HELP I AM AT MY WITS END!

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Ham549   10 W

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HELP I AM AT MY WITS END!

Post by Ham549 » Apr 14 2012 1:07pm

I have a former Lashout bike. I say former because it has been heavily upgraded with a 1,000 watt motor and a 48v system. Now the Lashouts motor mounting plate is designed to be adjustable so you can adjust the tension on the chain that goes from the motor to the rear wheel. This is done by having the bolt hole elongated so you can move it around and then tighten the bolt to hold it in place. However with the torque of the motor being so high no matter how much I tighten this bolt the motor will move the plate causing a lose chain that will then pick the gear. I will get a load clunking sound and the bike will jolt slightly until the chain catches. At first I solved this problem by puring solder into the gap in the bolt hole to keep it from sliding. This worked until I had to replace the drive train. I reapplied solder but the problem has come back, now I am trying to figure out why. Is it because the solder I used this time was lead free and has more ductility than lead based solder, is the gear on the rear wheel worn to the point where the chain has a hard time latching on, is it a combination of these elements?
Image
Here you can see the lower bolt and the elongated mounting hole. Note the solder below the bolt filling up the extra space to hold the bolt in place and keep it from sliding down from the motors torque.
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The gear on the rear wheel that attaches to the motor drive train through a chain.
Image
My brand new broken chain (even when my old chain skipped it never broke).

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NeilP   10 GW

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Re: HELP I AM AT MY WITS END!

Post by NeilP » Apr 14 2012 1:17pm

Well that drive sprocket is totally knackered. The teethe are so worn, no wonder the chain skips. Even fully tensioned it would not take much to make the chain slip overt that
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Re: HELP I AM AT MY WITS END!

Post by kfong » Apr 14 2012 1:23pm

That sproket wheel looks pretty worn to me. That also tells me your chain is probably stretched out as well. Not an ideal setup either, I would want to use bike size chains and sprockets in this application. The chain adjustment is poorly done and not designed for the extra torque, lead solder is too soft. File out a peice of steel, that might get you going for a while till you replace it with a better setup.

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Drunkskunk   100 GW

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Re: HELP I AM AT MY WITS END!

Post by Drunkskunk » Apr 14 2012 2:06pm

Yep, that sprocket is dead. The teeth are so worn it looks like a saw blade in the pic.

And likely the front sprocket is just as dead. Replace both and the chain.


Also, that tensioner sucks. I'd ignore it's exsistance and get something like a Surly Chain tensioner. they work by putting pressure on the chain to take out the slack on the return side, so they aren't affected by torque.
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Re: HELP I AM AT MY WITS END!

Post by Tench » Apr 14 2012 2:44pm

With no driving face left on the spocket and the chain worn out of pitch any attempt to transmit power by that chain is going to result in it trying to ride over the few "teeth" :shock: it is engaged with, you will then have chain rollers sat on top of teeth because the pitch of the worn chain does not match the sprocket and the tension on the chain caused by this will force the wheel forward against the adjusters or snap the chain, a similar situation would occur if you put a screw driver between the chain and sprocket and tried to turn the wheel. You wont solve any problems with the tensioners untill you replace both sprockets and the chain. Your problem is not related to the power of the motor or the tensioner being inadequate but worn components.
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Ham549   10 W

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Re: HELP I AM AT MY WITS END!

Post by Ham549 » Apr 14 2012 10:40pm

Drunkskunk wrote:Yep, that sprocket is dead. The teeth are so worn it looks like a saw blade in the pic.
And likely the front sprocket is just as dead. Replace both and the chain.

Also, that tensioner sucks. I'd ignore it's exsistance and get something like a Surly Chain tensioner. they work by putting pressure on the chain to take out the slack on the return side, so they aren't affected by torque.
The other sprocket as well as the chain are brand new, also I don't see where I would put a tensioner.


Image
Here is a closer look at the gear with the chain on it for comparison.
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Here is the motor and drive train where the chain was driven from
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A better view
Image
Another problem I am having is when I lost the screw that went into the hole circled in green to hold the loop circled in red some helpful people put in a wood screw to help temporarily hold it in..... It was meant for a machine screw does anyone know how to fix the threads without fancy equipment?

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ddk   1 MW

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Re: HELP I AM AT MY WITS END!

Post by ddk » Apr 14 2012 10:55pm

if, by "fancy equipment" you mean a drill bit and a tap then, no I can't help you.

Do you know what a locknut or a lockwasher is?... juss askn'

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John in CR   100 GW

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Re: HELP I AM AT MY WITS END!

Post by John in CR » Apr 15 2012 2:42am

ddk wrote:if, by "fancy equipment" you mean a drill bit and a tap then, no I can't help you.

Do you know what a locknut or a lockwasher is?... juss askn'

:lol:
LOL! Damn, we just got upgraded to fancy, since we even have that stuff for cheap all the way down here. :lol:

Ham549,
Have you checked out your gearbox. I'd bet by now that thing is worn out. Maybe those gears have enough play that it got in a bind and popped the chain. My advice is to stop sinking good money into that thing and get yourself a good direct drive brushless hubbie and forget the chain and gear issues, so your only maintenance is changing 2 bearing every few years. What kind of hills do you have to deal with?

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Re: HELP I AM AT MY WITS END!

Post by d8veh » Apr 15 2012 6:52am

You need a jack-bolt of some sort to hold the adjustment. These examples here are for adjusting the rear axle on a motorcycle, but the principle is the same. You can make your own one by heating up a bolt head to red hot and then smashing it with a hammer until it's flat and thin; then drill a hole for your bolt. You'll probably have to weld on an "L" bracket to jack against.
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You can see how it should work in the picture here:
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friedwires   100 W

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Re: HELP I AM AT MY WITS END!

Post by friedwires » Apr 15 2012 6:56am

dont give up on it. the lashout bikes are a great setup. http://www.evdeals.com/LashoutParts.htm

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Re: HELP I AM AT MY WITS END!

Post by Harold in CR » Apr 15 2012 7:19am

If you get a REAL close measurement of the screw hole, there are "self tapping" screws made. They are used in sheetmetal, but, you already have a threaded hole, somewhat. The screws have a place on the end that looks ground out, and the end is tapered a little. They have a HEX head, so you need to use a wrench. Get several. 1 won't do, and, you don't want to break it off in the hole.

Go slow, use oil to help lube the screw(s), as you clean up the threads.

That is what I would try, BUT, you are going to spend coin on sprockets-chain- and maybe the gearbox IS stuffed.

I agree with JohnCR, go hubbie. They are cost effective and non-maintenance. As the man asked, "got hills " ???
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