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Mag Wheel bearings and CBR600F3

7K views 58 replies 7 participants last post by  shoegaze 
#1 ·
After much research, I am a bit confused.

Many of the people on here that are installing CBR600F3 rear wheels mention machining the wheel to accept the Triumph wheel bearing. Is this only necessary on a spoke wheel bonneville? My Mag wheel bonneville has a 17X47X14 bearing and the stock F3 wheel is 20X47X14. I should be able to press out the old F3 one and press in the new triumph one, right?
 
#2 ·
The mag wheel rear is the same as a spoke wheel, so you'd need to replace the Honda bearings with Triumph, make or modify Thriumph spacers in the wheel and sprocket carrier, and use a Honda rear sprocket. Again, there is no difference between the spoke and mag rear wheels.
 
#4 ·
When you press out your Honda bearings to replace them with Triumph parts, you'll
need to replace the distance tube inside the hub. If the Triumph part is a different
length than the Honda one, you'll need to have one made so that the ID and OD are the
same as the Triumph part, and the length the same as the Honda.

The cush drives are different. You'll need to use the Honda cush drive.

You'll also have to make sure that your chain lines up properly. You probably will
need to have new axle spacers made to get this right.

If you have access to back issues of Cafe Racer Magazine, there were articles on this
mod in the October/November 2010 and December 2010 issues.
 
#5 ·
After much research, I am a bit confused.

Many of the people on here that are installing CBR600F3 rear wheels mention machining the wheel to accept the Triumph wheel bearing....
As others note, the triumph wheel bearings are direct fit in the honda wheel. You use the honda cush drive. The machining you refer to is to make the honda cush drive accept the triumph cush drive bearing.

To avoid chucking the honda cush drive in a lathe and opening up the bearing journal, you can also make up a new cush drive spacer that is identical on the exterior to the honda spacer, but with a 17mm axle hole (instead of the 20 mm honda shaft hole). With this method, you use the honda cush drive bearing...

HTHs,

--Rich
 
#8 ·
Yes, you use the triumph spacers that are exterior to the wheel assembly in the stock locations. I did notice that the sprocket alignment is a little off...the sprocket needs to move to the right a bit.

At least that is what I saw with my 51 year old laser-calibrated eyeball when refitting the rear wheel & adjusting the chain. I may shim the sprocket a bit since the studs on the honda cush drive allow for about 1/8" of movement away from the centerline without losing an exposed thread on the outside of the nut.

As far as whether the wheel is precisely in line with the front wheel or not, I have no idea! The rear wheel sits about 1/2" to the left of center in the swingarm, but I'm uncertain of how that relates to the front wheel...which got fitted yesterday...



Cheers,

--Rich
 
#24 ·
I did notice that the sprocket alignment is a little off...the sprocket needs to move to the right a bit.

At least that is what I saw with my 51 year old laser-calibrated eyeball when refitting the rear wheel & adjusting the chain....

I measured the distance on each rim from the center of the wheel to the sprocket to see how far off from center the rear wheel would be with the sprockets lined up. The difference was about 2mm, so if you get the chain line straight,
the wheels will be pretty close.
The hard part about getting the spocket aligned without shimming it to the right is moving the brake caliper/rotor as a unit. I suppose you could try shimming the brake rotor in lieu of the sprocket to move the entire wheel to the right. An equal amount would then need to be added to the left side axle spacer and removed from the right side spacer. The right side already provides very little space for movement to the right, so that constraint would likely drive how far the wheel can be moved over.

Personally, I'm much less comforable with shimming the rotor than running the wheel ~2mm (~0.079") off center and then putting some washers under the sprocket/on the rather substantial spocket carrier studs to get the chain to align. The rotor bolts are soft and don't have tons of shear strength. The sprocket carrier bolts, however, were engineered for a machine that puts out 100+ crank HP.

Regards,

--Rich
 
#10 ·
I am going through this swap right now as well, I have a thread on the cafe forum. I am kind of a perfectionist when it comes to the thruxton so I will be wanting everything to be perfectly lined up when I am done. I should have some answers here in the next month or so. Trying to take alot of pictures as I go to explain the process.
 
#16 ·
That will help somewhat. I guess I should clarify my prior post. When measuring from the edge of the rim to the swingarm, the right side was ~1/2" greater than the left side. So I guess that would put the rim 1/4" to the left of being centered in the swingarm. I said 1/2" off earlier, but that was the gross dimensional difference between measurements and not the amount left of center.

Of course, measuring in this manner is only relevant if you have the wheel is sitting perfectly in alignment along the primary axis of the bike...therefore, it's a crude measure at best.

Regards,

--Rich
 
#19 ·
Like I said, it isn't very accurate or easy to measure for that matter. I used 2 straight edges...one along the straight portion of the swingarm to allow forward extrapolation of the straight swingarm section and the other to measure distance from the edge of the rim to the reference line.
 
#21 ·
If it helps, I took a (somewhat crude) measurement to compare the stock Triumph
wheel to a CBR wheel. I measured the distance on each rim from the center of the
wheel to the sprocket to see how far off from center the rear wheel would be with the
sprockets lined up. The difference was about 2mm, so if you get the chain line straight,
the wheels will be pretty close.
 
#25 ·
I had a conversation with Pieman today and in order to get everything lined up he had to get new spacers for both sides of the wheel, spacers behind the brake rotor, machine the face of the cush drive to allow the sprocket to sit closer to the rim, and a spacer behind the front sprocket to line up the chain.
 
#28 ·
I don't know the exact measurements for the rotor but he had 7mm machined off the face where the sprocket bolts up. He also had to have the studs that hold it on made shorter so they wouldn't hit the chain or something
Mike is meticulous in his work, so I'm assuming his goal was to precisely center the wheel in the swingarm. The cush drive sits pretty tight to the right side (i.e. the spacer doesn't have much meat to allow movement in that direction), so I'm assuming he moved the wheel 7mm in that direction?

If all he did was move the sprocket inboard, then this runs counter to what I see on my bike...which is that the sprocket needs to move outboard to get better alignment with the countershaft sprocket. When I get some time in the shop, I'll measure how far the sprocket has to move to the right to perfectly line up, but it can't be more than 2-3 mm. Any shimming of the rotor would take that amount out of this distance...

Regards,

--Rich
 
#29 ·
Correct Rich, my wheels are exactly centred. All the existing spacers required replacing as the CBR600 rear wheel complete with sprocket carrier and spacers is around 2mm narrower than the factory rear wheel complete with sprocket carrier and spacers. The sprocket carrier required 7mm taken off the outer face to give enough clearance to centre the wheel, and the sprocket studs required shortening to clear the swinging arm. To help compensate for the rear wheel moving over, I added a 3mm spacer behind the gearbox sprocket, I could have done with another 1mm, but that is the max you can get away with so the serrated sprocket tab washer still sits on the splined shaft. 2.5 years later the discrepancy between the front and rear sprockets has had no effect on chain or sprocket wear.

The front wheel also needed new spacers as the factory spacers moved the front wheel too far to the left. My wheels are inline to the millimetre and there is absolutely no bias in taking left or right handers.

If anyone is thinking about carrying out the F3 mod, go ahead, you won't regret it. It improves the caperbility of the Bonnie or Thruxton in every way. The factory CBR600 front calipers are more than enough to stop you very quickly and they work great with the factory Triumph master cylinder. The F3 cartridge forks, although old technology compared to modern cartridge forks, are far better than the antiquated factory damper rod forks and also seem a perfect match for the ZXR rear shocks with lighter springs. Also using 160 rear and 120 front rubber on rims that they are intended for, is excellent. It's not easy to lock front or rear when braking hard and unusual for the rear to break away when accelerating hard out of a corner.
 
#30 ·
Thanks for the information Mike. For it to be done properly, it seems there's a bit more involved than the laundry list of details I've previously come across on the forum.

Or I can do what most other's have done and just shim the wheel sprocket to align it with the countershaft sprocket and call it good. I guess it's a good thing I like right-hand corners...

Regards,

--Rich
 
#31 ·
At the risk of incurring the wrath of the experts, I just made the Triumph wheel and carrier spacers the same length as the F3 units, reversed the cushdrive rubbers (as the wheel itself is reversed), and mounted it up. My uncalibrated eyeball says sprockets line up well, the rotor fits perfectly into the caliper, and 5000+ miles later, I'm still falling in love with it everytime I saddle up. If the wheel is offcenter a little, it sure isn't affecting handling, as I run some fairly serious twisties almost everytime I ride it.

 
#33 ·
...I run some fairly serious twisties almost everytime I ride it.

Eric,

Mo' badder each time I see her. The 2 into 1 is a tidy addition. Glad you have more than one curve these days to push the envelope on...

I'm with you on this whole deal. My caliper lines up fine with the rotor and the chain is pretty close...gonna toss some washers under the sprocket to move it to the right & get the alignment correct and ride the thing. Perhaps Rossi or Spies would feel the difference right to left in corners, but my novice arse can't tell any preference for the bike to tip in...hands off the bars & the bike runs true...

Of course my prior motorcycles have always been 'classics', not sport bikes, so anything that doesn't hinge in the middle in a corner is a big improvement...

Cheers,

--Rich
 
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