Brake Fettling

bmetcalf

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One step I didn't see in the brake setup story in the new MPH is to "pre-load" the shoes. It involves vise-grips, so many won't like it, but I like the better brakes. I assemble the arms, motion blocks and cable ends loosely, with the adjusters screwed not quite all the way in. Then, I rotate the cam in the direction the cable will pull it, using the vise-grip on the serrated washer, until the shoe contacts. Next, using a third hand, I tighten the nut. This leaves the lining almost touching the drum and leaves the maximum amount of adjustment. As with most things, there is a learning curve. An alternate to vise-grips is SS serrated washers with radial holes and a special pin spanner to fit.

I also have the KTB style balance beam outrigger and Doug Hollis design backing plate gussets.
 

timetraveller

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Perhaps using a vise grip on Bruce's nuts might stop some of this butchery. It is absolutely not necessary to do it the way he suggests.

:mad:
 

Robert Watson

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I find the best way is to put a flat washer between the back of the serrated washer and the boss on the backing plate, then the cam and nut, one can then tighten the nut until is is stiff to move the cam, rotate the cam to the desired opening and fully tighten the nut. Then turn the shoes to the correct diameter, disassemble and remove the washer and install on the wheel.

The vice grips should be applied to Bruce's nuts only!

Robert
 

bmetcalf

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Brakes!!

Does this mean you don't want me to work on your bikes?

Seriously, Robert's idea is pretty good, the washer one, I mean.
 

mercurycrest

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Bruce,
I'm pretty sure, although I must emphasize I haven't tried it myself, if you are ambitious enough, you could use both hands and have a vise and vice grip on all your respective nuts simutaneously..... :D:rolleyes::eek:
 

bmetcalf

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?

I said vise grip on the washer. On the nut would be, well, nutz.;)

Vice is the Squad that catches you "at play".
 
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Pete Appleton

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Vincent design not perfect

Leaving aside the reprehensible vices (vises) of some correspondents, has anyone thought of a way around the design flaw in the Vincent brake set-up?

Profiling the shoes to suit the drum, as suggested by Robert is surely the way to go to get a good brake, initially, but what happens after a few miles? The Vincent design uses leading and trailing shoes. The shoe with the operating cam at the leading end makes use of the 'self wrapping' effect and gives more braking effort than the trailing shoe. More braking effort = more lining wear. Conversly the trailing shoe will have less wear. This is demonstrated on many car and commercial vehicle applications where the leading shoe is actually supplied thicker than the trailing one from new. Unfortunately the Vincent design has no provision for wear compensation. The cam position and the anchor position are both fixed. This means that the leading shoe may only wear down at the same rate as the trailing shoe otherwise it will not contact the drum. We have, in effect, got twin trailing shoe brakes. The 8" drum system mentioned in MPH this month looks worthwhile but has it still got the same problem?

Has anyone got any clever thoughts for an adjustable cam or anchor that will allow for different rates of wear?

Pete
 

Robert Watson

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I ran "standard" brakes for almost 20 years with AM4 linings on stiff alloy plates and finned drums, and although adequate for that time I did not feel that with two up and luggage they were up to the job. I was just preparing to go to disks when Vincent Speet's TLS brakes appeared. I an very happy with the results of installing them.
As for making the original more effective, in an MPH early on in my tenure as Editor I think --- or perhaps just before, Bert Weisz (sadly no longer with us) laid out drawings to make the anchor pins in a floating arrangement which address the question Pete has asked. Unlike John Webber who kept endless lists with which to cross reference articles in MPH, I didn't, but I just spent a few minutes and found the appropriate page. MPH 632 from Sept 2001 Page 13. Hope that is of some interest.

Robert
 

Pete Appleton

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Scanner anyone?

MPH 632 from Sept 2001 Page 13.

Thanks for the speedy reply Robert. Unfortunately Sept 2001 was before my time with the club. Perhaps someone would be kind enough to scan the relevent page and post it in this thread.

On a slightly different subject, I assume that editors past and present compile MPH electronically. How difficult would it be to create an electronic archive of MPH back copies? Could this be done on-line or even as a cd ROM that could be sold through the club shop. Am I over simplifying matters and it would actually be loads of work?

Pete
 

clevtrev

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I have brake plates with indepedently floating shoes, and they do not work, at least, not with AM4 linings.
 
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