How do you Improve the Grip of a Drive Roller?

Discussion in 'Friction Drive' started by Fender100, Aug 31, 2009.

  1. Fender100

    Fender100 New Member

    I have a good 43cc Kawasaki Bike Motor Parts friction drive unit.

    It's great but you can feel the drive roller slip all the time. I soldered some blobs on the roller...and they all came off the first time I used it that way!

    Can anyone suggest what I can do to the metal drive roller to improve the grip? Does it take a particular type of solder to do the trick?


  2. SirJakesus

    SirJakesus Guest

    Several MBc members have welded rough beads onto their rollers to recondition them or used JB weld mixed with coarse like sand or broken grinding wheel. Solder will not stick to the steel under that kind of stress.
  3. fetor56

    fetor56 Guest

    BMP's drive rollers are fine,probably not as good as Statons for strength but never-the-less more than adequate for the job.Are u sure u have the correct tyre type & the roller is tensioned correctly to said tyre.Also your in England where it's wetter than most places....has that got something to do with your slippage.
    Sorry about stating the obvious but i don't know how much u know. :grin5:
  4. Fender100

    Fender100 New Member

    I have used it in the wet and dry. Wet, it slips like mad. In the dry, it slips at higher revs and generally so I am losing a lot of drive.

    I use a slick tyre.

  5. fetor56

    fetor56 Guest

    Sounds like your doing everything right.
    If the using the standard drive roller(with freewheel) & your thinking about soldering/brazing/welding anything to it be careful....freewheels & heat don't mix.
    What size roller are u using BTW & how far has it done?
    The Staton rollers are hardened steel where-as BMP's are mild....if your concidering using one you'll need to remove the inner surface coating for it to fit BMP's drive shaft(5-7HEAVEN knows much more about it than me)
    Out of sheer curiosity i'de try the JB weld/sand combination.....coarse sand.
    It doesn't necessarily have to be JB weld either....any REALLY strong acrylic resin glue/filler should do.
  6. loquin

    loquin Active Member

    I normally have the roller pressing 'into' the tire about a quarter inch, or a bit less. I use a fairly smooth tire, 26 x 2.125, inflated to about 50 psi.

    What tire size/type are you using, inflated to what pressure?
  7. Fender100

    Fender100 New Member

    I am using a 26 inch slick tyre at about 50 psi also.
  8. 5-7HEAVEN

    5-7HEAVEN Guest

    You could press the roller deeper into the tire.

    After setting adjustments you could lock the pivot points at the front of the engine housing.

    What I've also done is to replace the quick-release rear support lock with my own devices. Both struts lock independently so if one slips the other is still locked in.

    You could also replace the BMP rollers with more aggressive Staton spindles. This would involve removing the entire roller assembly which is clutch bell, spacers, driveshaft, bearings, collars, etc. The Staton assembly slips into place. The only thing you need to do is fabricate a bearing retainer on the outboard side. This is to prevent the bearing from falling out at 35mph, which is what happened to me.:ack2:

    The bearing will fall out only if you change the fit onto the friction roller from pressfit to slipfit. I did this to make it easier to remove and reinstall the roller and bearings.

    Good luck.
  9. Esteban

    Esteban Active Member

    Always use the throttle in a smooth & slow manner. Revving, quick bursts of speed, revving while stopped, will just lead to problems. Also, casually use the pedals to assist the motor, when starting off & when going uphills. Riding a friction drive this way will lead to a much better ride & is easier on all parts, including the tires.
  10. jjstanza

    jjstanza New Member

    I know this is an older thread but on my drive wheel for my weed whacker friction drive bike I jb weld a piece of #36 grit sanding belt (available @ home cheapo etal) all around the drive wheel (cut to fit diameter). Zip tie the piece of belt on the drive until it hardens, then cut the zip ties off and go. Works great even when wet. I tried the jb weld and sand trick first but I couldn't get it even enough to keep the vibrations down. I get about 300 or so miles out of a tire with this set up. With a real high quality tire I may get more miles.
  11. Esteban

    Esteban Active Member

    Another way is to go to a hardware store & get one of the small grinding wheels that have a 1/4" shank to fit your drill. Wrap it in a towel & beat with a hammer. Take the fine grit & mix it in with " J.B. Weld ' & smear a coat , as evenly as possible, on the steel drive roller. Grips the tire better, but can be rougher on the tire.
  12. cpuaid

    cpuaid Member

    has anyone tried smashing one of those larger grinding wheels, i think they're like a 5" or 6"? they're pretty cheap at harbor freight, about $4. i would think it's more cost effective that way if it can be broken down without using too much effort.
  13. jjstanza

    jjstanza New Member

    With the sanding belt you still get an abrasive just like with the grinding wheels or sand but you also get a consistently even surface which helps cut down on vibrations. One would be very hard pressed to get their grit/glue to be even close to the sanding belt's even surface.
  14. cpuaid

    cpuaid Member

    jjstanza, like you said, applying the JB Weld and grinding dust might give me excessive vibrations. I really like the sanding belt idea. what's the backing material and type of abrasive of that sanding belt that you used? how many miles until you have to reattach a new sanding belt roller? i put in 100 miles a week so if the 35 grit sanding belt frays prematurely or the tire gets chewed up where i have to replace it monthly then it wouldn't be that cost effective for me. maybe if a less abrasive sanding belt is used, tire longevity will be extended. i just bought an old island Hopper Viper rack mount kit with a completely smooth roller and really need something to give me some traction for that thing.
  15. jjstanza

    jjstanza New Member

    The backing material of the sand belt appears to be some sort of fabric material. I don't know exactly what the grit is made of. I have my engine pretty loose on the wheel because i am running a weed whacker with just one bearing. (trying to extend engine life) If you put more pressure on the wheel I don't think it would wear the tire near as much. I have only "tossed" the belt once when I used JB Quick instead of the longer curing JB weld. About 500 miles total on the sanding belt drive wheel and no apparent wear on the sanding belt.

    I had a friend use 120 grit on his drive wheel but it really sanded the tire down in less than a week, about 80 miles.

    I think 36 grit looks to be close to what I remember as the grit on the old Solex drive wheels.
  16. cpuaid

    cpuaid Member

    sounds like a winner to me. I can live with 500 miles on a belt. just read the specs on the viper kit and it uses a solid aluminum 1.50" drive roller. All of the rollers used on my other kits are hardened steel. now am kind of nervous about applying epoxy to that thing. i think it will vibrate regardless of what is applied to it. no telling what grade aluminum was used so am really afraid of snapping the threaded part which screws into the clutch drum. if that happens it doesn't look like they offer a replacement roller. it comes with a 2 HP / 49 cc 2-stroke tecumseh rated at "speeds in excess to 30 MPH" with the stock setup. if anyone has thoughts or comments on applying JB Weld on this setup, please let me know.
    Last edited: Oct 19, 2009
  17. Happy Valley

    Happy Valley Active Member

    Here's a thought:

    I've used epoxy and new aquarium sand. Mix the epoxy well then add the sand and mix that together. This insures the aggregate is represented throughout the mix and wears evenly. Place the epoxy/sand mix into a tray not much wider than the roller and make just one smooth rolling pass through the mix for an evenly distributed coat.
    It's then important to slowly rotate the freshly applied roller for a curing period, usually about one hour, to prevent the epoxy mix from sag or slump. (I make fishing rods and have a rod turner that is made for this job but it can be done by hand-1/4 turn every 60 seconds)

    Results are nice and smooth.
  18. cpuaid

    cpuaid Member

    happy valley, have you ever applied on an aluminum roller? as i've stated earlier, really worried about excessive vibrations on an aluminum roller. i have a picture of one of my steel rollers breaking off where it's threaded into the clutch drum and don't want the same problem on this aluminum one.
  19. fetor56

    fetor56 Guest

    Handy to know. :cool:
  20. loquin

    loquin Active Member

    per Happy Valley...
    • The new aquarium sand is screened so that it is uniform in size.
    • Mixing the sand and epoxy well ensures that the sane is uniformly distributed and wears evenly
    • The single coat ensures that it is evenly distributed
    • The rotation during curing ensures that the single coat STAYS distributed until the epoxy cures.
    The one note that I would add here is that IF you have a smooth metal roller, you would want to sand it thoroughly first, probably with 80-100 grit sandpaper, or thereabouts, to rough up the surface, just to make sure you get maximum epoxy adhesion.

    As far as your excessive vibrations question - the main cause of excessive vibration isn't the roller - it's the TIRE. Knobby tires will vibrate like crazy - a slick tire is best. Plus, a slick tire gets you the best traction on asphalt, under all conditions except (possibly) snow.

    Is the Island Hopper Viper drive roller supported on both ends, or on just one? If it's only supported on one side, I'm not that surprised if the roller broke where it threads into the clutch bell.

    And, a smooth distribution of epoxy/sand should HELP the life of your roller, as aluminum is pretty soft, and it would wear rapidly...
    Last edited: Oct 20, 2009