How do I test if gears/motor slipping? I have no torque

[Stumper]

My original post was here when I thought my problem was about batteries. Now I think it's about motor/gear/clutch slippage:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=30009

Problem: No Torque

Ebay purchase: the bike has only done a couple turns around the block by the previous owner, 6 months old, no warranty. I suspect it has never worked correctly. Previous owner said he didn't gun it because he was cautious about running it in (as per eLation instructions). He may not have got to the point of it slipping.

Qn: HOW DO I TEST IF THE MOTOR/GEAR?CLUTCH IS SLIPPING?[/b]

Kit: eLation V3, 200w

When I put the motor under throttle the rear wheel turns (via chain drive) and the motor makes a certain noise. When I forcibly stop the rear wheel (not requiring much force) while the throttle is still on the noise of the motor stays exactly the same- which I'm presuming means it is doing the same thing - ie still turning. From this I'm assuming there is a slippage on one of the shafts (gear, motor, clutch).

The motor has a gear casing on it (see photo below). I took off the gear casing and clamped the primary gear (with some soft wood). I cautiously applied throttle and felt the force on the clamp until a heard a sort of click noise and the power went off. A little bit worried at this point - perhaps overload trip? I took the clamp off and tested the motor. It worked as previously. THIS MIGHT SUGGEST THE PRIMARY GEAR IS OKAY because the gear did not slip on the shaft??? But it was a pretty tentative test and I'm not sure if I sure do it again

The gear box goes from the primary gear into a another, then another with a sprag clutch/freewheel, then through the casing to the external sprocket (which has a chain on it and connects via the chain ring set). Perhaps then it is the sprag clutch failing (as had been suggested in the other thread linked above).

Qn: HOW WOULD I CHECK THE SPRAG CLUTCH/FREEWHEEL FOR FAILURE?

Cheers
Stumped

 

[evp001a]

When I first received the motor, the problem I had according to the person from eLation was the clutch wasnt engaging completely. The motor would propel the bicycle to around 10Km/h then the motor would continue to increase in revs, but did not propel the bicycle any faster. They repaired it. Now again after some use the problem has reoccured, although the clutch seems to be somewhat engaged as it is able to propel the bicycle forward at about 20Km/h before it slips. This time when it slips it makes a clicking noise. I'm returning the motor to eLation again and will tell you the result. Not sure why you would need a clutch on an electric motor. Try forcing it to stay engaged, or replace it with a gear cog. There are other gear heads for motors available, but they're hard to find. If you want the eLation kit to work, pay for it to get fixed/replaced. If you want a cheaper alternative check out the ebay 200w kit available from edeals electric bikes (the supplied mounting kit is poor). I also have a 200w hub motor in a 20" wheel on a trike it has a top speed of 25Km/h and it has nearly as much hill climb torque has the chain drive system on a 26" wheel with 6 gears, hub motors are much easier to install too.

 

[evp001a]

I received my repaired motor back from eLation and the clutch had failed (for the second time), they replaced it with a more robust one. I'll bet thats the problem with yours too. Whilst wearing in the new clutch and gearset the clutch jammed on, meaning that when you turned the pedals with out motor assist, you had to also turn the motor over, like peddling up hill. Anyway more parts are on their way, let you know if I ever get the eLation working again.

As for testing direct to the output of the motor, there won't be much torque as the motor will spin at around 2500rpm, it is the gearbox 10:1 ratio that slows it down to 250rpm and gives it torque, I've tried direct drive 200w motors in the past and they suck. A good engineer may be able to make you a cog to replace the clutch using a lathe or laser cutter or similar. Germans make very good gearboxes for electric motors, you'll need more $$$.

The cheaper ebay kits (copy of cyclone kit) are a cost effective alternative but are a pain to fit, I welded a mount to the frame.

Hub motors are too easy to fit, just use brute force to climb hills and ride an illegal 750w motor. The Avanti Electra is a very cool hub motor but is too expensive. The ultimate kit would be a hub motor coupled to a hub gearbox like the sturmi-archer or the nuvinci. I've only ever heard of these being made for motor bikes though. If you're keen look at the 200w fischer and paykel brushless washing machine motor and find a way to use it with a constantly variable transmission.

Brett White is from Island Earth is a good source of information if you can find him.

Nothing about electric bikes is cheap. If you build it on the cheap it will suck unless you're some sort of engineering wizard and build your own parts.

 

[evp001a]

After returning the motor three times for repair the clutch still fails to disengage, meaning you have to turn the gearbox and motor over when you pedal if the motor is not running. It is like peddling up hill. Elation gearbox is crap quality, problem is with the design of the system and cannot be fixed without a different gearbox. Elation = fail.

 

[amberwolf]

Well, Elation is out of business now, so no one else will have to worry about it. I wish I had an easy fix for the problem you still have, but I don't.

There are some people here on ES that are working on "support" threads for Elation stuff of various versions; you might look at those and see what comparable spare parts they have been able to find from other sources.

 

[Stumper]

After returning the motor three times for repair the clutch still fails to disengage, meaning you have to turn the gearbox and motor over when you pedal if the motor is not running. It is like peddling up hill. Elation gearbox is crap quality, problem is with the design of the system and cannot be fixed without a different gearbox. Elation = fail.

Well after buying my elation kit off ebay in June I finally got it going for one half reasonable day. I discovered a bearing was as if seized, on I think, the secondary gear. I got the bearing of, used emery paper to sand down the shaft, put it all back together. First day on the bike there was a slight improvement. Second day I got up my driveway in 3rd gear (24 spd Mtn Bike), normally struggle to get up it in 1st gear (400m long, steep). So the motor had really improved. But 3 days later and it's absolutely crap again. It must be the clutch.

The bike could not get itself up the driveway in 1st gear when I was walking beside it, yet the motor was spinning seemingly at full revs. so it must be a clutch issue right?

The reason they have the clutch is so that you don't have to drive the motor when you ride. It's a free wheeling one direction clutch. I've had mine apart completely and just can't see what's wrong with it. It's a very basic design. how can it fail? It's a sprague clutch - funny shaped - not quite - ball bearings, held by a fine wire spring, around a shaft, inside a bearing race.

Oh dear. What to replace it with? How to fix it? What to do, what to do?

 

[neptronix]

That kit seems to be a dead end, going off posts i have read.. just my 2 cents.

 

[Stumper]

I solved the problem. It was the sprag clutch in the gearbox - it never worked from day one. I outline the solution in this thread:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=36905