My bike pulls to one side. How can I fix this?
From: Jobst Brandt
For less than million dollar bikes this is easy to fix, whether it corrects
the cause or not. If a bike veers to one side when ridden no-hands, it
can be corrected by bending the forks to the same side as you must lean
to ride straight. This is done by bending the fork blades one at a time,
about 3 mm. If more correction is needed, repeat the exercise.
The problem is usually in the forks although it is possible for frame
misalignment to cause this effect. The kind of frame alignment error that
causes this is a head and seat tube not in the same plane. This is not
easily measured other than by sighting or on a plane table. The trouble
with forks is that they are more difficult to measure even though shops
will not admit it. It takes good fixturing to align a fork because a short
fork blade can escape detection by most measurement methods. Meanwhile
lateral and in-line corrections may seem to produce a straight fork that
still pulls to one side. However, the crude guy who uses the method I outlined
above will make the bike ride straight without measurement. The only problem
with this is that the bike may pull to one side when braking because the
fork really isn't straight but is compensated for lateral balance.
This problem has mystified more bike shops because they did not recognize
the problem. Sequentially brazing or welding fork blades often causes unequal
length blades and bike shops usually don't question this dimension.
If the bike once rode straight, something has been bent.
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