Rear hub motor juddering when spun by hand /pedalled
- Thread starter Ianb84
- Start date
It sounds like the clutch is sticking. Is the juddering the same whether you rotate the wheel backwards or forwards when it does it.
That's a normal direct drive motor. They all cog in both directions to a greater or lesser extent. If you get more resistance than the normal cogging and the motor is disconnected, then there is a short on the phase wires somewhere. When the cable isn't connected, it's easy for the bullet connectors to touch each other, which would increase the resistance to turning a lot. If the resistance increases when connected to the controller, it's probably because the regeneration is not switched off.
Any wobble in the axle? - bad bearing??..
If ive read correctly these are all pre connecting power tests with just the wheel on its own?
May i ask why that motor/kit @Ianb84 ? while police interest in ebikes outside the regs has been slow to start, it seems that in some areas at least this is changing and the dinner plate motor is a easy to spot from a distance violation if looked for.
Depending on your needs a within regs set up might be available for less long term hassle allowing you to get your money back (distance selling rules) on the dinner plate kit?? after all its only the motor rating thats limited to 250w.. nothing is said about controllers and batteries feeding X000w when needed
If ive read correctly these are all pre connecting power tests with just the wheel on its own?
May i ask why that motor/kit @Ianb84 ? while police interest in ebikes outside the regs has been slow to start, it seems that in some areas at least this is changing and the dinner plate motor is a easy to spot from a distance violation if looked for.
Depending on your needs a within regs set up might be available for less long term hassle allowing you to get your money back (distance selling rules) on the dinner plate kit?? after all its only the motor rating thats limited to 250w.. nothing is said about controllers and batteries feeding X000w when needed
I will double check for wobble but sure it felt pretty solid , but I will need to try and wiggle when it is shudder and when it stops . I will check with battery once I have fitted but I’m expecting it be the sameAny wobble in the axle? - bad bearing??..
If ive read correctly these are all pre connecting power tests with just the wheel on its own?
May i ask why that motor/kit @Ianb84 ? while police interest in ebikes outside the regs has been slow to start, it seems that in some areas at least this is changing and the dinner plate motor is a easy to spot from a distance violation if looked for.
Depending on your needs a within regs set up might be available for less long term hassle allowing you to get your money back (distance selling rules) on the dinner plate kit?? after all its only the motor rating thats limited to 250w.. nothing is said about controllers and batteries feeding X000w when needed
Yes I never thought of that , perhaps a smaller 250w motor with a bigger controller and batteryAny wobble in the axle? - bad bearing??..
If ive read correctly these are all pre connecting power tests with just the wheel on its own?
May i ask why that motor/kit @Ianb84 ? while police interest in ebikes outside the regs has been slow to start, it seems that in some areas at least this is changing and the dinner plate motor is a easy to spot from a distance violation if looked for.
Depending on your needs a within regs set up might be available for less long term hassle allowing you to get your money back (distance selling rules) on the dinner plate kit?? after all its only the motor rating thats limited to 250w.. nothing is said about controllers and batteries feeding X000w when needed
IF you detail your expected use and donor bike, include terrain details (hills?) and speed/range expectations and budget.
Im sure the best minds in here could suggest set ups and kit that could provide what you want within the regs.. - Then you will be able to get theft insurance on the bike, and if anything bad happens on the rd you wont automatically be in the wrong..
Im sure the best minds in here could suggest set ups and kit that could provide what you want within the regs.. - Then you will be able to get theft insurance on the bike, and if anything bad happens on the rd you wont automatically be in the wrong..
Flat terrain , mix of roads and paths , around 20miles range with most usage between 15-22mph
You can easily test the motor for potential shorted windings by connecting two of the phase wires together.
Then when you rotate the wheel in either direction you should feel more cogging on the motor.
Then connect all three phase wires together and the cogging resistance should increase significantly.
Then when you rotate the wheel in either direction you should feel more cogging on the motor.
Then connect all three phase wires together and the cogging resistance should increase significantly.
imho a Nice big 48v battery 17ah matched with a 17a 36v/48v kt sinewave controller and suitable lcd display (there is a selection) which on paper could supply (54.6V x 17A = 928W) to a 250w motor..
Match that with a 36v 250w hub motor of your choice (fwiw i fitted a yose-power kit last summer - very happy with it) . and you should be very happy imho..
Generally A motor rated at 250W 36v will have a max rpm which will provide a max speed above the 15mph limit, circa 19-22 mph if unrestricted.. Supplying with power from a 48v batter/controller will increase this by circa 30% and also provide a similar increase in torque to get there..
KT controllers are more fully configurable than other options And have a number of compatible lcd display options.
Tho im not an expert, just a chap 1 yr into playing with his own ebike conversion and other bikes..
edit Just set the max speed to 15.5 mph for rd use and its totally legal, and you can ebay an en19154 sticker from ebay although kit conversions dont strictly require them.......
Match that with a 36v 250w hub motor of your choice (fwiw i fitted a yose-power kit last summer - very happy with it) . and you should be very happy imho..
Generally A motor rated at 250W 36v will have a max rpm which will provide a max speed above the 15mph limit, circa 19-22 mph if unrestricted.. Supplying with power from a 48v batter/controller will increase this by circa 30% and also provide a similar increase in torque to get there..
KT controllers are more fully configurable than other options And have a number of compatible lcd display options.
Tho im not an expert, just a chap 1 yr into playing with his own ebike conversion and other bikes..
edit Just set the max speed to 15.5 mph for rd use and its totally legal, and you can ebay an en19154 sticker from ebay although kit conversions dont strictly require them.......
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You don’t want to connect the battery when you do this test.
What you are currently experiencing is probably normal cogging, but it’s worth doing the short circuit test for peace of mind.
Hi guys. Turns out I was being really stupid, the phase wires that I took out the little joining block (to get some washers over and left them loose) were randomly touching causing the juddering, when I moved the bike they must have moved enough not to touch to let it spin freely . Thanks for everyone’s help and especially the guy who mentioned phase wires
Thanks for advice about the motor- I can see 250w kits although They say 36v, would this still work with a 48v battery? Just change the settings? Is a 250w still a direct drive ? Thanks for all your help,Any wobble in the axle? - bad bearing??..
If ive read correctly these are all pre connecting power tests with just the wheel on its own?
May i ask why that motor/kit @Ianb84 ? while police interest in ebikes outside the regs has been slow to start, it seems that in some areas at least this is changing and the dinner plate motor is a easy to spot from a distance violation if looked for.
Depending on your needs a within regs set up might be available for less long term hassle allowing you to get your money back (distance selling rules) on the dinner plate kit?? after all its only the motor rating thats limited to 250w.. nothing is said about controllers and batteries feeding X000w when needed
Ian
36v motor's will generally work at 48, which would make them 30% faster and 30% more powerful. It's not advised for one that's already fast, say more than 260 rpm at 36v. The controller and LCD need to be able to work at 48v too. Most 36v ones can't, except the KT dual voltage ones.
Very few 250w motors are direct drive. Most direct drive motors are in the 500w to 1500w range.
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