tterence said:
Hello there , I coming back to you because we have bought a r1 fork and we discover that it is mandatory to have some extenders to use this fork.
Can you help us with that? Do you have some drawing or sketch of what you've done? If not even photo of the part could help!
Again thank you for your advice !
Anyway does your bike still running good ?
Sent from my ONEPLUS A3003 using
DO THE TON mobile app
Cool! You're right they need fork extensions.
The pictures are included in the first page of this post, however here they are linked on another forum:
http://www.customfighters.com/forums/showpost.php?p=2813425&postcount=99
http://www.customfighters.com/forums/showpost.php?p=2817233&postcount=104
Note that the top fork extensions need o-rings in the machined grooves, obviously. Didn't have them in those pics. You'll need to get those somewhere as you still need the originals for the top caps!
We made spacers for the top of the fork tube and the bottom of the shocks inside the tubes (both are needed). I had to sub out the threading of the top fork extensions because they require metric thread to screw onto the top of the fork tubes. We have since gotten metric gears for our lathe, though.
I have no drawings to speak of unfortunately, so can't help you there. Basically we just measured how long we needed to add to the R1 forks to make them the same length as the stock Sabre ones (careful, though, as the axle locations on the Sabre fork are not the same as the R1, in my case anyway, not sure about the 750. R1 axle is right at the bottom of the fork, whereas stock Sabre is not, just changes the length slightly). In the end both of my extensions (top and bottom of the fork) are 3" long. I have about 1" sticking out of the top of the triple tree right now, so I have some adjustment if I want to.
Also if you do go ahead with this, make sure to calculate how much oil you need in the forks, as they will require more than factory. I believe when I did it, the R1 manual for the year I had specified a certain amount of oil, not a level. I did some calculations to find out how much volume I added with the 3" extensions and added that oil to the stock measurement. I think I originally went with 30 weight oil because I was afraid of the front end sagging too much under the heavy weight of the engine, but I can advise you that it is TOO much. My bike rides pretty hard, but I haven't had time to change it yet. If I were you I'd try 10 weight oil or something in that range.
There's really nothing special about the parts we made. The only tricky thing is machining the metric threads on these parts, and machining threads in general. For the steering stem, my dad machined a thread that our lathe could do (not metric), and we made locking nuts to match that thread. It's not something you can buy in the store, but it doesn't matter because we made the nuts too.
And yup the bike is running great, real healthy. Not much new but I did change out the tail light LED's because they were failing (crappy product).