I am the proud owner of a race/track day NC30 as of last night! It comes complete with 17" rear rim fitted with 165/ slick and also a technoflex shock, which leads me to the following question. Is a 4.5" rim wide enough for a 165 section tyre? If so its good news as I may be able to source the occasional 2nd hand gp slick but I suspect it may be too narrow.

Also, how do I check that the ride height is correct for the 17" rear. I guess its take the shock out and measure it? What length should I be aiming for?

Thanks and see you at the track!

Cant answer your questions, but i can ask one lol. Any pics?

Chris.

An Rvf dogbone linkage will sort out any ride height issues (although if your shock is ride height adjustable it may not be neccesary), the vfr750 wheel conversion would almost certainly do the job (160 section tyres for the road), funnily enough I have both items for sale if needed :D .

I used to run 165 slicks on the 4.5" rim, it changes the profile slightly but nothing too dramatic. They'll be fine.

165 slicks are the only suitable size available in Australia, lots of racers use them on the standard rims.

the ideal rim size is a 5 inch, pirelli use a 160/60 and dunlop use a 165/50 and i think michelin may use a 165/55 i'm not sure. But all the tyres in a roundabout way the same size. What i should say is that a 4.5'' rim will be fine but dont worry if you cant get the tyre to the edge.

Sorry but I dont seem to be able to insert an image. I would have like to see if someone knows the bike, as I want to find out what weight rider it was set up for. I suspect he was quite light as the suspension is rather softer than I expected for a race bike.

Have a look at this excel sheet I knocked up that shows all the tyres that will in theory fit on a rim, including the differences in profile height from the original(s).

http://www.jacksons-lair.co.uk/vfr-tyre-calc.xls

Bear in mind tho that as manufacturer tyre sizes vary this should only be taken as an approximation and it should be tested with an actual tyre.

Hope it's of use :)