Topic: CB750 forks on my '71 CB500? How can I tell?

[)joshf(]

So someone on this forum mentioned that the forks that are on my CB500 now look like they might be off of a CB750. How can I tell? Would the PO have modified the triple tree or anything else to make them fit if they are 750s? They really arent as nice as they look in the pic. She shine is just a plastic cover that the PO rigged up. The actual tubes are pretty rusty. If they are 750 forks would that explain why they are "extended" or would they have had extended tubes put in them as well. Also wondering if I should keep the lowers and just replace the tubes with stock lenght ones. I have a set I could rob the tubes and boots from. Any suggestions would be cool. Thanks.

[bryanj]

Those tubes are definately extended, send me a closer picture of the brake caliper and mouting and i will tell you which it is

[Ted Nomura]

Your CB500 looks like it has the early CB750 brake calipers (note the silver color) which came from 1969-1970 CB750s. Standard CB500Ks have smaller disc and brake calipers, which was also standard on 1971-1974 CB450Ks and 1975-1976 CB500Ts, with different brake lines. They also seem to be the same units mounted on the 1977-1978 CB750Ks. 1970 CB450K had early CB750 front brakes. Fork tubes are interchangable but the fork lowers are not.

[bill440cars]

           I too would like to know how you can tell the difference in forks. Between the CB450 (I know,
   DOHC), 500,550, & 750 how do you know which is which? I have read on here that the 750 tubes are longer than the 500 or 500 but, by how much? Does anyone know the measurements or identifying features of the different ones? I'm sure there are others who'd like to know as well. Any info would be appreciated. Later on, Bill

[Ted Nomura]

           I too would like to know how you can tell the difference in forks. Between the CB450 (I know,
   DOHC), 500,550, & 750 how do you know which is which? I have read on here that the 750 tubes are longer than the 500 or 500 but, by how much? Does anyone know the measurements or identifying features of the different ones? I'm sure there are others who'd like to know as well. Any info would be appreciated. Later on, Bill

Diameter of the CB750, CB550, CB500 and CB450 are the same in most cases but lengths are different. But my CB400F forks won't fit because it's smaller and narrower. Looks like his 1971 CB500 got the extended CB750 forks(about 6") because the previous owner probably exchanged his CB750 chopper forks with stock CB500 units to make the CB750 look more stock, but the 1971 CB500 can be just as valuable if it can be returned to stock because it still has the standard mufflers. Of course if he doesn't want them, I'll gradly take it because I too have a stock CB500 that needs original mufflers to make it complete. You might want to check ebay although I haven't seen early CB500 forks and wheels on the sale list lately but I noticed some parts bikes with them. Forks for the 1971-1975 CB500 and CB550Ks are mostly the same.