17x150/60 race tire for small displacement race bike

[Delboy]

A quick question for smaller displacement racers.

I used to run a 150/60 Pirelli Supercorsa on the back of my RZ 350 endurance bike but they stopped importing them into North America. I emailed Pirelli and they said it wasn’t worthwhile as they didn’t sell a lot. That’s fair enough. I can see their point.

I’m thinking about trying Michelin Power Cup Evos in the same size. Does anyone run these tires or run the bigger sized Power Cups? What do you think of them?

My other option is the Bridgestone R11’s but I thought I would give the Michelin a try.

 

[bakaboy]

We changed from the SC 110/150 DOT setup on the EX400s to the 110/140 slick setup. I was afraid that I might have to play with geometry but the math told us not to change it which was correct.

The 110/140 became in short supply by year end. We entertained changing to the 120/160 with a 4 mm shock length change but never implemented.

I have about 6 sets of the 110/150 Pirelli DOTs scrubs that you can have for dirt cheap. Fronts are all SC1. Rears are both SC1 and SC2.

 

[Delboy]

Thanks Bakaboy.

Unfortunately the class rules specify DOT's

If I were closer I would take your up on your offer to get me over the hump but I'm stuck down here in the US and it would probably take a small fortune to ship.

I could try a 140 Pirelli as the load rating is not much different. I think one is 66 and the other is 69 and the bike + me is only around 450 lbs. Its just the Horse Power I'm worried about as the bike is around 78 or 79 on the dyno. I don't know if the 140 would handle it. It chews up the 150 pretty good.

CTRaceTires are the local dealer here and they have 140's in stock so I guess I could try one and just keep an eye on it.

 

[boyoboy]

holly batman delboy. 78HP rz350 ?!%*
endurance build !!??
luv it..

 

[Delboy]

holly batman delboy. 78HP rz350 ?!%*
endurance build !!??
luv it..

I have photos somewhere of the cylinders. I’ll post them. It was done by Glyn at GPL in Nova Scotia. He was really good but his marine business took off and I guess there is much more money in that than in two strokes.

It also has a set of Brian Turfrey pipes as well and being 390cc which doesn't hurt. And it’s still not really that competitive with the FZR400‘s

 

[gammaguy21]

And it’s still not really that competitive with the FZR400‘s

Really, why? Seems you have the changed over the tires to run 17 inch rims for modern rubber. Is the rest of the rz chassis stock?

 

[Delboy]

Really, why? Seems you have the changed over the tires to run 17 inch rims for modern rubber. Is the rest of the rz chassis stock?

It has a little bit of bracing on the steering head but that deltabox frame on the FZR is really good. I have friend who races a 400 frame with a FZR600 engine in the VRRA and he said the frame is 100% better than even the 600 frame.

Its also a bit peaky so you really need to keep it between 7 and 10k where the FZR pulls from 6 to 14k . I think with a nice set of cams and carbs they are a great small race bike. I remember a company in the UK (BDK Race Engineering???) published dyno results on one they built and it was 92 HP - now I don't know how accurate this is or how long it lasted before a rebuild.

Don't get me wrong the RZ is really a fun bike to ride, but if the same rider was on both I think the FZR would always come out on top.

 

[Delboy]

What you really need is something like this. It would need a cradle built to take the RZ motor but its really, really stiff and light.

 

[gammaguy21]

What you really need is something like this. It would need a cradle built to take the RZ motor but its really, really stiff and light.

View attachment 51704

That would be awesome! Didn’t Glyn build something like that?

 

[Delboy]

That would be awesome! Didn’t Glyn build something like that?

He did. I can’t remember what frame He used though. The Mito rolling chassis is also a nice upgrade.