frame wobble

GoldenMotor.com

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Active Member
Dec 4, 2011
399
37
28
CA
have any of you guys had a frame that just wasn't quiet straight?how did you straighten it out?
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Wobble and out of alignment are not the same thing. I'd like some clarification about what the OP is asking. If the frame is flexing or "wobbling" something is very wrong. It could be there is a broken weld at a critical point.

The problem might also be in the wheels. If one or both are out of true then a wobble could result. Even the cheapest department store bikes shouldn't wobble, even with an engine installed.
I think we're looking at a potentially serious problem and certainly a safety issue. My advice would be not to ride the bike until the source of the problem has been found and fixed. Examine the frame carefully for any sign of a broken weld or frame tube. Elevate the bike and spin the wheels to check them for concentricity and lateral alignment. Check bearings and axle nuts and handlebar attachment.

Tom
 

rustycase

Gutter Rider
May 26, 2011
2,746
5
0
Left coast
dnutTom is correct. you really should identify the problem before getting out in traffic, at speed.

Alignment of a bicycle frame can be 'adjusted' by setting down on the ground, grabbing ahold of the frame with your hands, and pushing here or there with your foot.
(they are kinda ez to bend, so be cautious!)

Wobble could be caused by loose bearings, (wheel, or neck), spoke mis-adjustment, or a bad tire casing with a burble in it. A blow-out at speed is NOT a fun thing!
A speed wobble can be caused by too little trail in the front fork.

Best
rc

Oh, and I just thought of another.... the extended-back seatposts that seem to be popular with some folks can cause poor weight distribution on the cycle which will lead to poor control authority on the front wheel and this may amplify any condition leading to a wobble.
Weight should be properly balanced, front/rear, for decent steering and braking.
.

dnut
 

\./

Active Member
Dec 4, 2011
399
37
28
CA
Wobble and out of alignment are not the same thing. I'd like some clarification about what the OP is asking. If the frame is flexing or "wobbling" something is very wrong. It could be there is a broken weld at a critical point.

The problem might also be in the wheels. If one or both are out of true then a wobble could result. Even the cheapest department store bikes shouldn't wobble, even with an engine installed.
I think we're looking at a potentially serious problem and certainly a safety issue. My advice would be not to ride the bike until the source of the problem has been found and fixed. Examine the frame carefully for any sign of a broken weld or frame tube. Elevate the bike and spin the wheels to check them for concentricity and lateral alignment. Check bearings and axle nuts and handlebar attachment.

Tom
the frame is a bit out of allignament, and has a "wobble" in the downtube. not a wobble as in it wobbles or flexes, but a wobble as in it has a bot of an "S" shape

thanks CCC, that jig looks great.