Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: alexdecker on November 19, 2023, 03:57:39 PM
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Hey all
Just installed new brake shoes from CMS bought specifically for my model. But after installing them, I can't make them fit into the actual drum. The brakes are fully retracted, but they just won't fit. Am I missing something here? Usually it goes in really easy and is actually slightly loose.
These are the brake shoes I bought: https://www.cmsnl.com/products/shoesetbrake-non-oe-kevlar_06430390405p/
And then I bought a new brake cam as the old one broke: https://www.cmsnl.com/products/camrear-brake_43141374000/
- Alex
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Hi Alex my new shoes I just fitted were a tight fit in the actuator recess, make sure they are seated properly, I would even take a file to the ends to make fit easier. And obviously make sure you have the right shoes.
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Hi Alex my new shoes I just fitted were a tight fit in the actuator recess, make sure they are seated properly, I would even take a file to the ends to make fit easier. And obviously make sure you have the right shoes.
Hey, thank for the input! Can you elaborate what the actuator recess is?
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The flat spots on the cam that the flat end of the shoe fits into
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So found out these are Vesrah brake shoes. And they fit perfectly in the actuator recess. So I guess they just aren't a fit in general, or that CMS sent me the wrong ones…
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I'd check the part number of those supplied against the manual.
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I'd check the part number of those supplied against the manual.
Here is the part number of the Vesrah brake shoes: VB128S
And here is a picture where I have overlaid the new brake shoe on the old one. You can clearly see that the Vesrah shoe is quite a bit longer. No wonder it didn't fit into the drum.
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You bought 750 ones which are bigger than 500/550 the middle part number should be 323 not 300
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You bought 750 ones which are bigger than 500/550 the middle part number should be 323 not 300
Really? I know this might be misleading, but even on the packaging it says it should fit my bike?
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Just a thought Alex, is your rear wheel hub original or correct for your bike?
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The cms link you posted says they are 750 by the part number, when fitted use a tape measure to measure the diameter of the shoes, there is also a max dia cast inside the drum.
Also has it been relined and machined too small?
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I'm wondering IF the rear drum has been replaced by a previous owner as the 500/550 drums are renowned for cracking, maybe something like a CB500T was used instead.
Any pics of the inside of the drum and the drum in general Alex so we can see if it looks correct.
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Would the inside diameter of a 500 brake hub be handy - it's just slightly under 18.0 cm between the inside edges of the liner measured with an expanding ruler. That probably 17.98 -17.99 cms.
Amended I can't read my stupid tape measure.
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Stamped on the inside of the hub Ted
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If that's the case Ken then Alex should easily know if he has a 500 hub.
Only markings in my hub are E-7 & opposite B 1 3
My error it 18.0 cms less a tad not 8!
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Rear drum is 180mm dia. on 550. 390 is 550F part no. With the shoes centralised on the backplate, what is the diameter?
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I only took this before I assembled the wheel with the old brake shoes for now. Can you guys make anything of this image?
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That looks to have been relined but you're also trying to fit 750 shoes which won't fit your hub anyway Alex.
Edit... Have you got a photo of the brake plate.
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Put your ruler across the drum does it look like an I/d of about 18 cms?
If the answer is yes then it's the wrong shoes.
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I only have this photo of the shoes mounted. The packaging per earlier said specifically they should fit a 550F. So either Vesrah wrongly packaged 750 shoes in a 550 packaging or something else is amiss. But the shoes really are quite a bit longer than the other ones.
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The shoes look ok mounted Alex, IF they were 750 ones they wouldn't fit. Everything is looking to be correct yet they won't fit. Try measuring the shoes mounted on the plate as per the pic and see what they measure out at their widest point. I do remember many years ago of members saying they had shoes which didn't fit as they just had to much friction material on them compared to the OE shoes. I think the cure was to sand them down until they fitted. I've bought SBS shoes but as yet I haven't test fitted them, must check them to see if they have the same problem.
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It's not an exact science but measuring the width with the shoes when in place it's 17.8-17.9 cms measuring from the centre section of the shoes.
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Take the shoes off the brake plate, then put each one inside the drum to see if there's difference in radius at any particular point around them.
Shoes are often shamferred at their ends to fit then in to the drum, if they touch just at the ends then you can file that ramp onto them easily to get them touching along their full length.
In other words, you may not need to file the whole brake material, just a "ramp" on the end location of the friction material.
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Is there a big lip on your drum liner by any chance?
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Take the shoes off the brake plate, then put each one inside the drum to see if there's difference in radius at any particular point around them.
Shoes are often shamferred at their ends to fit then in to the drum, if they touch just at the ends then you can file that ramp onto them easily to get them touching along their full length.
In other words, you may not need to file the whole brake material, just a "ramp" on the end location of the friction material.
Good point K2-K6
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I had the same problem with my 550 rear shoes, filed a bit off the ends and sanded shoes a bit and inside rear hub to get them to fit and no problems since.
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I agree with all the comments about the friction material. If that is not the problem it could be that the new brake cam is too wide and is holding the brake shoes too far apart.