Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: alexdecker on February 25, 2024, 04:43:39 PM

Title: Any reason for this specific bolt for the brake arm?
Post by: alexdecker on February 25, 2024, 04:43:39 PM

Hi all

Replacing some parts for the rear brake of my 550F from 1977. Just got all the parts from CMS and discovered too late that I forgot this part, and attaches the brake arm to the frame:

https://www.cmsnl.com/honda-cb550f2-super-sport-550-four-1977-european-direct-sales_model17122/bolt-stopper-arm_90133286000/

Would there be anything wrong with using a normal bolt and riding with that until my next part order? Feel like it’s a little much doing a part order for just one bolt.

Why does this need a special bolt to begin with? Just to be able to lock it with a pin? Seems to me I could just use a regular bolt the same thickness as the thick part of the original bolt? But as usual, I might be missing the bigger picture, so wanted to hear your opinion in here  :)

- Alex

Title: Re: Any reason for this specific bolt for the brake arm?
Post by: Bryanj on February 25, 2024, 05:29:09 PM

Its a shouldered bolt so that when the nut is done up tight it can still allow the torsion arm to pivot.
You could probably get away with a collar of the right dimensions and a nylock nut

Title: Re: Any reason for this specific bolt for the brake arm?
Post by: McCabe-Thiele (Ted) on February 25, 2024, 06:30:50 PM

I agree with Bryan for a short term solution, personally I see a split pin as an essential long term safety feature.

Title: Re: Any reason for this specific bolt for the brake arm?
Post by: davidcumbria on February 25, 2024, 06:43:27 PM

If it’s like my 550 k1 it is specially shaped to locate in brake shoe holder. Also it needs a spring clip not a split pin making rear wheel removal easier. Here is a photo of the bolt. You might want to look at your backplate because a hex head wouldn’t fit - but the 500f might be different.

https://www.cmsnl.com/honda-cb550-k1-four-1975-usa_model466/bolt-rear-brake_90127323000/

Title: Re: Any reason for this specific bolt for the brake arm?
Post by: McCabe-Thiele (Ted) on February 25, 2024, 06:46:26 PM

I think were talking about two different pivots in the rear brakes.

Title: Re: Any reason for this specific bolt for the brake arm?
Post by: davidcumbria on February 25, 2024, 09:32:11 PM

Yes I’ve highlighted the brake end not the frame end.

Title: Re: Any reason for this specific bolt for the brake arm?
Post by: alexdecker on February 26, 2024, 05:44:14 AM

Thanks guys. I will try and do an intermittent solution until I make my next part order, and save a bit of money and the environment then :)

Title: Re: Any reason for this specific bolt for the brake arm?
Post by: Bryanj on February 26, 2024, 07:36:47 AM

Try your local dealer, its probaably still available