Manic hub question..

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Beej

New Member
Jun 7, 2010
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San Diego, CA
So I built my first bike and am about a half tank through it. I used the manic mechanic hub adapter on the bike. When I roll the bike the chain goes from a nice 1/2" of play each side to about an inch of play each side as the wheel rolls. I take it that something is out of alignment. With the manic hub what should I check? Could it be the motor gear? Where do I start? To the eye it looks to be nice and straight.
 

NunyaBidness

Active Member
Jun 29, 2008
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memphis tn
If it was the traditional 'rag joint' I'd say it wasn't centered good on the hub. Since it's manic mechanic hub adapter, I dunno.
 

Beej

New Member
Jun 7, 2010
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San Diego, CA
That is where I am stumped. I went this route so I didn't have to deal with the rag joint. Hopefully Jim and he other pros will chime in.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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Well, lets think about this... spin the wheel without the chain & look at what the sprocket is doing. Maybe the adapter is installed wrong? maybe the hub is bent?? There has to be a simple reason that can be found!! ;)
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
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living the dream in southern california
make sure the adapter is tightened down evenly. look at the gaps between the two pieces and make sure they're the same amount.

there can be play in the sprocket holes, however slight, and it'll make a big difference on the chain.

as an example, almost every bicycle has a tight spot and a loose spot in the pedal chain. as you only pedal hard going forward, the hole (or holes) on the sprocket will deform from the torque. in serious cases on one piece cranks, the sprocket will click back and forth because the hole enlarged.

first, check the gaps like i typed above. make sure the sprocket doesn't wobble side to side at all. the adapter could be very slightly crooked, or the sprocket could be warped or tightened unevenly. it's only aluminum, and aluminum will flex and bend and distort. so will steel, for that matter.

with the chain off, spin the wheel and hold a marker near the top of the sprocket, getting it closer and closer till it finds the high spot. mark the sprocket and the adapter in that spot. loosen up the three bolts a little and tap it down on the high spot and re-tighten. if there's still a high spot there, take the sprocket off and move it over one hole. if the high spot is on the same mark on the sprocket, the sprocket's a little off. if the high spot is on the spot of the adapter, the adapter's a little off.

it could be that the sprocket hasn't worn into the chain yet, also. after another half a tank, it might go away.

or maybe Jim just didn't get enough sleep the night before making yours...:)
 

Beej

New Member
Jun 7, 2010
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San Diego, CA
I will check it again. Couple things, I did switch the sprocket around to gain more tire clearance. I have the flat side out. Also, there is six holes on the sprocket with only three arms to hold it on. Should I try switching mount locations on the sprocket holes?
 
Sep 20, 2008
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Beej,

The two sets of holes are for two different sprocket adapters.

I make one adapter on a 3 1/8" bolt circle, the other on a 3 5/8" b.c.

The sprockets that I ship to Pirate Cycles are drilled for both adapters.

Changing the sprocket to the other holes will not work! The sprocket will not even bolt up!

Remove the chain and spin the wheel...check to see that the sprocket is running true.

If it is then your problem is more than likely in the chain.

Provided that your hub is matched correctly with the adapter...It is virtually impossible for the sprocket to run out of true.

Jim
 

Beej

New Member
Jun 7, 2010
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San Diego, CA
Thanks Jim, that's the exact reason I waited and bought one of these adapters, to be a true fit. If I do check it and it is true what should I check on the chain?
 
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Beej

New Member
Jun 7, 2010
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San Diego, CA
Yes...and also look at the chain from the rear of the bike to see if it's twisted. Spin the wheel a bit...have a look...spin a bit more, and have another look.

I've had new chains that were twisted for about a foot, maybe a foot and a half.

Jim
Now I think you got it pinned. It is a bit twisted for about a foot or so. Can it be straightened or am I looking at another expense?