CB77 Disk Break on Front Wheel

pinkandersond · Post by **pinkandersond** » Thu Aug 05, 2010 5:54 am

I really want to install disk breaks on my CB77's front wheel. From what a couple of people told me, they said it would be easier to buy a new wheel. I managed to find a CB350 wheel on ebay. It's in pretty good condition and will take the disk break. I know I have to switch out the forks, but I was wondering if anyone else had any advice to hand out. Thanks.

cyclon36 · Post by **cyclon36** » Thu Aug 05, 2010 2:25 pm

From what I've read, it's best to go ahead and buy new forks as well unless you want to start fabbing up caliper mounts

pinkandersond · Post by **pinkandersond** » Thu Aug 05, 2010 8:54 pm

Yes, I was just thinking of buying new forks. The forks on my CB77 are pretty beat up. Has anyone ever attempted to install a CB350 fork on a CB77 or something similar to it?

davomoto · Post by **davomoto** » Fri Aug 06, 2010 11:57 am

installed an SL350 fork on a CL77. Only issue was with the fork stop, had to enlarge tabs on frame. Should be the same for CB350 , or CB400-4 forks.

ricksd · Post by **ricksd** » Fri Aug 06, 2010 2:08 pm

First, I just tore down a set of steel legged CB77 forks, and the quality of design/construction is much better than CB350 forks. The CB77 forks are double bushed- a great fit into the fork legs and if you ever did wear them out, the bushings could be repaired to return them to new condition, The CB77 forks are really well made.
It would be hard to fit a caliper to the CB77 legs, so you should find a high quality replacement. The 33mm CB350 forks are usually thrown away by guys who race them, and replaced with 35mm CB550 or CB750 forks. I've been measuring forks in junk yards, and the CB550 forks would be my first choice- the length is about right, and CB750 aftermarket tubes will fit- the CB750 aftermarket tubes don't fit into CB500 forks. I'm mentioning this because the fork tubes on CB750/550 forks are almost always pitted and rusted- the tops are so bad that it's a chore to even get them apart. If you don't have a problem buying cheap Chinese copies of an original design, there's a site that sells 35mm cartridge emulators for Yamaha XS650s that should work in the CB legs- I do have a problem with that, so I'd recommend the genuine RaceTech emulators.
You're going to spend a lot of money to make any real improvement, but I'm a hot rodder myself, so I know the feeling.
If you saw the forks,dampers, etc laying side by side, I'll bet you'd agree that the CB77 forks are built like a watch, and the later forks are built to be cheap/disposable.
Rick

pinkandersond · Post by **pinkandersond** » Sat Aug 07, 2010 4:17 am

Thanks for the info guys. I found an extremely good deal on CB550 forks that I let slip through my fingers. Thanks for the tip about that the CB550 forks. I really want to keep the 35mm.
Rick, would I stumble into any problems installing the triple tree and/or the frame to the forks? I've been having a really hard time finding the right calipers; I'm just gonna have to be patient with those.

teazer · Post by **teazer** » Sat Aug 07, 2010 10:13 am

Swapping forks is always a fun exercise. First the new forks have to be a similar length and offset or the geometry will change too much.

Next problem to overcome is the stem. If it's the same length but different diameter, it's quite easy to get different bearings to fit. if they are different lengths, the new stem may have to be swapped or modified.

And the last problem is the steering stops and lock may need to be modified. And of course if they are wider, the headlamp might need spacers.

None of those are insurmountable, but all make for part of the challenge. Don't limit yourself to Honda parts though. RD Yamaha might work and they work quite well with emulators. Suzuki GT750 would could also be made to fit but they are a little heavy.

Or you could get Vintage Brake to re-line you shoes and have them work as well as an early disk brake with a lot less work.