150/60/18 Tire on a VFR??

Does anybody know if a 150/60/18 rear tire will work on the 86 VFR700? I converted to a Hurricane front wheel and have a 120/70/17 radial Michelin on the front, but the only rear radial I can find in a decent compound (for roadracing) is a Bridgestone and the only size that's even close is their 150. Converting to the 17" rear is not an option for this season. Can I squeeze it onto the stock rear rim without creating too many handling problems? Or can I mix a radial front with a bias ply rear? I have been warned about mixing radials with bias tires. Any info is greatly appreciated. Thanks.

Kris Larrivee

 

The actual section width of the tyre varies a bit by manufacturer. I currently run a dunlop 140/70VB18 in the rear on my '86. There is plenty of room to work with the chain guard(which you might remove for weight-saving purposes on race-day) but depending on chain adjustment, there is precious little clearance with the brake caliper stabilizing arm. People I know who have done the F2 conversion for the rear have had to clearance one side of that brake arm to ensure that there's no mingling of rubber and aluminum. As far as the 18 inch rear, the only decent compound tires i've seen are pirelli sport demons. They are designed specifically to bring new rubber technologies to our older bikes. They have 140/70VB18s for about $95 at MAWonline.com . There will definitely not be a clearance problem with 140 section rear. If you are bent on running a 150 in the rear, you might investigate changing the brake arm to a different model's piece, making your own from steel or aluminum tubing, or just clearancing the one that's on there. Chuch Crites of Cobalt Racing (pioneered the F2 wheel swap and even sells a kit for a few hundred) used to have some tips for performing the clearancing procedure on his website, I don't know if he's still got a web presence at all. His eBay name is VFRchuck, and he sells bodywork on a regular basis. You can go there and E-mail him for a webURL or just details, he's a nice guy and really likes to talk about the old VFRs(he raced one when they were new, it's a great story if you ever find it). Hope this helps

 

I actually found some Avon bias-ply race compound tires that were the perfect match for the VFR, and was able to get them through one of my sponsors. The rear is a 150/70/18 and according to the Avon site, will work with the 3.50 rim. I mounted it and clearance and contact patch are perfect. The front was a 120/70/17 (hurricane front wheel) and again works very nicely with the rim. They are available through any Tucker Rocky dealer, but are not DOT, being for racing only. I've raced Avons for years on other vintage racebikes, so I have an idea what these will work like. The first racetrack test comes April 16/17, can hardly wait. Now if only I could find somebody to sell me an aftermarket shock for the 1986 model......

Kris

 

hey, all,

i have an '86 vfr 750, which i believe is the same as the 700, except for a smaller motor. i was running a dunlop 140/18 on the rear, but wanted more and put on a bridgestone battleax 160. i have put several hundred miles on it, and it seems to be fine, with nothing rubbing.

bryan

 

It´s not recomended to have much more than 140, because you´re making the handling poorer.
The rim have to be wider as well.
I´ve seen that there are som that mount a CBR600F2 rims and tires. Both front and back, and that seems to work much better.
The disc brakes is the same size, so U don´t have to worry about that.

 

Michelin used to recommend a 150/70/17 m59x rear tyre for the vf700. The current replacement for this is the macadam 100x in the same size. I have run these tyres and can report no clearance problems. If the hurricane wheel you have ios from a 600 it should have a 110/80/17 tyre if it is from the 100 the 120/70 is fine.