Premature GEBE belt wear? Read this.

Discussion in 'Rack Mounted Engines' started by Roy Carpenter, Jul 12, 2008.

  1. After going through a belt every 500 miles or so, suddenly the problem even got worse. Strangely, I was not able to adjust my tracking any more. With the front of the engine visibly pointing off to the left, the belt continued to track against the inside of the drive pully, (nearest the motor). Then it hit me....Had the lower mounting strap lost it's original geometry? I removed my engine from the mount strap, (still mounted firmly to the axles), and gave the entire mountstrap a good eyeballing. Then I saw that the horizontal part of the strap, (where the engine mounts), wasn't exactly level. I must have bent the strap when my rear wheel bearings were giving me a hard time, without realizing it. The whole rear mount strap had "shifted" to the right about 1/2 - 3/4 of an inch. This caused the engine to "sag" downward, and thus threw off my tracking, and trashed my belt in a rapid fashion. After removing the lower mount strap and bending it back to it's original geometry, (just eyeballed it), my belt tracking was a cinch to adjust, that was over 300 miles ago, and hasn't needed adjusting since. I haven't seen any more belt dust, and the belt isn't showing any ravelings on the edges either! YES! I definitely fixed my problem, and if you are having premature belt wear, give the lower mount strap a good eyeballing. Remove it from the bike, stand it on it's legs on a flat table top, and look at all the angles of the bends to ensure that they are all uniform and that the horizantal top of the strap is level. Also check the vertical section of the strap to ensure that it is perfectly straight. If not, use a bench vice and get 'er straightened out. That should do it for ya...worked well for me:grin:
    Last edited by a moderator: Jul 12, 2008

  2. augidog

    augidog Banned

  3. graucho

    graucho Active Member

    Good job Roy. Thanks for the heads up.
  4. DetonatorTuning

    DetonatorTuning Active Member

    yep, agreed and amen,

    this very thing and the addition of a few others related to it was the cause of my 2 day and 5ml. original belt life.

    it can not be over stated or underestimated that the precise and totally stress free level standing of the "U" mount be achieved.

    having gone thru this and found the balance in my mounting system i now have 350 high speed miles on my belt and that it is tracking deadon with out any need of other or further tweeking, nor does it shed dust or ravel on the edges in the least. i have every reasonable expectation that this belt will last a good long time indeed.

    my GP460 is getting stronger and fast it seems daily and is TOTALLY under control and in synch with the GEBE drive system in every way.

  5. Same thing happened to my bike when that truck hit me.
    I know I don't have the same kit but this thread has a good message.
    Alignment is ALL and Look at EVERYTHING!!
  6. augidog

    augidog Banned yer baby and she'll love you back...rack-mount theory is rack-mount theory...

    a properly aligned rig is a joy to ride :cool:
  7. Yep...looks like we might be on to something here. Augi, you may want to mention this to Dennis because if this little morsel would have been included on the GEBE site in the "belt tracking" section, it would have saved me a world of hurt, and many others as well. It's just something that's awfully easy to
  8. augidog

    augidog Banned

    i understand that new & more comprehensive info is in the GEBE site's future, but as you know it may be a while before the webmaster can put down the allen-wrenches and hit the keyboard ;)

    meantime, we've got each other...our gebe collection at MBc is growing with every new topic like yours :cool:
  9. I guess that's what it's all about...he he...we're here to help. I know when I stumbled onto this forum, I didn't have a clue about these It saved me a lot of heartache/money!:)
  10. cthomatz

    cthomatz New Member

    I am in the process of putting togerther my gebe kit and have already taken it on several test drives. Some how I have missed the part on adjusting the belt traking. After reading this post I ran out to check mine. I pulled the saftey cover off and there was a lot of black dust on the inside and the belt is rubbing against the left side of the gear. Thanks for the heads up.
  11. vegaspaddy

    vegaspaddy Member

    i had the same problem when i dismantled my engine from the mount a couple of weeks ago, when i remounted it was off by 1/2 an inch or so, took it for a ride but i was lucky i heard the extra noise of the belt rubbing which hadnt been their before. Have to be so careful in reassembly.
  12. sabala

    sabala Guest

    I'm in the final stages of setting up my GEBE to ride. Today I got everything mounted up, (still haven't put in oil or gas yet) and checked the belt tracking to avoid those 50 mile belt breaking horror posts!

    Rolling the bike forward the belt tracked over to the left or away from the engine. I read the posts here mentioning proper belt tracking and on the GEBE site "how to" page.

    So I loosened the left engine mount bolt and holding the engine to the right, I rolled the bike forward and got perfect center tracking! However, after holding the "turned" engine and tightening up the bolt, the belt tracked to the left again.

    I repeated the earlier steps but this time I didn't hold the engine "turned" as I rolled the bike. It tracked perfectly center again this time.

    It seems I get perfect tracking with only the right engine mount bolted on but when I lock down that left one it throws it outta wack. I also tried raising the left side rear mount leg a bit and tightened er' back up. Still, the belt tracked left.

    My front mount strap was bolted to the left side of my seat tube so I switched it over to the right hoping that might work but no luck, still goes left.

    If anyone has any ideas, they are much appreciated! In the meantime I will continue to try and find the magic formula! I think I'd read about adding washers or spacers to the axel bolts or the gear somewhere too but haven't tried em. I admit I'm starting to feel a bit frustrated but just cause I'm SO CLOSE!!

    Oh, since I'm not sure how bad it's moving into the gear edge, would anyone advise against just getting out, riding and then checking the belt for slight wear or dust? Maybe it's not bad enough to cause damage.... Or should I keep shooting for that perfect centered track beforehand? :confused:
  13. I had to file out the mount holes in the top of the lower mount strap just a little with a rat tailed file, so that the adjustment could be made. Otherwise ya can't move that engine enough to substantially change the tracking. Afterwards tracking adjustments were a breeze. Keep an eye on the geometry of the lower mount strap to ensure that the top of the strap is parallel with the ground when the strap is standing on a flat surface. Don't overdo it with the filing out of the holes....just a little will do!;)
  14. astring

    astring Member

    this is my weekend project this weekend.
  15. JemmaUK

    JemmaUK Guest

    Oddly mine has always run straight but on the engine side of the gear.. I dont get any dust or odd noises from it (unless I forget the tensioner and it soon reminds you)

    I have a few threadbare parts on the belt, but nothing on the side I would expect problems on since that side is running tight to one side of the gear.

    I have done 730 miles (+-100 or so) and have just fitted up the all white tyres (came with good tubes as well). I have also adjusted the speedometer calibration. 26x2.125 tyres on that computer were set at 2124mm - My new ones are 2140mm (I measured) so that would throw out speeds and such substantially.

    Jemma xx
  16. I've often thought that it would be better for the belt to track to the inside...if the engine shifted any at all when torque is applied, it would cause the belt to move towards the outside, (away from engine), of the gear. Since I adjusted the geometry of the lower mount strap, it doubled my belt life. I would already be replacing a belt by now, and I haven't had a hint of slippage, and the belt looks pretty good. I did already order one though. If I were to loose another hundred think I could boast better news pertaining to belts....he he.:-|