Friction Drive causing flats?

Discussion in 'Friction Drive' started by thevacilando, Jul 6, 2008.

  1. thevacilando

    thevacilando New Member

    Sorry if this is the wrong section for this question, but I'm not sure what to do about a persistent flat I'm getting.

    I'm running the staton friction drive on an 80's touring bike with 27inch road wheels. I've gone through three innertubes in a very short period of time and I'm wondering if the added pressure from the friction drive is the cause.

    With the first two wheels, I noticed that the tubes seemed to have marks in them from the bead of the tire, It was the original tire and the bead actually seemed to be separating from the tire at certain spots on the inside. I put a new tire and a new tube on the bike yesterday, went out for a ride today and in no time I had another flat. Looks like I might have pinholes on either side of the valve.

    The rim itself only has a thin plastic/rubber type guard around the spoke heads. Could the spoke heads be my problem? Could I fix that with electrical tape?

    Or could I be using too much pressure with the drive system? Pushing it into the tire too far? Or are the tires improper? Would it be better to have this system on a mtb with lower pressure tires?

    Basically, I feel like this has been caused by something I'm doing with the friction drive, because I wasn't getting flats like this by riding the bike alone.

  2. kerf

    kerf Guest

    Make sure that a spoke end is not protruding through the nipple. You might want to get a high quality fabric rim tape from a bike shop.
  3. motman812

    motman812 Member

    I had a problem with some Kenda thorn resistant tubes I bought at a local bike store that failed at the seams (that run across the tire), apparently from being flexed backward (from the depression made from the friction drive). Maybe it was a bad lot of tubes. I bought another brand at another bike store, filled it with Slime and haven't had a problem since. (I run Tuffies on the outside of the tube and the rubber rim liner that came with the bike (1981 Schwinn Cruiser 5) on the inside.
  4. uncle_punk13

    uncle_punk13 Guest

    I had this problem as well with one of my friiction kits. I found that the softer tire I was using, combined with the friction roller was causing problems. A harder tire compound, less drive roller pressure, Mr. Tuffies tire liners, and extra thick thorn resistant tubes helped immmensly...
  5. Mountainman

    Mountainman Active Member

    Doesn't take (I have noticed on my MB) very much pressure down on the drive unit - to have no slippage - I figure the less the better as long as there is no slipping.. Spokes (if coming through) need to be filed down smooth.. Maybe a thicker better grade tire and tube ? Happy Riding from - Mountainman
  6. Esteban

    Esteban Active Member

    One thing that may seem stupid to ask,,, but you aren't using screwdrivers to get your tire back on the rim, are you ? That will usually leave what I call, " Snakebites !" Two small holes less than an inch apart.
  7. thevacilando

    thevacilando New Member

    Tire levers and fingers. Thanks for the suggestions, everyone.
  8. Dankoozy

    Dankoozy Member

    Twice now ive had a puncture that is more like a tear across the width of the tube. No sign of any thorn in the tyre so I wonder is the FD roller eating them up as it's on the side that would be going against the roller. After repairing the puncture the roller slips for a bit each time it goes over the patched area since I couldn't patch it while it was pumped the tear being the size it was. These were Commie Land's finest bargain basement tubes so that might have something to do with it. If the patch on this one stays good I might hold on to it for use in the front tyre
  9. rawly old

    rawly old Member

    A 27" tire isn't very meaty when it come to friction drive. How much power are we
    talking about here? Going WOT with a lotta torque will likely drag the tire across the
    tube surface pinching it. Braking hard might do the same.
  10. coln72

    coln72 New Member

    Just a quick question, what tyre pressures are you running? Tried pumping the up a bit harder? The reason I ask this is that I run a trike assisted by a 50cc Honda using a self designed/built friction drive. Competed in this in a 24 hour race and never touched the rear wheel. Tyre still showed tread after close to 800km. Guess running a 20" rear wheel with a BMX type tyre helps.
  11. SunkyWorks

    SunkyWorks Member

    This is the biggest tire I have found:
    Kenda K40 Street Tire, 27 x 1-3/8 Wire Gum Wall
    Good reviews on Amazon.
    $7.50 at Niagara Cycle.
  12. rawly old

    rawly old Member

    Mtn. Man said it, and I agree. You don't need to press the roller very far into the
    tire to get grip. But... the narrower your tire, the less surface there is to contact.
    This means you'll likely be needing more pressure to get the same grip you'd have
    with a wider tire. A road tire/tube simply isn't designed for that much stress.
    Even running 1.95"s, I over stressed my tire recently when I went to a more powerful
    engine and compressed the roller a bit too far. The new engine had so much torque
    it popped the axle right out of the dropouts delaminating the tread in the process.
    Lesson learned: Don't use too much down force & don't gun a friction drive if you're
    runnin' a badass 2stroke.
  13. Mountainman

    Mountainman Active Member

    possibly some or all of the above
    I have been riding a Station friction drive for over 6 years now
    only had a few flats and changed a couple of tires
    I think the key to long tire life is
    the adjustment of roller to tire (light as possible but with no slippage)

    for the rim strap -- elect tape works fine -- couple of wraps
    make sure no spokes are poking through -- if so file

  14. rawly old

    rawly old Member

    Pedaling off to 7 or 8 mph before opening the throttle will save your tire
    and your clutch. Don't open the throttle too quickly.
  15. seanshonda

    seanshonda New Member

    I have a 2.1 tire, was using slime super thick tubes sized 1.75-2.1, tubes wouldn't last 30 mi. switched to a panaracer DH super tube size 2.1-2.5, problem solved.
    I think by the time the slime tubes were stretched to 2.1, they were thin, most holes were on the mold seems from manufacture.
  16. darwin

    darwin Well-Known Member

    It helps to have a Kevlar tire, thorn resistant tube and tire liner. Makes for a really solid surface and helps with no flats. Running the tire at near max tire pressure helps too. Pedaling like was stated above helps to keep the roller from spinning on a stationary tire, burned up one tire that way by not starting out pedaling. You'll learn real quick that way.
  17. rawly old

    rawly old Member

    You're probably right, Sean, about the thin tube. I had a similar issue with
    one of my pedal bikes. The tire I've really come to appreciate is a kenda
    k-841 semislick. I have a concave roller for tires with a curved profile,
    but for my flat roller the 841's straight profile works great. It's forgiving
    if i accidentally spin the roller and doesn't get chewed up like another
    tire might. A thick, thorn resistant tube is always a good idea.
  18. rawly old

    rawly old Member

    I need to post a correction to the above; k-841 is incorrect. It
    should read K-847 semislick. 700 x 40 841s are what I have on my
    touring road bike. 841s are economical general use tire if you want
    something on a road bike that can also be used on trails.