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Help! Dax shift kit, SBP BB adapter, crank has play!


Discussion at Motorized Bicycle Engine Kit Forum in the Motorized Bicycle General Discussion forum. Okay, so I've come upon the first problem that has me truly stumped. History: Frame: 10 year old Target "China" ...
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Old 02-08-2010, 09:03 PM
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Default Help! Dax shift kit, SBP BB adapter, crank has play!

Okay, so I've come upon the first problem that has me truly stumped.

History:

Frame: 10 year old Target "China" special. (Essentially the 10 y/o Target equivalent of the "Roadmaster" bikes that WalMart is selling now)

Trying to install a Dax shift kit. My bike originally had a 1-piece Bottom Bracket. I purchased the 1-3 Bottom Bracket adapter from Sick Bike Parts and installed it tonight.

Here's the problem:

Once installed, the new crank from the shift kit has WAY too much play, I'd say a little under a 1/4", even if I leave just enough threads for the left side lockring to barely grab. I can take the slack out, but if I do, the bearing cup threads disappear all the way into the adapter, and I can no longer install the lockring.

Pics to follow.

Last edited by OKflyboy : 02-08-2010 at 09:13 PM.
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Old 02-08-2010, 09:10 PM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

Bearing cup installed enough to remove play (no threads left to install lockring):


Enough threads to (barely) install lockring but about 1/4" lateral play in the crank:

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Help! Dax shift kit, SBP BB adapter, crank has play!-sany7186-small-.jpg  Help! Dax shift kit, SBP BB adapter, crank has play!-sany7187-small-.jpg  Help! Dax shift kit, SBP BB adapter, crank has play!-sany7188-small-.jpg  
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Old 02-08-2010, 10:21 PM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

There are two widths of BB tubes. One requires a 68 mm bearing spacing and the other requires a 73 mm bearing spacing. Never seen a one piece with the 73 mm but there is a first for everything. What you are looking for is a 7R spindle. 134 mm wide with 73 mm bearing spacing.
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Old 02-08-2010, 10:38 PM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

Quote:
Originally Posted by Ghost0 View Post
There are two widths of BB tubes. One requires a 68 mm bearing spacing and the other requires a 73 mm bearing spacing.
After googling for a while, I came to that same conclusion, at first. But when I went to measure the BB tube to confirm, I came up with 68mm. Unless I'm measuring wrong. Its just the tube, without the adapters that I'm supposed to be measuring, right?

Like this?:


Or is it from the outside of the adapters? If so then I get 74mm.

Quote:
Originally Posted by Ghost0 View Post
Never seen a one piece with the 73 mm but there is a first for everything. What you are looking for is a 7R spindle. 134 mm wide with 73 mm bearing spacing.
Thanks for your help, Ghost. (Truth be told I'm already regretting not buying my shift kit from you guys. I've been using your instructions this whole time since Dax includes no instructions with his kits and his video instruction series appears incomplete as of yet...)
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Help! Dax shift kit, SBP BB adapter, crank has play!-sany7191-small-.jpg  

Last edited by OKflyboy : 02-08-2010 at 11:16 PM.
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Old 02-08-2010, 10:48 PM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

Quote:
Originally Posted by Ghost0 View Post
What you are looking for is a 7R spindle. 134 mm wide with 73 mm bearing spacing.
This one?

Sick Bike Parts
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Old 02-09-2010, 08:33 AM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

Alright, that's got to be the problem, I can't find anything else. So I went ahead and ordered the 7r crank from you guys.

Thanks!

Ara
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Old 02-09-2010, 09:13 AM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

I am sure the 7R spindle will solve your problem but I am still stumped why you have this issue in the first place. It appears that you assembled everything correctly. Dumb question I know but do you have both bearings installed and are they facing the correct direction? Just throwing out ideas.
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Old 02-09-2010, 01:28 PM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

Quote:
Originally Posted by Ghost0 View Post
I am sure the 7R spindle will solve your problem but I am still stumped why you have this issue in the first place. It appears that you assembled everything correctly. Dumb question I know but do you have both bearings installed and are they facing the correct direction? Just throwing out ideas.
I don't mind the question, in fact I welcome it, I'd hate to find out it was all because I missed something simple but was too proud to check. But yes I do have both bearings installed, and correctly. I double checked those too during my head scratching session last night.

I will not claim to be an expert, by any means, but I'm pretty good at being able to read about something then apply it. But like I said in my first post, this one has me stumped... Its a 68mm bracket tube, as far as I can tell, everything is installed correctly, also as far as I can tell, and yet, the crank does not fit correctly. I suppose its possible I got the wrong size crank in my kit from Dax, is there a crank shorter then 68mm? Will have to measure the crank, but I'm only on lunch right now, so it will have to wait until I get home tonight.

Thanks again, Ghost!

Last edited by OKflyboy : 02-09-2010 at 01:47 PM.
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Old 02-09-2010, 03:18 PM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

i had the same problem. the 7R spindle worked perfect
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Old 02-09-2010, 07:26 PM
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Default Re: Help! Dax shift kit, SBP BB adapter, crank has play!

Quote:
Originally Posted by pdubs View Post
i had the same problem. the 7R spindle worked perfect
Good to know I'm not the only one, then.
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