New Q128C Motor locked..

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
I thought I would start a new post as the bike is near completion.
I bought a Q128C from BMS and had the wheel built today.
I put it on the bike and found that the hub would not turn in the dropouts.
It appears locked and will not budge.
This was before it had ever been connected up.
I have since connected it to power and that has not 'unlocked ' it. Still solid.
Any ideas?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,918
8,533
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West Sx RH
Probably disc rotor bolts are to long and have pinched up against the internal motor housing, the tapped holes aren't blind but go strait thru.
You shouldn't apply power if it won't turn as you can damage the controller.
 
  • Agree
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Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
Thanks. Got the same info from Dave and you are both right.
Just took the bolts out and it is spinning merrily.
Thanks.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,918
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Shorter ones then or use the plastic spacer on the outside of the rotor as a washer.
 

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
The motor did not come with any screws so I will try and find some shorter ones but they all seem to be 10mm. Or use washers/spacers.
Which plastic spacer do you refer to?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,918
8,533
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West Sx RH
The motor did not come with any screws so I will try and find some shorter ones but they all seem to be 10mm. Or use washers/spacers.
Which plastic spacer do you refer to?
AFAICR my hub came with rotor screws and a circular 6 hole spacer.
 

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
Yes no screws or spacer from BMS. The motor had a circle of sticky tape over the disc holes.
I have used washers as a temporary measure and ordered some shorter screws. 8mm. Will order the spacer above if still too long.
Do you think my dropout is deep enough? Will it need a torque arm?IMG_7296.jpg
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,786
The European Union
Aluminium dropouts + Q128 = torque arms!
 

spanos

Esteemed Pedelecer
Feb 18, 2011
250
64
Just broke some expensive forks with a hub motor. Snapped dropouts

To be fair it was in an altercation with a white van and torque arms were in place

Still. Deffo get torque arms !
 

jarob10

Esteemed Pedelecer
Jan 22, 2017
270
83
51
Uk
Yes no screws or spacer from BMS. The motor had a circle of sticky tape over the disc holes.
I have used washers as a temporary measure and ordered some shorter screws. 8mm. Will order the spacer above if still too long.
Do you think my dropout is deep enough? Will it need a torque arm?View attachment 23156
I think full depth dropout is essential to preserve derailleur operation -zooming in on your picture, I don’t think the axle is fully seated at the bottom of the drop out.

Also, your dropouts look too shallow to accept the supplied tab washers, so torque arms are a must
 
D

Deleted member 4366

Guest
The Axle will sit about 2.5mm off-centre because of the axle's different diameter. That's not necessarily a problem, but re-centering won't do any harm either. Either way, I'd fit a single torque arm on the disc side with a proper anchor point, not a jubileee clip. I anchor mine to the caliper adaptor with a self-made tie-bar, though some frames have other suitable holes to fix the tie bar to.
 

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
Ok will get me for the disc side.
Any recommendations for a good one, as not keen on making my own !
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,918
8,533
61
West Sx RH

PC2017

Esteemed Pedelecer
Sep 19, 2017
1,319
334
Scunthorpe
Neil5403 they do paint up well, I used that black anti rust paint I am sure it was Hammerite, it was the only black paint I had spare but it came in handy as my forks were steel and needed a touch up