Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: Beddgelert on June 18, 2016, 02:55:42 PM

Title: Front brake arm and caliper
Post by: Beddgelert on June 18, 2016, 02:55:42 PM: I would appreciate some advice on fitting a front brake caliper arm to my 1974 cb550ko. When I bought the bike as a USA imported barn find it didn't come with a front brake assembly. I have now bought two new brake caliper arms of eBay because they don't seem to fit onto the front fork without clashing with the top of the brake disc. I have checked all of the usual resources but nothing seems to illustrate the assembly on the bike and as it was never fitted on my bike when stripping it down I have no back reference, so....

Should the the arm be able to swing over the top of the disc because I assume that the arm centres on the disc and the caliper sits either side, or

Am I being totally mislead and the arm actually does sits spoke side of the disc and does actually clash with it?

Any help would be greatly appreciated
Title: Re: Front brake arm and caliper
Post by: Honda Al on June 18, 2016, 04:12:57 PM: Do you have any photos of the problem? We love a photo

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Title: Re: Front brake arm and caliper
Post by: hairygit on June 18, 2016, 04:30:23 PM: Arm should swing freely over the top of the disc, could be a couple of reasons why you have the problem you have. the arm may well not be what it was advertised as, it could be from a 250/350/360 or 400/4, which have a smaller diameter disc, therefore will cause the issues you describe, OR somebody may have fitted a disc from a 750, which has a larger diameter than the 500/550, also giving the issues you describe. Best thing to do is measure the diameter of the disc to check.
Title: Re: Front brake arm and caliper
Post by: matthewmosse on June 18, 2016, 04:48:23 PM: If that fails to pinpoint an issue, then in my expirience, the pivot can wear allowing the arm to drop onto the disk, if that had happened it is possible that someone might have attempted a repair and got it wrong with an inserted bush or chemical metal.
Title: Re: Front brake arm and caliper
Post by: Bryanj on June 18, 2016, 05:10:07 PM: If its a US import I would be 99% certain its a 750 wheel and disc, as said measure diameter and post size. Wheel is ok to use but not disc
Title: Re: Front brake arm and caliper
Post by: Beddgelert on June 18, 2016, 07:26:20 PM: Thanks Guys, just to recap

The arm definitely doesn't travel over the top of the disc as I suspected it should (thanks hairygit), I have checked the part number of the arm and actually I have two different arms now which are (I believe) the right part for the bike. The disc diameter is 296mm (brianj) is that a 750 disc?

Which is easier/ least expensive, change the disc or can I fit a 750 arm which will fit the disc without changing the lower fork tubes?

thanks for the knowledge! And anyone want a couple of 550 brake caliper arms?!!!
Title: Re: Front brake arm and caliper
Post by: Bryanj on June 18, 2016, 09:50:03 PM: Its too dark to go and measure my 500 but the only solution that makes sense is a 500 disc if the one you have is 750 as the mountings are higher up the slider for the 750
Title: Re: Front brake arm and caliper
Post by: Johnwebley on June 18, 2016, 11:31:09 PM: easier to get correct disc,

check this out,

offer around Â£24

http://www.ebay.co.uk/itm/Honda-CB500-Four-4-1972-Front-Braking-Brake-Disc-/311616198943?hash=item488dc5d91f:g:oGEAAOSw9k5XPtCs
Title: Front brake arm and caliper
Post by: SteveD CB500K0 on June 19, 2016, 07:14:50 AM: I have a couple of discs as part of my barn clear out. One may be from a 550 though.
They will be cheaper than that! (Like about Â£20 cheaper)
Watch this space.

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Title: Re: Front brake arm and caliper
Post by: Bryanj on June 19, 2016, 08:21:53 AM: 500 disc is 278mm diameter so there is your problem and take Steve up on his offer as the 550 is the same disc
Title: Re: Front brake arm and caliper
Post by: SteveD CB500K0 on June 19, 2016, 04:00:16 PM: Both measure 276mm so look to be what you are looking for. One has C01 stamped on it and the other has R2. No idea what they mean.
Those of you who knew Eamon will understand why he took these perfectly good (but drilled) discs off and replaced them with standard

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Title: Re: Front brake arm and caliper
Post by: SteveD CB500K0 on June 19, 2016, 04:04:01 PM: Quote from: SteveD CB500F on June 19, 2016, 04:00:16 PM
Both measure 276mm so look to be what you are looking for. One has C01 stamped on it and the other has R2. No idea what they mean.
Those of you who knew Eamon will understand why he took these perfectly good (but drilled) discs off and replaced them with standard

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Title: Re: Front brake arm and caliper
Post by: Bryanj on June 19, 2016, 05:40:53 PM: My 278 was with a tape measure with the wheel in the bike so 276 is probably right
Title: Re: Front brake arm and caliper
Post by: Beddgelert on June 25, 2016, 10:55:32 AM: Thanks Steve, sorry I haven't been checking my posts and missed your offer of a disc but much appreciate the effort

I managed to source one from DK and it arrived yesterday so will get it on the bike today

Thanks again to everyone for your advice
Title: Re: Front brake arm and caliper
Post by: Nurse Julie on June 25, 2016, 01:59:36 PM: Hi Steve.
Is the disc still available?
Title: Re: Front brake arm and caliper
Post by: mickwinf on July 03, 2016, 02:31:02 PM: hey Julie I have a disc you can have if you are stuck
Title: Re: Front brake arm and caliper
Post by: SteveD CB500K0 on July 03, 2016, 03:00:19 PM: Yep. Two of them. Just packing up the rest of the barn clearance stuff.
Â£10 each plus shipping (heavy)
They are drilled. Did you see the photos?

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Title: Re: Front brake arm and caliper
Post by: Nurse Julie on July 03, 2016, 04:22:52 PM: Is that reply for me Steve, I'm getting lost with this lot 😃😃😃
Title: Re: Front brake arm and caliper
Post by: SteveD CB500K0 on July 03, 2016, 04:42:44 PM: Yes Julie

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Title: Re: Front brake arm and caliper
Post by: Nurse Julie on July 03, 2016, 04:53:24 PM: Quote from: SteveD CB500F on July 03, 2016, 03:00:19 PM
Yep. Two of them. Just packing up the rest of the barn clearance stuff.
Â£10 each plus shipping (heavy)
They are drilled. Did you see the photos?

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Yes, I saw the photo Steve. I only need the top one though, not the pair. I'm going for a twin disk conversion on my 550, not a triple 😃😃😃.
Title: Re: Front brake arm and caliper
Post by: Nurse Julie on July 03, 2016, 05:11:47 PM: Quote from: mickwinf on July 03, 2016, 02:31:02 PM
hey Julie I have a disc you can have if you are stuck
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