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Drum Brake issues (CB500 1994)

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Vardypeeps
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Drum Brake issues (CB500 1994)

Post by Vardypeeps on Thu 27 Jul 2017, 1:40 pm

Ey up guys.

I'm coming to my wits end with the correct brake issue I have.

Both pivots on my rear drum brake lubed and cleaned twice now but for some reason the EBC shoes since I fitted them seem to catch inside the drum hub and hold the rear brake on ever so slightly.

Am I missing something when I'm cleaning the pivots? Had the footrest completely off, C-Clip off pivot cleaned everything?
Should I attempt fitting the old Honda drum shoes back in (kept them as they seemed to have a lot of life left).


Is it time to start looking at a disc brake conversion at the rear, what would be required?
Swingarm
Wheel
Spacers/Brake Mount
Caplier and Pads
Brake Line
New right hand footrest to fit master cylinder?

Thank you in advance. I had a search through the forum but it can be hard to find specific answers
Just realised it's in the wrong forum area too!
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Jameshambleton
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Re: Drum Brake issues (CB500 1994)

Post by Jameshambleton on Thu 27 Jul 2017, 1:58 pm

Have you ensured that the chamfered edge is there on the pads and/or it is fitted and going in the correct direction?
Have you adjusted the nut on the end of the brakearm (usually there is a spring with it?) to compensate with the new pads? 

With a rough guestimate a disc conversion with "going rate" prices for parts would come to £260
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ANDYC
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Re: Drum Brake issues (CB500 1994)

Post by ANDYC on Thu 27 Jul 2017, 5:32 pm

You'll need to add a disc to your list as well Very Happy
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Vardypeeps
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Re: Drum Brake issues (CB500 1994)

Post by Vardypeeps on Thu 27 Jul 2017, 5:56 pm

ANDYC wrote:You'll need to add a disc to your list as well Very Happy

Bugger!! haha.

Could be a case that I've installed the shoes the wrong way around?

I'll give it all another good check and the bearings too whilst I'm there.

£260 isn't too bad it's finding everything.
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Jameshambleton
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Re: Drum Brake issues (CB500 1994)

Post by Jameshambleton on Thu 27 Jul 2017, 6:05 pm

It'll be about £300 in total but then there would be postage on top, you can pick up a rough cb disc  model for about £400-450 at the end of the year so might be doing that route and breaking the rest of it for spares. 
Then you've got to do that thing and tell your insurance company you've changed the swingarm, wheel and brakes
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eternally_troubled
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Re: Drum Brake issues (CB500 1994)

Post by eternally_troubled on Thu 27 Jul 2017, 8:24 pm

Certainly don't rush to put disc on - you just get different problems! (I'm not joking) Definitely better to fix your drum if you can. I'm not saying the disc is bad (it isn't) but it isn't magic either...

I'd say it would be worth fitting the old shoes back, especially if you they have a fair amount of meat left - if only to rule out the new shoes as the problem - if by some chance the old shoes work just leave them in there (they don't wear fast IME).

I haven't had this particular problem with any of my bikes that have drum brakes so sadly I can't supply a magic solution. There shouldn't be anything difficult about cleaning the pivots, other than the amount of grot that might be in there.

I remember that there's meant to be a felt washer in there somewhere - did you manage to find that?

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jchesshyre
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Re: Drum Brake issues (CB500 1994)

Post by jchesshyre on Thu 27 Jul 2017, 10:35 pm

Have you tried this: before you tighten the rear axle nut, spin the back wheel by hand so it gets a bit of momentum, lock the brakes on hard with your other hand, and then hold them on as you tighten the axle nut?
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Vardypeeps
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Re: Drum Brake issues (CB500 1994)

Post by Vardypeeps on Fri 28 Jul 2017, 12:17 pm

jchesshyre wrote:Have you tried this: before you tighten the rear axle nut, spin the back wheel by hand so it gets a bit of momentum, lock the brakes on hard with your other hand, and then hold them on as you tighten the axle nut?

Good tip for aligning it all up, will try this too
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Vardypeeps
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Re: Drum Brake issues (CB500 1994)

Post by Vardypeeps on Fri 28 Jul 2017, 12:20 pm

eternally_troubled wrote:Certainly don't rush to put disc on - you just get different problems! (I'm not joking)  Definitely better to fix your drum if you can.  I'm not saying the disc is bad (it isn't) but it isn't magic either...

I'd say it would be worth fitting the old shoes back, especially if you they have a fair amount of meat left - if only to rule out the new shoes as the problem - if by some chance the old shoes work just leave them in there (they don't wear fast IME).

I haven't had this particular problem with any of my bikes that have drum brakes so sadly I can't supply a magic solution.  There shouldn't be anything difficult about cleaning the pivots, other than the amount of grot that might be in there.  

I remember that there's meant to be a felt washer in there somewhere - did you manage to find that?    


Agreed that it may just cause more heartache going forward!
To be honest I found the rear drum very responsive before this issue began.

I'll try the old shoes in there.

My EBC shoes are glazed slightly from the drum brake pivots getting gunked up and holding the brake on slightly, is it also possible I have warped the wheel hub that much? doesn't feel any different when riding?
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jchesshyre
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Re: Drum Brake issues (CB500 1994)

Post by jchesshyre on Fri 28 Jul 2017, 1:14 pm

When I had a drum model (which I marginally preferred to the disc model for ease of rear wheel removal and refitting) I did occasionally have the issue you're having and that alignment trick always sorted it. Incidentally, even though I did use the brake a fair bit, I never had to change the shoes from when I bought the bike in 2008 with 24,000 miles on to when I retired it in 2014 with 145,000 on it.

If I had another drum brake model I definitely wouldn't bother converting it to a disc brake, but each to their own of course.

Hope you get the issue sorted - it won't surprise me if that alignment trick sorts it and I don't know why Honda don't tell you to do that in their manuals. I learnt it from the Haynes 'Motorcycle Maintenance Techbook' I think.
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Vardypeeps
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Re: Drum Brake issues (CB500 1994)

Post by Vardypeeps on Tue 01 Aug 2017, 12:34 pm

Quite certain the alignment trick sorted this issue out but I can confirm my findings Smile

The EBC shoes were catching the inside lip of the rear wheel, just beyond the braking surface.

Honda shoes still had loads of life so I swapped them back in, did the alignment trick and also re-painted the brake hub too.

All working fine now and I'm a very happy man!


Not sure if the EBC shoes are slightly wider across the braking surface, if I had tightened it up mis-aligned or if the spring mounting points on the EBC shoes made the springs sit on the metal supports lifting the shoes away from the pivots slightly causing them to catch/rub.

Only changed them as I had the drum off to work on the pivots at one point Smile
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trevor machine
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Re: Drum Brake issues (CB500 1994)

Post by trevor machine on Tue 01 Aug 2017, 3:39 pm

jchesshyre wrote: I never had to change the shoes from when I bought the bike in 2008 with 24,000 miles on to when I retired it in 2014 with 145,000 on it.

So awesome.
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skyerae
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Re: Drum Brake issues (CB500 1994)

Post by skyerae on Wed 02 Aug 2017, 6:21 am

I had an issue with a Honda VT500 I used to own that was kind of similar. There was no progressive feel to the rear brake when it was applied and then it would suddenly lock up and the bike would try and throw you off then - in which it succeeded once in the rain. Took the drum apart a number of times and eventually found the issue. A previous owner had replaced the brake shoes with EBC ones and they were ever so slightly wider than the original shoes and as you applied the brake the shoes would catch on the lip between the worn section and the new and unworn drum surface. Had this lip removed and then sold the bike as it was still in about 300 bits at that time.

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