Filing Quick release Drop out

my.motion

Pedelecer
Jun 26, 2009
115
0
Hi Team,

I want to file my rear dropout by 2-3mm to fit a 12-14mm axel motor, by doing this will I be able to re-use the original wheel afterwards? Has anyone done this and were they able to switch between the two wheels without any problems?
If i chose not to file the droputs but use two torque arms on each side is this ok? The torque washer lip doesnot fit into the droput at all as is.

Thanks
Motion
 

flecc

Member
Oct 25, 2006
52,818
30,381
I always prefer to file the dropout width. If the curve at the top of the dropouts is retained, that will centre the normal wheel when it's replaced at any time and the normal wheelnut/clamp tightness should keep it in place.

Adding a torque arm also is advisable when with the motor.
.
 

my.motion

Pedelecer
Jun 26, 2009
115
0
Thanks Flecc, but filing the width of dropout will be inviting spinning inside the dropouts, both the axle and dropout are 10mm wide hence a nice fit. The issue is the length and how deep the axle sits in the dropout. So I would like to use both wheels with no issues if possible.

Regards,
motion
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
I've done it.

You may have to adjust the brakes a bit, as the un-powered wheel will sit further into the dropouts. You don't say if you have discs or rim brakes, but with rim brakes (eg v-brakes) it will be easy. With discs, worst case you'll need a couple of washers if the disc hits the inside of the calliper.
 

my.motion

Pedelecer
Jun 26, 2009
115
0
Thanks Alan.it's v brakes. So I will have modify the v brakes if I want to use the original wheel again?​
 
C

Cyclezee

Guest
Thanks Flecc, but filing the width of dropout will be inviting spinning inside the dropouts, both the axle and dropout are 10mm wide hence a nice fit. The issue is the length and how deep the axle sits in the dropout. So I would like to use both wheels with no issues if possible.

Regards,
motion
Hi Motion,
A couple of photos of your dropouts would be useful to see how much you could safely increase the depth.
 

Flyingppg

Finding my (electric) wheels
Feb 7, 2018
16
3
58
Kent
Hi, my partner and I have a pair of 622 hub (700c wheel) hybrid bikes that I fairly recently fitted a Yosepower 350w rear wheel kit to hers also running their 13ah 36v rack battery. It's been a nice conversion for both of us because she can now keep up and I'm not waiting at the tops of hills. I had no experience of e-bikes previously but I otherwise have a professional engineering background.

When I was fitting it I realised that the 12x10mm e-hub axle mis-centred the wheel by 1mm compared to the QR hub that it replaced but I adjusted the v-brakes accordingly, the torque washers in my judgement make a decent interference fit with the frame and otherwise it works fine. However I see others are filling the drop outs a little to properly centre the wheel because of the thicker axle.

I'm always reluctant to go permanently removing metal unless absolutely necessary so interested in what the issue and risks really are from those with real experience? For example, is the wheel going to come out under power at speed at some point or is this more a bike specific issue for some where others have operated their conversions, albeit with a 1mm mis centred wheel, without a problem and one has to make an engineering judgement for your own particular bike/kit conversion?
 
D

Deleted member 4366

Guest
Every bike is different. You have to make a judgement. If the axle doesn't look like it's in far enough, then file the drop-outs deeper.

Does anybody ever convert their bike back again to non-electric? Even if you did, having 2 mm deeper drop-outs won't do any harm.

One thing you have to watch for if you have a disk brake is that the pad will be offset a couple of mm when you fit a 12mm axle and don't file deeper. You could compensate that by shaving the adaptor, or, if you filed and are converting back, add a couple of washers. In most cases, there's enough disk area for the pad to be offset a bit. It's only those very narrow discs that you have to worry about.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,134
8,230
60
West Sx RH
Filing also depends on the fork some drop outs have a slight recess for the nut so will necessitate filing, as d8veh say's each situation is different.