Racers: RVF 4.5" vs VFR750 5.0". Weight diff worth it?

[StrayAlien]

Hi all,

I have an NC30 race bike. Your honours and esteemed racers in the GB 400 community. I present the following evidence:

Exhibit 'A' is a RVF400 4.5" x 17" rim + Pirelli Superbike 160/60 slick.



Exhibit 'B' is a VFR750 5.0" x 17" + Metzler 160/60 slick.



Now, assuming the tyres to be near the same weight .... using my very sophisticated bathroom scales with me standing on them with above wheels/tyres I see the RVF kit to be at least 1.5kg lighter than the VFR750 kit. Truth is, just picking them up the VFR750 wheel *feels* a lot heavier.

The VFR750 kit is guilty of a few too many pies.

So ... I know a lot of people use these 750 wheels for extra edge grip .. but .... 1.5+ kilos is quite a lot of unsprung weight on such a small beastie as is my NC30.

Is the alleged extra edge grip really worth the significant extra unsprung weight?

("Why don't you just try it? I hear you say .. well ... I have the wheel ... but one needs an axle etc etc and yes, I know RO sells 'em, but before I dig into my very short pockets I thought I'd ask ...)

[CMSMJ1]

I reckon with the swinger and hub weighing so much that lighter on the wheel is better.

You'll never tell anyways..but lighter will surely give the bike better mechanical grip and the blag edge grip due to profile is in your head...surely...or everyone would be using the heavy and stinky wheel?

[Smev]

I'm not a racer - I use the 750 wheel for style.

I think they were originally used as a cheap alternative to the pricey rvf wheel to use the 17 inch stickiest rubber :)

[StrayAlien]

They don't look too bad ... not as good as a stock wheel but not ugly anyways.

Re the edge grip/weight thing. It might be in my head but when you see championship winning bikes kitted with the 750 wheel it does make you wonder.

I guess I'll just give it a go ....

[venom51]

They don't look too bad ... not as good as a stock wheel but not ugly anyways.

Re the edge grip/weight thing. It might be in my head but when you see championship winning bikes kitted with the 750 wheel it does make you wonder.

I guess I'll just give it a go ....

It's not the size of the rear wheel winning championships. A 4.5 offers plenty of grip. The heavier wheel is going to hurt performance in an area you can't afford to give up on a small CC machine. You'll lose more time trying to spin the rotating mass back up from a slow speed corner than you will gain with any minor grip gained from the 5.0 inch wheel.

You also are going to hurt the handling of the bike if you shove the same size tire on that 5 inch wheel you were using on the 4.5. The profile will flatten and you'll actually lose edge grip.

But I could be just guessing...

[Cammo]

Good advice.

Ken: I can't find your clips on youtube these days? They were some of my favourite nc30 clips, are they hosted anywhere that you can share?

Sorry for the hijack...

[venom51]

Good advice.

Ken: I can't find your clips on youtube these days? They were some of my favourite nc30 clips, are they hosted anywhere that you can share?

Sorry for the hijack...

Google screwed the pooch with the whole + thing. They should be available again.

https://www.youtube.com/user/VenomKen/videos?view=0

There will be some more HD vids to replace the older SD stuff. We are headed back to the track this year to see if we still know how to ride. My good friend, engine builder and all around good guy Charlie will be hitting the track on the FZR400 we are building for him. So we'll throw a camera on his as well.

[Cammo]

Awesome, plenty of weekend viewing there.

[Drunkn Munky]

You also are going to hurt the handling of the bike if you shove the same size tire on that 5 inch wheel you were using on the 4.5. The profile will flatten and you'll actually lose edge grip.

Id say grip would increase due to the fact nearly everyone is fitting 160 supercorsa's to their 4.5" which would suit the 5" wheel much better. But i do agree the minimal edge grip your gain when you actually push it that far isnt going to outweigh a lighter, slightly narrower wheel. Dymags are the answer

[hunter]

I have just weighed my 750 wheel bare no tyre on my bathroom scales 5.1 kg.
Does anyone have a bare 35 wheel with tyre off that they can weigh.