My friction build (attempted)

Discussion in 'Friction Drive' started by globalenigma, Mar 23, 2009.

  1. globalenigma

    globalenigma New Member

    Here is my attempt at a friction drive system. I know there are a few problems but I am trying to work those out. If you can see any room for improvement let me know ( i know there is plenty). Well here are my pics.

    Attached Files:

    Last edited by a moderator: Mar 23, 2009

  2. srdavo

    srdavo Active Member

    the small diameter friction roller ought to have good low-end torque.

    what brand of engine?
    how many cc's?
    Is there a gearbox attached to the engine?

    is there some sort of bearing, on the outer side of the friction roller?

    I dig friction drives....tell me more!!
  3. globalenigma

    globalenigma New Member

    A little revision

    I made some modifications. The roller was just slipping too much. The roller still needs some mods but this is much better now. Also not shown in the pics I added a bungee cord to hold it down on the tire a little. I think it works much better. I am looking into putting a disengagement system and some permanent springs on the read to hold down the roller when engaged.

    Attached Files:

    Last edited by a moderator: Mar 23, 2009
  4. 5-7HEAVEN

    5-7HEAVEN Guest

    Good job, globalenigma...

    However, the engine should be mounted on the other part of the frame that swings with the tire.

    What diameter is the friction roller?

    You get better results with a street tire.
    Last edited by a moderator: Mar 23, 2009
  5. globalenigma

    globalenigma New Member

    Questions Answered


    WeedEater --> FeatherLite LE
    Size --> 33cc :( (hey it was picked up down the road, neighbors were throwing it out.)
    Yes there is a bearing on the right side.
    No gearbox... yet

    When tested it got me to 17mph at about half throttle. Only problem is after half throttle it just spins freely even with the new bungee

    I feel like I cant get all the power to the wheel.
  6. globalenigma

    globalenigma New Member

    Thanks for the support and advice but I can not understand what you mean about mount the motor on the frame that moves with the tire? (Both the right and the left sides move up and down together... please explain more)

    So a street tire will help me out? I need to look into that.. Thanks for the heads up
  7. 5-7HEAVEN

    5-7HEAVEN Guest

    You need to lock down the roller to the tire.

    Some do it with springs or bungee cords.

    Staton does it by locking the engine assembly to the rear axle, via long support struts.

    I did mine with a lever to lock the assembly firmly onto the tire.

    NOTHING will work well until you mount the engine assembly onto the bike's swingarm.

    If you don't, the wheel's movement will break the roller or its attachments.

    This is a dual-suspension bike. The rear suspension moves independently of the main frame.

    If you were to disconnect the rear suspension strut, you will see how the engine will not be in contact with the tire at all times.
    Last edited by a moderator: Mar 23, 2009
  8. Nuttsy

    Nuttsy Member

    I would agree on the tire. Although, your center tread where the roller contacts seems semi-tame.
    The trick with friction drive is the tension between the roller and the tire. Bungy seems too light to me. Either find a way to LOCK the roller down mechanically (nuts and bolts) or heavy springs.
    The roller seems a little on the small side. But, I don't know your terrain or the weight you're pushing. It may be right for you. Some more GRIP on the roller would help too. On homebuilts, some here advocate a JB Weld and sand recipe to help the roller grip better and stop the slip.
    Hang in there and search the forum...lots of answers here.
    You're off to a great start!
  9. globalenigma

    globalenigma New Member

    Allright 5-7 HEAVEN, I understand you now. That is something I will have to fix... Things are starting to make sense now. That is one reason I did not weld to the bike frame yet, I wanted to make sure I could remove it at any time (for movement to another bike) or to just remove it an mod it like you are saying. That will have to come soon, I don't have time during the week to work on that. I am glad i posted now.
  10. 5-7HEAVEN

    5-7HEAVEN Guest

    You can do it.

    You are so close.:grin5:
  11. fetor56

    fetor56 Guest

    I'm putting together a friction drive at the mo with a Honda 35 engine & this kit,on a dual-suspension Giant MTB.See if u can get any ideas from their website(FAQ's etc)
    If necessary order parts,their good ppl to deal with.The correct tyre pattern is pretty important.
  12. globalenigma

    globalenigma New Member

    Made some changes

    Ok, First of all I would like to thank everyone for their input. It was definitely helpful and I took it all into consideration. I am glad I did. The set up I have now works better in my opinion. But guess what... I can see that there will need to be more mods in the future. The thing I am most happy about is now my gas tank is mounted upright. I can use it to its full potential. Before when it was on its bottom it had air in the tank. There was no way to fill it completely due to its shape. Now I can also carry my 20 oz bottle around with me and fill it on long rides. Never know when I will need back up fuel. Also it makes it easier to fill any time... Well im taking notes so blast away at my new design.

    Attached Files:

  13. fetor56

    fetor56 Guest

    Did u make that concave drive roller it rubber?
  14. 5-7HEAVEN

    5-7HEAVEN Guest

    1. Attach a spring-loaded lever to your engine pivot. Its default position will have the engine off the tire. Pulling up on the lever presses the roller securely onto the tire.

    Similar to a hand brake/parking brake.

    2. Change to a road tire.
  15. globalenigma

    globalenigma New Member


    Yes I made that myself. I got the idea from the forum, It is made using a hole saw and a hockey puck. I drilled two out of the puck then drilled the center holes. The center is a steel rod and i put threads on with a die. I put a washer then both cutouts and a final washer with a nut to get it squished. I then used grinder while i spun the rod to get the concave.

    1. Will try to rig that up soon... I like the idea

    2. Advice noted. Will implement when this tire wears.
    Last edited: Mar 29, 2009