Widening a motorcycle rim

[gav]

Any one had any success with this? I'd like to know if it would be possible to widen a rear FXR150 rim from a 2.15 rim to at least 3.00 or 3.50 ? Yeah, I know it might be easier just to find another rim that fits, but so far, havent had too much success finding something. Do have one rim here that might be suitable but its causing issues trying to get it to fit with the disc and sprocket carrier fitting etc. I also do have a spare FXR rim here as well. Was also wondering if you could cut the outer rim off each and fit the FXR inner wheel minus the rim inside a wider rim and weld the "spokes" to the new wider rim. Would this work? Its for a bucket racer ...

[Grumph]

Can be done - has been done. Jim Landrebe widened the front rim on the Honda Bros he built some time back.
In ChCh see Thorpe's - they have a machine shop on site.
Won't be cheap.....

[p.dath]

Way out of my area, but I know a lot of mathematics are involved in rims. We used to have a client that had simulation computers set up, and they were commission to "test" new rims. You don't want rims deforming or coming apart, or them becoming unbalanced through minor deformation under load, or simply failing under mechanical stress at some point in the future.

Simply making an existing rim wider might solve one problem you have, but make sure it doesn't create several others ...

[bogan]

Can be done - has been done. Jim Landrebe widened the front rim on the Honda Bros he built some time back.
In ChCh see Thorpe's - they have a machine shop on site.
Won't be cheap.....

There are a few other RC-31s over at hawkgtforum.com with widened rims, a google site seach will show some good info. Having a weld bead all the way around the rim also looks a bit different but in a good way :D

[tigertim20]

agree with pdath, unless its done really well, it could cause other issues wheels need to be properly weighted and perfectly round (or damned near), neither of which is particularly conducive to the amount of heat in welding the circumference of the wheel.

[bogan]

agree with pdath, unless its done really well, it could cause other issues wheels need to be properly weighted and perfectly round (or damned near), neither of which is particularly conducive to the amount of heat in welding the circumference of the wheel.

It's pretty easy to check the runout on the wheel after they are done, definetely not a job for amteurs though :no:

I dug up the link for the place hawkers use http://kosmanspecialties.com/services/wheel-widening-and-weldups/ Some info on what they do too.

[Crasherfromwayback]

Gary McPhee has done a few for me, always perfect. Not sure if he's still doing such work/things. Was too busy being the Mayor of Carterton for a while there! I would be happy to get hold of him and ask if you'd like.

[p.dath]

It's pretty easy to check the runout on the wheel after they are done, definetely not a job for amteurs though :no:

I dug up the link for the place hawkers use http://kosmanspecialties.com/services/wheel-widening-and-weldups/ Some info on what they do too.

I can see how you can check the run out on a slow moving wheel. What about one on a bike pulling .8g on a 30 degree lean going around a corner at 200kmh/h - when the rim is under some stress?
Like I say, I don't know anything about it. But I do know a lot of complicated maths is involved in rim design.

[Crasherfromwayback]

What about one on a bike pulling .8g on a 30 degree lean going around a corner at 200kmh/h - when the rim is under some stress?
Like I say, I don't know anything about it. .

On an FXR150? Don't think there's much chance of that.

[Grumph]

I pointed the OP at an outfit in ChCh who have done the job before and know their metallurgy well. The important point when doing the job is retaining ductility.
Math and computer simulations only come into play when you're trying to pare a wheel design down to the bare miimum weight. In this case where the original rim is for a lightweight bike and the proposed use is still a lightweight bike I see no need for computer simulations....A competent welder and an equally competent machine shop to ensure the finished job is acceptably round will do nicely.
As far as cornering loads and wheel stiffness goes - find a vid of wire wheels under stress to see how far things move.

[pete-blen]

The guy on the speedway sidecars do it all the time..
BUT..the rims balance/trueness is not as important on the dirt
compaied to a road unit....

[F5 Dave]

I've had it done a few times welding on a larger RIM to RG wheels. Mixed success, it is hard to get the wheel to not ovalise & be central. I have however corrected a little for this with some careful lathe work to recentre the rim where the tyre hits rim which is what is the crucial part.


Failing that someone:innocent: is selling a Gixer thou front wheel (see bucket parts for sale thread) & it isn't too hard to make a rudimentary RS style rubber donut cushrive & bolt a disc on the other side.

[codgyoleracer]

On an FXR150? Don't think there's much chance of that.

.8 of G, surley its possible (if you really really try...... ;-) )

[malcy25]

Why not just badger a 125GP bike rider to sell you an old wheel....

[F5 Dave]

gee that's a great idea. See original post 3rd sentence. They aren't giving them up.

[Rikkido]

Hi guys,
Anyone know who widens motorcycle rims in auckland? I want to put a 150/60 tyre on the rear of my Ninja, so I need the rim widened atleast half an inch, one inch would be ideal.

- Ricardo

[F5 Dave]

Why on earth would you want to do that? The little 250 won't put out enough power to worry a 150. And it would be in imbalance with the front. Consider that RS125 GP bikes that touch 50hp run 120 rear tyres in race conditions.

Besides you won't get a warrant ever again. Spend the money on some decent tyres in the correct size.

[ducatilover]

Hi guys,
Anyone know who widens motorcycle rims in auckland? I want to put a 150/60 tyre on the rear of my Ninja, so I need the rim widened atleast half an inch, one inch would be ideal.

- Ricardo
I wouldn't expect a 150 to fit in the swing arm?
It'd look nice, yes. Will make it handle worse.

[Rikkido]

Why on earth would you want to do that? The little 250 won't put out enough power to worry a 150. And it would be in imbalance with the front. Consider that RS125 GP bikes that touch 50hp run 120 rear tyres in race conditions.

Besides you won't get a warrant ever again. Spend the money on some decent tyres in the correct size.

I've got 150/70 on it now, it feels nicer with the wider tyre I just thought a rim to match and a lower profile would be better. The 130/70 profile is 91mm, the 150/60 profile is 90mm but the 150/70 I have on now is 105mm. Thats not taking into account the tyre bending but I see your point.

And I was just thinking because the bike is in the shop anyway.

[F5 Dave]

with no question of a doubt you have made it worse by overtyring it. Well documented, the odd shape will give you less rubber on the road. If it is taller it will make the bike tip in quicker, but you could probably achieve the same thing with the forks through the clamps. Whether it remains stable is another question.

Save up for some decent tyres in the right sizes.

[The Singing Chef]

Some of the Hornet 250's I have seen have 180's on the rear...makes no sense at all. :blink:

[ducatilover]

Some of the Hornet 250's I have seen have 180's on the rear...makes no sense at all. :blink:
Looks good.
Harley's do not need fat tyres (all they need is a sturdy chain and hoist IYKWIM)

[hayd3n]

Some of the Hornet 250's I have seen have 180's on the rear...makes no sense at all. :blink:
its coz they are fireblade rims
same as the 600 hornets :laugh: a rim designed for a 180 is fine,
when im real broke(usually always )
ill fit what ever i can afford somtimes 190 or 170 yes it changes the characteristics but i ride accordingly