The Unofficial 'CroMotor' Owners Tech-Tips Thread

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shorza   1 kW

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by shorza » Apr 05 2012 6:49pm

Can anyone please tell me the length to the axle on these?

It must have an axle length 205-210mm for me to be able to get the nuts on outside my 140mm dropouts and torque arms.
Last edited by shorza on Apr 06 2012 1:22am, edited 1 time in total.

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Alan B » Apr 06 2012 12:44am

The Cromotor freewheel threads are too long for the White Brothers freewheel. What is the best remedy?

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by cassschr1 » Apr 07 2012 11:48am

I don't see why thats a problem. Is the motor to wide now?

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Alan B » Apr 07 2012 9:25pm

If I use a spacer on the freewheel it will require extra dropout width. I need to get some numbers.

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by alex77roma » May 21 2012 7:26am

I have the avid rotor and already made the same modify, but I don't find the Magura Gustav.
Are there any alternative silm rear disc brake to Magura Gustav for fitting the cromotor in a 135 hub with?


andreym wrote:If you have only 135mm of dropouts and still want to fit some torque arms inside, you can use the following disk rotor adapter mod:
-remove original adapter,
-get avid g2c2 203mm rotor
-get magura gustav M rear brake for enough clearance
-dremel a bit of avid rotor to make it fit and screw it up INSTEAD of original adapter

here is your additional ~5mm clearance for torque arms with CroMotor and 135mm of dropouts!
and some pics:

Image

Image

Image

Image

Image

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by GCinDC » May 21 2012 7:40pm

alex77roma wrote:I have the avid rotor and already made the same modify, but I don't find the Magura Gustav.
Are there any alternative silm rear disc brake to Magura Gustav for fitting the cromotor in a 135 hub with?
from here.
gregborgusa.com wrote:...Like many rear hub motors you can run into caliper clearance issues, but I managed to get a Hayes Stroker Ryde on the back of my custom bicycle by using a 203mm rear disc. This larger disc allows the caliper to stick up high enough to not rub on anything but it’s a tight fit due to this particular caliper being very wide compared to others such as the Avid Juicy brakes I’ve run.
i wonder if the magura mt2, mt4, etc would be good. i believe kepler said they've got 17mm of clearance from disc to edge.
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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Olly3012 » May 22 2012 4:00am

I have just purchased a croMotor and was wondering what the ultimate controller available for this I have 30S2P lipos 111V-126V with 30C cells, I don't care about mileage at all just want maximum power any suggestions cheers.

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Emoto » Jul 18 2012 8:18am

andreym wrote:If you have only 135mm of dropouts and still want to fit some torque arms inside, you can use the following disk rotor adapter mod:
-remove original adapter,
-get avid g2c2 203mm rotor
-get magura gustav M rear brake for enough clearance
-dremel a bit of avid rotor to make it fit and screw it up INSTEAD of original adapter

here is your additional ~5mm clearance for torque arms with CroMotor and 135mm of dropouts!
and some pics:

Image
Image
Andreym Good to see this mod, are you using regen, how long have you been using it like this.any problems yet

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Alan B » Jul 18 2012 8:22am

Nice technique! May have to do that myself.

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by binlagin » Jul 18 2012 8:25am

Unfortunatly I snapped my Cromotor axle yesterday after a heavy acceleration from a dead stop. I had made some room for larger phase wires... but apparently I shaved to much down :(.

Now I have to figure out if it's even possible to replace. I have no idea where I can source a replacement axle and/or how to install it.
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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by fractal » Jul 18 2012 8:56am

binlagin wrote:Unfortunatly I snapped my Cromotor axle yesterday after a heavy acceleration from a dead stop. I had made some room for larger phase wires... but apparently I shaved to much down :(.

Now I have to figure out if it's even possible to replace. I have no idea where I can source a replacement axle and/or how to install it.
That sucks! Could you weld it back together? Finding a replacement that fits could be a challenge!
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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Doctorbass » Jul 18 2012 8:56am

binlagin wrote:Unfortunatly I snapped my Cromotor axle yesterday after a heavy acceleration from a dead stop. I had made some room for larger phase wires... but apparently I shaved to much down :(.

Now I have to figure out if it's even possible to replace. I have no idea where I can source a replacement axle and/or how to install it.

did you used single or DUAL strong torque plate? ( one on each side)

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by gensem » Jul 18 2012 9:03am

binlagin wrote:Unfortunatly I snapped my Cromotor axle yesterday after a heavy acceleration from a dead stop. I had made some room for larger phase wires... but apparently I shaved to much down :(.

Now I have to figure out if it's even possible to replace. I have no idea where I can source a replacement axle and/or how to install it.
Go to a machine shop and ask for a new one... btw why did you have to use larger phase wires?
Justin we really appreciate what you did!

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by binlagin » Jul 18 2012 9:08am

I'm using the Kiwi's drop outs for the Giant DH Team. They seem to be pretty heavy duty and have held up so far.

I haven't actually taken the motor out of the rear swing arm yet to get pictures and confirm 100% that thinning the axle is what truely caused the failure.

I've messaged Zombiess to see if he's able to get his hands on a spare axle. *crosses fingers*

Oh and Gensem why did I do this? I'm a noob and I thought those wires where to thin....
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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by gensem » Jul 18 2012 9:17am

binlagin wrote: Oh and Gensem why did I do this? I'm a noob and I thought those wires where to thin....
They arent super thick either like 10awg tops.
But the deal is that they will not have to deal with constant current so it should be good for a lot of amps.
I ll find out it soon as im planning to run 160a main 240a battery on a cromotor.
Justin we really appreciate what you did!

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Emoto » Jul 18 2012 9:54am

Alan B wrote:Nice technique! May have to do that myself.
ive got my motor and frame only atm, 135 dropout, and im thinking, i saw your thread and you have less to work with, but i have a couple of ideas that will work.
finding a disc that has enough materal to re drill the pattern is one thought

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by hillzofvalp » Jul 18 2012 5:04pm

I haven't set up a rear brake yet over 800 miles.. Regen is soo strong and I have a lot of trouble mounting the caliper.

Sorry to hear about the snapped axle! Makes me worry! Tell us about your regen use, wheel size, phase/battery current, etc as well once you catch your breath. So far the dp420 and .5" thick dropouts have held up... But I'm quickly being deterred from bike frames for this type of power.

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by binlagin » Jul 18 2012 5:31pm

I've made a post with more detailed information about my failed axle here:

http://endless-sphere.com/forums/viewto ... 56#p611756
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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Emoto » Jul 19 2012 8:39am

hillzofvalp wrote:I haven't set up a rear brake yet over 800 miles.. Regen is soo strong and I have a lot of trouble mounting the caliper.

Sorry to hear about the snapped axle! Makes me worry! Tell us about your regen use, wheel size, phase/battery current, etc as well once you catch your breath. So far the dp420 and .5" thick dropouts have held up... But I'm quickly being deterred from bike frames for this type of power.
Yeah regen being strong i can imagine is handy in you situation , but i would like to fit a rear brake,removing the adapter is a good aproach. ive got a dh frame and the swingarm is quite strong [i may modify it/ wider] would'nt be confident in a normal frame.

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Emoto » Jul 19 2012 10:00am

binlagin wrote:I've made a post with more detailed information about my failed axle here:

http://endless-sphere.com/forums/viewto ... 56#p611756
Ive just received mine, on first inspection i thought this was the obvious weak point, and now im a bit worried, as you can see the phase groove machining is quite deep only leaving 12.1 mm :shock: is this normal.
Attachments
E1011849.JPG
cromotor shaft

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by hillzofvalp » Jul 19 2012 11:54am

I found it a bit questionable as well. That's nearly worse than m14.. Which would be something like 12mm of solid metal. Your measurement minus 1 mm of thread... :roll:

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by nicobie » Jul 19 2012 12:59pm

I wonder why they don't put the groove on the same side as the axle flats?
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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by Emoto » Jul 19 2012 2:44pm

nicobie wrote:I wonder why they don't put the groove on the same side as the axle flats?
Nicobie, your absolutely! right.
My other problem is the groove machining should not pass the shoulder and therefore weakening the shaft

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by hillzofvalp » Jul 19 2012 3:54pm

If they put on the axle flat side, the wiring harness wouldn't come out where the dropout channel is. for most frames this would present an issue.

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Re: The Unofficial 'CroMotor' Owners Tech-Tips Thread

Post by hillzofvalp » Jul 19 2012 3:55pm

Emoto wrote: My other problem is the groove machining should not pass the shoulder and therefore weakening the shaft
I agree, but it still conflicts with the design constraint of getting the wires in line with the axle slot. Don't they do it this way on other brands, too?

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