bent frame fix?

I found out that my frame is bent today (after riding Jerry G’s uni).

It is kicked inward from the left and the right fork is farther forward than the left. My guess is that this bending is from pulling hard with the left hand up and to the left. The seat is flatter on the left side and the handle is cracked on the right (so everything matches) :roll_eyes:

I expect that the frame will bend again, so I would like to learn to fix it myself. Any tips on how to go about bending back right “the first time”?

Should I just take it to a bike shop?

What kind of frame is it?

Good point.

It’s just the wide Nimbus II frame (for 24").
I’ve cracked it 3 times, but it’s been rewelded.
I know I could get a “better” frame, but I like it.

Well, this thread can die (as if it wasn’t dead already).

I rode the toughest trail today and then took the uni to the bike shop to align the frame.

Once I removed the wheel, I noticed that the frame had cracked THROUGH THE WELD. The dude that welded it said that the weld would hold 11,000 pounds or something like that and that the frame would crack above or below that spot. Instead, it cracked across the weld diagonally (as if to add insult to injury).

Anyway, I will probably elect to weld it again.
I like the Nimbus frame for the mud clearance.
I guess getting a different Nimbus frame will not help.

The stamped steel main cap bearing holders on the Nimbus/Yuni/United and many other similar frames are wider than the bearing. They also fit loose enough that the frame can twist and rock on the bearing. A though I’ve had is to glue or weld a shim to the side of the bearing cap so that it fits snugly and flat against one side of the bearing. That could take up the slack inside the bearing holder and prevent the frame from rocking or twisting on the bearing. It would stiffen up the frame. The frame and bearing holders twisting on the bearing under heavy pedaling loads is probably what is causing your frame to flex and crack.

I’m not sure if my idea about shims is clear or not. I may have to work on drawing up a picture if it isn’t clear or if it doesn’t make sense.

dont let this thred die because i would like to no if there is any whay to re bend a frame???

There IS a way to bend frames. I took it to the bike shop, and they claimed they had some alignment system. I simply convinced them to “think of it as a bike fork.”

Thanks JC! I would have never thought of that.
It SEEMS like I could get the same effect by hammering on the side of the bearing holder to make it more narrow. I understand that is not “the best” solution. I will try to determine if this is the cause. It may be wise for me to get another frame as well. I really like this one (when it works). I like having mud clearance, and the it is easy to wire the cyclometer cable through the frame.

UDC UK’s fix for bent frames HERE

Thanks PDC!
Exactly what I was looking for! Niiiice illustrations!

Actually, I have two types of bends.
One is like the picture addresses.
The other problem is that my right fork seems farther forward than my left (as though the frame has been twisted to the left - which is undoubtedly has). Well, I guess I should simply twist it some back to the right.

Bike shops that do frame building or old school shops that know about frame building are more likely to have the tools and knowledge and willingness to bend a unicycle fork or bicycle fork to make it straight again. Bending and aligning a fork is something that an old school bike shop should know how to do. A new school shop that opens up in s strip mall and sells on price may not be set up or willing to do that sort of repair.