Chain alignment for non-stock wheel

[rosso75]

I tore the bike down and had the frame powder coated a low gloss black, along with the swingarm, and about 15 other pieces.  The CBR wheel is also a low gloss black, and it looks really nice in mock up.  I'm working on a paint scheme that will be a traditional Yamaha yellow, black, and white.  The black will be a combination of gloss and flat. 

Current issue, aside from the sprocket alignment which I think I can fix, is the axle.  The Thunderace uses a 28mm axle.  The CBR uses a 25mm axle.  I can't use the CBR axle with the Thunderace swingarm because the axle isn't long enough (13 inches).  I'm looking at a couple axles on eBay that should work.  One is from a '00 ZX6 (25mm x 13 3/4"), and the other is from an '07 ZX14 (25mm x 14").  They're both the same price, so it's gonna depend on whether one of them has chain adjusting blocks that will fit in the Thunderace swingarm, rather than me having to make new ones.

On that note, if anybody has one of those two bikes, I'd appreciate if you could measure the slot in your swingarm where the adjusting blocks sit and let me know what the height is.  I seem to recall that the slot in the Thunderace arm is 45mm.

Beyond that, I'm sure I'll have brake caliper issues, but I'll cross that bridge when I get there. 

[fj11.5]

guessing they don't make the size bearings that would solve the issue , maybe use 3mm shims in the bearings you have

[axiom-r]

Gotta say I also thought you were doing the Thunder Ace conversion.  I can tell you with some certainty that if you are mounting a 6" rim you are almost certainly need to go with an offset countershaft sprocket and the XJR countershaft sprocket cover with associated longer clutch pushrod and shift shaft.

I eliminated the need to make custom spacers for placement of the wheel on the rear axle by using the entire rear end from an R1.  You will have to do some custom spacer work for the wheel placement I assume and this gives you another variable to adjust for a perfect alignment.  This could be a life saver or a pain in the ass.

My advice would be to go straight to the XJR cover and accept it - that way you don't necessarily machine the wheel at all and nearly all of the work is bolt on.

Regarding the axle issue...  I source custom bearings all the time from a local electric motor shop.  I can get virtually any size bearing from them.  Perhaps a set of custom bearings for the rear wheel will resolve the axle selection for you?

tim

[Derek Young]

Yes. Different bearings and new spacers may be the way to go.  would allow use of the ace axle. A bit of machining to be done though.

[rosso75]

I thought about putting different bearings it it, but the problem is that I don't have the Thunderace axle.  All I have is the swingarm.  If I've gotta buy an axle, might as well just get one that fits the bearings in it now.  Besides, I don't see any Thunderace axles on eBay currently

I have the VF1000 sprocket on it now, but I need a little more offset to clear the tire.  Obviously I'll have to work that out, but it will give me more flexibility with where I locate the rear sprocket.


This is the reason I'm reluctant to use any wheel that requires modifying the rubber in the cush drive.  The dampers in the FJ are huge compared to pretty much any other wheel one would use, so the ability to absorb driveline shock is already reduced.  I know, there are wheels to use that don't require modifying the rubber, but like I said, this CBR wheel is what I've got laying around....free, and in hand.  Besides, it's more fun to figure out something new. 

[rosso75]

Quickie shot of the wheel / swingarm.  I'll have some better pics, probably in a project thread, when I get the issues with the wheel worked out.

[Pat Conlon]

I thought about putting different bearings it it, but the problem is that I don't have the Thunderace axle.  All I have is the swingarm.  If I've gotta buy an axle, might as well just get one that fits the bearings in it now.  Besides, I don't see any Thunderace axles on eBay currently..."

You will wait a long time for T-Ace parts on the US eBay....
As far as I know, the T-Ace (YZF1000R) was available in the US for only one year.
The UK eBay is where you should look. The T-Ace had a long run in the UK and lots of used parts are still available.
The T-Ace axle is still available new from Yamaha for ~$45
http://www.powersportsplus.com/parts/search/Yamaha/Motorcycle/1997/YZF1000RJ/REAR+WHEEL/parts.html

I have a extra T-Ace wheel if you are interested.....

[axiom-r]

This is the reason I'm reluctant to use any wheel that requires modifying the rubber in the cush drive.  The dampers in the FJ are huge compared to pretty much any other wheel one would use, so the ability to absorb driveline shock is already reduced.  I know, there are wheels to use that don't require modifying the rubber, but like I said, this CBR wheel is what I've got laying around....free, and in hand.  Besides, it's more fun to figure out something new. 

Am I missing something or are you?  The machining of the cushdrive to bring the rear sprocket closer to the rear rim does not impact the rubber bits in anyway as far as I know...  Is there some mod that requires the rubbers be changed out?

tim

[rosso75]

Am I missing something or are you? 

Entirely likely it's me.  I bought this bike in April '09, then took it apart in June '09 for a quick paint job.  It's been in project form ever since, due to a ridiculous work schedule at the time, and moving 3 times in 3 years.  I'm trying to recolect from foggy memory.

However, I seem to recall seeing a thread that involved using a wheel that requires cutting down the thickness of the rubber.  I'll see if I can find it again.

As for the axle....

If I get a new one for $45, I don't know what else is gonna nickel and dime me....the nut, washer, spacers, etc.  The two axles I'm looking at on eBay are each less than $20 shipped, and include all that stuff. 

[rosso75]

If you scroll down to the part about using an FZR1000 wheel, the article explains that you have to shave 5-7mm off the cush drive rubber.  There's a pic in there.

http://www.fjmods.btinternet.co.uk/Wheels.htm

[fj11.5]

your right, thats what the article says 

[axiom-r]

Ohhhhh Yeah - I do recall that now- but that is just shaving them down on the side that doesn't matter in order to accommodate the mod- its a minor amount.  I never considered that reduction to be a threat to the cushdrive because the rubbers stay the same length all along the side that the force is absorbed on.


PS-  I might have a spare Thunderace rear axle for you.  I do have an 07 R1 swingarm already modded to mount on an FJ and the rear axle set too.  I'll check my stash.

[lyonsee]

If you deviate from Marc's installation shown here:
http://www.fjmods.btinternet.co.uk/MarcRittner.htm

According to Marc's measurements, the unmolested cush drive will add 0.195" to the outward offset on the chain in relation to the counter shaft sprocket.
Therefore, instead of using the oem Honda VF1000 offset sprocket, which has a offset of 0.070", you will need to special order a custom sprocket with a offset of 0.195+0.70= 0.265"....or about ~1/4" offset on the counter shaft sprocket.

I believe Sprocket Specialists can make you such a sprocket. Don't forget to specify the sprocket's countersink relief necessary for the bolt and locking tab to fit on the shaft. I would go ahead and order custom 2 sprockets to have 1 on hand when time comes to change out the worn custom sprocket.

What is unclear to me, is what this 1/4" outward offset will do to the clearance of the 530 chain inside your c/s cover. You may need a XJR sprocket cover.....others can chime in here..

On the plus side, you will have more room between your chain and the back tire.

Hope this helps.  Cheers!

Do you know what sprocket he used on the back wheel

[Pat Conlon]

The Thunder Ace wheel uses the same sprocket as our FJ's, just flip the sprocket around so that the offset faces the inside...

[lyonsee]

Thanks for that Pat,saved me €100.I got back end from UK minus sprocket,I was'nt sure if it needed the Ace one.