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Front brake improvement

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I read in The Classic Motorcycle mag an article on a plunger ES2 in which the owner, Jim Hill, had fitted a strengthening plate across the two pivots of the front brake drum to increase braking efficiency by stiffening the plate. Has anyone got any pics of this or tried it? Is it a straightforward job? I do find the front brake on my '55 ES2 a bit lacking in the anchor dept.

ps I've re-posted this from "General" to "Singles".

George

Ah! Many thanks Ian. I was thinking of something quite different and I must admit I didn't dash into the garage to check. I'll obviously have to look at some other area for improving the anchors.

George

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Hi George,

Just wondering. If keeping it 'Norton', as opposed to 'how it came from the factory' is ok, then perhaps a later wheel with a full width 8" drum could be used? You could always keep the proper one for 'show' days.

If looking 'brochure perfect' is very important,  then you need to confirm your lining material is a/ the best for your needs - there is no need for racing linings if all you are doing is pottering about and vice versa, and b/ the shoes fit your drum perfectly. The effect of shoes machined to fit your drum can be amazing!

Remember that there is no asbestos nowadays (thank goodness) so modern linings may not perform as well as original ones did. Could be worth talking to someone like, e.g. 'Villiers Services' to see if you can get some better linings to suit your needs.

 Elsewhere, look carefully for any 'lost' movement between lever and brake cam - wear in cam bush, wear in lever pivot and outer of cable 'compressing' as any/all can make the brake perform poorly.

Nothing worse than 'no need for ABS as the brake is no good!'

Good Luck!

George Farenden 

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Hi George, If you can find one Norton also used a half width 8" hub for a while. I've heard some people refer to it as an International brake. This would have used the same alloy brake plate as the early full width hubs so probably stiffer than the steel 7" brake plate. Apart from the suggestions that George F has made have you tried swapping the shoes over? The leading shoe wears quicker than the trailing. Eventually the thicker lining on the trailing shoe limits the cam movement and prevents the leading shoe making full contact with the drum. If that has happened swapping the shoes over should restore some stopping power.

Cheers, Ian McD

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The article posted about brakes looks very plausible with all its formulae, but I am suspicious of its validity in many respects. There is no obvious reason why the area if a shoe should make friction better. For the same application force, the pressure is less if the area is more.  What it does is to make it better at dealing with heat in repeated heavy braking.

Also, with an SLS brake using mechanical cam, both shoes are forced to move by exactly the same amount as they wear. In that case, the leading shoe may very well do more work to begin with, but it's contact force will drop accordingly so the actual effectiveness will necessarily be that of the average of a brake with two trailing shoes and a brake with two leading shoes. There is thus no point in swapping them because the benefit if any will only be very short term. Better to have separate actuators for both shoes.

I don't know how to reliably tell if old shoes are asbestos. I suspect my unrestored 16H has asbestos. It's front brake is excellent, just as the prewar journalists said, even though they are nowadays mocked for saying it.  My other single had new brakes in the 90's, skimmed to fit, and the front is much worse. I'd like to know if I can improve it. Levers, cables etc are in good condition. The front plate lever has been extended from the original. All I can think is to make another even longer, unless there are better shoes for road use.

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Hi David.  I do as Ian does and regularly  swop my shoes over , if nothing else it means they last longer. I use a vernier caliper to see which is the thicker. A few days of use and in my mind they are better. (may be wishfull thinking!) . I have an extended SS  arm . One trick I do is to closely adjust to lightly rub  then spin the wheel and gently lever the brake plate away from its stop on the forks .If the rub clears ,I fit a small shim betwix plate and leg  to correct the distorsion .this allows closer adjustment and better  alignment  shoe to drum. Done this on the Ducati 250  and  It helped a lot.  Later I discovered that with  very hard braking  at the end of the straight at Jurby   (parade !)  the brakes got hot  and  then  really  did the job. Racing linings . Of course this does not happen in real life on the road (I was only showing off to the spectators how a 250 single sounds with 10000 on the clock, silly old sod !) .

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... that isn't often mentioned is the direction of the operating arm relative to wheel rotation. On my 1952 ES2 (which BTW has the 8" single sided front brake mentioned above) the lever "trails" the wheel rotation - right hand side brake, cam and lever behind the fork leg. This has the effect that the trailing shoe moves further than the leading shoe as the effective contact point of the cam on the trailing shoe abutment is closer to the wheel spindle. This probably sorts itself out as the linings wear but certainly is likely to reduce effectiveness.

Having said that, a handlebar lever with 7/8" pivot distance and centralising the backplate (by holding the front brake hard on while tightening the wheel soindle) has made the brake acceptable. I've used Villiers Services for brake lining and asked them for high friction linings.

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evening all

I experienced front brake fade and failure on the the Irish National Rally a few years ago, resulting in a fairly high speed off on my '35 Inter. There was an Irish cow ambling down the road and i had to take avoiding action as the lads in front had broadsided across the whole road. I had the brake drum skimmed on returning home, not a lot of meat left on the drum, and new donated shoes skimmed to fit. The 'new' brake was not very good and whereas it improved marginally on bedding in,  I still had to make almost an appointment to stop, not good. I decided to have the shoes relined by Villiers a few weeks ago, £21.99, 7 day service, and the front brake is now superb. A revelation. i have fitted the same to a '37 model 50, equally superb. Recommended.

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I tried all sorts of things to improve my single leading front brake, including some of the above. Finally I took to the trailing shoes friction material with a hacksaw and chisel. I removed more than a third but less than half of the lining from the trailing end i.e cam end. This was achieved by hack sawing down to the shoe material in a series of 1/4 inch cuts. Then I used a chisel to remove the `lining. This improved the brake noticeable.

The effect of this is two fold. The trailing shoe wears quicker thus allowing the leading shoe to do it's job without the trailing shoe negating it's progress. With less material the trailing shoe flexes away from the cam so allowing more pressure to be applied to the leading shoe. Obviously you can't see this flexing when it happens, it is my conclusion that it does take place.

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Hi David Gibson,   Do you know what spec linings Villiers fitted?   ,Were they of a gold colour with a woven appearance?. I got some like this for the Atlas rear from RGM  and they turned a useless brake into one that would lock the wheel if required. They replaced some "ferodo " ones bought on the internet .(Never again).

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Villers used a gold coloured woven material on the set of BSA 8" singled sided shoes I sent them. Made to a given size they bedded in very quickly and the brake performance is equal to a 7" tl s brake with original linings. The material looks the same as the RGM hi performance rear brake shoes.

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.. fitted the same gold woven material to the shoes on my ES2 and it works very well. Good people to deal with. I specify high friction (the way I use my bike I have no real need for super fade resistance).

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If Villiers can supply a range of thicknesses  that will be good.  Wear and skimming  can  increase the drum diameter to a point that std linings are a waste of time. 

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When you place an order with Villers you include the ID of the drum and the OD of the shoes with no lining fitted to the brakeplate. They fit bespoke thickness linings to give you a set clearance (can't remember the figure), its the closest you can get to arcing the shoes without actually arcing. None of this fitting metric dimensioned lining giving you new but already half worn shoes that touch in two small places.

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Interesting points on the  mechanics of brake performance and improvements.  I use Saftek (Leeds) for my classics. Good service no issues

I used to be a stickler for "performance enhanced", "racing" or top spec linings till you realise just how much braking you actually do on a vintage single...  Very Little! 

If you ride within the "other" limits of the machine my Inter will just clip a ton (legal environment) but will not stop well with AM4 linings, the first or second application.  But fit it with the same soft linings as in the Model 50 and it compresses your front end down to the bumps. 

On track they would soon fade, but on the road, they will be as cool as when you set off.  Feel the drums at the next coffee stop, they don't generate the heat that the "performance" linings are  meant to deal with.  

Now how often does your speed exceed the national limit on these ancient machines? rarely on these busy roads.  So the braking requirement is not determined by the performance of the  machine its the environment you run it in.

 An adjustment in the brain will improve your stopping performance. Ride it with your riders head on and you will hardly touch the brake. 

I had an Advanced riders course once; the instructor wanted to "cat an mouse me" over  some sweeping  A and B roads we both knew well.   He kept right up my pipe, watching every move of foot, hand, body.  Then he would reverse the role after understanding my actions and telling me what to look for. If he touched the brake once on a 12 mile run it was to pull over and stop.  Planning, throttle control and anticipation... and the moment it all goes wrong the brake will be your last resort....   

Safe riding!

 

I agree with Johnathan, When I need to stop to avoid an accident I want a really good stopper. I too ride on the throttle, this can be a problem if you are following modern bikes. They brake so hard and late into the corners I have to brake to avoid ramming them, then they accelerate hard leaving me in an acceleration void.

I want a brake that works really well when I need it, which is rare. Like Johnathan I'm not concerned with brake fade, just give me one good pull on the brake lever. The mountain ranges to the east of Melbourne are great for bend swinging. I indulge as often as I can, however this area is home to deer in plague numbers. A couple of years ago I came across a large deer in the middle of the road, without an excellent front brake I would have to have gone off the road because she wasn't going to move.

If you have good brakes you can confidently go faster into the corners knowing you can take evasive action.

 


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