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lath down a 15" rim

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have any one took off mat. on a 15" alum. rim? I think ill give it a try its only 0.112 so I can run a car tire again, a 165/80-15 ct went right on a 15" spoke wheel with tube. but I change to a case wheel . not so lucky I blow it in half with 90 lb max pres was 44 lb. a car rim is 14.986 and bike is 15.080 that's 0.112 diff. if I got my cal. right that's least than 1/16". if any one has any neg. thought let me know thx

billod1 - 9/18/2013 5:18 PM

have any one took off mat. on a 15" alum. rim? I think ill give it a try its only 0.112 so I can run a car tire again, a 165/80-15 ct went right on a 15" spoke wheel with tube. but I change to a case wheel . not so lucky I blow it in half with 90 lb max pres was 44 lb. a car rim is 14.986 and bike is 15.080 that's 0.112 diff. if I got my cal. right that's least than 1/16". if any one has any neg. thought let me know thx

15.080" -14.986" = 0.094" which is 3/32". So you would be taking it down one half of 3/32" or 3/64" which is less than a 1/16", you are correct! You are failing to acknowledge the bead area on a motorcycle rim has a different shape than that on a automobile wheel or tire. Of course you will be able to seat the tire with less air pressure, avoiding the blow up scenario but I for sure would not want to be the test rider!

im planning on reshapeing the rim to car profile

I have been running a car tire with a tube with out a problem. worst would be a blow out I guess I have had 2 rear n 1 front over the years with mc. tires and didn't crash on two wheels. don't know what it would be like with 3 wheels. but thinking it would have to be better.

I have been riding on 2 or 3 wheels for 47 years and have never experienced an actual blow-out. I've had tires go down but in a less volatile fashion. Your math is correct and if you can reshape the bead area your bases are covered; although running a tubed auto tire on a spoked MC rim may be more resistant to slippage than a tubeless on a cast rim.

Good luck with your machining and let us know how it goes.

i think im allow + or - a small bit when I get ready ill let you know. I been rideing 50 years also, that means were a cup of old bucks lol

I have put 5 dark side michlyns on rear rims of suzuki s-40 bikes with sidecars with very good success. I blew one apart trying to put one on a honda Aero 750.
Actually I got it on but it was destroyed inside and went flat on the first ride.
All of the above were on spoked rims using tubes.
One of the problems is a raised rib that the bead has to expand over tho set on the rim. It may be that simply removing this rib will do what you want.
This rib could be ground off with careful use of a portable disc sander. The heavy duty type that usually spins a cut off disc would work. If you need to reduce actual diameter of the rim you need a really big lathe.

I do have a friend that has a lathe that will take the rim. I have change many many tires so it wasn't cause I did something wrong that blow up the tire. I mean I guess I did by putting way to much air in it lol. another dum move I did one time was put a 90 deg. rubber valve stem on my front wheel so it would be easy to put air in what happen was from the cen force the stem broke off going down the road not a good thing. just give you that tid bit so no body did it. metal one would be fine.

I put A car tire on my Honda rim, the only problem I had was getting the tire to slip over the "safety" bump on the rim

well I guess all though I got blew up. wheel did not fit lathe like I hope. so I mounted wheel on bike, put it in first gear had it blocked up real good an used it like a lathe. it worked better than I though it would. no bounce it ran true . but I did have to take more than the bump that locks the tire on off. also had to take some mat. off cast rim itself about 3/32 it was trail an errow till I got it right. but now I have 6,000 miles on it with no problems. I am not telling any one to do this . I just wanted you all to know how it worked for me.

I was curious about trying this with a 15" rim as well. My bike has a 16" rear wheel stock (Venture), but the Vmax came with a 15" rear wheel and otherwise the rear is the same. Can't find a 16" car tire narrow enough to fit the swing arm, but there are 15" options available.

It's good to know it can be done.

Contact KOSMAN Racing out in California. They also have a web site. They have been recutting wheels for the drag racers, forever. They will be able to help.

like I said its only 3/32" that has to come off that leave plenty of meat left I didn't try to shape out side bead but it don't seem to make any diff. just do ba little at a time

like I said its only 3/32" that has to come off that leave plenty of meat left I didn't try to shape out side bead but it don't seem to make any diff. just do ba little at a time

There was an article written on one of the sidecar forums, maybe HPsidecar? What they actually showed was the drawing and measurements of the car tire bead vs MC bead and corresponding rims. They are not the same. Therefore they can not be co mingled in terms of rims and tires and be expected to seat properly. Does it matter, well, maybe. It is an unknown until something bad happens.... I would spend the $ and do it properly, especially with a loved one in the sidecar. Just a thought.

some thing bad happens? I have had blow outs with mc. tires over the years now that's not good on two wheels. have not had any on 3 wheels yet and I have been running car tires on the push wheel for many 1,000 of miles. but that's me and yes I ride my gran kids 400 miles back an forth to there house. many times. just cause some pep say you cant do it ,don't say you cant.

The way I see it is that if the tire holds air. runs true. and can be balanced than all is good. One other thing to note is the diference between tube type and tubless rims. The slite diferance in beed countor will not be a probluem once the tire is seated on the rim.

My understanding is that the guys running car tires on MC rims aren't having issues with the bead profiles, but that the issue with the 15" rim in particular is with the difference in diameter.

The increased diameter is causing the tires to be damaged when pressured up enough to seat on the slightly larger bead? If that's truly all it is, it shouldn't be hard to take off enough material to get the tire to seat at a lower pressure.

I never said one cannot run a car tire. I would get the rim cut as to insure a proper fit per the manufacturer. Must be my engineering side. On my current rig, I run car tires too, along with car rims.

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rayg - 2/11/2014 1:16 PM

I never said one cannot run a car tire. I would get the rim cut as to insure a proper fit per the manufacturer. Must be my engineering side. On my current rig, I run car tires too, along with car rims.

I sure would like to see that setup. Have any pictures of this?

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