Bad Frame? Damaged Frame?... (Rear Triangle Out of Spec))
 

Well, I kept thinking that I just needed to adjust my rear wheel re-dished... But then I took a close look at the frame itself and I found this...

http://www.garberdesign.com/bike/badFrame1.png

My rear triangle is 'pushed' to the left by about a 1/2"... It's an aluminum frame (got it used from the Internet) and is made by KHS.

http://www.garberdesign.com/bike/newBike3.jpg

I doubt the frame was hit that hard, because a 1/2" movement would take a serious blow, and the frame looks brand new. No cracks, no impact areas, everything fits fine, just has an offset by a half inch. Grr...

What should I do? Trash it and get another frame?

It looks that way. Make sure and ask if the frame is straight next time. We don't always think of these things beforehand.....and it's wrong of sellers to do this.... but that's life. I almost got hosed buying a misaligned frame online, but it was steel, and was able to get it repaired.

You'll find another frame...

If it is a new bike from a bike shop...I would call them and see if KHS would warranty it. If it is a used bike then yeah, you'll just have to pick up a new frame. Sounds like the frame came that way...and in mass manufacturing, that happens sometimes. I would think it should definitely be covered under "manufacturer's defect".

Do you have a photo of the bike from above, similar to the sketch? I would think the rear tire would have some clearance problems?

Nope, no clearance issues. The whole rear triangle is off to the side, therefore the wheel fits perfectly in the center of the triangle. Okay, a 1/2" was a bit of an over-statement. It's about 1/4" shifted to the left... I took the frame to the local KHS dealer, and they informed me that I needed to have the original recipe, and that I needed to take it back to the dealer I had originally bought it from... :notamused:

I don't know what to think about this. I would think that any damage caused outside of manufacture would cause some major alignment issues. It is possible that the wheel was re-dished to realign in the frame. Have you tried a different wheel? If a second wheel fits then i would ride it & forget it. It may be just KHS's way of building bikes.

Maybe they made it offset so there would be clearance for a rear disc brake? As long as the rear wheel is centered in the frame, I wouldn't worry too much.

But if the bike doesn't track straight, it's a problem.

Also, if something has happened to an aluminum frame to distort the rear triangle, I'd be leary of riding it.

I agree about trying another wheel. This is an interesting situation.

Wait a minute, this frame is Al. Al can bend, but not like that. To move a triangle like that, it would take much force, which in turn would crack or break outright. What the OP is describing is similar to what I found in a steel frame I bought used, except the wheel did not sit straight between the stays. The whole triangle was about 3mm off to the left between the chainstays. Framebuilder no.1 thought he staightened it, by measurements at least. When he put a wheel in though, it was the same 3mm off! He didn't have the expertise to do further repair, so it was off to framebuilder no.2, who I should have taken it to in the first place. He had an alignment table, and it turned out the front end was off 6mm, and one chainstay was 1mm shorter than the other. That's why the rear appeared aligned, but the rear follows the front.... if the front is off, the back will always be off. He re-brazed the chainstay, aligned the frame and all is well.

Interestingly, the people who originally sold the frame told me "just ride it". Hey, it's my health, not theirs. I knew something really off, and it was. If you've ever ridden a frame out of whack, it can be a chore, if not dangerous.

With the KHS frame in question, what ever is off was likely done from the factory. Wet your tires and see how it tracks. I really can't imagine it being designed that way. KHS themselves really can't help you either , they're just suits, not actual builders.

I would post this on the framebuilders forum and see what they say.

I'm not a framebuilder, but I stayed at a Holiday Inn last night :)

Ooh, wet your tires. I like that suggestion.

I haven't measured my frame yet, but I recently bought a no-name bike from Nashbar, and it doesn't go straight when I ride it no-hands. I bought it months ago. If I discover it is defective, have I lost my chance to return it?

I have never measured my center line though my rear dropouts, but I think it might be fine.
If it were BENT that much I would think there would definitely be some tire/brake clearance issues. Or some metal/paint issues where the max bending occurred. Since disc brake bikes need added clearance for the disc, this might just be the way it is.


Actually I just looked at my KONA Kula Primo, and by eyeballing it I would say mine is the same.
1) The disc is on that side
2) the larger dish is on that side
3) I think thats the way it is!

I just called customer service at Nashbar about my own problem. The guy said they have a 100% satisfaction guarantee and there's no time limit. So good. I'll go measure my frame now.

I will use this technique which I learned long ago:

Take a long piece of string and run it around the front of the head tube. Bring the ends to the dropouts. Using a vernier caliper, measure the distance between the string and the seat tube. There are two sides of the string passing by the sides of the seat tube, leaving two distances to measure.

Uh, did I state that clearly? I'm not sure.

Tom,

Yes you certainly can. I would too.

http://www.nashbar.com/bikes/PolicyI...icyInfoContent

FYI .....As an alternate method, I started using a Craftsman 4' straight edge. It's a 1'"x4'" I beam, straight as heck. The Park frame checker is not long enough for long wheelbased frames! It works incredibly well if you happen to have one around. Place the edge in the same place on the head and seat tube, then measure the difference from the inside of the dropout to the straightedge.
I get consistent results.

I'm just not good with string :lol: