The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: stevie on January 18, 2007, 09:33:24 AM
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Hi Guys. could anyone tell me if a 110/90 18 size tyre would fit the front wheel of my 1980 r65, or would it be better with the 90/90 or 3.25 sizes
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I'm not real sure, Stevie. Some might say you would have clearance issues.
Others might say it would affect handling, while others would say it wouldn't.
I have a 100/90 on the front of mine, mostly because I don't think the Bridgestone Spitfires are available in a 90/90.
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Only reason Im asking is because I bought the 110/90 off ebay presuming it was a rear. If it won't do I will have to relist it.
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Now I am even more confused! I just remembered this link to tyre sizes for the r65 http://www.webbikeworld.com/Motorcycle-tires/sizes.htm. As I need a new rear it would be interesting to know what tyre sizes other members have fitted to the early model r65's. cheers.
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Aaaaah it's me again! Can anyone help? The tyre I purchased from ebay is a metzeler me 77 which has front stamped on the sidewall, however I have just been on the metzeler site (amongst others) and the tread pattern for the 77 is identical for front and rear. Even though the tyre has "front" stamped on it could I put it on the rear, would it affect handling and is it legal ? I think Iam going mad!!!!!
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I wouldn't worry so much about handling or legality as much as I would safety.
Front tires are engineered differently from rear tires, AFAIK.
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I think a 110/90 would be a pretty tight fit, but don't know for sure, I think it would also be a pretty fair bet that the 110 is designed for a minimum rim width that is greater than that of the R65 front rim. I would stick with the factory sizes (90/90 F and 110/90 R) or your neutral handling will suffer. With a much larger front tire the bike will want to "stand up" when leaned into a turn and you'll have to keep it muscled. With neutral handling, you can get into a turn, take your hands off the bars, and the bike will continue where you aimed it! ;D
On the Macadams, the front and rear tread pattern look the same but point in the opposite direction. I'm not sure, other than this, what other differences there might be between design/construction of front vs rear tires. Would be an interesting question to pose to one of the tire manufacturers - post a response if anybody does! ;)
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i have both a 90/90 and a 100/90 on my bikes. the 100/90 is much slower in response. I am going to stich with only 90/90 from now on on both bikes. 110/90 is WAY too big, if it would even fit.
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Hi Steve,
I have a 110/90H18 Macadam on the front of my 1980 R65LT. It is a rear tire and although the handling is different I have gotten used to it. The reason I put the tire on was for stability. In my situation bigger IS better. Also the 110 size rear tire will work properly with a narrower rim than a 110 size front tire. (Have you noticed how narrow the front rim is?) If you don't have stability issues then I do not recomend this tire.
If you do put it on then you will have to modify the fender mounts as the larger tire will rub on the inside of the back of the fender. Since on my bike the fender was closer on the back than the top, I took a 1/4 inch drill bit and elongated the aft fender/brace hole down a bit to rock the fender forward. This creates a a tight but evenly tight fit all-around. There are distinct disadvantages to having a fender tight like this. If you get in mud, the mud will jam the front tire in the fender and you will lose control of the bike. There is a reason GS bikes have lots of space between the fender and the tire. But if you are going to do nothing but ride clean roads then have at it.
As far as mounting a rear tire on the front wheel - put it on in the opposite direction of the rotation arrow. The reason for this is the way tires are constructed. Tires start life not as round but as a long single strip of rubber. This strip is joined in the construction process at each end to form a loop. Where the joint is usually a diagonal (not a butt end). The direction of rotation of the rear tire is such that under acceleration the tire will not start peeling back at this joint. When you switch a rear tire on to the front you have to turn the tire around so that when under braking (What a front tire does) the same tire will also not start peeling back at the joint. Clear as mud right. :-/
It can be done but only for the right reasons.
8-)
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Hi guys found tire site about front tire on the r65 110/80 battleaxe tire, think it was abridgestone wow what difference in handling. It this my bike I am thinkin. Plus I have a e77 on the rear, think about turning and leaning over and responds. Feels like a completely different bike. Its seems lower to.
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Hi Stevie, I always run a 100/90/18 on the front of my LS. If you decide to run the (front) ME77 on the rear I would run it with the arrow AGAINST the direction of rotation.
Tyre belts are laid up to resist the accelleration forces on rear tyres and braking forces for front tyres.
These forces would be opposite so therefore IMO you would be safer to run the tyre the other way around.
BUT how would that affect the water shedding properties of the tread pattern??
Probably better to put it back on eBay!
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Haha, now I know why my old front tire was installed backwards! :)
BTW, I'm using 90/100 on my front. I find it ok.
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I run the 100x90-Bridgestone Battleax on the front of my LS and have no complaints.
Different manufacturer's tires come out differently. Just because they call it a 90x90 doesn't mean they'll be all alike. Some will be too small and others fairly large. In the Bridgestones I've found the 90x90 to be very small and prefer the 100x90 - which also looks closer to the stock size they originally came with.
My other airhead beemers with wire wheels - same width as LS snowflakes - are fitted with 100x90 Bridgestones.
I'll have to agree, the 110 is too wide for an R65. Save it for the rear or put it back up for sale.