1978 Cb750 k8 spoke wheels to mag wheels

[d4rkne33]

I decided to buy some mag wheels for my cb750 k8 to replace my spoke wheels (some spokes broken, etc, etc). I wonder what kind of modifications I'll have to do to make them fit on my bike. Can I put the same drum system and drum cover on the rear wheel ? Since the front mag wheel is a dual disc brake, is there any modification I should do to keep the original single disc system from the original spoke wheel ?

I believe the mag wheels are either from a F model or from a late Cb750 model (80's).

Thanks !

 

[my-79-750-k]

Yes and no. Yes, the rear brake drum is the same, the spacing is the same, width is the same. The only difference might be the sprocket bolts (4 vs 5). As far as the front goes, the mag wheels are completely different from the spoke wheels. You'd need the forks and triple trees from a later model bike that came with both the mags and dual brakes. The F and later models had 37mm forks and dual disc brakes, the earlier bikes had 35mm forks and single discs. Basically, you can't keep a single disc brake with mags. Also, why would you want to keep the single disc brake system? It wasn't great when it was new, the dual discs are a huge upgrade. Financially, it costs more, but in the end, it's so much better it's well worth the extra $$. Find a junkyard and look around for dual disc CB750's, you can usually grab a front end for 100-150 without the wheel. Good luck.

PS: Look at my build thread to see the front end conversion I did with a 750 Nighthawk front end. It was also spoke to mags.

 

[d4rkne33]

The reason I want to keep the single disc brake system is because I'm on a pretty tight budget. Since I already have the whole thing, I didn't want to buy a new set of calliper, pads, discs. Is there a way to use the same front end (let's say I get a dual disc system) and just use spacers to compensate for the fork size difference ?