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Widest wheels on stock swingarm/forks?

Posted: Sun Nov 13, 2016 1:54 am
by Lopper
I've been looking at these http://www.marvic.it/en/prodotto/vintage-campagnolo/" onclick="window.open(this.href);return false;

What are the widest wheels you can fit on the stock swingarm and forks?

Also is the stock swingarm steel or aluminium?

Re: Widest wheels on stock swingarm/forks?

Posted: Sat Nov 19, 2016 1:05 am
by hondaror
Swingarms on RZs are steel. A magnet will prove that.

Re: Widest wheels on stock swingarm/forks?

Posted: Sat Nov 19, 2016 3:17 am
by Questo vecchio rz
You'll have to do some vintage racing research, but Im thinking a 2.75 & 3" is the widest you can go on a RZ/RD YPVS 350.

Tire sizes are likley similar to stock. 100 front 110 or 120 maximum @ rear. Although the minimal increase in rim width might allow a slightly wider lowet profile while retaining a proper contact patch. I beleive your limited by the width of the stock swingarm to a 130 max regardless.

FYI If you didnt already know, tires wider than stock really screw up the RZs handling. Wider IS NOT better...period. You can use a 100 front & 120 rear but thats generally the absolute max..otherwise they often just dont like to steer. There are a few "newer" vintage race tires being manufactured recently that may provide better contact patchs with sidewall height..but you will have to research them as well

Re: Widest wheels on stock swingarm/forks?

Posted: Sat Nov 19, 2016 4:58 am
by evan_calgary
You can run a 130 but the clearance on the rear is very tight to the front of the swingarm. The limiting factor looks to actually be the tire to front, not side of the swingarm. I would have to disagree on handling with a 130 on the rear, mine is superb but that is with a different shock in there as well. The 130 rear looks a bit weird due to the much taller profile. I would have gone skinnier if the tires weren't already on the bike.

Re: Widest wheels on stock swingarm/forks?

Posted: Sat Nov 19, 2016 5:45 am
by Questo vecchio rz
Lopper wrote: Also is the stock swingarm steel or aluminium?
Yes all stock factory swingarms are steel. There are swaps , the most common being the 1986-87 FZR600 alum arm, also many other makes & models have been fitted by enthusiasts.

There were/are bolt on Aluminum swingarms both used and relatively current depending upon who has them available. A quick list would be (past) manufactures: CalFab, Toomey Racing, JMC, and current Metachex. Occasionally Moto Carrera has a small run as well as a talented indavidual and aerospace machinist named H2Ken whom took it upon himself to replicate Calfab & DG swingarms for RDs & RZs. He frequented the USA2Strokers site up until a couple years ago.

Re: Widest wheels on stock swingarm/forks?

Posted: Sat Nov 19, 2016 6:52 am
by MK
A friend of mine is using the RZ350 swinger in his LC (welded the LC cradle onto the RZ part).
He is using a 150/70-17 tire with a 4.5x17 RGV rim. Very tight, but it works in race use.

Note that tis is not a contrast to what's been said before.
First it's a 17 inch tire (smaller radius) and secondly it was an LC application where you don't have the L-links to connect the swingarm to the linkage/shock.

Re: Widest wheels on stock swingarm/forks?

Posted: Sat Jan 07, 2017 10:22 am
by motoholic71
MK wrote:A friend of mine is using the RZ350 swinger in his LC (welded the LC cradle onto the RZ part).
He is using a 150/70-17 tire with a 4.5x17 RGV rim. Very tight, but it works in race use.

Note that tis is not a contrast to what's been said before.
First it's a 17 inch tire (smaller radius) and secondly it was an LC application where you don't have the L-links to connect the swingarm to the linkage/shock.
Hello Martin.

Do you happen to knowif he had to move the chain to clear the tyre?

I'm fitting a swingarm to a ypvs from a first generation FZR 400 that came with a 18' 140 tyre and would like to not use offset sprokets, do you know if it's possible the 140 clear the RZ chain ?

Thanx, I have your manual of mods.

Re: Widest wheels on stock swingarm/forks?

Posted: Sat Jan 07, 2017 12:10 pm
by kpke
moto, this bike is using FZ alu swingarm and 18x3.5 fzr600 or maybe fzr400 rear wheel with 150/60-18 tire.

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The front sprocket has no offset. The rear sprocket carrier was machined down 4mm(???) to get the chain aligned. The chain does not hit the tire. I am in the process of setting up a SV650 17x4.5 wheel on this bike.

A second bike is set up the same altho the rear wheel is 18x4.0 not 3.5. I don't have a recent photo of this one. But again chain is aligned with no offset front sprocket by machining down the rear sprocket carrier.

Image

Re: Widest wheels on stock swingarm/forks?

Posted: Fri Jan 13, 2017 8:58 pm
by motoholic71
kpke wrote:moto, this bike is using FZ alu swingarm and 18x3.5 fzr600 or maybe fzr400 rear wheel with 150/60-18 tire.

The front sprocket has no offset. The rear sprocket carrier was machined down 4mm(???) to get the chain aligned. The chain does not hit the tire. I am in the process of setting up a SV650 17x4.5 wheel on this bike.

A second bike is set up the same altho the rear wheel is 18x4.0 not 3.5. I don't have a recent photo of this one. But again chain is aligned with no offset front sprocket by machining down the rear sprocket carrier.
Thank you, that was the info I was after.

It seems that the FZR 400 is a good candidate as a donor for the cycle parts since is about the same weight and power but a generation further.

The only difference from your 2nd bike to what I aim to do is that I want to use the fizzer swinger also.Thanx.