dynawolf

Hi,
I have a 2017 Spec Roubaix Comp with Conti GP 400 II size 28 tires. The bike manufacturer claims it will hold a size 32 tire. The left side is a few millimeters from the left chainstay and the right side has plenty of room. Is there a way to adjust on modern bikes?

Thanks

Litespud

Do you mean that the tire is mm away from the left chainstay (the horizontal part of the frame extending rearward from the bottom bracket) rather than the dropout (the part through which the rear axle goes)? Tires don’t go anywhere near dropouts. There’s no easy way to adjust the alignment in a frame with vertical dropouts, short of throwing yourself on the mercy of a frame builder or other qualified individual, and I imagine that anything he/she suggests will depend on what the frame is made of. First thing for you to check is that the misalignment isn’t the wheel or the tire. Measure the distance from the rim (not the tire) to the inside of the chainstay on both sides. Is the rim misaligned? Reverse the wheel (ie cassette on the left hand side). Does the misalignment also reverse (ie closer to the right chainstay)? If so, then the wheel is the problem and needs to be redished. Short of the tire simply not sitting square on the rim, this would be the best result, as a redish is a simple and cheap job

jimc101

What your saying doesn't make too much sense, this is a case where a photo would really help to ID if the issue is th the brake setup, wheel (dish, unlikely if a factory wheel) frame (again unlikely with mass production and QC checking) or user error

dynawolf

CORRECTION: Left Chainstay.

Brocephus

I scored a cheap bike (Diamondback hybrid/metro-commuter) off Craigslist not long ago, that I realized later also had an off-center rear wheel. I could see (as you did) that the gaps at the chain stays were a little different, but I most noticed it by looking past the seat tube (from above and from the front), and I could see the right side of the tire was almost flush with the seat tube, but the left side of the tire stuck out a good 1/4+ of an inch. (my tires are 42 cm wide.)
I searched the internets, and asked some questions here, and what I gathered was that steel frames can be tweaked a bit, but alloy and carbon frames can't.
I was told to ride the bike with no hands and see if it had any tendency to veer to one side, and it actually rode fine. But, it was one of those things that bored into my brain, LOL, so I bit the bullet and scored a deal on a nice Marin hybrid frame on-line, and transferred the parts myself.
Anyway, first, you'll want to make extra sure you have the wheel securely fitted into the drop-outs. Another recommendation i got was to flip the bike over, and pull the rear wheel, and reverse it, and insert it into the drop-outs. If the wheel still leans to the same side, then it's the frame that's off. But if it leans off the othe other side, it's the wheel (I just noticed Litespud already recommended this).
Did you buy the bike new, or was it used ? If it was new, have you had any crashes or any incidents that might have torqued the frame ?

edit: BTW, while i was neurotically fixated on the issue, I came up with another test. I flipped the bike upside down in the garage, then got a piece of dental floss, about 2.5 ft long, and centered one end on the tire, and taped it in place. Then carefully centered it along the middle of the tire as far as it would go, then taped the opposite end to the tire (giving me a thin white stripe down the middle of the tire).
I closely checked to make sure it ran consistently down the center of my tire, then slowly rotated it, watching to see how well in centered on the little bar that is welded to both chainstays, just behind the bottom-bracket (not sure what those are called).
Those little crossbars usually have a little drain hole facing to the rear, and i used that as my reference point, and very oddly, the dental floss ran right down the center of the hole in the little crossbar. So according to that, my rear wheel was straight, when there should have been some deviation. So, that was kind of a head-scratcher.
So, you might try something like that to get another reference on how your wheel is actually rotating.

davidad

Redish.

Phil_gretz

Flip the wheel in the dropouts (as said above) and test whether it's a rear triangle frame alignment issue or a rear wheel dish issue. If the offset flips to the other side, it's a dish problem. If the offset stays where it was with the wheel in the previous orientation, then it's a frame issue.