'82 BMW R Snowflake front wheel question

Discussion in 'Airheads' started by scooteraug02, Jul 11, 2004.

  1. scooteraug02

    scooteraug02 Dog Rancher

    Joined:
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    I was helping a friend change a tire on an '82 BMW R bike. The front wheel is a cast aluminum "snowflake" wheel. The owner's manual says it is a tube type wheel. The tire we took off was a tubeless type with a tube. We mounted the new tubleless tire with the old tube (tube was in excellent condition). All went well except when inflated the tire would not seat uniformly. We only inflated the tube to 50 psi and inflated and deflated and worked it a bunch of times but no luck getting the one area to scoot up to make it uniform. We checked the wheel for uniformity on the truing stand and all was normal.

    Questions:

    Is there a stem made that will fit the snowflake wheel? The hole is only the size of a tube stem and is close to one of the cast spokes. I haven't seen a rubber stem the size needed and I think a bolt on stem might not work because the hole is so close to the spoke.

    Is there any problem using a tube on a tubeless tire? I don't think so but don't know for sure.

    The owner's manual says it is a tube type wheel so I would think that is why it looks like no stem will fit the wheel. Does anyone know for sure about these wheels and this age BMW.

    I don't know the size or brand of the tire we mounted. It was my friend's friend's BMW. I showed up to help because my friend and I have changed a lot of tires and they asked for my help. It became a comittee situation and was hard to get anything done. I think we could have solved the seating problem by deflating the tire, strapping down the high side and reinflating slowly. That should have solved the problem. BUT the focus was on wether using a tube on a tubless tire was the problem. Any help will be appreciated. I know a lot of you guys have had older BMWs Thanks Rick :D
    #1
  2. TX_ST_Tom

    TX_ST_Tom n00b

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    First, saving the $10 for a new tube is not worth the risk or the hassel. Since you're in there anyway replace the tube, if the old one is perfect save it for a spare.

    Yes you should use the tube, the profile lip of the rim is different on a tubeless rim and if you hit something it can cause rapid deflation of the tire, which can be very exciting! Getting the tire to seat usualy isn't much of an issue, IF the rim is clean and you use plenty of tire lube. If you're really stuck use a ratchet strap around the out side of the tire to slightly compress the tire into place while filling it.

    That being said, may people run their snowflakes tubeless. To do so all you need to do is take the wheel off and drill it out to the proper size. (exact size escapes me at the moment.) debur, and fit your new stem. Or, I think BMW sells or used to have a special stem that bolted in that would fit in the Snowflake rim with no modification.

    He has checked the wheels right? The early 19 inch snowflakes had an issue with cracking along the spokes near the hub. The improved ones have a reinforcing rib that runs from the crossover to the hub. This was a big deal back then and the entire wheel should be repalce at ZERO cost by the dealer if it's part of the recalled ones.

    HTH
    #2
  3. KL5A

    KL5A Bugs are the new black

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    Had a similar issue with a Moto Guzzi, old style cast rim (tube type) and a tubeless tire, used a new tube, still had a heck of a time getting to seat uniformly. I finally gave up and took it for a ride. 100 miles later, the tire worked it's way around the rim properly and the shimmy went away-was really bad for the first few miles. That tire is still on the rim and no complaints that I know of from the new owner.
    I'd be really cautious about running it tubeless on those old rims. There isn't really enough rim height to hold the tire on if something bad happens, and some of the old rims are porous enough to not hold air properly
    #3
  4. scooteraug02

    scooteraug02 Dog Rancher

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    Thanks guys. It was 5:00 p.m. on a Saturday and getting a new tube wasn't possible at the time. We gave up to figure it out. I'll suggest he check to see if the wheel is a recalled one. The bike isn't going anywhere until he gets it right. I heard about the ratchetin tie down trick, that ought to work.

    Rick
    #4
  5. Chopperman

    Chopperman I am dead

    Joined:
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    27,033
    My process is thus:

    Inflate some (no specific psi just some to hold the shape) bounce the tire and wheel on the floor. Rotate, bounce, repeat. then inflate to normal psi. usually the bead will seat and I use a goodly amount of lube. As a precaustion I usually deflate then re inflate.
    #5
  6. ebbo

    ebbo Been here awhile

    Joined:
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    I’ve changed quite a few tyres on an 82’ airhead with snowflake wheels. All the tyres I fitted were a very tight fit on the rim, and being rubber grip like hell and very reluctant to bed down.
    The usual solution is some form of lubrication to stop the rubber tyre sticking on the rim, I’ve used talcum powder, washing up liquid and hand cleaner as a lubricant (talc smells best) that, and around double the normal pressure and much bouncing on the floor, it’s a lot of fun!
    Note, there is normally a fine line moulded in to the tyre wall, near the bead so you can check the tyre is evenly seated.
    #6
  7. bmwmick

    bmwmick Old and Slow....Sorta

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    Rick,
    You should NEVER run a tubeless tire without a tube on BMW Snowflake cast wheels! :deal

    There! That takes care of that!

    This valve stem: http://tinyurl.com/36rvz OR
    http://patchboy.com

    works well in the Snowflake wheels. No machining needed. The inner washer 'does' need to be made a little concave to seat perfectly. This is a 45 degree angled valve stem and it makes checking/filling the tires WAY easier.

    Mick(Not that I would ever run tubeless on my Airhead) :evil
    #7
  8. Rad

    Rad Just me

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    try deflate'n the tire and lay'n the wheel on its side and run'n a bead of dish soap around the inner edge of the tire. Do this on both sides. Then reinflate and get ready for a nasty sound'n, very loud "crack" as the bead pops into place :lol3
    #8