front mini hub motor - off center

[kefa]

to build a dished wheel you need to have shorter spokes on one side to pull the hub one way or another. try to find a spoke length calculator online that allows you to specify asymmetrical hub measurements.

[Bikemad]

If the spokes on the cable side are long enough, and the spokes on the other side are threaded enough you should be able to re-dish the wheel in the correct direction.

Start at the valve hole and loosen each spoke on the cable side by two complete turns until you reach the valve hole. Then tighten each spoke on the non-cable side by two turns each and then see how far out the rim is from being centred in the forks.

You may have to repeat the process again if the rim still needs to move over more, but you might want to just do a single turn on each spoke instead if it's not far off centre.  As long as the threads on the spoke are not visible at the spoke end of the nipple, you should still have plenty of thread holding inside the nipple.

You might want to check out this video for more information, and don't forget to let us know how you get on with centring the rim correctly.
 
Alan

[Pullitap]

I went this morning to local bike service with this transvestite hub to get it dished and I left it there. Few hours later I got a message to my phone telling that my wheel was ready. But when I went there they said nothing could be done. Some nibbles where so rounded that they could not even be loosen with normal nibble tool. Obviously some spokes have been tightened over threads and stucked. And even if the spokes could be loosen you could do nothing because all the spokes are allready 2 mm too short even for straight alignment. That´s it.

As I looked closer the rim this evening, I found out that on some spokes there is 1.5 mm thread visible out of the nibble. Looking from the tube side there is 2 mm thread left in allmost all nibbles. The spokes are truly too short. The rim is double wall type, there is room for longer spokes.

The spokes are 2.5 mm thick (not 2.2 as I wrote before). Now I have to find a supplier who has 212 mm and 214 mm 2.5 mm spokes to rebuild the wheel.
Or I will build a windmill with all this unusable junk I received from china.

[kefa]

where abouts are you located?

you should be able to find some places that can cut spokes to length. thats pretty poor the bike shop can't do it for. did they at least tell you the right spoke lengths you need? maybe you can source the right spoke lengths and then give it back to the bike shop to fix up.

[Pullitap]

I live in Finland. We don't have here bike services who cut spokes and re-thread them. Too difficult jobs are rejected by them. Or I do not have right contacts to find whoa are able to.

[kefa]

a couple of solutions for you:

http://www.crystalyte-europe.com/product.php?productid=16253

http://www.bmsbattery.com/index.php?main_page=product_info&cPath=7_28&products_id=77

i built my first wheel after watching a few youtube videos! all you need is a spoke key really. just turn your bike upside down and use your v-brakes for alignment. it took me maybe 2-3 hours first attempt.

good luck!

[MonkeyMagic]

Good lord

No bicycle shop in Finland that re-laces rims??

Yipes...

[Pullitap]

This evening I measured every spoke´s thickness in the wheel with caliber.
There was 9 pieces 2.2 mm and 9 pieces 2.5 mm spokes on the brake side and 6 pieces 2.2 mm and 12 pieces 2.5 mm spokes on the cable side. I didn´t notice that earlier because I have a poor near sight.
No wonder if some nibbles are rounded. Try to turn 2.2 mm nibble into 2.5 mm thread!

Perhaps this child who assembled this wheel had borrowed spokes from the another production line.

[GM Canada]

Somehow I have missed this entire thread from the begining. I see Tom posted choosing old style or new style mini motor. I just wonder where you would make this choice? I have never seen anywhere on the GM site for this option, nor have I heard of it when ordering. I have a few front hubbed mini motors in stock and will open the boxes to see exactly what I have. Of course I have no Idea if they are the "new" style or "old" style at this point, but will take a few pictures and measurments and get back to this thread with the results.

Gary

[GM Canada]

As promised, a few pictures of front and rear mini motors. Both sit perfectly center in the drop outs or forks and look indentical. The only difference is the axle length is longer on the rear wheel and there is a place for the freewheel to screw on.

Gary

[GM Canada]

A few more pictures. If anyone needs anymore detailed pictures to figure it out let me know. Ill leave the wheels by my desk for a few days incase they are needed.

Gary

[kefa]

hi gary,

did you have to dish the wheel though to get in centered?

[GM Canada]

Actually I didn't do anything this is how they came out of the box.

Gary

[Bikemad]

Who wants to play spot the difference?

In the first picture (Pullitap's wheel), the rim is clearly offset (dished) towards the cable side of the axle, but unfortunately this is the wrong direction for this particular hub when fitted to a front wheel (although it would be the correct way for a rear wheel).

In the second picture (Gary's wheel), the rim is clearly offset (dished) away from the cable side of the axle, which is the right direction for this particular hub when fitted to a front wheel.

 

I still don't understand how such a mistake can occur, as the wheel should be adjusted on a truing stand to ensure the rim is perfectly centred within the forks (and concentric with the axle).

Either GM do not use any form of truing stand, or Pullitap's wheel was originally assembled as a rear wheel and the motor and axle assembly was subsequently removed and replaced with a front one, thus making the offset totally wrong.
I'm guessing if GM had plenty of ready built rear wheels in the required rim size, but had sold out of ready built front wheels, then they could have opted for a quick fix solution (swapping the axle/motor assembly) without realising the alignment problem this would cause.

Regardless of how this mistake has occurred, if GM have supplied the wheel in this condition, it should be their responsibility to rectify the problem and ensure that Pullitap is able to use the wheel that he has purchased.

Alan
 

[MonkeyMagic]

Hey what country has "ULOS" for the word 'exit' I think is on the sign in Pullitaps picture??   Gary's looks centred more... Is the fork design anything to do with certain bikes?

Nothing to do with GM but the bikes I import that have spokes are NEVER true!!!

It took me weeks of trying to communicate with my lack of Chinese language, but I found the factorys building the wheels, workers did not know what "tension" was... good lord... So I'm not sure what it translates to in Chinese. Someone tell me lol

To add to the humour I was asking what the correct tension is for the spokes on different models (different wheel sizes etc.) and was just given the spoke length and diameter...Great.

From what I've seen the wheels come pretty much near true from GM but generally unless a wheel comes built from well known factory (Giant etc.), or calibrated in quality checks it always comes off centre to some degree.

You could put it down to the worker who assembled the wheel but it would be a very hard thing to monitor. With any bike with spokes adding a new wheel you should really true it up when you first fit it, then again in a few weeks to a couple of months, then on intervals to maintain alignment.

I could see in the assembly line a worker assembling a wheel (obviously as quick as they can) would be fitting the spoke then tighten to a certain degree and that's it... On to the next wheel....

There is a heap of videos on youtube on how to 'true' your wheel, Alan pointed out the truing stand and you use a few methods to correct your wheel. Make sure you have the correct spoke wrench... You can get a set on ebay for around $10 delivered that will do the job.

Do you have an old bike trainer?
Like these:


I picked up one of these on the side of the road and you prop it up to just sit the wheel in it and I just calipers to align the wheel as I tension the spokes accordingly. If you use caliper brakes theres a method to do it without taking your wheel off. I just use the stand, and I am no expert by far but what I do know is practice and patience is the key

No kidding after the amount of wheels I have trued up is the sole reason I went for cast wheels... Haha I would be running dual 16"/18" wheels if the newer 20" cast wheels never came out.

Anyway even if the wheel did come true, it would not be calibrated for the weight proportion of your bike and you would end up having to align it in future anyway as part of maintainence

Peace out
MM