Seems as though all sizes are poretty close between car and motorcycle tires except 15" It is off enough to potentially cause problems during mounting or even after it Is mounted.
Some argue that bead designs on the motorcycle rims are different than on the car rims etc etc as far as holding the bead in place for sidecar or trike usage but that has not proven to be a real issue as far as I have heard.
Bottom line ...if you mount a 15" car tire on a motorcycle rim you are taking a chance when mounting and also after it is mounted.One of the old sidecarist magazines had pictures of blown out sidewalls and an article on the dangers involved in trying to do this...it is not worth taking the chance.
Guess I'll stick with my $100 a pop MC tires.
Ron
Thanks for the input guys.
Like I said: I never have used auto tires on any of my sidehack rigs. The 5.00x16" Firestone cycle tires used to work great on my early Drag cars with 16" Ford wheels though. A 16" was a little wheel in 1950 when Drag racing went National.
Lonnie
A 15" car tire works perfectly on the BMW model stated. Go to Pokies site on Chromeheads. The stats that were quoted are old news and need to be updated.
I have just (2 weeks ago and about 300 miles) replaced my Metz on my Montauk with a 165/15/86T car tire and am very happy. Better ride, and I believe much better value. $30.00 for the tire and 30 to 40 K mileage possibility. I had 13.7K on the Metz and still have the Metz on the front. Very happy with the Metz but dollars are dollars. The car tire went on much easier than the Metz came off. No balancing issues.
Uber
The car tire will fit on a MC rim IF that MC rim has been modified to fit the profile for the car tire. As the car tire is about 1/8 inch smaller you will stretch the hell out of the mounting beads trying to get it to fit otherwise. The hard part will be in trying to get it to seat properly and not go over the maximum inflation pressure of 40 psi or whatever the manufacturewr has stamped on the side of the sidewall. If you exceed this you are taking a big chance on premature life of the tire. We have had them explode during installation and injury of personnel during installation. Some have been fortunate and have not been injured. If you ever get this 15 inch auto tire mounted on an unmodified 15 inch MC rim and do not get yourself killed or injured in the process you might get a very useful tire life, or you might not. Certainly, this is something we cannot endorse under any circumstances, you are on your own.
The safe choices are:
1. Use 15 in MC tires on 15 in MC rims
2. Use 15 in Auto tires on 15 in Auto rims
3. Use 15 in Auto tires on 15 in MC rims that have been professionally modified to meet the 15 in Auto profile.
Originally written by hackellis on 6/10/2006 1:18 PM
A 15" car tire works perfectly on the BMW model stated. Go to Pokies site on Chromeheads. The stats that were quoted are old news and need to be updated.
Can you give us a link to this? When I search, all I find is http://motosites.com/Motorcycle_Makes_and_Models/BMW_Motorcycles/R_Bike/The_Chromeheads_forum_is_for_R1200C_owners,_prospective_owners,_and_anyone_interested_in_the_Cruiser_L3516/ and if I search for Pokie it comes up blank.
hackellis wrote:
>>,,,,,The stats that were quoted are old news and need to be updated<<<
Do you have verification on this or an official source for the information? I hope you are right as it would sure make some tire swaps easier BUT as Hal noted it is someting that needs to be documents in order to make any recomendations. No one wants to see anyone get hurt.
Note that just because it was done does not make it right or soemthing we really should recomend.
Claude is correct. It is possible to fit a fat 165SR15 auto tire onto a skinny unmodified WM3 MC 15 rim and some have in fact done this without having the tire explode during fitment. But because a few have done this does not in any way make this a practice that any recognized sidecar body can endorse. You are entirely on your own here.
Contact me if you want to see the actual photos of the brand new Firestone 165SR15 tires that exploded during fitment. These were the second set that exploded in a row, the first when blown up by the Firestone dealer, the second when another new tire was blown up by the sidecarist who had nor learnt his lesson.
A very few have done it successfully on an unmodified rim. And that is what we are talking about. I have heard of those who have finally seated the beads by exceeding the maximum allowable casing pressure of 40 or 45 psi - but then you have permanently weakened your tire whether you can see it or not. You have caused the wires in the seating bead to become unvulcanized from its surroundings. It may last 10,000 miles. It might last 100. Who knows. That is exactly how the tire blows up during fitment. From the inner bead outwards as the beads let go. The tread is fine. The sidewall is all shot to hell. Comprende?
Hal Kendall
hkendall@houston.rr.com
Let's be real!
The tire has been installed sucessfully many times. Installing a 15" tire is not any more dangerouse than any other tire. If one feels that it is necessary find a station with a split rim cage and fill it in the cage. Once the tire bead seats the danger is over.
NOT A PROBLEM. Let's have this from ANY authorized or legitimite source. Not - well, Joe said that I think Bill did this or that. There are too many stories and too few facts. Until then, we can only go with what we know to be true.
Hal,
I had the same thoughts but refrained from posting.
