Gebe Drive Gear help!

Discussion in 'Rack Mounted Engines' started by heathyoung, Aug 26, 2008.

  1. heathyoung

    heathyoung Member

    Hey all...

    I'm located in Australia, and have bought a Gebe knockoff, which unfortunatly has a 16 tooth drive pulley on an underpowered 31cc 4 stroke.

    The problem is, it uses a 10mm (or around that size) fine pitch threaded shaft, with a nylock nut, wherease the GEBE units look like they use a square shaft/hole.

    Does anyone have any concrete measurements of the hole construction/size of the Gebe pulleys? It would be much appreciated!

    Also - is there a difference between the standard and HTD belts/pulleys, and how do you tell what you have?

    Heath Young

  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Can you upload some detail pics of their set up?

    Give us a review of the bike?
    How long have you had it?

    I emailed that seller and it was hard to get a straight answer out of them
    They did say they had different pulley sizes like a 13 or 14 tooth which
    is what you should be using?
    16 is way too high geared for your engine or maybe any engine

    I am pretty sure the GEBE pulley has a round threaded hole

    DetonatorTuner bought some larger pulleys (15 & 16 ) and had them drilled out and tapped to fit his GEBE
    Last edited: Aug 26, 2008
  3. heathyoung

    heathyoung Member

    I'll upload some pics tomorrow.

    Its a poor knockoff of the gebe, it uses a similar wheel on the spokes, but has 10 teeth X 4 at the quadrants of the ring, rather than the teeth all around version as per their HTD version.

    There is no dynamic tensioner as per gebe, and the belt is made by SumTingWong brand in china (no not really but you get the point).

    The HTD belts and pulleys are very different, the teeth on the standard one are trapezoidal, whereas the HTD are rounded teeth.

    Interesting that they stated that they had different teeth configurations available. I might send them an email and find out what spares they have on hand.

    I got sick of not being able to fill up the tank (and having it leak grrrr...) because the engine has to be tilted to avoid the caliper brakes, so I made up a mount to spin the tank around. Works much betterer now, it had some fuel starvation issues before. Now its just stupid fast on the flat.

    I bought a dual brake lever from a local seller on ebay, its **** though. Really poor design, crappy plastics - was going to use the RHS brake lever for throttle, and LHS for brake. Now thinking of using a motorbike throttle grip.... Decisions decisions....
  4. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    This what they said to me by email

    There are 2 ebay IDs selling the kits but they are probbaly the same company

    The teeth on the spoke drive ring don't go all the way around?
    LOL that doesn't sound right
  5. heathyoung

    heathyoung Member


    Yep same company, they are in the same suburb (Marrackville, Sydney)

    Someone couldn't count, its definitly 16 teeth. I marked one with a pencil and counted them very carefully. They are an XL style timing belt.

    The kits that they are selling are a bit different to their ones shown in their fitting instructions - the dynamic tensioner has been removed (the tensioner bolt was sheared off (!!!) on mine. :confused:

    I'll send them an email, see what happens, worst comes to the worst I could bore and helicol a gebe XL if the thread is wrong.
  6. ocscully

    ocscully Member


    The GEBE drivers are 5/16th in. dia with 24tpi threading.

    There is a difference between XL and HTD tooth profiles. Here is a link to a manufacturer here in the states that specializes in Metric Timing Belt Drivetrain parts.
    They are a great company to do business with and are very knowledgeable in all things to do with metric timing belts. I've bought severl of their pulleys for my bike project. There website has alot of information available and they are a company that responds well to e-mail requests.

  7. heathyoung

    heathyoung Member

    Thanks for that information, very useful. 5/16 X 25.4 = 7.905mm = 8mm.

    Hmmm. Would have to bore and retap, not impossible, just get someone to toss one on a lathe and centre drill and tap.

    I'll see if I get a reply from the importer of the kits. 16 teeth is fun on the flat, but not so good up a hill.
  8. heathyoung

    heathyoung Member

    I checked the size with a pair of calipers, and a thread gauge, and it looks to be identical to the Gebe XL... So looks like its OK.

    Also got in contact with the seller, they stock new belts and pulleys for $30 AUD + postage, only have an 11 tooth. From a 16 tooth - should make rather a lot of difference! Hmmm... Its rapidly becoming a trailbike...

    Also made another mod after a bolt came loose and the drive belt chewed itself out against the bracket - 2 X M8 X 20mm bolts, fitted with a 5/16th locking washer, and a M8 nylock nuts at the rear - also a pair of 3/8th nylocks on the axle after I found one loose. I think I need to ride on less rough trails...
    Last edited: Aug 31, 2008