The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: CaptainSlow on February 27, 2013, 03:58:16 AM
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I've done a search but surprisingly didn't find much on tires, please humour me if there is a section that I've missed!
So, I've noticed that the date stamps on the tires fitted to my R65 show that I need to replace them regardless of their lack of wear - they're dated 2000 or earlier! I'm thinking along the lines of the Avon Roadrider as motorcycle couriers over here seem to rate them highly.
I have two questions - firstly, the sizes. As mine is an LS and has the wider front rim, the front should be a 100/90-18 ? And the rear a 120/90-18 ?
Secondly, these are tubeLESS tyres. I've contacted Avon and they said that you can use these tyres with tubes, but they wouldn't be drawn on tube sizes - is anyone on here doing this, or can you give me the correct size tubes?
Many thanks!
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Hi Sam, you will need a 100/90 front and a 110/90 rear as it is limited by the swingarm clearance. You can run them tubeless on LS rims.
Personally I recommend Bridgestone BT45's. excellent grip and long life.
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Thats fantastic news about running tubeless, thanks Bruce. Rear size noted as well. I had the BT45s listed as a second choice, so I guess it'll depend upon prices at the end of the day - they both seem to have excellent reviews.
Thanks for the help once again. If you need help with a Land Rover Discovery Td5 I'm your man, but I'm an utter novice on the R65... :-[
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... You can run them tubeless on LS rims...
If you decide to go tubeless, remember to factor in the price of a pair of tubeless valve stems. I like the "angled" stems on my R65. Much easier to get an air chuck on the rascals. [smiley=thumbup.gif]
Prior to mounting the new tires, confirm the rims have no burrs, spurs or boogers. Tubeless tires have a much stronger bead than non-tubies. If you plan a DIY mount and balance, keep young ears away from the shop and maintain a good supply of malt beverages.
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Greetings from the US. My 82 LS have the OEM "white" wheels, and in replacing the tires. MAX's BMW and METZLER's site, show the front to be
90.90x18 front
4.00x18 rear
When I acquired the LS the front had 100 x 18, when I freshened them up I used the smaller (OEM) size, the handling is better IMO. I used tubes in mine, for no other reason than it had them when I acquired it. It is nice to know the LS wheels DONOT need tubes.
jgp
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Hello !
Actually, LS wheels are NOT tubeless rims.
So the tire will NOT be properly seated and can escape the rim !
The manufacturer did not certify these rims for tubeless use. So you have to put a tube into them otherwise you risk a brutal pressure failure if you run them totally tubeless.
I do not know what they where thinking at BMW at the time with these rims !
At the same time Michelin in France issued a set of special tires which had to be used on special rims. Citroën used them on some cars. If you still have the car, you can't use them because Michelin does not make these tires any more and no other tires fit the rims.... Unless you find standard rims and pay for the certification process...
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Here's an article from Snowbum's BMW site .
It doesn't specifically mention the LS wheels, but the monoshock bikes had the same wheel as the LS .
Hope it doesn't confuse you any more than it needs to !!!!
http://bmwmotorcycletech.info/section6.htm
Here's a BMW service letter that has the description of the LS wheels, which are referred to as 'composite' wheels .
https://www.bmwmc.net/catalog/2044.pdf
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Last time I changed the tires I took a picture of the rim profile for future reference. This illustrates the lack of an obvious bump in the profile before the drop into the well. There is no doubt that these rims were not designed for tubeless tires however some have run tubeless without incident and apparently safely for many many years. For those who are considering doing so I recall BMW themselves described these as safety rims due to the wide seating area and relatively narrow well. The well on the front rim is particularly narrow.
This rims may not be certified to run tubeless but I believe they are safer than early spoked wheels. You only have to experience the difficulty of breaking the bead and dismounting a tire to know that.(http://)
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I note that your in Yorkshire, National Tyres in Barnsley are bike specialists I run Michelin MT45,s nice retro look to them and good handling i am calling in there tomorrow for an opinion on my K front wheel which looks like its bent............. seems Avon Roadmasters dont like Diesel
Lou
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Hi Lou, yes I used to use that depot when I had the Guzzi, they are very helpful. Sorry to hear about your K having some excitement, luckily thats something I've never had to deal with. I take it you are ok?
I thought I'd ask about the tyres here first though as the LS wheels seem to be unique and I'm not sure National Tyres would know anything about them. I've contacted Rainbow BMW to ask their opinion so I'll write back here with what they suggest. My initial thought is to go tubeless with the RoadRiders, however that *may* affect any possible future insurance claim - you know how insurers will use anything to get out of a payout!
George - I had one of those Citroens! It was a CX 2.5GTi Turbo and had a unique Michelin metric TRX tyre - they were incredibly expensive and only available to special order! It was a superb car though, not as complex as many people make out, but still quite a challenge to work on due to all the special tools needed. I sold it as my licence was being seriously endangered - it was an absolute hoot to drive :)
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LS wheels are unique to the R65LS, although similar to the later Monoshock wheel rims they are not the same.
Although BMW never say that the LS rims are 'Tubeless' my tyre technician inspected my rims and confirmed that they do have the correct profile to safely run tubeless tyres without needing tubes.
A number of paragraphs in the original sales brochure refer specifically to the new wheel technology and includes a diagram which shows the tyre (apparently without a tube) located in the required extra lips in the wheel well profile.
I have run without tubes for 25 years on these rims without any issues.
Barry, just to be clear the wheel rim photo you have posted is a snowflake from your R45, not a LS wheel?
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Barry, just to be clear the wheel rim photo you have posted is a snowflake from your R45, not a LS wheel?
Yes it's a Snowflake rear.
Sorry I missed the fact that the original poster was talking about LS wheels.
I've never seen that diagram before and I have an original 82LS brochure. It would certainly be enough evidence for me to run tubeless and it also shows the composite wheel constuction nicley.
It's interesting that all tubless wheel profiles slope down toward the well so they really do need the hump where as the snowflake profile is dead level. I wonder if that's because the air seal is meant to be on the bottom of the bead rather than the side. That would explain how they mange to make tubeless spoked wheels work or are they more like this construction.
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Regarding Montmil's post - right-angle valve caps are (or used to be) available. I have them on my 79, see photo. They don't seem heavy enough to affect wheel balance, at least not at the grand-dad speeds I go at. I bought them some years ago from a company here called Sound Distribution. Don't know if they still stock them.
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BMW has the 90 degree valve stem extensions if you can't find them elsewhere .
Take this for what it's worth, not my comment, that the 90 degree valve extensions are for servicing only, not to be left on while riding .
Maybe not so much in the R65 application, but where there is a rubber portion of the valve stem that protrudes past the jamnut, can cause valve stem failure .
A co-worker has a late model Honda sport bike, he had a valve stem failure at 70 mph, due to the 90 degree extension being installed all the time
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I have one of those right angle valve extensions that came with the bike tool kit. Never needed to use it though.
I believe it must cause a small out of balance force so I wouldn't leave it on.
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That's interesting. I did suspect out-of-balance but have not noticed any sign of it. Tmr I'll weigh the adaptor! Should be possible to counterbalance with something like 30 amp fuse wire. As seen on the photo, on my rig both valves are so close to a spoke that many modern air lines will not fit at all.
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I'll look back to my sales receipts and post the source for the tubeless valve stems. The ones I bought are fabricated with a 45-degree angle. As to why BMW put the stem hole so close to the spoke is beyond me.
Be back later...
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The hole is a weakness. Putting it close to the spoke (one of the strongest part of the wheel) help keep the strength of the whole wheel.
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Well, I had a reply from the local BMW dealership (one of the best in the country luckily), and they very strongly advised that tubes should be fitted. Now that may be just a bit or arse covering, but I think I'll fit tubes to be safe - especially as the tyres I want to fit are approved for use with/without tubes anyway.
So its booked in for new tyres and tubes to be fitted in readiness for the MoT (I'm taking the wheels off the bike). I've ordered 100/90 front and 110/90 rear on Bruce's recommendation - thanks for that ;)
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The right-angle valve adaptors weigh 9 grams with end cap in place.
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Well, I had a reply from the local BMW dealership (one of the best in the country luckily), and they very strongly advised that tubes should be fitted. Now that may be just a bit or arse covering, but I think I'll fit tubes to be safe - especially as the tyres I want to fit are approved for use with/without tubes anyway. <snip>
IMO, the small price of the tubes is worth the additional safety that it provides (even if you do not absolutely need tube).
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"IMO, the small price of the tubes is worth the additional safety that it provides (even if you do not absolutely need tube). "
Two sides to each coin, one reason every modern vehicle runs tubeless tyres is that they are more resistant to sudden deflation in the case of a puncture.
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Well, in France, there are a lot of horror stories about the sudden deflation of tubeless tires on LS wheels...
So ....
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Well, I had a reply from the local BMW dealership (one of the best in the country luckily), and they very strongly advised that tubes should be fitted.
Typical "dealer-speak". Especially in our litigious society.
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"IMO, the small price of the tubes is worth the additional safety that it provides (even if you do not absolutely need tube). "
Two sides to each coin, one reason every modern vehicle runs tubeless tyres is that they are more resistant to sudden deflation in the case of a puncture.
It would seem to me that if a tube were to suddenly deflate when you have a tubless tire, the fact that the tire itself is tubless (and even capable of being used on these rims without tubes) should slow down the suddeness of any deflation by keep some of the pressure between the tire and the rim. Am I missing something?
k_enn
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LS wheels are NOT rated for tubeless tires. They lack the correct profile and so are dangerous when fitted with tubeless tires without tubes.
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Have you looked?
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RE: Angled Valve Atem
Took some looking. Finally located the invoice from September 2006. Here's the link:
http://mcenterprises.com/products/search/dsp_searchForm.cfm
Search Key Word: Valve Stem
After the install, I went ahead and balanced the tire/wheel combo.
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It would seem to me that if a tube were to suddenly deflate when you have a tubless tire, the fact that the tire itself is tubless (and even capable of being used on these rims without tubes) should slow down the suddeness of any deflation by keep some of the pressure between the tire and the rim.Am I missing something?
k_enn
I agree. The tire should deflate more slowly than it would with a leaky spoked rim. I even go so far as to put an O ring under the valve stem nut to reduce leakage at that point.
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Hello !
Actually, LS wheels are NOT tubeless rims.
So the tire will NOT be properly seated and can escape the rim !
The manufacturer did not certify these rims for tubeless use. So you have to put a tube into them otherwise you risk a brutal pressure failure if you run them totally tubeless.
I do not know what they where thinking at BMW at the time with these rims !
At the same time Michelin in France issued a set of special tires which had to be used on special rims. Citroën used them on some cars. If you still have the car, you can't use them because Michelin does not make these tires any more and no other tires fit the rims.... Unless you find standard rims and pay for the certification process...
Some BMW cars were sold here with "TRX" tires. Most owners bought standard size alloy replacements.