Montague Allston Frame Question - Dogtracking or Crabbing

[ridedog]

My bikes' front and rear tires are not aligned.

By this I mean a straightedge held against the front or rear wheel will show an appromixately 2 inch offset as compared to the other wheel.

The dealer says this is "within specification". This is the second bike with the identical situation.

So the wheels are in a different track. If this were a car they would call this dogtracking or crabbing.

This is a folding bike so the frame is in two pieces with a hinge.

Belt drive so it's hard to move the rear wheel to the right or left with spacers.

Any ideas?

https://i.kinja-img.com/gawker-media/image/upload/c_scale,fl_progressive,q_80,w_800/bfdl8alkje9lkasfzzjp.mp4

[ichitan]

(07-16-2022, 09:52 AM)ridedog Wrote:  My bikes' front and rear tires are not aligned.

By this I mean a straightedge held against the front or rear wheel will show an appromixately 2 inch offset as compared to the other wheel.

The dealer says this is "within specification". This is the second bike with the identical situation.

So the wheels are in a different track. If this were a car they would call this dogtracking or crabbing.

This is a folding bike so the frame is in two pieces with a hinge.

Belt drive so it's hard to move the rear whell to the right or left with spacers.

Any ideas?

Ask another bike dealer if they believe this is something that they think can be claimed on warranty. Maybe you can get a straight bike, or your money back.

Try to determine where the problem is. I have seen some bikes which have been loaded with heavy things on top of them for transport, which has bent the frame. Maybe the front forks are out of alignment. Maybe the rear dropouts are out of alignment. Maybe the problem is with the joint where the bike folds. If two bikes are the same, maybe it is poor quality manufacturing. There are bikes coming out of China, where they don't care about quality. There are shops which will sell them, and people who will buy them.

Do the wheels line up in the middle of the frame, or is a tire closer to one side of the frame than the other?

It is not a good idea to fix something crooked, by making something else crooked. If you determine where the problem is, that is what you address.

You could try to figure this out yourself. Or you could post photos of the bike from as many different angles as possible, to see if people on this forum can help.

Is the frame steel, aluminum, or something else? Any type of bike can be repaired, but a lot more people can repair steel frames.

You can also post photos of the bike on this forum, and warn people not to buy this type of bike, or at least check alignment before buying a bike like this.

[Jesper]

(07-16-2022, 09:52 AM)ridedog Wrote:  My bikes' front and rear tires are not aligned.

By this I mean a straightedge held against the front or rear wheel will show an appromixately 2 inch offset as compared to the other wheel.

The dealer says this is "within specification". This is the second bike with the identical situation.

So the wheels are in a different track. If this were a car they would call this dogtracking or crabbing.

This is a folding bike so the frame is in two pieces with a hinge.

Belt drive so it's hard to move the rear whell to the right or left with spacers.

Any ideas?

https://i.kinja-img.com/gawker-media/image/upload/c_scale,fl_progressive,q_80,w_800/bfdl8alkje9lkasfzzjp.mp4

My understanding is that the frame appears to be straight, but with front wheel positioned in a manner where it aligns with the frame, the rear wheel points at an outward angle from the centerline of the frame. Your problem is not where both wheels point along 2 parallel planes which are offset by 2"? Either way, 2" is excessive.
Without seeing a photo I assume that the wheel position cannot be adjusted in the drop-outs to fix it. Does the tire sit centrally positioned when the wheel is properly installed in the drop-outs? If the tire doesn't sit equally aligned in the rear fork between the chain stays then there is damage to the frame causing misalignment, or bad framebuilding (e.g. misaligned drop-outs).
If the rear wheel is aligned in the fork then it could also be due to the frame's folding linkage(s). Also, maybe suspension (if applicable) related; something I am unfamiliar with.

Previous comments pretty much cover what you need to do. I would like to see a photo of the wheel alignment. If your previous bike was the same maker/model with the identical misalignment I would more suspect a defective manufacturing process or common assembly issue. Although bike damage is not uncommon during shipping and handling, the damage, even though similar, will not (in most cases) be the same.

If you received it boxed, any damage that was significant enough to misalign the frame would also be readily apparent in the condition of the box. If you bought it from a dealer shop I would ask for one still in the box if possible and have them assemble it so that it can be immediately checked.
I would be quite specific in asking the dealer what the tolerance specification is for the that frame and where it was referenced from (lets you verify).