Rc51 Wheel/usd Front

[festertruck]

hey guys,

getting ready to start USD front end conversion on my 4th gen. very excited! i am planning on using RC51 front wheel with everything else from 954/929 (bearings, outer spacers, discs, etc.). i am running into an issue with the inner collar for the front wheel. i have one from an RC51 and one from the CBR. The CBR doesn't seem to fit in the hub of the wheel properly (too thick on one side of wheel and seemingly too long, just a little longer thatn RC51?) and the RC51 fits fine, but is too narrow for the CBR axle to slide through. i am referring to the long collar that sits inside the wheel hub and the axle slides through from one side to the other. have others run into this issue? if so, what was the solution? didn't see any mention of this in any of the USD posts. it is my understanding from here and other locations that the RC51 wheel works as a straight bolt on if used with CBR internals. any thoughts and advice would be greatly appreciated.

thanks in advance,

colin

[Kel]

IIRC, I used 929 wheel bearings and cut down the CBR spacer. I used an SP2 wheel. Don't recall the CBR spacer not fitting inside the hub but it's possible it didn't and I fixed it somehow(real helpful huh?). Which forks are you using? The RC51 fork lowers I used would not accept the CBR's 330mm rotors without custom or aftermarket caliper carriers to pull the calipers up and back slightly. RC51 uses 320mm rotors.

[festertruck]

kel,

i'm using 954 triple and forks. spacer goes in the big side no problem but hits the inside of the hub on the opposite side that is smaller. the RC51 spacer travels all the way through that smaller side no problem. they are definitely different sizes. not sure if that makes sense, but some modifications may be necessary. if anyone has any more info, i would be happy to hear from you.

thanks!

[V4 Rosso]

Yes, I had to cut some material from the wheel hub.

[zRoYz]

It is a very easy problem to solve it just depends if you want to do the garage hack or do it properly. I use a RC51 front wheel with my CBR1000RR front end so use CBR1000RR bearings & the internal bearing spacer that goes inside the wheel which is needed for the bearings to clamp onto when you tighten the axle if you don't have this part your bearings will side load & fail & your wheel wont turn.

The CBR1000RR (same as 954/929) internal spacer is larger due to the axle is larger than the stock RC51 items.

The procedure is as follows:

You measure the RC51 internal spacer length & have your CBR spacer machined to the same length.

Now if your doing garage hack there is a cast ring inside the RC51 wheel (it is about centre of wheel, it isn't the bearing location rings) this is what fouls when you try to insert the larger dia CBR spacer so you need to use a dremel or round file to remove material to make the CBR spacer fit. You do need to try to keep the material you remove central so the spacer stays centred or you may find a problem when trying to insert axle with bearings as the spacer has to line up with bearing bore (you can have a 45deg chamfer added to internal CBR spacer bore that will help the alinement so you have more tolerance but not to big because you still need the face area to butt up against bearing). This internal ring is only there to help with that alinement so internal spacer doesn't drop when you remove axle. The proper way is to centre wheel on a boring machine & have the internal ring machined out so it is going to be dead centre 100% this is what I did (it has a decent tolerance you can tell this by using your RC51 spacer & moving it around in the existing bore)

With those steps done you just press in your CBR bearing one side, insert machined same length as original RC51 spacer, CBR spacer & then press in other bearing.

Yes I should wash my bike but that is one thing I have no passion for lol

[festertruck]

zRoYz,

thanks. very helpful. i'll take another look at this with your words in hand.

V4 Rosso,

thanks to you too.

[zRoYz]

Just a word of warning, the fact is when I think about it your CBR axle spacers won't be long enough you will need to add length because the standard CBR wheel internal spacer & bearings measure a longer distance than the RC51 wheel combination. Because you had to remove some length from CBR internal spacer that will be needed to be added evenly to each side of standard CBR axle spacers. (example you remove 2mm from CBR internal spacer you need to add 1mm to each CBR axle spacer)

I removed misleading quote from above post as the 100% correct way to know your axle spacers are correct is measure total length of each set up:

RC51 internal spacer length + RC51 bearings = xxx

CBR internal spacer standard length before machining + CBR bearings = yyy

yyy - xxx = ??? divide by 2 (length needed to be added to each side standard CBR axle spacers)