Can a tire be perfectly equally out of lateral true?
 

Last night I notice that my rear wheel is about a quarter inch offset from being inline with the center of the bike. I checked the QR skewer and it's seated properly in the frame. But the center of the wheel is not in line with the center of the bike.

I never noticed this before.

The wheel is true. It spins perfectly round. No wobble at all. It's not crooked in the frame. It's in a straight line with the frame. It's just not centered on the frame.

Is this normal?

Or could the wheel be perfectly out of lateral true so it's a quarter inch offset from the center of the bike?

This is not a super high end bike if that makes a difference. It's a Specialized Crosstrail. Not junk but not fancy either. It rides perfectly fine. It just looked weird when I noticed it and I'm wondering if this is normal.

Dish? Just move it over until it's centered.

Yes, could be one of two reasons, incorrect dish (as mentioned above) or incorrect spacer placement on axle. Clearances of cassette and accurate measurements per Sheldon Brown or some other visual representation of factors in rear wheel offset would show what is responsible.

I'll try to get some pics later.

Do I care if it's offset? I've had the bike for 3 years. This is the first I've noticed it. And I only noticed it visually, not because it was riding weird. So do I care about this and need to fix it or can I leave it the way it is and never think about it again?

I did have the cassette replaced a few months back. Could it have changed then?

Yes it could have changed, if the spacing was changed for some reason.

It is possible that the wheel is not properly dished or the frame is out of alignment. If you put the wheel in the frame backwards (cogs on the non-drive side), is the offset still there (same side/amount)? If so, the frame is out of alignment. If the offset moved to the other side with the wheel reversed, then the wheel is not properly dished.

I'll check that out later.

I gotta say...the mechanics forum is the best forum on Bikeforums.

I swear I could ask the proper number of chain links to make a chain for an obscure Italian bike from 1922 that only 3 people have ever heard of any someone here would instantly know the right answer and will be happy to share their knowledge.

Seriously. Best forum ever!

I've worked on lots of bikes that had improperly dished wheels. That would drive me crazy. The fix is to loosen all the non drive side spokes 1/2 turn and then tighten the drive side spokes 1/2 turn and repeat the process until it's centered. If you are careful and precise during this process, you shouldn't have to do any additional truing afterward.

To answer your second question: Since you noticed, now you have to fix it or, like me, it will probably drive you crazy too. If you hadn't noticed it, you wouldn't have to do anything about it.

I have selective OCD

The amount I HAVE to do something is directly correlated to the amount of patience I have to deal with it at any given moment

It matters if you want to cram as wide a tire in the bike as possible.

I put 38 mm Compass Barlow Pass tires in my wife's Specialized Sirrus, and noticed the dish when one side had good clearance and the other side is like 4 Å from the tire.

My kid's BMX bike came with a wheel that was true but very skewed/dished to one side. I made the bike shop fix it.

Looking for a "problem" to solve? If the offset is toward the NDS, then re-dishing will not likely improve anything. Rather, it will somewhat weaken the wheel and it's very easy to ruin the trueness.

Maybe look at your bike less and ride more.

BTW, the universe does not allow a tire to be "perfectly" centered.

This is assuming that the rim is offset towards the non-drive side. I would always assume the opposite, that the rim is offset to the drive side due to low non-drive side spoke tension.

Stretch a string from one rear drop out around the head tube back to the opposite drop out. Measure from the string to the seat tube to see if the drop outs are centered. If they are then it's the wheel's dish needs adjustment.

It's probably more important that the plane of the rear wheel be in the same plane as the front wheel. Or at least as close as can be. Less important that it line up with the frame. However if you've been riding it and there aren't any odd noticeable quirks............ who's to say? Maybe just faster tire wear than others.

Without knowing how the axle is set up on that bike, I'd suspect like a few others that a spacer was put on the wrong side or something.

1/2 turn on both sides: that would work fairly well on a front wheel. (If a wheel had differing spoke tension due to a rim that's not perfectly flat, then it might get slightly out of true. That's easily adjustable, of course.)

But I don't think that's correct for a back wheel. The drive side spokes have much more tension. I think it would be a bigger amount of turn on the non-drive side compared to the drive side.

~~~~~
Frame out of alignment
My old bike had a noticeable offset in the wheel. A very slight filing of one aluminum dropout moved it back to the center. It only took a small number of careful filing strokes with jeweler's rounded file. A very tiny change in the dropout makes a much larger movement way out at the rim.

Yes, try flipping the wheel and see where the tire centerline goes. same side: frame is out of alignment. Opposite, equal movement: wheel dish

That's why you loosen the non drive side first. It makes it much easier to tighten the drive side spokes. Incidentally, I suppose it's possible for the wheel to be dished too far to the drive side, but I can't remember that ever being the case.

I had a similar issue once with a front wheel. The kid at the shop only tightened the spokes on one side. The hoop was exactly, perfectly centered over the flanges, but he failed to realize that 1 flange was moved inboard a bit to accommodate the disc. I made the shop fix it.

On a group ride we had a guy on a Trek carbon bike whose rear wheel was so improperly dished (or maybe improperly installed) that the tire/rim was dragging on the seat-stay. It made squeaking noises when he pedaled. I mentioned it to him, he said: "Ok, yeah, thanks" and rode off. Squeak, squeak, squeak.

So a few miles later, I mentioned it again. He said "I'll deal with it later" & rode off in a huff ahead of the group. Like he thought I was trying to slight him or something.

Since I was on-duty, I felt obligated to ensure he was duly informed, of a potential safety issue with his equipment, & I did so, for the safety of himself and the others I am responsible & potentially liable.

Later, he gave me tons of attitude for being too fast (I was riding the posted pace) & he yelled at me after passing him on a relatively easy climb he had a full-on headstart on...I didn't see him the next week & I hope his carbon seat-stay is fully worn through...

Sorry, I know this has little to do with the OP's thread, I just wanted to share a dishing related story.

I did initial and what I hoped was final truing of a rear wheel at a local bike co-op. I had my choice of fancy park truing stands. Unfortunately it was out of adjustment, so my lateral truing was fine, but the dish was off.

Unless you own a Park truing stand that you bought brand-new and haven't allowed ANYBODY else to use, I'd advise assuming they're all off. I just flip the wheel over repeatedly until the two sides check the same.

I bought a used TS2 that was out of adjustment.
Park had the instructions to set it up "true".
https://www.parktool.com/product/docs?cat%5B%5D=11