Rear Wheel off Center

GoldenMotor.com

Tinsmith

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May 15, 2009
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I have been slowly getting started on rebuilding my first chopper bike. I have replaced the rear skinny tire with a 3" tire. This required the motor to be offset a bit and with the help of 2-Door that worked out fine. My problem is for the rear wheel drive sprocket to line up with the pedal sprocket the rear wheel sets off center about 5/8" to the right side. Both chains are lined up nicely and I do have some room to move it closer to the center, but then the freewheel sprocket won't line up any longer. I can adjust the drive side without much problem, but the question is other than looking crazy from the rear is it an issue?

Thanks, Dan
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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It depends. I have my tire offset a bit on my OCC and it doesn't really affect much beside my feelings. I notice it when I'm riding on crowned roads mostly but then again I am VERY sensitive to weird stuff on any bike. Most people won't feel a thing as long as it's not too far off.
I'd say ride it and see if it bothers you.
 

2door

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Sep 15, 2008
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Dan,
When you changed to the 3" tire did you also replace the rear rim, or is it the original? I'm a little vague on exactly what the problem is. You say the chains line up well but I gather the tire is off-center to the frame?

As for pedal chain misalignment, you can get away with a little, unlike an engine drive chain that needs to be near perfect. Bikes with derailers and gears have lots of misalignment between the pedal crank sprocket and the cassett and they work just fine.

I agree with maniac, ride it and see if it is a noticable annoyance. Also, how much engine off-set are you using? I found, on the Nirve Switchblade that 9/16" worked perfectly but all frames are not created equal.

Tom
 

Tinsmith

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May 15, 2009
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Thanks fellas. I didn't think 5/8" off center would be a big deal, but figured I'd ask if anyone else had this issue and if it might be a dangerous thing to do.
Tom, no the tire is mounted on an 3" wide aluminum rim that I re-spoked on the original rear hub which had a band brake set-up that I really didn't like a whole lot. With it gone I intend to mount a set of wide caliper brakes on the frame and with the wheel offset they will be also. Just looking at things it appears to me it should work OK, but after some years at this, I work real hard at eliminating as many mistakes as I can before hand. The advice on the motor mounts worked out great. (I just used some angle I had laying around). Being quite technically challenged, and I will stay that way), I'll get Jackie to take some photos and try to get them posted. I won't have a chance to get on it this weekend but will try next week some time.

Thanks again guys!
Dan
 

a_dam

New Member
Feb 21, 2009
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Momence, IL
Could it be a matter of dishing? I've respoked a few 27 inch and 700c wheels, and when I first lace them up, I adjust all the spokes about evenly (same amount of threads exposed) until the wheel starts getting some tension. Even with shorter spokes on the drive side, the dish can easily be 3/8 off before checking and correcting it. Just loosening all one side's spokes one turn, then tightening the other side's can change the dish quite a bit.
My bikes are mostly old skinny tire and frame "10-speeds" which won't allow the tire to be off much side-to-side.

Do you use a dish stick (gauge) when wheelbuilding? I made a very simple one and could post a pic if you want.
 
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Tinsmith

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May 15, 2009
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Thanks a dam for taking the time to explain what you have experienced building wheels. This was my first attempt at a wheel and it took a good while to get it as right as I could. A wider rear hub to go along with the wider rim I used would help, but I stuck with the hub that came with the original wheel on the bike. I have been pretty successful with the fabrication of my two bikes, but when it comes down to knowledge of things bicycle I am lacking a good bit, and I don't have anyone here who really knows. Most of the people I know who ride bicycles just know a little about the 10-15 speed bikes. Not any wingnuts here who try to do what "we" do.

The wheel does run quite true. I also made up a "feeler stick" gauge and was able to get it running pretty straight.

Thanks for taking the time and trying to help

Dan
 

2door

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Sep 15, 2008
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I had the same thought as a dam. When I read that you used the original hub the only thing that made sense to me was the rim was off-center to it. That would be in the 'dishing' of the spokes.

I've never laced a rim but I have sucessfully 'trued' a few and he's right about only taking a little to move the rim side to side based on hub center. That might well explain how the rim/tire are off center to the frame centerline.

Looking forward to seeing some photos of your chopper build.

Tom
 

a_dam

New Member
Feb 21, 2009
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Momence, IL
This was my first attempt at a wheel and it took a good while to get it as right as I could.
I hope I could be of some help to anybody brave enough to try their hand at wheelbuilding. From a young age I was never afraid to tear into things and learn all I could (often with no help or advice). But even after a lot of mechanical experience, the first time (or tenth time) building a wheel is surprisingly hard!
Even if you're reusing pretty much all the same parts, it takes (me, anyway) a lot of work and time to do a wheel. And going to different sized rims and/or hubs will be an extra challenge.

We are lucky nowdays. With the internet, we have sites like motorbicycling.com, Google, Sheldon Brown (invaluable resource for learning bicycle basics and not-so-basics... RIP Mr. Brown), free spoke length calculators, etc..

If you got a new rim spoked-up and running true, then you must have mechanical knowledge and patience.

Keep us up to date on the chopper build, Tinsmith.
 
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Tinsmith

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May 15, 2009
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Maryland
Just returned from a trip to North Carolina for a long weekend to attend the wedding of a young Marine Captain Pilot family member. He had six of his Squadron Pilots perform the crossed/sword entry which most is great and I was able to talk with these young men a little about how it was 45 years ago. Man am I old!

Anyway, hope to get back at the chopper this week and will try to get some photos. I've done a lot of thinking about the wheel while being gone. I do think it's laced up pretty well and is true as I can get it. As for my mechanical abilities, in my mind they are questionable at times, but probably pretty average. Patience is something I excel at I believe. Being able to sit on a tractor day after day and cultivate hundreds of acres at 3 to 4 mph develops patience.

There is room to still move it to the drive chain side, but by doing that the pedal sprocket will be out of alignment. If there was some way to shim out the freewheel sprocket 1/2" or so it would get things pretty close. Like I said, I'll try to post up some pics later in the week.

Thanks for the input guys.
Dan
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
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You came to the right place, Dan. Jackie's pictures will no doubt help people see the problem and maybe a solution. I hope so. Hi to Jackie & Willie, too. Moosh says hi & I'm waggin' me tail.
SB
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
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northeastern Minnesota
Freezing your tail end reminds me of a traditional Ojibwe animal story. Lots of stories supposedly explained how animals look or their behavior. I think I told you the one about why dogs sniff each others tails, if not I'll share it. (Traditional stories are only told when there is snow on the ground, but there is, so I can tell one.) The story that came to mind is about our elder brothers, the black bears (ni siiyay mukwahwug).

Long ago, before the coming of the white man Mukwah had a magnificent bushy tail, better than anybody in the forest including the fox. One day Mukwah woke up from his hibernation nap and realized his stomach was growling... that's what woke him up. What to do? He stepped outside his den and not only it wasn't spring thaw yet, it was really cold and there was lots of snow on the ground. He looked over at the nearby lake and saw that it was frozen and figured maybe he'd do some ice fishing. Fish would be good. Walleye, maybe.

He managed to break a hole in the ice and figured his tail would be attractive and when a fish took a nibble he'd yank his tail out and land a fish! So he carefully lowered his bushy tail under the cold water and wagged a little now and then, kind of like what we do today jigging for walleye. That's what he did and he kept at it even though the fish weren't biting. He did it for so long that he ended up falling asleep sitting there on the ice.

When he finally woke up he discovered that his tail was frozen into the lake! Holy ....! He yanked as hard as he could with all his bear power and his magnificent tail broke off so that all that was left was just a little stub. Talk about a bad day.

So that's how Mukwah lost his bushy tail and ever since that's the way it is for brother bear.

Moosh and I are inside by the wood stove, so even though it is cold and blowing snow outside we are not freezing our tails off!!!
SB
 

KCvale

Well-Known Member
Feb 28, 2010
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Phoenix,AZ
Well, if your wheel axle is not at a 90 to the frame neither is the sprocket to the engine.
A misaligned back wheel will wear your tire, sprocket and chain.
When your chain loosens up and starts jumping off in the back you'll know where to look.

Pictures would sure help us help you find a fix.
 

Tinsmith

Well-Known Member
May 15, 2009
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Maryland
Thanks KC, The wheel is aligned with the frame and motor, it's just off-center. I aligned the freewheel sprocket on the wheel with the pedal sprocket then off-set the motor and made a mount for the drive sprocket on the rear wheel. If the wheel is near center the pedal sprockets will not be aligned. I can modify the drive side sprocket set up to compensate and am trying to figure a way to modify the freewheel pedal sprocket mount. If I can do that somehow it will be close to center.

Thanks for you input.

Dan
 

Tinsmith

Well-Known Member
May 15, 2009
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Yep, I've picked up on that way of compensating from threads you guys write, but being the simpleton I am, I'm trying to keep it within my limited bicycle knowledge. I'm gonna put some pics tonight I hope and show what I have and then entertain you guys with my take on a solution. The fellas at the machine shop always bragged they had seen it all. I promise if I'm in the mix, you haven't seen or thought of it all. I "expanded" my mind quite a bit in the 60's and 70's and once in a while I surprise myself.

Thanks,
Dan
 

2door

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Sep 15, 2008
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I'm looking forward to seeing some pix cause I'm confused, Dan. If you're using the original hub I can't understand why the pedal chain sprockets don't line up. What did you change? Even if the rim is dished one side or the other, that would have no bearing on where the sprockets are in relation to the frame using the original hub. Are you sure the pedal chain was aligned before you started?

Get some photos up soon so we can see exactly what's going on and maybe get you out of this dilemma.

Tom
 

Tinsmith

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May 15, 2009
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OK, let me throw this thought out and see what you guys think. Although I haven't been in the shop in over a week to even look at it since we have been travelling some, it has been on my mind and listening to you guys and myself trying to describe the situation has given me a thought. Maybe this wheel wasn't set up running in the center to begin with. The only thing I have changed is the width of the rim and tire to 3" wide.

The bike and motor were a "kit" that my wife got me probably 5 years ago. I put it together and rode it a couple years until the drive sprocket set-up started to fail. At that point I was building my stretch Worksman and set it aside and haven't really looked at it until a couple months ago. Given that I can't remember squat these days I don't recall if the wheel was centered in the first place so I am of no help on that point.

Regardless, it is what it is now and I'll just have to work with what I have. I have tried to attach some photos so we will see if that worked. If not, I'll send them to SB and see if I can sweet talk him into putting them up for me.

Thanks guys,
Dan
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
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northeastern Minnesota
Since there doesn't seem to be a simple solution to having it centered it seems to me the suggestion of others to ride it and see what you think is a good one. Knowing you as I do I'm sure that it not being centered doesn't feel quite right, but you're the one who will be thinking about it and noticing. Nobody else will care or probably even notice. There are better, more interesting things to look at on the chopper, as I recall. Just pretend that this one was supposed to be like that, slightly off center. And it is perfectly off center. Just right.

Forgive the diversion of more story telling several posts back. Can't help it, I guess. Like when we worked out in your shop on Saturday mornings tinkering and trading stories. Those were good times, my friend.

Keep us updated on what you're doing with the chopper. In fact, why not turn this into a rebuild thread with some more photos? What did you finally decide to do about fabricating a gas tank for it? Come on, show and tell!
SB
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Dan,
What are the two things the red arrows are pointing to? It appears the stays have been spread quite a lot to get them in there. Was that necessary to get the drive chain to clear the frame? How is the sprocket attached to the hub? Maybe a top hat on a disc brake hub?

Another thought: If the original tire/rim were narrow as compared to the 3" one you have now, it could have been off-center but it wouldn't have been as noticable. The wide tire now brings that off-center situation to focus because of its close proximity to the frame.

Tom
 

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