What is the biggest/fattest tire someone has managed to put on an R81 seven hollie? I know the "Safe limit" is plus 20 mm, and the standard tires are 175-55, but I saw some JCW challenge pictures that looked like they were going wider than that.

 

It's not a problem to go as wide as 205/50-15 on 15x5.5" stock rims. I've done it many times and use them for road, track and autocross. Outer tire diameter is only 22.9 inches so speedometer will be off a bit but it's rather fun to drive with the speed showing greater than it really is.

It might be possible to put 225/45-15 tires on stock 15" rims but it won't be easy as they are really meant for 15x7" rims or wider.

Always use a specialty wheel shop to do the mounting and balancing since most shops don't have the equiptment to try it. I went to costco and they flatly refused- said it could not be done. So I took it to a tuner shop and they got it done fast.

 

225-45? wow. I thought 205 would be pushing it. 225 on a 7 hollie, golly....

 

205/50-15 is a common size and there are many tires that will work for street use, autocross or track using the versatile Stock 15x5.5" rim. It isn't pushing it (to use) because the tire is designed for rims as narrow as 5.5".

225/45-15 is a more serious performance size. I have a new set of Avon Tech RA tires that are unmounted and the side wall is super stiff- would be tough to try to mount it on a rim too narrow or too wide than what it is designed for. I'll mount them on 15x7" rims.

225/45-15 would be used only for high performance applications, not for daily driving.

 

Correct me if I'm wrong here, but wouldn't tram-lining become a problem with the excessive width?

 

225/45/15 is commoly streched for competition use. R compunds like to follow pavement contours allready, wich covers up the tramlining tendencies. Street rubber, and street driving it might be more noticeable.

Alex