tighter tension on gebe bicycle, better traction and nothing wrong so far

[errolprowse]

like most, i have experinced the slipping with the gebe belt system when going up hills or on take offs. Once it got so bad (mainly because my drive ring was moving all over the place on the spokes) that it chewed right through a brand new belt. I also used to have the problem that the tension lever would bob up and down after a few weeks of use after "fixing" it, it just seemed to come back over and over.

soooo
i decided to ignore what gebe told me previously which was to always have the lower mount strap sitting all the way down on the axle and to have the belt wrapped around the gear to what they had told me. Instead, i lifted the whole engine till the belt was almost taught, then i tightened the axle nuts. Below there is a picture of how much i lifted it, and what the belt looks like when i was done. (I ONLY SUGGEST DOING THIS WITH .105G SPOKES!!!) and be sure to lift up both sides the same amount.

Results:
Never has ran better! no slipping on take off, i just press the throttle without peddling and i go(im only 130 pounds also...). There is practically no wear on any of the teeth of the belt at all because the fact they cant slip and grind themself on the teeth on the drive ring or the gear. i have put on almost 500 miles on since this setup(i wanted to test it to make sure it worked before i told you guys).

tell me what you think if you decide to do it

 

[augidog]

i kinda misread yer subject line, thought you were gonna say tighten down the tensioner...whew!

the stock setup is intended to accomodate the entire range of gears with a single height-setting, and it's always a good practice for a maker to recommend following original intent and design.

that said...yes, dennis had me "raise" my system a bit when i raced, but i use mounting tabs so the adjustment was easy...the straighter the run on the belt, the better for overall performance...just make sure you haven't tightened things so much that a drivering hop makes the belt TOO tight.

 

[errolprowse]

thats for sure, thats why i posted that picture to show how tight the belt should be when the tension lever is engaged.

 

[bamabikeguy]

In a few months, you'll build up road grime around that tension lever, which interferes with any bounce you might have.

After you scrape away the muck, buy a small tube of white lithium grease to lube that tension arm area.

That same grease is also good to put on the ends of throttle and brake cables, where it goes into the black outer covering up on the handlebars and down at the brake connection.

That little dab usually solves any kinky/sluggish feel the cables have.

 

[errolprowse]

sweet, ive wanted a solution for that not just for the lever but for my cables!! thanks!

 

[duivendyk]

I'm not familiar with the Gebee belt drive,I presume the tension lever is spring loaded in order to apply tension to the belt to keep it from skipping teeth and also to permit easy drive sprocket changes & accommodate a certain degree of excentricity in driven ring.In this situation it is advisable in my opinion to adjust for minimum slack (without the belt tensioner applied),just to take care of the effect of residual excentricity of the drive ring mounting,for instance by raising the engine drive.If substantial slack remains this should be corrected first.Then the tensioner can be applied.Ideally the belt should have twin tensioners, one fixed tensioner for the "static" adjustment as I mentioned before,the other for taking care of the excentricity slack modulation (on the other side)
I recently did a study for a high velocity chain drive that caused trouble for one of the members and was surprised to find out how large the centrifugal effects were on a high speed chain(or belt) going around a small sprocket.If the wheel is driving the sprocket (on deceleration) the chain or belt could actually lift off the sprocket if there was slack available in it (big trouble).A single spring loaded tensioner on the normally slack side could certainly make this possibe.So I recommended a dual system and came up with appropriate tension values.In my opinion such a dual system if applied to a belt drive would be less troublesome.Of course there is no remedy for excessive ring excenticity except taking remedial action by getting the ring properly centered.

 

[bamabikeguy]

I frame mount all my builds, so if I need to add a little more tension to it, I can slide the axle down a bit in the slot. (But I have it pretty much right where I want it when I bolt the whole thing together)....

I suggest an extra item in your road repair kit, they have a rope/pulley device in bike parts department, to hoist your bike in the air for repairs.

If you get a flat on the road, having the axle mount, unless you want to detach the entire engine before removing the wheel, hoist it in a limb or a rafter with that hoist AND have a second length of rope to hold the engine/strap up in the air also.

Then you fix the flat, reattach the wheel, and loosen that second rope to slide the mount back onto the axle.

It doesn't have to be heavy duty rope, and/or in a pinch you could string together 8-10 zip ties, in a loop, to do that engine lifting.