Author Topic: Question : About wheel centering  (Read 7300 times)

Offline diverdon

  • Confirmed
  • Bachelor of Magic
  • ****
  • Posts: 178
Question : About wheel centering
« on: December 05, 2009, 01:08:57 AM »
   Hello all , OK sorry to be a pest . I am trying to get my Magic Pie Motor together .
  Had to get the 6 speed freewheel hub as I had an 8 speed on there and found out pretty quick that you aren't kidding when you told me you can't use it.

    Actually the pro at the bike shop told me that when I took in both wheels (original and new m-pie one) So I got the new free wheel and a new tire tube .

    So ... The Motor was really tight in my "Drop out" Part of the frame it goes in . And when I got it in and tightened up good the tire seems to be off center some?? It is sitting more to the right side (Chain Side) than the left by 1/4 to 3/8 inch by my guess .. Both sides are tightened up good and it looks like it couldn't go to the other way any more as the Axel won't let it being as it is right up to the machined "flats" part as far as it goes ..

     I am just asking if this is OK? to be off center a little ? I have to take this bike in to the shop anyhow as I had an 8 speed "click" type shifter and have to have it changed to the 6 speed . I am just asking if I should ask the bike mech to look at this too or is it sometimes normal to be off center some ??

     I really don't see any way to center it up any more and took it for a short 2 block test ride which it doesn't seem to "pull" either way. I just don't know and am not afraid to admit it .

      Maybe my problem will help someone else in the future . Thank You for any replies I can get ... Don J.
« Last Edit: December 05, 2009, 10:00:06 AM by diverdon »

Offline diverdon

  • Confirmed
  • Bachelor of Magic
  • ****
  • Posts: 178
Re: Question : About wheel centering
« Reply #1 on: December 05, 2009, 10:12:45 AM »
     Hello All , I added 2 pics of the unit in the bike frame . The bike is a Trek 7500 multitrack . A Hybrid type bike .

        I am hoping you can see how tight the left side is as the flats in the axel are right up to the frame .. And the cassette on the gear side is almost touching the frame . Paper thin gap between gear casette and frame "Drop Out" ..

      I will take this in to the bike shop tomorrow to be checked . They need to hook up the new 6 speed shifter anyhow . I was just hoping for some expert advice from you all .. Does this seem normal . The Off center might be as much as 1/2 inch but I see no way to change it or any real problem from it . But I don't know much about tech. things like that .

     So should I be pressing the mechanic to look at this too or is it somewhat normal ?? Once again sorry to be such a pest and I really do appreciate anything you can tell me . Don J.

Offline diverdon

  • Confirmed
  • Bachelor of Magic
  • ****
  • Posts: 178
Re: Question : About wheel centering
« Reply #2 on: December 06, 2009, 07:04:39 AM »


        ???41 People looked at thia and no one has an opinion  ???

      Well I guess is's better than guessing wrong although I'd be OK with it .

                     Thanks anyways ' Don J.

Offline Bikemad

  • Global Moderator
  • Professor
  • PhD. Magic
  • ******
  • Posts: 5,499
Re: Question : About wheel centering
« Reply #3 on: December 06, 2009, 01:50:54 PM »
Don,

So long as it's not binding against the brakes or frame, it should not be a problem.
You may notice a slight difference in handling, but it shouldn't effect it too much.

It may be possible to offset the rim slightly by adjusting the spokes, but I don't think you'll be able to offset it very much.

Check this post

If you didn't have an aluminium frame, I would suggest spreading it slightly and putting a spacer tube or washers on the non-gear side.

the flats in the axel are right up to the frame
You really should have a washer between the flats and the frame to spread the load and prevent the flats on the axle from damaging the dropouts as the axle is tightened.

I would reverse the tabbed torque washer and fit it inside the dropout instead of outside.

Alan
 
P.S. I thought you were going to use disc brakes?
 

Offline diverdon

  • Confirmed
  • Bachelor of Magic
  • ****
  • Posts: 178
Re: Question : About wheel centering
« Reply #4 on: December 06, 2009, 08:10:07 PM »
Don,

So long as it's not binding against the brakes or frame, it should not be a problem.
You may notice a slight difference in handling, but it shouldn't effect it too much.

It may be possible to offset the rim slightly by adjusting the spokes, but I don't think you'll be able to offset it very much.

Check this post

If you didn't have an aluminium frame, I would suggest spreading it slightly and putting a spacer tube or washers on the non-gear side.

the flats in the axel are right up to the frame
You really should have a washer between the flats and the frame to spread the load and prevent the flats on the axle from damaging the dropouts as the axle is tightened.

I would reverse the tabbed torque washer and fit it inside the dropout instead of outside.

Alan
 
P.S. I thought you were going to use disc brakes?
 


        Thank You so much for the reply .I thought it was OK but feel even better now ..

    
        Gotta wait till next week to take this in to have the 6 speed shifter installed

  
                 Get paid every 2 weeks if you know what that's like .1 weeks pay every 2 weeks ;D..

       I have to get batteries also .. gonna order SLA batteries 4-- 12 volt ones and put them in a saddlebag (Panniers) 2 batteries on each side trying to keep them low as possable ..

    So it's just time waiting for $$$ now till I get this thing going ..

    I have done a few short "Test Drives" in the 1 gear I have and it seems OK .. not pulling or anything ... Gonna stay with the standard brakes for now they work fine ..

       Excited can't wait but just gotta .. Thanks again for the Reply ..

      

Offline Hardcore

  • Confirmed
  • Master of Magic
  • *****
  • Posts: 422
Re: Question : About wheel centering
« Reply #5 on: December 06, 2009, 08:21:42 PM »
very nice looking bike ;)

Offline diverdon

  • Confirmed
  • Bachelor of Magic
  • ****
  • Posts: 178
Re: Question : About wheel centering
« Reply #6 on: December 06, 2009, 09:29:38 PM »
very nice looking bike ;)

    Thank You Hardcore . That's a Trek .. What is called a "Hybrid" and I added a couple of things to make it even more comfortable for me .. Basically just different bars and the seat ..

      Haven't been on it for a while and my tight clothes are telling me I better do something .. So this motor might be just the answer .. I really disliked the wind here in Florida . Planned my rides to ride into it at the begining.. Just hope I don't depend on the motor too much  ::).. Thanks for the help , Can't wait .. Don J.

     

     

Offline Leslie

  • Confirmed
  • PhD. Magic
  • ******
  • Posts: 2,047
Re: Question : About wheel centering
« Reply #7 on: December 16, 2009, 01:48:58 AM »
If your frame is steel.

Get a threaded rod two washers and nuts.
Place threaded rod into dropout and screw bolts and washers in between them.

Make it so as you screw the nuts outwards it spreads the dropout. b Ever so slowly even over a day as continue to spread the dropouts further appart.  Undo them and see if you get 10mm extra width then use large supporting washers to centre the hub.


excerpt with quote below
Quote
They have to be opened up a bit more than 1/2". So of course you have to open it up about an inch and a half to achieve that. It was very easy to do. I just got some axle size threaded rod two large washers and two nuts to fit the rod. I cut the rod to about 7 inches, marked the center of the rod and clamped on a pair of vice grips on the center mark. I rolled on the nuts on each side of vice grips, then the washers. I then inserted the rod in the rear drop-outs as you would install a rim. I lined up the vice grips with the seat post tube to make sure it was centered, then I backed the nuts off so the washers were snug against the inside of the rear drop-outs. Then I started doing a few turns at a time on each side to widen the dropouts. Once it is at about an inch and a half, leave it there for a couple of hours......take your time, don't rush it. The frame had been freshly powder coated and I had no problems.

In this picture he secures the centre of the threaded bolt to a bench or wood but to achieve this properly the base of the rear fork needs to be secured as well.  There is no way in hell you need a 1.5 inches so all this maybe totally unnecessary.

Just a couple of large eye/hooks at the base of the rear forks just after the weld to stop the frame moving should do this easy plus anything that will avoid moving things at the welds is better.




If you have an aluminium frame.

Do not do the above.

Get a smaller cassette.

Or

The off centre spoke idea  can work however you may find a combination of spreading an aluminium frame 3 or 4 mls will allow you to maintain enough thread in the nipples to make the design optimum.

Spread the aluminium frame too much and it will either crack the frame before your eyes or when you ride over some time.
« Last Edit: December 16, 2009, 02:01:53 AM by 317537 »

Bring it on

Offline Leslie

  • Confirmed
  • PhD. Magic
  • ******
  • Posts: 2,047
Re: Question : About wheel centering
« Reply #8 on: December 16, 2009, 02:36:20 AM »
Warning Steel frames only.



Here I drew up how I could imagine the correct method to spread drop outs evenly.

This way you can both have your 8 speed pie and eat it.



Using a 3 point anchor design will allow both sides to spread evenly.

The total cost shouldn't be that much for the proper job.

The bolts that touch the frame could be covered with some garden hose to avoid scratches.  On some frames, a hole is supplied on the reinforcement plate at the base of the bottom rear fork for installation of a ike stand, this too could be used as an anchor point into the ply base.

Leaving the frame in the hot sun to heat up the metal before and when spreading the drop outs and then allowing to cool before releasing it should stop the frame from closing back up substantially. This would allow you to not have to apply too much force to gain the best set width from your work without initially having to spread the drop out too far.

On the top rear fork you would only need it to be held together with a G clamp or not at all.

My HSB36 doesn't centre also too far from the chain side.  I placed both the torque and outside washer on the inside of the opposite of the chain side and for the chain side I used a thin washer I ground down by half its thickness as not to compromise its strength. By hand and great super human strength, I pulled the rear fork over the all washers.  This solved my problem.



Or get a 5 speed cassette and removal tool.
« Last Edit: December 16, 2009, 03:22:39 AM by 317537 »

Bring it on