Author Topic: Brake lever  (Read 2747 times)

Offline Gavin

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Brake lever
« on: 07.11. 2009 13:10 »
I am getting pretty close to finally getting my 51 A10 plunger on the road.... but stopping it would also seem like a good thing.... when I drop the lever from the brake housing down a notch i can't get enogh length to connect the cable. when i bring the lever up a notch i have a cable that is now too long. since i can't find the middle ground, as it were, i am wondering if i am missing an adjuster on the brake lever on the handlebars? Can anyone supply me with a photo of their brake lever please? and or let me know if 51 Plungers had the adjuster.... or if there is another way to resolve this challenge. i have included a photo of the current lever. hope it helps. Thanks.

Online bsa-bill

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Re: Brake lever
« Reply #1 on: 07.11. 2009 13:21 »
Hi Gavin
I'm not familiar with the plunger brake so this might be rubbish, - some levers on brake plates can give a setting half way if they are turned.
Maybe not describing this very well but the square hole in the lever is offset compared to the hole in the end for the clevis pin.
Probably way off the mark here but you never know.

All the best - Bill
All the best - Bill
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1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Rusty nuts

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Re: Brake lever
« Reply #2 on: 07.11. 2009 14:33 »
Have you tried fitting a ferrule between lever & cable? This will take up some slack.
To give some extra length you could detach brake cable & remove locknut from the bottom thumbwheel adjuster.
The problem with this is you end up having to adjust the brake all the time as the locknut ain't there & the adjuster moves a fair bit from pressure/vibration etc.
If you forget to check regularly it is possible to discover no front brake when you need it most!
Once linings have worn/cable stretched you can re fit locknut.

Rusty
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Offline a10gf

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Re: Brake lever
« Reply #3 on: 07.11. 2009 15:17 »
(If I did get the question right...) You can't get any correct cable length using the cable adjuster? or is the adjuster missing ? The standard adjuster fitted on the brake plate provides substantial adjustment of cable length.

If the cable is too short, move the operating arm on the brake plate up a notch, if too long, move it down, and do any finetuning with the cable adjuster. If totally out of spec, get a new cable of a more appropriate length.

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Offline Rusty nuts

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Re: Brake lever
« Reply #4 on: 07.11. 2009 16:02 »
There should not be an adjuster on the lever on the handlebar. There should be an adjuster on the brake plate, as in E's pic
Is that what you have?

when fitting dont try to force nipple over operating toggle end in situ, remove clevis pin/screw whichever you have & fit nipple & replace.

You could fit a different h/bar lever with an adjuster but there should be no need to have adjusters both ends unless something is wrong with the cable/drum/linings.
The most usual cause is knackered linings or drum has been skimmed without fitting o/s linings.
1949 A7 Plunger
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Offline MikeN

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Re: Brake lever
« Reply #5 on: 07.11. 2009 22:53 »
For best efficiency (assuming new linings) and maximum brake shoe life.You want to obtain an angle of about 70-80 degrees between your brake lever and the cable.
If you cant do this with what you have then you need to obtain or make a new cable.
  When applied the lever should pull up to nearly 90 deg.After this point braking efficiency will fall off.
Mike

Offline Gavin

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Re: Brake lever
« Reply #6 on: 09.11. 2009 14:33 »
Thanks for helping me re think the issue. I decided to use part of an old cable (Throttle I suspect) and made up an adjuster at the lever end. As the brake pads were new 20 years ago and probably swollen a little with time i thought this would give me a safe enough option to at least test the bike with. (as I haven't had it running for over 30 years.) If this is not satisfactory i think I"ll go for a different cable. here's 2 more pix to show the end result.

Online groily

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Re: Brake lever
« Reply #7 on: 09.11. 2009 16:51 »
I'd get another cable, as with the obtuse angle at the bottom, it'll never be as good as you want. I had exactly the same problem with my s/arm bike when I got it, and in the end there was nowt for it but to get the right bit. Difference in operation was well worth it.
A better temporary bodge would be to make an extension clevis link to go from the lower lever to the bottom of the cable. Maintains the straight line of the Pull, allows the bottom lever to be put back to the correct acute angle to the cable line and saves having to use cheesy distance pieces.
But probably easier to get a new one to complete what looks like a very pretty beast.
Bill

Offline beezalex

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Re: Brake lever
« Reply #8 on: 09.11. 2009 19:05 »
Did you try flipping the lever over to obtain the same angle that's shown in the pic above.  With the lever in the position you are showing, an already marginal brake will probably be horrid.
Alex

Too many BSA's


Offline a10gf

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Re: Brake lever
« Reply #9 on: 09.11. 2009 19:28 »
Indeed, beezalex.

Gavin, as mentioned above, get the lever one notch or more down at the drum plate side to get the angle within a decent spec., then get rid of the adjuster at the brake lever, adjust the cable at the drum side. On your pic the lever is far past what should already be absolute max possible braking, and as beezalex points out, the loss in braking power will be substantial.

And check the shoe cam action, should not move to a too steep angle (against it's brake shoe contact surfaces) before max braking occurs.

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Offline Rocket Racer

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Re: Brake lever
« Reply #10 on: 10.11. 2009 08:53 »
Not that it affects the brake, but the bolt on the brake plate to the brake stay usually sits behind the front mudguard stay, where as your brake plate seems to be rotated anti clockwise about 10 degrees -Its as if your brake stay is too short. This certainly makes your brake lever and cable angles all look a bit odd. unlike the other image shown that is correct but doesnt show the brake stay relative to the mudguard stay. Persevere!
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Online Brian

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Re: Brake lever
« Reply #11 on: 10.11. 2009 09:24 »
I reckon Rocket Racer has hit on the problem Gavin, you need the correct brake stay and then start again with cables etc.

Offline Gavin

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Re: Brake lever
« Reply #12 on: 10.11. 2009 15:08 »
Yep I think Rocker racer and Brian have given me something fresh to think about after taking on baord the other helpful comments and concerns. can somone with a plunger frame measure the length of their brake stay and let me know what that is please? as I've been rebuilding the bike I keep coming accorss swinging arm bits that have been there since I took it on..... as I am not aware of how many more parts are swining arm, this may be another one of the several I have discovered so far. MAybe i have a Swinging arm cable as well??

but for now if i could have the measurement of the stay on another plunger frame that would help me heaps. Thanks.

Online bsa-bill

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Re: Brake lever
« Reply #13 on: 10.11. 2009 15:52 »
I'm not sure rotating the brake plate in relation to the fork is going to alter anything.
Gavin could you say if you have flipped the lever (turn it inside out) as suggested by myself and Beezalex ?

All the best - Bill
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Gavin

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Re: Brake lever
« Reply #14 on: 10.11. 2009 17:07 »
Bill I must admit i have thunked about it, and you will imagine that I am so dense that light has to bend around me, but I can't figure how to flip the lever. Can you explain how to achieve this? After reading your first post here, I did take another look at the lever and found that I could gain about 1/16inch by aligning both sides, one edge of the split in the lever was not quite in line with the other. Now both "Faces" of the lever sit flush on the stop where the lever rests against the handle bar arm.