Kit fitting problem

[Blink]

thanks to everyone who has answered my questions so far.

i didn't get a chance in the end to fit the kit(8fun with rack) on the weekend, however i found time today to fit the kit and all was going well until it came time to set the brakes up and i notice the wheel not sitting straight in the forks, there is a bigger gap between the rim and fork on the side that the wire comes out of than on the other with and without the wheel tightened up. i checked with the original rim and that is sitting fine, so i was wondering if anybody had any tips or if the wheel itself may be at fault?

 

[NRG]

Front wheel? Are there any washers still in place on the motor shaft...is it possible to shim the tight side to move the wheel back into the centre?

 

[Blink]

yes its a front wheel motor. i've tried shimming it by putting washers between the torque nut and motor on the tight side, which did seem to help a little bit but not much. the only way i can seem to get it to sit straight is to angle the wheel so the motor bolt rises up in the drop out (with the bike upside down)on one side and then tighten the nuts up. but this doesn't seem right to me.

 

[Scottyf]

The wheel probably needs a slight off set.
However if you can get a picture of how you've fitted the motor in the forks and the order of washers and torque nuts would be useful just incase something is round the wrong way.

The front wheel motors usually require no real wheel offset and they normally slot in with no real issues.
Others than maybe adjusting the front brakes to accommodate the rim change n

There's also a couple different revisions of the front bafang motors.

 

[paulhipwood]

Dear Blink

Just checked my 8Fun front wheel.
The motor flanges are offset; but the rim is central in the forks. This means that the wheel has been dished to put it central to the forks.
How much out is your rim. I used a vernier and my rim was within a mm. of the fork legs.

regards
paul

 

[Blink]

The wheel probably needs a slight off set.
However if you can get a picture of how you've fitted the motor in the forks and the order of washers and torque nuts would be useful just incase something is round the wrong way.

The front wheel motors usually require no real wheel offset and they normally slot in with no real issues.
Others than maybe adjusting the front brakes to accommodate the rim change n

There's also a couple different revisions of the front bafang motors.

when i first put the wheel in i had it-motor/washer/torque washer/fork/washer/locking ring/nut now its the same but with a one extra washer on the tight side between torque washer and motor.

Dear Blink

Just checked my 8Fun front wheel.
The motor flanges are offset; but the rim is central in the forks. This means that the wheel has been dished to put it central to the forks.
How much out is your rim. I used a vernier and my rim was within a mm. of the fork legs.

regards
paul

i haven't got a vernier to check with but i'll use a ruler tomorrow, i only notice when i was having trouble getting the v brakes set back up. hardly a scientific measure i know but at the top by the brakes i can get 2 fingers between rim and fork one side and i can't on the other.

thanks for the help so far.

 

[Scottyf]

I think from memory when I fitted a front motor I missed out one washer so the order was

it-motor/torque washer/fork/washer/locking ring/nut

 

[paulhipwood]

Sounds as if the wheel is not dished (offset) correctly.
I will measure my rim relative to the hub flanges and post tomorrow.

Regards
paul

 

[paulhipwood]

My kit was assembled

Hubmotor/oversize thin flat washer/torque washer/fork/washer/spring washer/domed nut

regards
paul

 

[bigroy]

never add more washers between the motor and number 2 (tab washer)

 

[amigafan2003]

If the motor can accept a disk then it needs dishing over to the side that the disk mounts to.

 

[Blink]

thank you to everyone who has helped so far, i am of to give it another go now. the motor has the fitting for disk brakes but am using v-brakes. how can i tell if the wheel has been dished right?

 

[Blink]

update- i took the tyre off and the rim seems to be off-set to the hub on the side where disk brakes would go, this would seem to be the problem. the ad said that it could take v-brakes or disks but would the wheel be specifically dished for each one and i have the one for disks and i should have one for v-brakes, the ebay ad didn't say that i had to specify.

 

[jerrysimon]

View attachment 3363 never add more washers between the motor and number 2 (tab washer)

I am curious, why not ?

Does the motor shaft only have flats on the non threaded part ?

Regards

Jerry

 

[flecc]

update- i took the tyre off and the rim seems to be off-set to the hub on the side where disk brakes would go, this would seem to be the problem. the ad said that it could take v-brakes or disks but would the wheel be specifically dished for each one and i have the one for disks and i should have one for v-brakes, the ebay ad didn't say that i had to specify.

The ideal way to deal with this is for the spokes to be adjusted to alter the rim offset, re-truing the wheel at the same time. Best done with some experience, but possible for the owner if done patiently. Any slight spoke protusion beyond the nipple ends will need to be filed off before refitting the rim tape.

Alternatively, if the offset is not too serious, altering the spindle height on one side as you've mentioned is practical. Only do this if the bike will never be converted back. File out a tiny amount from the top of the dropout slot on the appropriate side, remembering that the amount of shift there is multiplied at the rim. On a 26" wheel, 1 mm filed out shifts the rim laterally by 6.5 mm.

Finally of course, another method with V brakes is that they can be adjusted to accommodate an offset if it's not to severe, and an offset rim does not affect a bike's handling. Some bike designs actually include a severe front-to-rear wheel offset.

 

[paulhipwood]

I am curious, why not ?

Does the motor shaft only have flats on the non threaded part ?

Regards

Jerry

On my 8Fun kit the flats are on the non threaded portion only. Putting extra washers will move the locking washer off the flats. You will then have no anti-rotation protection on that side.

I am about to measure my offset and post it in the next 30 mins

regards
paul

 

[paulhipwood]

Dear Blink

My rim is out of position in the forks by 5 mm. I did not notice this when I assmbled the wheel.
The hub flanges are offset from the forks by 19 mm on the power cable side and 26 mm on the other side.
So there should be a 7 mm dish on the wheel. I have only got a 2mm dish.

This will have a small effect on the tracking of the bike but I am not going to worry about this.
I could increase the dishing by carefull tightening and loosening of the spokes; but will wait for a rainy day.
I would also think I am maesuring with an accurace of 2 mm anyhow.

Hope this helps
paul

 

[Blink]

Dear Blink

My rim is out of position in the forks by 5 mm. I did not notice this when I assmbled the wheel.
The hub flanges are offset from the forks by 19 mm on the power cable side and 26 mm on the other side.
So there should be a 7 mm dish on the wheel. I have only got a 2mm dish.

This will have a small effect on the tracking of the bike but I am not going to worry about this.
I could increase the dishing by carefull tightening and loosening of the spokes; but will wait for a rainy day.
I would also think I am maesuring with an accurace of 2 mm anyhow.

Hope this helps
paul

thanks for checking,

i haven't measure it yet but looking at it on the disk brake side the rim is inline with where the spokes attach to the motor casing. its this off-set causing trouble with the brakes.

i feel i should mention as well that i've been emailing 8funuk and they've been helpful and very quick to response to emails too.