The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: tc80211 on March 13, 2014, 01:38:53 PM
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'83 R65LS... I have the 18" "cast" wheels... any recommendations on tire/tube sizes?
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I just installed the Bridgestone Battlax BT-45's, 90/90-18 front and 110/90-18 rear. I bought them based on recommendations I read here and other places, but haven't had a chance to ride on them yet.
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I just installed the Bridgestone Battlax BT-45's, 90/90-18 front and 110/90-18 rear. I bought them based on recommendations I read here and other places, but haven't had a chance to ride on them yet.
Tubeless? I guess thats what im struggling with. Have never had a wheel that required tubes before.
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I like metzler tubes and use them on my LS - they are somewhat heavy, but the thicker rubber seems to last well, and the metal valves seem to be a little bit longer than some other brands, which is handy with that narrow, deep well and tall central rib in the LS wheels. I use the ME E18 tube on the front, and the ME F18 tube on the rear, though the ME E18 tube is rated to fit tires from 3.25 up to 4.1 or more inches, so I just carry one of these as a spare tube under the seat as it can do dual duty front or rear if I get a flat. I am sure other brands will work too.
If you don't already know - one thing about motorcycle tire sizing - metric tire sizing anyway - is that the numbers don't actually give the exact dimensions of the tires height and width - the actual dimensions may vary significantly from the value of the number and vary depending on the rim width, but the RATIO of height/width WILL match the ratio of the numbers specified. For example, Vendor A tire in 120/90 x 18 metric size may actually be 116mm when mounted on a specifc rim, while Vendor B tire in 120/90 x18 might be 122mm when mounted on the same rim and inflated to the same PSI. But, the RATIO of height to width for each tire will both come out to the same 120/90 fraction. So, getting that out of the way, be aware that some brand's sizes may not be the exact same physical size as a different brand's sizes.
That said, I like the performance of the Bridgestone Battlax BT45 bias ply tires on my LS. The rubber is quite sticky and rides smooth and resists following rain grooves and metal decking. While you can still get some tires in the original imperial english sizes that came on the bikes (3.25x18 front, 4.0 x 18 rear), I am running the aforementioned BT45 tires in 100/90x18 (front) and 110/90x18 (rear). I could also have run the 90/90x18 front tire instead, but it was harder to obtain, and the slightly larger front tire I am using has only made the straight line stability of the bike slightly better, IMO. The snowflake front rim wheel on the non-LS models is narrower than the LS wheel's rim, and it should ideally use the 90/90 tire for that application, if choosing theis metric size tire model.
The Spitfire S11 tires are also good and used by many airhead riders. There are some other brands and models out there to consider as well, but I've settled on the BT45 for my LS.
Some people ride the LS wheels without tubes - the rims do have an internal shoulder "bump" that many claim is appropriate for bead retention with tubeless tire mounting. Some have told me that the bump isn't quite the proper size, but is quite close. BMW shipped the LS fromt he factory with tubes installed (some will argue that this is simply the traditional German reluctance to change) but I feel if they shipped them out with tubes, I'm going to continue to use them with tubes. Others choose to run tubeless and haven't reported issues - or simply haven't had a flat yet at speed to report whether the bead was retained in position or not. I'm going to err on my own personal side of caution in this case and use tubes, but you will definitely find others here who go without and are happy to do so. Your mileage may vary, etc.
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Thanks guys! I was searching through tubes and came across a plethora of sizes for 18" rims, just wanted to make sure I make the right decision. I have the Battlax on my Zook and love the ride, so now with this recommendation, I dont see any reason to ride anything else, at this point.
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Looking at the pics of your bike in the other thread - you don't have the LS wheels, you've got the snowflake wheels (Actually it doesn't appear that your bike has the LS specific parts on it, but it may indeed have had the engine/frame from an LS bike from the factory - they are the same as the non-LS of course. But, the wheels are definitely snowflakes (the "normal" wheel on the R65) versus the LS wheels. Keep this in mind as per above tire fitment info... and, the snowflake wheels definitely should be using tubes.
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I've had excellent luck with Michelin Macadam tires on the irheads.
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... and, the snowflake wheels definitely should be using tubes.
Point and counterpoint.
I've been running tubeless Bridgestone Spitfire S11's on my snowflake-equipped 1981 R65 for the last six years without any issues.
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On my LS I'm running Spitfires with a 100 up front and a 110 in the rear
One thing I noticed when I put those tires on, with the sizes so close together, was that it tracked much better over grooved pavement and tar snakes.
::edit:: Not sure if you can run a 100/90 on the narrower snowflake front rim though
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For what it's worth, Snowbum's website section on tires is where he states his belief that the Bridgestone Spitfire S11 tire is the best all-around performer for BMW Airheads.
Not attempting to start a DTT... ::)
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I could also have run the 90/90x18 front tire instead, but it was harder to obtain, and the slightly larger front tire I am using has only made the straight line stability of the bike slightly better, IMO.
Not really an opinion.. wider tire means more surface contact and thus harder to turn. Which is why I have the 90/90 on my front end. Pretty sure I have metzelers on again, but next time I change I'm going to order ahead.
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WOO HOO ADTT!
Michelin Pilot Active is a great tire.
But if I still had the original Snowflake I would put a Heidenau 3.25-18 on the front and the 4.00-18 on the rear. I have the Heidenau K60 scout 4.00-18 on the back of my BSA Dual sport bike and it is the all-around best street/dirt tire I've ever had on the BSA Firebird Scrambler. It beats the Avon Roadriders hands down.
If I still had the stock set up on my R65 I would put on a K34 3.25-18 on the front and K36 4.00-18 on the back. As it is I will have to wait for the Dunlop K70s on my 1964 BSA Lightning Rocket to wear out to try out the Heidenau street tires.
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So here is a pic of my ride (when i first took her home) and sort of a shot of the wheels in question... can I run tubeless on these? Should I?
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... question... can I run tubeless on these? Should I?
You have the "snowflake" wheels.
Yes, you can run tubeless.
Should you? That decision is up to you.
BTW, that's not an LS seat/tail piece.
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BTW, that's not an LS seat/tail piece.
Nor does it have double discs, black exhaust, and a black top triple clamp.
Are you sure this bike started life as an LS?
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Those handlebars are LS, right? ::)
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Honestly no idea what this bike started life as. It certainly was rough to say the least... Tank has "patches" welded into one side where he removed 1 petcock... Vetter fairing that was def not fit correctly... Original seat though... So R65 for sure. Trying to bring it back to its stock R65 glory with some needed enhancements...
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Hello !
NO, you CAN'T run tubeless tires on them.
Snowflakes rinms are NOT designed to run tubeless tires.
Some use them and had no accident still. But this is pure luck.
Tubeless rims have a different profile than the one on the snowflakes rims.
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Tank has "patches" welded into one side where he removed 1 petcock...
Welded patches, you say? If that tank is an OEM R65 fuel tank, it was never a two-petcock-er. R65s have a single petcock on the left side. We are unique in having close to a quart+ of fuel stored on the right side of the tank. All you need do is tilt the bike a bit and slosh enough Reserved reserve fuel to get you several miles further down the road. Could mean less or no pushing.
The lower seam area on your tank -and for the rest of us, too- is also an excellent water trap. Eventually, rust eats through the seam area and you have a nasty leak. Thinking that's the real reason for the patches on the right side of your tank.
An annual ritual of removing the tank and draining the fuel along with any accumulated water is a good preventative measure in preventing rust, leaks and wallet burn.
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I'll give my usual take on snowflakes and tubeless tires. No it was not designed for tubeless use but it was designed as safety rim to :-
"improve stability should a tire blow out. The shape of the rim itself provides some support for the deflated tire as well as holding it firmly on the rim. BMW consider this to be a more important development than tubeless tires which they feel presents private owners with numerous pitfalls regarding safe fitting and adequate sealing"
Taken from a 79 road test and presumably the sort of press release information BMW gave out at the time our models were introduced.
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I will be "diving" into the tank this weekend to get a closer look at to what is up... Thinking the KBS sealing system to cleana nd seal its interior...
As for tires, I think Spitfire after reading Snowbums page, he makes a convincing argument and I want the best ride quality I can get....
Only a couple hundred other parts left to go!
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Only a couple hundred other parts left to go!
if brake shoes are on the list, don't get them that fit the LS (the LS wheels have a bigger drum and mucho-more-expensive shoes).
You'll be happy with the spitfires, they're a great all around tire.
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R65s have a single petcock on the left side.
'84 and older, Monte.. don't forgot about those monoshockers!
I treat mine like a single petcock though.
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An annual ritual of removing the tank and draining the fuel along with any accumulated water is a good preventative measure in preventing rust, leaks and wallet burn.
Either deliberately give your bike a dose of Ethanol blended fuel or every 6 month sor so give it a tank of high octane and add a bottle of methylated spirits.
This is making use of chemistry. Water does not dissolve in petrol, but alcohol does. Water dissolves (and this is the wrong term cause right at this moment I can't remember the right one) in alcohol.
Petrol/alcohol/water comprise an intermiscible solution which gets rid of any water that has accumulated in the bottom of your tank without all that tedious removal, sloshing about and use of hair dryers etc.
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Alcohol fuel is all we can get around here. :(
Steven
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R65s have a single petcock on the left side.
'84 and older, Monte.. don't forgot about those monoshockers!
I treat mine like a single petcock though.
Monoshockers are just too modern for me. ::) Oldskool don'cha know.
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these! cheap as chips and great! michelin m45 s less than £100 quid fitted .
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To perpetuate a tire thread, I'm ordering a new set of Bridgestone Spitfire S11s, along with new Bridgestone tubes. A question asked online is whether I want a TR-4 / TR-6 Straight metal stem (8mm dia.), or PV78 Tall 90 degree metal stem. I like the idea of using the 90 degree valve stems, and wanted to ask if anyone here has tried them, yea or nay. Getting to the straight stems with the snowflake wheels can be a wee bit difficult at times, or at least more so than a 90 stem, and using some pressure gauges would be much easier too. Thoughts?
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You shouldn't have any trouble with a 90 degree stem. You might slightly change the weight of the valve assembly... and you might also slightly change the center of gravity of the valve assembly.
As long as the wheels are balanced with the 90 degree stems--if you bother-- you won't notice a difference; and having your valves easier to access with an air chuck/pressure gauge will probably promote better and more frequent tire pressure checks and adjustments.
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these! cheap as chips and great! michelin m45 s less than £100 quid fitted
Lou uses them and I've bought a set to be fitted later this year. I reckon the low price is down to them being marketed as commuter tires. Michelin actually recommend them for fitment for my bike.
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As I have a detachable 90 deg converter for the valve stem I'm not sure a fixed one would be my choice. They do seem to be widely used without problems though.
Just out of curiosity I put some numbers into a centrifugal calculator.
If we assume maximum 1300 wheel rpm (approx 100 MPH) and the angled portion of the valve stem weighs 10 grams (wild guess) the max. bending force on the stem is 4.3 KG or 9.5 lbs.
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actually its because theyre only 's' rated 112 mph , or so stuart at national told me, seen lots of good stuuff about them online , so theyre probably going to stop making them any minute! lol
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I'm fanatical with Heidenau tires. Cheap, handle very very well and in S speed rating are quite cheap. Only drawback is that they're stiff and mounting them is a PITA. But if the mounting is done by a pro .... who cares ?
As the thread is thick, I bet they last long... will report in a couple of years...
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Looks like a late model R100 tank. Keep that - it holds more fuel and you get a second petcock on the RH side the rest of us don't have.
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I live in an area with lots of boats and get alcohol free gas at the local marina. They say it's 90 octane.
Dave