1991 FZR1000 front wheel

[ccsct203]

Ok... I'm updating my FJ1100's front end to a 1988 FZR1000 and what do I do.. Stupid me buys a 1991 front rim.
The problem as many of you know is the bearing size... 15mm x 40mm x 13mm and  guess what they don't make any bearings that size. I did much research and I found a "deep groove track rolle bearing" which is sealed both sides and is good up to 70,000 rpm. load and impact rating is very high because of the high side impact on track bearings. The size however is 15x40x11mm. 2mm per bearing narrower then oem.
I figured I'll try them.
I'm doing a new front wheel and I bought all new collars, seals and center spacer and as stated bearings too.
I have a 18" rear rim with the modifications to the carrier bearing spacer,  construction of the center spacer and modified brake caliper bracket as I found online.
Wish me luck
if it comes down to it I'll buy a FJ1200 front wheel and call it a day.
Hey at least i'm trying. What's the worse that could happen?

[racerman_27410]

Hey at least i'm trying. What's the worse that could happen?

let's not find out that answer please......if you dont trust the mod dont ride it... plain and simple since it's your hiney on it..... that being said i firmly believe anything can be done if one chooses to invest the research, time and money into it.

Kookaloo!

Frank

[ccsct203]

I would never put myself in danger. I'm worth more then the price of a wheel.
If the bearing specs were not what they are, I would never have posted.
I'm not an engineer but I have never risked my life over any of the mods I have done.
I have done countless wheel bearings and I never would ride a machine which is not safe.

[SlowOldGuy]

Just trying to be a monkey in the wrench here.

Is it possible to use the FZR 17mm (?) axle and bore out the fork legs?  Does an FZR have upside down forks?

DavidR.

[Pat Conlon]

Three areas of concern;
1) The 11mm wide bearing (vs.13mm oem) can the bearing carry the load?    Probably....
2) The narrower 11mm wide bearing in the aluminum rim, can the inside diameter of the aluminum stand the higher loads? i.e.Loads spread over a  smaller surface area.  Not sure about this, we have very heavy front wheel loads with our 550lb bikes and 300+lbs of riders and gear...
3) Now you do realize that your axle spacers need to be 2mm longer on each side....

[andyb]

I just woke up or I'd do the math myself, I swear:

So assuming that a healthy FJ can run an honest 150mph, how much rpm would the front wheel be turning?

[bama1]

I bought a 89 rim by mistake and I had the same problem as you.I took my rim to a machine shop and had them machine out the bearing housing.The wheel works great.I live in the mountains so I have put the wheel through alot.Good luck with your mods.
Buddy

[candieandy]

instead of trying to fix it at the bearings. change out the front forks to fzr1000 forks and save yourself the hassle.  and then you can update the front calipers and rotors too.

[FJmonkey]

I am no rocket scientist or engineer but here is my crack at answering your problem.

To get a number I am making assumptions since tires are a variable that you did not provide. Not to worry, the numbers will be close enough to get the gist of it.

Assumptions, your tire is 17 x 60 x 3.5.

Your tire circumference is about 54.22 inches (I used the gearing commander page to guesstimate the circumference, http://www.gearingcommander.com/). A mile is 5280 feet (Times 12 inches) equals 63,360 inches. Your wheel/tire will rotate (63,360 inches divided by 54.22 inches of circumference) or 1,168.57 rotations per mile. Save this bit of data. 150 miles per hour is 2.5 miles per minute. Multiply the 1,168.57 by the 2.5 miles per minute equals 2,921.42 RPM.

Now, if I murdered this one I will justly deserve the crap that comes my way. But its all fun and games till someone looses his Kookaloooooooo.

[Harvy]

I bought a 89 rim by mistake and I had the same problem as you.I took my rim to a machine shop and had them machine out the bearing housing.The wheel works great.I live in the mountains so I have put the wheel through alot.Good luck with your mods.
Buddy

I've wondered if that was a viable option........bearings are only 2mm larger from memory........there seems to be plenty of metal in the bearing housing area to accommodate this without weakening the hub.

Glad you've confirmed the idea.

Harvy

[Pat Conlon]

I just woke up or I'd do the math myself, I swear:
So assuming that a healthy FJ can run an honest 150mph, how much rpm would the front wheel be turning?

It's raining and I'm bored,so...

@150mph you are going 2.5 miles per minute; @5280ft. per mile x 2.5 you are going 13,200 ft. per minute

Convert into inches; 13,200 ft. x 12 = 158,400 inches per minute (@150mph)

Assuming a 120/70-17 front tire with a circumference of 74.19 inches 
http://www.ajdesigner.com/fl_tire/tire.php

158,400/74.19 =  2,135 rpm (no biggie).

I don't think rpms are the issue, @150mph it's the same oem vs.FZR;  but the lateral loading from the narrower bearing is more concentrated.

[bama1]

Hey Harvy
I had actually posted this mod last year and you had left me a reply.Somebody had said there wasnt enough material there to do the mod.The machine shop had no problems with it.Take care Harvy.
Buddy

[Pat Conlon]

  Does an FZR have upside down forks?
DavidR.

Yes, I have a set on 1992 FZR USD forks on my '84... I love 'em.

[andyb]

158,400/74.19 =  2,135 rpm (no biggie).

I don't think rpms are the issue, @150mph it's the same oem vs.FZR;  but the lateral loading from the narrower bearing is more concentrated.

Thanks for the math guys   I just was wondering if that 70krpm bearing was rated for it, and didn't want to personally bugger the math in a half awake state.

Hell, I'm still only half awake and it's been an hour or two.  Maybe I should give up and go back to bed...

[Harvy]

Hey Harvy
I had actually posted this mod last year and you had left me a reply.Somebody had said there wasnt enough material there to do the mod.The machine shop had no problems with it.Take care Harvy.
Buddy

What can I say......Old-timers must be setting in......lol

You to Buddy.

Harvy