Topic: Front Fork Interchangeability

[PoppaT]

I'm sure this info is probably embedded in the thousands of pages of info provided by all you knowledgeable SOHC owners, so forgive me if this is easily findeable (but I couldnt quicly locate it)

My 1973 Honda CB 500 Four was "frankensteined" from multiple bikes by the prior owner.  My front forks are about 4 inches too long, sticking up nearly even with the top of the speedometer. ..and still I have to be on my tip-toes to reach the ground.  Other than that, the bike looks original.   I'd like to go back to the original fork length....whatever that is.   I see quite a few fork assemblies available on line, but dont see any for this specific year and model.   So my questions are:
-interchangeabliltiy of forks between years  72-74
-interchangeablilty of forks between bike sizes (cb 350, 450, 550, 750)
-Can I keep the existing lowers and only replace the upper tubes?   ...and if so, will I need different spring sizes, etc.

I'm not a mechanic, but am a relatively handy tinkerer.  So any other helpful advice would be appreciated.

[Pielz]

I'm 6 feet tall with a 34 inch inseam and I can't flat foot my k7 750 with the stock seat. I sit the same on it as I do on my 6'7" friend's Suzuki DRZ400. Lol

[754]

Are your triple trees correct for your bike ?

[PoppaT]

good question.  I assume so. But not sure how to tell.   there arent a lot of 1973 models around to compare side by side. 

[754]

Take a picture.

[PoppaT]

Here's a few pics.  The fork length from axle center to top of the tube (not including the bolt on top) is 35.25 inches.

[Scott S]

 Looks like someone "chopper-ized" the bike at some point and added extended forks.

 Any CB500/550 will fit. The CB750 is also 35mm but they're longer than the 500/550 forks.

[754]

750  is only like 3/4 inch longer, a bit stiffer spring I think.

[bryanj]

There are internal differences 500 to 550 and by year but if you fit a PAIR of complete forks from one bike you will have no problem as long as you know what model and year for future parts supply

[jonda500]

+1 any four cylinder CB 500 or 550 forks will fit
John

[PoppaT]

Much thanks to all the knowledgeable responders.

John, Can I assume forks from a 350F or 450F will not fit?  (not sure about the tube diameter)

[Gurp]

great looking Bike too bud!

That jade green is to die for!

[PoppaT]

Thanks for the compliment.  I love the green also.  Here's a couple more pics so you can see what a beautiful bike she is for a 47yo that is regularly ridden.

[PoppaT]

Can anyone provide me with the original CB500 full fork length (from center axle to top of the upper tube)?