Topic: Identifying Forks for Correct Calipers.

[bahia]

When I bought my project '73 CB500, the owner told me it was a Franken-build, and the forks were "mystery forks." He said they might be off a CM400... But no guarantee.
They look like normal CB forks (but I'm no expert by any means).

I'm about to purchase the caliper mounts and caliper parts, so need to make sure I'm buying the right brake system.
Am I safe with just buying CB calipers?

[robvangulik]

I think these forks were made for drumbrakes.

[Alan F.]

Need more photos showing the left fork slider

[robvangulik]

Need more photos showing the left fork slider

Why? There is nothing there but fender mounts...

[Alan F.]

Ok, so fender mounts only on both sliders = a set of drum brake forks.

[754]

Yes made for drums or you must custom make a caliper mounting system. Cheaper to get used forks and trees. The wheel will work for Honda brake parts, should be 6 holes to mount rotor.

[bahia]

Damn! It totally escaped me that those were fender mounts.
So yeah, looks like I'm gonna be after a frontend after all.

Now... I have to decide on going with a modern front end, or trying to find a CB front end on the cheap.
Thanks all.

[Alan F.]

I've actually got a CB400T front end just like yours that I'm saving for a project, it's got a drum brake 19" spoked wheel but I want to run tubeless Comstars with single disc on the left slider. I found a left slider from a CX500 is the perfect solution (on paper) and found one with a bent fork tube for ~$35 shipped. I stood them side by side and it looks like it'll work. There's no telling when I'll get to it though.

If you're interested in the drum wheel send me a PM and we can figure something out, it's in nice shape and will be plenty of brake for that bike depending on your riding style. It's the same size that came on the 350 twins and the CB/CM 400s so it's good for a 43hp, 400lb bike give or take.

[robvangulik]

Keep it simple, put cb(500/550) forks on it. Ample good enough for the performace of a CB500.
You might need new trees too, what is the measure of the forklegs, 35mm like it should be?

[754]

Easiest way to go big brakes, get a 77 or 78 75 F front end,  swap stems.....or use 500 trees.....easy to mount big rotors and calipers, Scotty did it a while back.
 750 legs are a bit longer but some desire more ground clearance.

[bahia]

Keep it simple, put cb(500/550) forks on it. Ample good enough for the performace of a CB500.
You might need new trees too, what is the measure of the forklegs, 35mm like it should be?

Looks like:
38 on the ear covers.
33.45 on the leg itself.
28 ID on the triple.

What do you think, do I need forks AND triple?

[bahia]

If you're interested in the drum wheel send me a PM and we can figure something out, it's in nice shape and will be plenty of brake for that bike depending on your riding style. It's the same size that came on the 350 twins and the CB/CM 400s so it's good for a 43hp, 400lb bike give or take.

Thanks for the offer, but I think I'm gonna try to get a disc on here.

[Alan F.]

You've got a CB400T front end on there, not sure about what the wheel is from.

https://www.allballsracing.com/forkconversion

[754]

It's a disc brake wheel if 6 bolt it works on 450 Honda thru to early goldwing.
 Measuring outside of fork cover tells us nothing, fork diameter does
 .get a front end and trees., , go black fork 77 m 8 750 if you want real good brakes. That don't weigh a ton.

[jonda500]

For your information:
-CB750 chrome fork tubes are over an inch longer than CB500/550 ones so when used on a 500/550 will result in the side stand and centre stand being shorter than the ideal lengths.
-CB750 triple tree steerer tube is also over an inch longer than the CB500/550 so it can't easily be used on a 500/550!
John

[754]

 Yes I had mentioned a stem swap, or to use 500  triple trees, you have about  1  1/4 inch of room to slide your tube up toward handle bars.......should you decide not to use that extra length.
 The reason I suggested 750 tubes, Is easier brake mounting for big brakes, and  500 forks with the internal rods may be a bit harder to service. ..

[bryanj]

The US had so many 550 that a set up from one of those should be easy to get, internals are easier and possibility of twin disc with 550 sliders

[robvangulik]

Keep it simple, put cb(500/550) forks on it. Ample good enough for the performace of a CB500.
You might need new trees too, what is the measure of the forklegs, 35mm like it should be?

Looks like:
38 on the ear covers.
33.45 on the leg itself.
28 ID on the triple.

What do you think, do I need forks AND triple?

That is what I would do, find a complete 550 fork, like Bryan says, it will fit right away and gives you the possibility to go dual disc if you want.

[Bankerdanny]

Yep, find yourself some 550 forks with the triples.

[754]

It depends what you really want, for better stopping , go newer components, bigger rotor, 4 piston caliper or more.
 A single big rotor will maybe out stop, dual disc old style stock stuff.. And it will  weigh a third as much if not less.
 So if it's a rider, it matters..

[robvangulik]

Sorry Frank, the first sentence I can make out what you mean, after that you lost me

[754]

Wow thst was some messed up stuff  my tablet puts out while I type.. i try to check.. i did correct one word in there,  came out worse for the fixing..

[PeWe]

Typical for keyboards and telephones, my fingers hit rate are not that good!
Installed huge keyboard on my phone did not help either.
Auto correction can write something very different. So that is off.