clamp QR (fig 1) should be kept adjusted so that the lever closes firmly when doing the clamp up; if the movement is slack and easy, with little resistance, the seat pillar will not be properly secured. As a guide, with the seat clamp lever forward (i.e. done up), the adjuster nut should be tightened with a torque in the range 5-8NM and the maximum closing force needed at the end of the lever while securing the clamp should lie in the range 80-120N. The correct setting will depend on the weight and strength of the user. Do not overtighten, as this can cause damage. For normal tightening during the life of the machine, a sixth of a turn or less of the adjuster nut will normally be quite sufficient. If after adjusting the clamp, the seat pillar slips in use, then the cause is almost certainly oil or grease. Remove the seat pillar from the bike, and using soapy water, thoroughly clean both the seat pillar and the sleeve in the main frame. Saddle clip bolt: Because this passes through the body of the saddle, which is moulded nylon, some settling of this nylon during early use may reduce the clamping force in the clip bolt: you should now and again check that the nut on this clip bolt is firmly secured (torque 13NM). Brakes: The brakes should be set up so that the blocks are as close to the rim as possible without actually interfering with the free running of the wheel. When setting the rear brakes, the bicycle should be in its unparked position. Adjustment is carried out using the threaded cable stop on the caliper. Cup and cone bearings: If these are set over-tight, damage is likely, and in the case of the rear hub, the freewheel will tighten up as well, (in turn causing chain problems during folding). Always ensure that the relevant locknut is secure after adjustment:
a) bottom bracket: set so that play is just discernible at the crank ends (when a sealed cartridge unit is fitted, no adjustment is needed) b) wheel hubs,; set so that play is just discernible at the wheel rim. Do not use the RH cone for bearing adjustment on the rear wheel: move the LH cone only. c) steering head: set so that no play is discernible, but with the steering still free, and without tight spots. SECTION J: LUBRICATION. When lubricating your Brompton, avoid getting oil or grease on the seat pillar or the wheel rims. Grease is the correct lubricant for all wearing parts (oil does not last as well), and where it is practical to dismantle an assembly and apply grease, you should do so. However, this is often inconvenient or impossible, and oil can be used instead, but you should he aware that applying oi! to a greased assembly can cause the remaining grease to be washed away fairly quickly, and frequent re-lubrication is needed thereafter (unless you re-grease). Choice of lubricant: any good quality general purpose grease is satisfactory, especially lithium based. For the chain, proprietary chain lubricants with good penetrating properties give the best results. As for oil, "Super Spray Lube" is a good quality general purpose lubricant, which is convenient to use, otherwise employ an ordinary light mineral oil. For the rear hub, a thixotropic grease is recommended by Sturmey Archer and is available through Sturmey Archer agents. The chart on p 22 shows what to lubricate. For medium frequency items (marked "3"), a sensible guide for the interval between lubrication is a year, or 5,000 miles. Notes: a) chain: for smooth pedalling it is vital that the chain is kept well lubricated: if the bike is used in the wet, this should be done frequently. The easiest way to cover the whole chain is to turn the pedals backwards while applying oil: make sure that the oil flows onto both the rollers and the side plates: turn the pedals a few more times to allow the oil to work in, and then wipe off excess oil. b) hinge clamps: a thin smear of grease on the inside faces of the clamp plates ensures that these release correctly: the thread of the clamp bolt, and its washer, should also be greased c) the folding peda! bearing, which is grease packed, should not normally be oiled: however, if the bearing is not running freely, some oil fed in past the seal will extend its useful life d) rear hinge: this comprises a stainless steel shaft running in pre-greased bushes and these will normally give a very long maintenance free life; however, after the first say 10,000 miles or 2 years, an occasional application of oil is recommended. e) hub gears: the gears and bearings are sealed; greasing need only be carried out during major service.
SECTION K: ROUTINE REPLACEMENTS. Planned replacement is advised to ensure both safety and good performance. The recommended intervals between replacements given are for bicycles subjected to normal use: the most appropriate timing depends on the conditions of use and your riding style. 1. Transmission: if the chain is allowed to stretch unduly, through lack of lubrication or long term wear, power transmission will be inefficient and rough and the sprockets will also wear quickly. A replacement chain is not expensive: replace every 3-4,000 miles (or sooner if it has lacked lubrication or been used in harsh conditions). If you have allowed the chain you are replacing to stretch unduly, you will almost certainly have damaged the rear sprocket, and possibly the chainwhee! too: these should be checked when fitting a new chain and if worn should be replaced at the same time as fitting the new chain. 2. ALUMINIUM FRAME COMPONENTS: as on other lightweight machines, aluminium alloy is used in the construction of the Brompton, and this material has a finite life before failure. In normal use, the risk of aluminium fatigue failure on the Brompton is remote, even after many tens of thousands of miles. However, with hard riding or other severe loading, the possibility of failure, whilst still small, increases. As such a failure could cause injury, the hinge damp plates and the handlebar should be replaced every 5,000 miles, and we recommend that these items are checked regularly on any machine subjected to hard use. 3. Brake cables: these do not have an indefinite life, and to reduce the risk of brake cable failure, replace the inner cables at intervals of 3,000 miles or less. If there is any doubt about the free running of the cables, the outer cables should also be replaced. 4. Gear cables: though less safety critical than brake cables, the inner gear control cables should be replaced at the same interval as brake cables. On 5-speed models, the outer cable should be replaced at the same time. 5. Tyres: the risk of punctures increases with the mileage covered, as the tyre accumulates small sharp particles in its tread: worn tyres are particularly susceptible to punctures, and usually provide less adhesion. You should reckon on replacing the rear tyre every 2-3,000 miles and the front tyre every 4,000 miles. 6. Lighting on the T-type: a) repeated flexing of the wires around the rear hinge when folding eventually causes failure - replace the wiring loom connecting the dynamo to the front light at intervals of 7,500 miles: b) lamp bulbs and dynamo: these can have a very long life between failure, but performance deteriorates - replace after 150 hours. 7. Chain tensioner idler wheels: replace every 10,000 miles 8. Suspension bush (flanged bush under the suspension block): 10-15,000 miles.
SECTION L: SPECIFICATION OF SPARES. Chain: it is vital to use the correct length of chain; with the standard 13 tooth rear sprocket, and 50 tooth chainwheel, use a 98 link chain. The joint in the chain must be made without using a connecting link/spring clip (i.e. as for derailleur chain). The chain specification is: 1/2" x 1/8" . Use good quality chain. Rear sprocket: The normal specfication is 1/2" x 1/8" x 13 tooth, and for a single speed, 1/2" x 1/8" x 14 tooth, dished. Chainwheel and RH crank: If a new chainwheel is fitted, use a Stronglight 50 tooth chainwheel with offset crank. If you have to use an alternative, make sure that it fits the tapered end of the crank axle (ISO 6695), that it has the correct chainline, and that the end of the crank does not hit against any part of the rear frame when the bicycle is parked. Alternative gearing: different size chainwheels and rear sprockets may be used in the following combinations, (the third figure is the number of links to be used in the chain): 54/13/100; 52/13/100; 52/14/100; 48/13/98; 46/13/96; 44/13/96; 44/14/96, Chain tensioner idler sprockets: 10 tooth x 3/32" wide on the outer part, x 1/2" wide at the centre, mounting hole to receive M5 bolt. Brake blocks: Saccon PT 205 Tyres: 16" x 1 3 /8" (ETRTO 349) inner tube and cover, with Schrader valve: insist on first rate tyres, as some of the inexpensive types cannot be inflated properly or loose pressure quickly. Control cables: The cable routing is critical: when a new outer cable is fitted, the routing and the length of the cable must be exactly the same as that which it replaces. On the front brake cable, the outer must be in two parts of the correct length, so that the cable gathering ring can be retained at the same position on the cable as before. You are best advised to use cables supplied by BROMPTON. If you have to use cables from another source, specify low friction cables (PTFE coated inner cable, lined outer cable). Lamp bulbs: front, 6 volt x 2.4 watt; rear, 6 volt x 0.6 watt. "Spares pack", recommended for users who may find it hard to visit their dealer, or who are spending time abroad. The Brompton spares pack contains both special Brompton parts and those standard items which may be difficult to find, and provides for most contingencies.
BROMPTON BICYCLE LTD. Kew Bridge Distribution Centre, Lionel Road, Brentford, Middlesex TW8 9QR Tel: 0181 232 8484 Fax: 0181 232 8181