Disc interchanageability

[Seamus]

Probably not even a word, but i hope you know what I mean.

I bought another disc for my K1 and it is a good bit bigger in diameter. I think it was from a 76 bike. I thought that the front disc was the same throughout the K series. Did Honda change the disc size at some time? Any idea which models had yje larger disc?

Thanks

Seamus

[Bryanj]

As far as i know 750 had the same diameter 69 to 76. the 500/550 was smaller has somebody fitted one of those front ends as the tubes are the same diameter? Pics might help

[Seamus]

Thanks for the reply. I measured the discs, my one is 275mm and the replacement is 295mm.

The picture shows the setup before I took it all to bits.
Does the disc look small in this pic?

[SteveD CB500K0]

That gap looks very big.

On my 500, the gap between the outer edge of the disc and the caliper is only 1-2mm

[Seamus]

Thanks for the info. I will have to check when I start the rebuild. The frame and other bits are off being powder coated and some other bits being chromed.

I may be able to test the disc on the wheel against the fork leg with the caliper in position.

Apreciate the help

Seamus

[Bryanj]

Caliper and bracket are 750, gap is way too big i suspect a 500 disc, or more likely a complete front wheel due to accident. what are the markings on the rim and check against a known 750 one as the 500 is narrower

[Seamus]

Thanks for the info. Just rebuilt the front wheel with a new rim (750). I still have the old one and will measure when I get home for comparison.

Was the hub the same for both bikes? as the speedo plate and drive etc match the workshop manual diagrams.

Cheers

Seamus

[Seamus]

Measured the rims and they are both the same. Guess it was a replacement disc

Thanks
for the help

Seamus