Chain "Rubs" Motor Mount

FrizzleFried

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OK.... first off... SUCCESS! I managed to actually get the drive chain to run direct without a tensioner. Unfortunately, it's come at the cost of my rear disc brakes (for now). The mount I have simply will not work except for the last 1/2" of the drop out (rear)... and right now, this brand new non-stretched chain has my axle at the front of the drop out. I am going to have to either retrofit this one (unlikely looking at it) or I'm going to have to pick me up a BikeBerry version and see if I can get that one to work... but for now, I'm not going to stress on it because during early break-in (the first couple tanks) I'm not planning on going much faster than 25mph anyway...

But on to my current problem. Going direct without a tensioner, the bottom portion of the chain runs right across the area where the rear motor mount is. This is bad as it's hitting the end of the mount as it goes by... pretty badly. I'm assuming the "fix" for this issue is to bust out the ole dremel and shave down the mount/bolt a little bit ... or at least smooth it out some... but I figured I'd ask here ... JUST IN CASE I am missing something.

:)

I did a cursory google search and actually came up empty handed ... oddly.
 

DAMIEN1307

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A picture, or in this case pictures are worth a thousand words...always use pics since that is helpful to see just what you are seeing...lol.
 

FrizzleFried

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Here you go.

I know this can't be a unique issue as my other bike has the same problem... slightly. Because I use a tensioner on it, the chain runs ABOVE the mount slightly so there is only cursory banging going on there... not like this where it continually rubs.

I figured I could take off about 1/32from the flange... and maybe make sure the nuts are sitting "flat".

It appears this particular stud OR the actual drilling is slightly tweaked outward... which isn't helping either.

FWIW - This shot is with the bike upside down... you're seeing the BOTTOM.


PHAN_BACKMOUNT1.jpg
 

Chainlube

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A spacer between the sprocket and hub. Or, like you said "grinder".
 

FrizzleFried

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No option for the spacer... there is no more room with the disc back there.

...so yeah, I'm left with the "grinder" option" I suspect. I'm guessing I'll get some clanking from the area for ever however ... even with it cleaned up a bit.

:(

>sigh<
 

DAMIEN1307

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Here you go.
Its a simple situation of just repositioning the motor just ever so slightly so the chain can still run true but will also clear the motor mount.

I found with my Hyper, it was actually more "all important" to get the front mount fitted in properly first while being sure you know exactly where the rear mount is being mounted and accounting for the clearance.

This was another reason why I made my own front mount as well as recommending the CNC front mount for those who can't make their own.
It's also the reason my motor is installed higher than most people mount there motors...I avoided all the clearance problems people have...Not by much, but just enough...lol.
 

FrizzleFried

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Rear mount is pretty solidly/firmly centered. I see no way to adjust that end. That said, I might be able to adjust the front mount slightly... but that's not really going to do much I suspect (but I'll give it a go). That said... I suspect my dremel grinder bits are going to get a little love today.
 

Chainlube

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No option for the spacer... there is no more room with the disc back there.

...so yeah, I'm left with the "grinder" option" I suspect. I'm guessing I'll get some clanking from the area for ever however ... even with it cleaned up a bit.

:(

>sigh<
The chain hitting the mount won't last long, you might as well go buy a 100' roll of chain and a box of masters, because it will break often.

I've done that on a few bikes, "Oh it's just ticking off the frame, should be fine", not! That was just the frame that wore the rivet off.
 
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