Mountain Bike Reviews Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
1,500 Posts
Discussion Starter · #1 ·
Many hardtail frames have rear triangles that are asymmetrical. There can be up to 0.25" more clearance in the stays on one side when compared to the other. This limits the rear tire choices. Walt, what should one expect from a custom builder?
 

·
Premium Member
Joined
·
7,491 Posts
Huh?

There are lots of reasons to make something purposefully asymmetrical (ie, a chainstay yoke designed to clear the chainrings on the driveside and not on the nondrive) - is that what you're talking about? Or do you mean, one stay just isn't bent as much as the other, so it's just a random accident?

If the frame is aligned, and the tires you want to run will work, it's probably not a big deal. If it's causing problems, it's obviously something you should take up with the builder. What did he/she say? 1/4" is quite a bit, IMO. That would be visually obvious even at a glance. Doesn't sound quite right to me.

-Walt

fos'l said:
Many hardtail frames have rear triangles that are asymmetrical. There can be up to 0.25" more clearance in the stays on one side when compared to the other. This limits the rear tire choices. Walt, what should one expect from a custom builder?
 

·
Registered
Joined
·
1,500 Posts
Discussion Starter · #3 ·
Walt; sorry, I should have been more explicit. The frame in question was not one that I had purchased, but a custom, steel frame that was not built to be asymmetrical; it ended up that way by "accident". I wondered what could be expected from a manufacturing standpoint.
 

·
Premium Member
Joined
·
7,491 Posts
Hard to say

For non-aligned parts (ie, we're assuming the BB/seat tube/head tube/dropouts are in plane and such) I shoot for <1mm asymmetry. So if I bent some seatstays, for example, and tacked them, and stuck a true wheel in, I'd expect the stays to be very close to the same distance from the rim.

Occasionally I have to remove some stays and throw them in the scrap bucket/start over to hit that mark, of course. You could certainly be more precise than me, but IMO it's not worth the hassle. If one stay is 10mm from the edge of the (mythical perfectly even/round) tire and one is 10.5mm, whatever. 6 or 7mm difference is quite a bit, though. I don't think my first frame was that bad (well, ok, it might have been, since I had no idea how to use the "bender" I had and only had one pair of seatstays to work with...) I would not send something out the door with that much asymmetry now, certainly.

-Walt

fos'l said:
Walt; sorry, I should have been more explicit. The frame in question was not one that I had purchased, but a custom, steel frame that was not built to be asymmetrical; it ended up that way by "accident". I wondered what could be expected from a manufacturing standpoint.
 

·
Registered
Joined
·
2,228 Posts
Make sure you flip the wheel around to take that variable out of the equation.
 

·
no dabs
Joined
·
410 Posts
Thylacine said:
Make sure you flip the wheel around to take that variable out of the equation.
And if you are going to that point, might as well use the same spot on the rim to take errors in true out of the errors in measurement.
 
1 - 6 of 6 Posts
Top