Puch Moped Rear Hub

the axle shouldn't pull anywhere if it's tightened down.

regardless, just take your time and cut straight.
 
I agree it makes sense to take meat off the bottom of the dropout slot (if possible) to ensure correct alignment. However, in my case, I'm going to have to spread the dropouts/rear stays quite a bit in order to get the rear hub in. This Dyno frame has alot more material on the topside of the dropout slot so I think I will have to remove from that area.

In theory, the axle should be resting on the top surface of the dropout, and not rely on the clamping force of the axle nut to hold the wheel in place vertically.

I agree with Bairdco that it you cut straight it shouldn't be an issue either way. You'd have to be way off on your cuts to make an appreciable difference.
 
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I realize that this is an old thread, and maybe I'm being a bit of a curmudgeon, but this thread is the #1 result on Google when you search anything about moped hubs+motorized bicycle. If you're in a situation where you need to modify horizontal rear dropouts to make a larger diameter axle fit, the suggestion I've ever gotten from bicycle frame builder or fabricator of custom things with wheels(whom I respect and have never been steered wrong by) is to maintain the center line of the axle. So, if you're going from 10mm to 14mm that's 2mm off the top and bottom sides. You know what they say, measure twice cut once. In this situation apply layout fluid, scribe a line 2mm from each surface of your dropout, and use whatever power tool you're comfortable with to remove that 2mm ALMOST to the line you scribed and finish it off with a mill file. It'll be straight enough, probably. If not, oh well, adjust it and do better next time. Maybe put in a little more practice. But definitely try to maintain the center line of your axle if you like your drivetrain and brakes to work the way theyre supposed to. Esp. important with rim and disk brake setups. That's my two cents, no disrespect to anyone here who does differently, every build on this thread is impressive and speaks to the skills of the contributors. Cheers!
 
Miscreant said:
I realize that this is an old thread, and maybe I'm being a bit of a curmudgeon, but this thread is the #1 result on Google when you search anything about moped hubs+motorized bicycle. If you're in a situation where you need to modify horizontal rear dropouts to make a larger diameter axle fit, the suggestion I've ever gotten from bicycle frame builder or fabricator of custom things with wheels(whom I respect and have never been steered wrong by) is to maintain the center line of the axle. So, if you're going from 10mm to 14mm that's 2mm off the top and bottom sides. You know what they say, measure twice cut once. In this situation apply layout fluid, scribe a line 2mm from each surface of your dropout, and use whatever power tool you're comfortable with to remove that 2mm ALMOST to the line you scribed and finish it off with a mill file. It'll be straight enough, probably. If not, oh well, adjust it and do better next time. Maybe put in a little more practice. But definitely try to maintain the center line of your axle if you like your drivetrain and brakes to work the way theyre supposed to. Esp. important with rim and disk brake setups. That's my two cents, no disrespect to anyone here who does differently, every build on this thread is impressive and speaks to the skills of the contributors. Cheers!
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Here's a couple of helpful suggestions.

1) Start your own thread and post references to old threads.

2) Paragraph your post so the readers aren't looking at a wall of words.

Thanks for the advice.
 
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