Some good tire info here. This is by A well know airhead BMW authority who many of us know as 'Snowbum'. Click on th elink below . I have copied one part of it for thoise who do not wish to read all of th einfo not directly petinent to this thread.
Item #5. SIDECARS: Sometimes sidecar folks will use a rear wheel on the front. If you do so, and the tire has a directional arrow, do REVERSE the tire, so the direction arrow is in the wrong direction of travel. For sidecarists, 16 inch rims CAN be used for passenger car tires OR motorcycle tires (if rim width is proper), but do NOT use a 15 inch m/c tire on a 15 inch car rim, nor 15 inch car tire on a 15 inch motorcycle rated rim. You MAY be able to do it if a rim is skimmed on a lathe....HEED THIS WARNING!!! The 15 inch car tires and 15 inch motorcycle rims are NOT the same diameter!!!
Link to whole page:
http://www.cdegroot.com/cgi-bin/mirror/pweb.jps.net/~snowbum/section5.htm
Come on guys the Tire and Rim association and the tire manufactures recommend that no car tire should be mounted on a motorcycle rim or for motorcycle use! The motorcycle manufactures recommend that sidecars should not be attached to their respective motorcycles or the warrantees will be void.
However, it has now become acceptable to mount car tires on motorcycle rims because some of you have determined it is ok on all sizes except 15" even though I provided evidence to the contrary.
If the stories would be kept consistent they would be more believable. I am having a hard time following the logic of your arguments.
You still do not get it. Just because a few have mounted 15 inch tires means ZILCH! You have not come with how it was done, procedure, who did it, where it was done, etc. Give us some details - not just a picture.
How many times must you be told the SAME thing. Understand the basics of tire construction.
ALL auto and MC rim profiles are different. Period.
The general statement is true in that a MC tire is designed to have a V or a round profile, a stiff hard sidewall, and a narrow rim width. Unlike an auto tire which is designed to have a flat profile with slightly rounded corners, a flexible sidewall, and a wide rim. An altogether different tire for an entirely different purpose. When an auto tire is force fitted onto a narrow MC rim it no longer takes the form it was designed to take. It becomes more rounded - hence the general statement as to non usability. Hence, the statement from the Tire & Rim Association is 100 % true and correct.
However, because the other properties of the auto tire are so superior for sidecarists, and when the critical rim size is IDENTICAL so that the auto tire can be SAFELY fitted, which is true ONLY for the 14, 16, 17, and 18 inch sizes, then sidecarists have used those sizes, and only those sizes for use on their rigs.
The 15 inch size was deliberately pulled out and given a DIFFERENT rim size for the auto rim because some wanted to fit the auto tire to motorcycles. At the time, that was the ONLY tire that the practice of mismatch was going on.
There is no problem. For those wanting to retain the 15 inch auto tire to a MC, just replace the MC rim with a 15 inch auto rim, or modify the MC rim to accept the 15 inch auto rim.
We have heard from Jay of Dauntless Motors. He casts his 15 inch wheel for the 1500GL with the 15 inch auto profile to accept the 15 inch auto tire.
We also heard from Doug Bingham. He uses the 16 inch auto tire on the 16 indh H-D rear wheel, again in complete conformance with our suggestions.
We have also heard from Wagner's Cycle Shop. They would refuse any request to fit a 15 inch auto tire onto a MC rim.
Therefore, it is only the 15 inch tire and rim that is CRITICAL. It is ONLY the 15 inch size that has been singled out for special treatment.
After reading all the information posted on this subject I have decided to put an Metzeler 880 tire on the rear of my bike. Thanks to all for your advice and comments. Ride safe. Egor.
Do it right and safe.
Hal
Originally written by Egor on 7/10/2006 2:33 PM
After reading all the information posted on this subject I have decided to put an Metzeler 880 tire on the rear of my bike. Thanks to all for your advice and comments. Ride safe. Egor.
Originally written by Egor on 7/10/2006 12:33 PM
After reading all the information posted on this subject I have decided to put an Metzeler 880 tire on the rear of my bike. Thanks to all for your advice and comments. Ride safe. Egor.
Just out of curiosity Egor, what is the bike you're going to mount this tire on and what size is the wheel? I'm thinking I'll eventually go to car tires on my Harley/Liberty and it's 16" wheels...
You lucky dog - 16" wheels - no problem.
The rim OD is the same for auto tires as for MC tires.
Doug Bingham does this all the time.
No controversey. Just good vibes.
I have run car tires on Harleys for many years. And not just on rigs in the 40s and 50s alot of riders did, NO PROBLEM just NOT on 15" wheels
Ron in Co
Originally written by hal77079 on 7/10/2006 2:37 PM
You lucky dog - 16" wheels - no problem.
The rim OD is the same for auto tires as for MC tires.
Doug Bingham does this all the time.
No controversy. Just good vibes.
Precisely!!
Summary,
1. The Tire and Rim Association recommends against the installation of a car tire on a motorcycle rim regardless of size. There position is 100% against any application or exceptions.
2. The tire manufactures are in 100% agreement that car tires go on cars and motorcycle tires be put on motorcycles with no exceptions.
3. No reputable tire installer in their right mind would install a car tire on a motorcycle rim because of the exclusions in their respective General Liability Insurance Policies would exclude a willful disregard for a industry standard.
4. Motorcycle Manufactures and 100% against car tires installed on Motorcycles.
However, this Association has decided that it is ok to install car tires on motorcycles as long as the size is not 15".
Hal,
My question to you. Given the facts what tire installer would install a car tire on a motorcycle given the liability issues? Seems to me that any business that knowingly installs a car tire on a motorcycle is risking his entire business. Either they are not aware of the liability or choose to ignore the liability. Either way not a type of company one would want to do business with.
Mike
Yes, it is a compromise. And that is the very first lesson one learns about sidecars and sidecaring. Sidecaring is all about compromises and compromising. But learning to find the right ones among the many. That is called the sweet spot. It is often extremely elusive. It applies to all aspects of sidecaring.
But not all tire manufacturers are in lock step.
And sidecar manufacturers do use common sense with regards to their products as we have discussed in this column. And they do install tires. That is an element you have overlooked. There is a lot of common sense that goes hand in hand with the compromises. Such as the decision of many to use 16 inch auto tires to replace the 16 inch MC tires - done by some sidecar dealers and by ordinary sidecarists with no axe to grind, and supported by many on this list - except by yourself, apparantly.
Safe riding.
Hal,
I think it is not about compromises but the management of risk and to determine what is acceptable for ones own use. That is the same for riding motorcycles or the use of sidecars.
Would you agree?
We have covered some very different ground here.
We do not set the policy for the dealers - they do. They are guided by various Association guidelines - BBB, SIC, State, federal, some as laws, regulations,customer relations, etc. Not the least is insurance and yes, liability, real and implied. Customer relations. etc.
Then we have informal chat lines such as this where we can share our views. I, for one, feel that while I can state what I have done for myself and the advantages or otherwise I have seen to me, that I cannot advise or recommend this another - but he/she can make his own independant assessment based on my experiences and the experiences of others.
As far as risk management is concerned - this is very personal. One person might have a severe aversion while another given the same facts sees no problem. Example. We have a 6 ft deep pool at home. My wife will under no conditions ever contemplate even getting her little toe wet. I, on the other hand, have no problem jumping in. And I know damn well she can and has swum. Seen her do it.
Safe riding.
Hal,
We have come full circle.
I assumed the risk of installing a 15" car tire on my motorcycle as others have done. Nothing more and nothing less.
Safe Riding
