Which Forks

I am trying to put together an XR front end. I have been given to understand that the 400, 600, and 650 are supposed to be more-or-less interchangable in the regard. But what I have is a set of forks (and front wheel) with the fork tubes measuring 43mm in diameter, and a triple tree with 39mm holes. Which is which?

Thanks in advance for any help,


The clamp you have doesnt happened to have the bolts snugged without the tubes in it does it?

I know its a dumb question but ya never know...

39 seem really small for even for a 400. Are you sure your clamp isnt from a 250?

Not a stupid question: I rushed home hoping that was the answer, but no ... the clamp bolts are loose, and it's definitely 39mm. Could it be from a 250? I don't know, I was hoping some XR experts on this forum could tell me. For example, are the 43mm fork tubes (that I have) correct? Are the various front-end parts from the 400, 600m, and 650 in fact interchangable?



Now I really am flummoxed - an additional top triple clamp I have measures 46mm, which is consistent with the data sheet I have seen on the 650. So what the heck are these 43mm forks from? They have a small sticker that says "Howa Mk2-771".

39 Mm Forks Are From The Honda Xl 600r Models, 43mm Forks Are From The Honda Xr 600r Models. Sounds Like You Have A Triple Clamp From A Honda Xl600r And Forks For A Honda Xr 600/400 Model. You Can Hone Your Triple Clamps To 43 Mm At A Machine Shop But It Will Certainly Weaken The Structure. Ther'es My 2 Cents...

Thanks. Some research at motorcyclespecs.co.za was pretty illuminating - looks like the Honda XR models were all over the map in this regard, depending on model and year. For example, the late 650's have the 46mm, but the earlier ('96) 650 had 43mm. Most of the 600's '85 and later had 43mm, but as you point out, the '84 was 39mm. The later 400's and even the 250's have 43mm. And there are oddballs: the '83 350 had 41mm, and the 83 '500 had 37mm. Quite a hodgepodge. At least now I know what I'm looking for.

Thanks all,


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