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Vincent Brakes - an ongoing collection of VOC members experience and recomendations that should be valuable to review.

Brake Cables:   The early Cs (before late 1950/early 1951) had no balance beam stop/return spring and the long cables were affixed on the right side.  And, since so many then converted their machines to having the stop and right hand return spring, some might have ignored the then correct long cable placement on the left.   Bev Bowen  11/3/2011

Relining Vincent Brake Shoes:
259 East Butler Ave.
Memphis, TN 38126
901 523 1418

2LS Brakes: The physics is that you can't put a 1ls brake on as hard as a 2ls servo can, which is why virtually all race brakes are 2ls. Great brakes are 2 x 2ls.
Road riders can almost forget fade resistance, unless they habitually make two or three stops from 100 mph plus to 30 mph minus, about 20 seconds apart, so IMHO, lining area is irrelevant. Physics says that a 250 mm 4 shoe brake should be better than a 210 mm, but racing experience says that 250 is too much for a 130 mph classic racer, 210 is more than enough: so it isn't curt and dried.
What is relevant to me as a road rider is "do these 8" brakes grab the wheel and provide instant stopping?"  PVS 7" 2ls brakes do, and I bought a set, so I won't be looking elsewhere - and at the time my alternatives were discs, or possibly different discs. (Grimecas were there, but weigh about a hundredweight, and left me, as did all serious 4 shoe drum options like Menani's,  with a speedo drive problem.)
But I'm not conducting a jihad for PVL brakes, just asking for first hand opinion that 8" 1ls brakes (with the bonus of no speedo problems...) are better, or even as good.  Tom ) Sunbea,)  3/10/10
Brake Restoration Tips

The invention of the wheel made it possible to move mass in a more efficient way, but then came the problem of stopping the mass.  Hence the invention of brakes. Brakes have evolved from foot dragging to retro rockets, but unfortunately, the Vincent brake, it seems, is nearer the former than the latter.  So with this in mind, if aiming for a proper restoration, brakes must be considered.  At first glance it doesn't seem to be such a big deal to go through the brakes.  Those who have, have probably learned the hard way that it ain't necessarily so.

It should be noted that the surface area of the braking mechanism on a Vincent, along with all of the mechanical leverages which determine surface area contact pressure, with the drum diameter to wheel diameter factor, when all are fitted properly, are adequate to lock up both front and rear tires in most cases on a dry surface when brakes are cold.  With the four brake drum design, (excluding the D's, of course, with the three drum design) it's more difficult to achieve 100% efficiency, due to the extensive amount of brake parts that move each time the brakes are applied.  Optimum equal pressures and optimum surface area contact aren't easy to achieve.  The two front wheel brake drums, by utilizing a balance beam when the brake is applied, provide equal shoe pressure.  Not the case with the rear brake.  It's almost impossible to achieve equal shoe pressure to drums on the rear brake mechanism, and usually only an experienced wrench can achieve best results from the adjusting wing nuts.

When brake restoration is undertaken, one of the important factors is how true the drum rotates with the wheel axis.  Most restorers who "over restore" the Vincent often get carried away with polishing hubs, chrome plating spoke rings, and painting brake drums.  All of this can be done, if done properly, but sometimes it isn't.  The brake drum is shouldered on the hub for alignment.  The aligning shoulder on the hub, and the mating surface of the hub must not be disturbed during polishing.  If there's any doubt that the hub flange mating surface doesn't run true, it's a good idea to take a light truing cut in the lathe.  Next comes the plating of the spoke rings.  Best to do your own preparation work prior to sending it off to the plater.  When you do this, take a felt tip pen and mark the inner and outer mating surface, that's the surface where the 5 or 10 bolt hole pattern exists.  Mark the surfaces.  Do not plate.  The plater has a way to mask the area not to be plated.  Next, inspect the paint job on the brake drum, and remove any runs or paint on the outer mating surface to the spoke ring and any paint that may be on the aligning bore of the drum.

After going through the steps above you're pretty much certain that you've eliminated any wobble of the brake drum.  This would be a port and starboard movement of the brake drum in relation to the wheel's hub.  The next step is to see if the brake drum's friction surface is concentric with the hub's aligning shoulder.  This can be accomplished by truing the wheel hub in the lathe, then bolting the brake drum to the wheel hub and dialing in, checking the concentric of the drum.  In most cases it requires a very light cut to clean any rust deterioration, any surface scoring, and any out of roundness from a long time sitter.  Usually 5 to 10 thousandths will do the job.

The next thing to make ready are the brake shoes.  The original brake shoes were riveted, various linings of different compositions were also offered, and still are.  The green lining seems to be the preference of most restorers, but most other linings work as well.  If you have the option to go with bonded lining or riveted lining, go with the bonded lining.  If for no other reason than that you gain contact area lining to drum.
It's virtually impossible to achieve an adequate mating surface arc of the brake shoes without dressing the surface in a lathe.  Dressing the surface isn't as straightforward as most would like to believe.  Doing it properly requires a jig fixture to locate the shoes in the lathe for machining, and building the fixture isn't that difficult.  With an 8" diameter 2" thick piece of aluminum, turn a 1 3/4"X 2" diameter stub.  Then chuck and true stub in 4  jaw chuck.  Take a truing cut on 1/2" thick 8" diameter flange.  You're now ready to drill the fixture to accept the dowels that will become the two brake shoe pivot pins.  One other precision hole will be required, and that's the bore in the plate that will accept the brake cam pin.  This hole should be made a tight fit as well.  Keep in mind that when setting up to drill the three holes, these are precision holes and must be done to a tolerance of plus or minus .001.  So with your best Vincent backing plate, measure well, then take a cut to true the outside diameter of the 1/2" flange.

The next step is to mike the four brake cams.  This would be the thickness of the cam flats.  Select the thickest of the four and use this one for your jig fixture.

Now it's time to profile the brake shoes.  Hopefully you marked the shoes in some way prior to having bonded lining applied.  It's like anything else mechanical, where parts can be swapped, it's always best that they go back into their original location.  If their location has been lost in the heat of things, with the four backing plates, shoes, and springs removed, you can usually fit the brake shoe by slipping the brake shoe over the pivot pin and turning the shoe towards the brake cam.  The shoe shouldn't hang up on the brake cam outer guide plates.  It takes a bit of fiddling, but by doing this you'll probably come up with pretty much where they were located originally.

The next step is to identify each of the brake backing plates as to their location on the bike.  An easy one will be the right front, as it will have a hole in it  to accept the speedo angle drive.  On most bikes the left hand side is identifiable by the water excluder, or in the absence of the water excluder, the rivet holes identify it.  The rear backing plates are normally the same, and are interchangeable.  Sometimes you'll encounter a machine wherein someone has discarded the larger side car sprocket, and installed a water excluder. In this case if not previously identified, it will be anybody's guess as to the left side backing plate, and the right side rear backing plate locations.  You might be able to detect a support wear pattern on the rear brake cam spindle brake backing plate boss.  After you've made a decision on brake backing plate location, and have the brake shoes fitted to the backing plates, it's time to match by felt tip marking, the brake shoes to the brake drums in which they'll operate.  One other mark to put on the brake shoes is the outboard location mark.  This will prevent inadvertently reversing the brake shoe location after machining, which is easy to do, as everything is identical in appearance, but not in actuality.

Now for the turning of the brake shoe linings.  Place your jig in the lathe, using a four jaw.  On the outer edge of the flange, eyeball and mark a felt tip line directly outboard of the center of the two brake shoe pins.  Dial the outer surface of the flange so it cams minus .005 at the felt tip mark.  Place the first pair of linings in the jig fixture.  With an inside mike, mike the drum in which they'll eventually find a home.  Adjust the cutter on the compound to turn the exact diameter of the brake drum, then subtract .005.  Using shims between the brake cam surface and the brake shoe flat, shim the lining's circumference on the trailing edge of the forward brake shoe, and do the same with the rear shoe, shimming the lining to the leading edge of the rear shoe.  From now on I'll refer to shoes as front and rear, no matter whether they're left side or right side brakes.

If you have properly shimmed the shoes, it's time to fix the brake shoes to the jig.  This can be accomplished by wrapping keying wire tightly around the spring shoe fingers.  When a cut is made, it will take a cut on the full circumference of both the front and rear shoe linings, taking approximately .004 more from the leading edge of the front shoe, and .004 more from the trailing edge of the rear shoe.  After this is done, mike the thickness of the total shims on each shoe.  Subtract .015 from the shim thickness, using standard mild steel cam scrub plates, you can achieve the .015 minus, by either shimming underneath the scrub plate by slightly loosening the ear tabs by bending, or if the scrub plate is too thick, you can file the aluminum brake shoe flat and rebend the scrub plate for a tight fit.

Now it's time to cam the leading and trailing edges of the brake shoe linings.  This is done by using 80 grit sandpaper wrapped around a block of wood.  This work is best done by placing the brake shoe in a vise and sanding with the block of wood to achieve uniformity across the width of the shoe lining. It's best to identify leading and trailing edges prior to chamfering, as the chamfering is somewhat different.  The reason to chamfer is to provide smooth engagement and smooth release from the drum.  Chamfering also prevents inadvertent lock up.  You don't have to go to extremes to achieve the desired results.  The angle of the chamfer and the depth of the chamfer causes a reduction in the surface area of the brake shoe lining that contacts the drum when increased, and reduces braking efficiency.  In lieu of this, it's recommended that when chamfering or relieving leading and trailing edges, that care be taken not to remove too much.  For best efficiency during the lifespan of a set of brake linings, as the brake linings wear, it's not uncommon to rechamfer or relieve possibly three times during the lining's life.  Doing this allows optimum lining area to drum during the lifespan of your brakes.

The next step is to straighten your backing plates.  Chuck up your hollow axle in the lathe and true.  Place the tapered bearing on the hollow axle, using it as a spacer, then take the backing plate and nut it on the hollow axle tightly.  With the paint removed from the brake backing plate, place a dial indicator on the outboard surface as close to the outboard circumference of the plate as possible.  Make sure that you're not hitting anything.  Turn the lathe by hand to see if there's any wobble in the plate.  If you find the plate is distorted, causing wobble, you'll have to straighten the plate.  Don't try to straighten the plate while it's in the lathe or attached to the hollow axle.  After straightening, recheck.  You're looking for a maximum runout of no more than .005.

The next step is to check the straightness of the brake shoe pivot pins.  These can readily be checked with a small machinist' square.  Straighten as necessary.  Now check to insure that the brake cam has adequate end float in it's backing plate bore for proper operation.  When this is done you can paint the backing plate and install any water excluder as required.  You can now install the brake shoes.  When doing so, insure the brake shoes float nicely in their pivot points.  Sometimes it will require a light ream job to achieve freedom of movement.  It's a good idea to lightly grease the pins and the backing plate cam boss prior to assembly.  Use the grease sparingly to prevent any from finding it's way into the shoe linings.  It's always a good idea to assemble with new brake springs.  This helps unintended brake drag, which isn't a good thing.  It can cause heat build up, lining wear, and brake fade.

After everything is put back together, this is what you should have:

When the brake cable arm is rotated approximately 15o to 20o, you'll experience full braking, nearing lock up.  Due to the mechanical design of the single leading shoe, when the brake is applied the front shoe lining of the front wheel comes into contact at it's leading edge first.  Next the leading edge of the rear shoe lining comes into contact, but has more lining pressure to drum than the front shoe leading edge pressure.  This is due to mechanical advantage, as the rear shoe distance between it's pivot point and the point of contact of the cam is greater.  This is the reason that the rear shoe lining wears out faster than the front shoe lining.  The machining procedure, which actually offsets the brake shoe lining circumference to the brake drum circumference is done to enhance a proper bedding in of the brake shoe lining to the drum.   Max Lambky  2/22/10

Installing water excluders is relatively easy and straightforward.  First, ensure that the four rivet holes in the backing plate line up with the four holes in the water excluder.  I've found that some of the after market water excluders needed a bit of grinding on the inner concave circumference, so the brake bearing boss on the backing plate doesn't restrict the turning of the water excluder for rivet alignment.  Lay
the backing plate outside up, align the water excluder holes with the backing plate holes, and tap the rivets in with a ball peen hammer.  There's usually enough interference to hold all four rivets in place.  In a vise, put a piece of round stock that's flat on the end.  Turn the backing plate over, and on the inside, with a small ball peen hammer, brad each rivet slightly to mushroom.  The first light bradding is to ensure that the three rivets that you're not working on, won't fall out when you get serious on setting the rivet home.  Max  12/4/09

Turning the brake shoes:
Chuck up a 3/4" diameter bolt with the head behind the jaws (in the spindle) and the threaded part sticking out.
Put a couple of big flat washers on the bolt, against the jaws of the chuck.
Install your backing plate (with shoes installed) onto the bolt, with the shoes away from the chuck.
Install a couple more big flat washers and a nut, and tighten securely.
Rotate the chuck by hand and check the runout of the backing plate; it should be pretty close.
Put a .010" shim between each side of the cam and the shoe, to hold the shoes out a little farther than fully retracted.
Fire up the lathe and take light cuts until the OD of the shoes = the ID of the drum. (When you remove the .010 shims, you will have .010" of clearance between the shoe and the drum.
Make sure the drums are round. Tom  Gaynor  7/1/09

When I was on my ride to Wisconsin 6 weeks ago, I discovered that my sprocket bolts were loose, so I tightened them up.  I intended to loctite them when I got home, but only did one then got distracted.  Today, I remembered and got back to it and all but one were loose!  Go check yours .   Bruce Metcalf  6/16/09

Shoes: I'm probably quoting Clever Trevor here, but the action of the trailing shoe is to push the shoes OFF the drum, and of the leading shoe to push them ON (this is physics, or at least mechanics, not opinion) so disabling the trailing shoe will increase brake efficiency. The only single leading shoe brake I know of that is used in racing is the Seeley, 2 x sls, and the designer (a guy called Robinson) included a linkage to stop the trailing shoe countering the leading. Ask Tim Kirker if it works...  I have a personal reason for knowing this (apart from once owning Tim's rolling chassis), because my 1922 Sunbeam has a trailing shoe front brake, called a dummy belt-rim brake but in fact a belt-rim dummy brake, which is completely ineffectual. The road surfaces of the 1920's were often loose, and a brake that worked resulted in losing the front. The back brake, same mechanism but leading shoe, is capable of locking the wheel. Interestingly however, the front brake is 100% effective in stopping the bike rolling backwards, when it becomes a particularly savage leading shoe brake. This tends to concentrate the mind, if concentration were needed, and to hammer home the point that brakes with one trailing shoe are not effective at all, brakes with one leading shoe  and one trailing are barely effective, brakes with one leading would be better then either of the above, and that the optimum set-up must therefore be 2ls.  Having twin drums doesn't alter this, but gives greater lining area to counter fade.  Which, IMHO, isn't the problem.  I take comfort from the fact that since about 1970, no one has made a serious drum brake that wasn't at least 2ls, with the serious contenders all 4ls.  Calibration point: 160 mph Patons use 210mm  Menani 4ls front brakes so as to qualify as IHRO Group 1, Period 1 classic racers. (I have one: as good as a disc). I believe Patrick Godet also uses 4ls Menanis, but the 250mm variety, presumably to deal with the extra weight of (even) an Egli Vincent. And, flattery, the fact that he's protecting works of art.  Sunbeam   3/24/09
I  have the
alloy plates, from the club, with ribbed drums.  They look great. My brakes have yet to bed in, but I'm not expecting too much. They aren't
really big enough in diameter . While I use a big drum (250 mm) for racing, it isn't anything like as good - and more importantly user friendly - as my Lockheed single iron disc with a Grimeca master cylinder (more sponge but better "leverage"). For me the key thing is that a 4 shoe drum comes on hard, and goes off as it heats up. It also comes on when it wants to - there's a tiny lag. A disc comes on immediately, comes on soft, and the braking is virtually linear with effort at the lever - which as one might expect increases as one realises that the tip-in point is getting closer and closer and closer......  I remember that the Seeley brake (double sided 2LS) felt the same but I was using that on the road. There might have been a time when I left my road braking to the very last moment, and every stop was a crash stop, but it isn't now.

A good source for exotic drums is  Most classic bikes in UK use magnesium replica brakes (Oldani, Manx, or Seeley) made by
Dick Hunt Racing.  I wouldn't buy a second hand magnesium brake or plates for reasons explained by Eddie Stevens in KTB.  Tom Gaynor 4/18/05

The front brake I use is a 230 mm Grimeca modified. I made an aluminium  brake plate to replace the Grimeca plate which looks like the Vincent one (middle black, polished water excluder) and fitted in it the Grimeca components (brake shoes and cams ). The benefit of this is that I have the brake plate anchor at the right place to be inserted as the std Vincent into the fork blades. I have made the brakes levers look like the std vin' and using some H13 washers for good ajustment. I have arranged these levers in correct place to use the cable brakes std 'route' and the balance beam . The original speedo gearbox is reused  on the right side, also I have inserted a magnet into the H23  speedo gear ring  and installed inside the r/h brakeplate a pushbike electronic speedo pick up so there is just a wire to route along the blade to the little speedo clamped on the handlebar; it gives the right speed (good to check the Smith), average speed, time,  max. speed, trip distance. ect; useful gadget.

The braking is far better than any very good std or 'racing brake' Vincent  but I think it still needs to bed in because I  feel 'sponginess' at the brake lever ...especially when hot. I will ride the bike with the brake cables and the balance beam  for a few more months and will change for twin lever cables without the balance beam to see what happens!

Several riders asked me to make the same for their machines.  I need to test and improve it more before to do some copies .
This is not a cheap modification but a complete wheel assembly. Grimeca brake and hub cost about £300  + 36 holes rim + spokes + brake plates castings and machining + spindle + levers  + and +   ....I don't dare to calculate, may be £500 !
I can suply some photos if you want to make your own.   Francois Grosset  1/12/03

Replacements: I haven't tried a different drum brake but I did fit double discs to the front and low and behold it stops quickly without panic or fear. no fade, dust or adjusting every week. Discs off a Honda CB 250 dream and calipers are Grimeca twin opposed piston intended for a late model Triumph T140 I think. The disc with a little modification will fit a Vincent hub. For more info contact Dave Lawrence in Derby UK.  Roger Lord  11/16/02

I have a 9'' dia. twin drum, twin leading shoe Grimeca brake fitted to my D. Not only does it ''look the part'' it is an excellent stopper, especially two up and 100lbs of camping gear as those who travelled with me at the International can testify.  The down side is that it is 5lbs heavier than standard, although it does not seem to affect the handling, and it needs to be laced into a new rim.  Jeff Bowen  2/9/02
Spongy Brakes: Grab hold of your brake lever, gently pull back until you feel resistance. Watch the brake operating arm on the plate. Continue putting pressure on the lever, does the actuating arm move a little more or does it remain stationary?  Did the lever move more after you applied further pressure?

1.  If the handlebar lever moved more and the actuating lever remained stationary, we can say it is the combined cable mechanism squashing up.

2.  If the actuating arm continued to move after you felt resistance and the handlebar lever travelled on, you have to consider that something inside the drum  is moving.  If the shoe is hard up against the drum, what can move ?  Nothing should until the drum is rotating. Then the servo effect may cause the shoe to bite into the drum. That will not be much. Is the shoe material compressing ? Try and squash some under a press. Which leaves you with one answer which is demonstrated by my cutaway hub assembly. You can watch the shoe touch the drum at the pivot end, and then bend itself to form its curvature to fit the drum.  How much it moves depends upon the wear.  Trevor  12/15/01

My father and i have recently fitted double front disc brakes to two 'c' Rapides and I will attempt to describe the fitting and assembly. The discs are off a Honda CB250N and the central hole is about 1mm (.040 inches) smaller than the alloy hub on a Vin and are 5 bolt fixing so they can be made to fit very well with no dragged holes or holes breaking out of edges.  The calipers are Grimeca twin opposing piston units which are supplied as direct replacements for the Triumph T160 and other disc braked models and the master cylinder is off a YPVS Yamaha.

The fitting is fairy straight forward. The discs are modified to fit the Vincent hub and are bolted on with a spacer between the disc and spoke flange to enable the calipers to clear the spokes. The calipers are mounted on outrigger plates held in place by the front wheel spindle and a special bolt going through the brake torque mount on the fork legs. The speedo drive is covered by a dummy back plate on the right hand side to carry the drive adaptor.

It works extremely well and is powerful, progressive, with plenty of feel and feed back. I can E-mail or snail mail pictures if any one is interested. Please note this mod was designed and manufactured by Dave Lambert of Derby, UK who is designing a single disc rear brake along the same lines.  For road safety in modern traffic this is a must-do mod. Whether you do this one
or another one, better brakes are a worthwhile investment. It certainly beats the hell out of pulling the lever back to the bar and praying.  Roger Lord   8/5/01

Brake Rivets: Rivets of every description are available by the llb or less from Rivet Supply Co. Ltd of Power Road, Chiswick, LondonW4 on the outskirts of London (junction M4 and North Circular). Wholesalers and Manufacturers.

Phone 020 8994 0102 or 6238 or 8484 or FAX 020 8747 1345.    A truly fantastic company, but be clear in what you wish--there are a million variations of size, head style and material.  They can also supply all types of "set".                        Arthur Farrow  9/29/00

From: Arthur Farrow

The other day I posted a note saying that if anybody wanted some of Derek Sayers (non advertised) front brake cables I would be happy to act as internet go-between since Derek is not connected.Many of you seem interested. I do emphasise my only interest is as an entirely satisfied customer of Dels who lives on the front brake. So here is the info and how you can order :- 2 types SHORT and LONG. Originally SHORT was fitted going to RIGHT arm of Balance Beam.No stop.( A,B & some C?) Then changed to LONG going to LEFT arm of Balance Beam with stop.This is the more normal set-up most of us have. Cable type: very large diameter, as big as the rear cable. As original Black with red stripe running down (weird) Some years ago and partly in response to my whinge Del had a batch made which sold promptly. Others may from time to time have had a few bashed out, but Del always has them and seems to me to be the modern reviver and thus deserves our business. ! have the cables on my A, B and C. HAPPY HAPPY HAPPY, but do remember they are PART of the solution. Cost to overseas orderers is £39 all territories of the world, inc air mail/packing in a stout padded bag. Different currency to £sterling is acceptable but only in the form of notes and with a surcharge of £3 to allow for exchange costs Del has no Credit cards facility. Bulk orders by negotiation!! Sales to UK are cheaper of course. Phone him for info. Cheques in £sterling or even notes (left over from International Rally?)are of course welcomed.

Order direct:  Mr. Derek Sayer, 75A, Grosvenor Park, Camberwell, London SE5 0NJ, Great Britain.  Phone/Fax (44) 171 703 6205 (change in april to 0207 703 6205)

I received today a set of front brake cables supplied by Derek Sayer.  These were brought to our attention a while back by Arthur Farrow, but have been undergoing testing and are only just now actually available.

I'm happy to report that they are very nicely made, and much heavier-duty than the usual cables such as were on my bike.  The brake action on my Shadow is substantially less spongy than before, and braking is much more effective with the firmer feel leading to higher pressure at the brake shoes.  These cables aren't precisely cheap, but are well worth the investment in my view.

Derek is not on email, but his address is 75a  Grosvenor Park, Camberwell,
London SE5 0NJ; phone 071-703-6205.     Dave Hartner  4/18/00

Bowden Cables , the originators of the British standard cable controls seen in general use also made a far superior racing grade product called Bowdenex . Identified by red flects in its outer woven housing differed in structure from its more common offering by the peculiar form of the wire from which its outer coil was wound . Rather than being round section wire -this was FLAT in section ! Thus a sries of flat to flat against flat , this being absolutely non- compressionable unlike its cheaper round wire brother which IS NOT ! All Pukka Race bikes utilized this far more stable and dependable pattern which rarely needed adjusting during a race -there being no shortening of its outer housing . Much better for clutch and brake control use . My street Lightning used this stuff throughout , front to rear never needing a replacement for 10 years of constant use . Superb and dramatically better !   S.M. Biberman 9/00
By 1955 the performance of my modified Rapide , now in Road Lightning trim encluding ribbed drums and BL plates far out stripped its braking ability . In despiration I relined with material used on Zundapt KS- 601 s which had a heavy quantity of metal wire ( bronze ) in its mix. This facinated me and I reas- one that these very heavy machines which hauled S/cars all over Europe must need powerful and effective brakes. I fitted these segments to my Vincent shoes and was amazed at the difference ! Both wheels could be brought right up to the very edge of what is referred to as incipient slippage and held there. I ran my own tests before and after this modification was done , on the very same secluded road . ts surface was chipped concrete thus offered a perfect and consistant surface. My stopping distance went down very dramatically to 19 & 1/2 feet from 30 mph . I acheved this figure twice and extreme care and steely nerves were needed as well as an altered riding position. One MUST sit well back onto the rear portion of the seat with arms locked ridigedly outstretched and a firm grip on the bars. All of this to position more weight on the rear wheel and to maintain secure control and grip on the motorcycle lest you go over the bars. These linings wore so slowly that 5 years later they were still on those shoes when converted to a dragster . Trevor is of course correct that the leading edge Must contact initally to set- up the wedging or self servo effect or one has in effect twin FOLLOWING shoes! Thus the assembled shoes on their plate is turned to match the drum s surface after a bit of feeler gage is inserted between the cam and its shoe faces to partually expand them , this to bring that leading edge out to where it can kiss the drum surface . This important situation is all important to having an effective and fierce bite. This edge MUST be champhered as they all need be to prevent locking -up the wheel , this a real possibility ! All brass rivets of course were used but today I would only use bonding.  Sid .12 Feb 2000 

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