Sheldon Brown said:cotterlesscrank said:Quoted message said:I've been trying to remove the Shimano 7spd freewheel on my beater in order
to replace three broken spokes on the drive side. I've got the Park FR-1
tool, tried everything to get the damned thing off, including using a box
wrench and whacking on the handle with a mallet as suggested on Sheldon
Brown's website, to no avail. I don't think the freewheel's coming off.
Quoted message said:Get a piece of pipe, as long as necessary, and put it on the wrench.
Get someone to hold the wheel vertically on the ground by the rim so
they can get good counter-torque on the hub, and then push down on the
pipe. I think the freewheel will come off.
Using a pipe and cheater bar like this won't allow any more torque to
the tool than the usual technique of using a good bench vise.
True, possibly, if you have a good bench vise. However, the bench vise
method is limited by the amount of torque you can apply through wheel
through the rim. It MIGHT be possible that someone counteracting the
force of the cheater bar by holding the wheel vertically against the
ground could apply MORE torque to the rim than someone grabbing the rim
and twisting it above the vice.
Quoted message said:The problem is getting enough torque on the wheel/hub, and the pipe
doesn't help with this.
Yes it does, but you DO need a way to hold the wheel. A second person
holding the wheel by the rim vertically against the ground gets
leverage against the hub.
Quoted message said:Quoted message said:I don't see how hitting it with a mallet will work.
The fact is that it _does_ work! The impact can generate a greater
instantaneous torque than you can supply with a steady twist.
That doesn't mean that the torque is guaranteed to be transmitted to
the freewheel threads, though. Furthermore, your comment indicates that
instantaneous torque in excess of what can be counteracted by holding
the rim can be useful. It that's true, then torque transmitted by a
longer cheater bar can also be useful. Finally, the fact that it does
work on some freewheels does not in any way prove that it would work
better than a cheater bar and a helper holding the wheel.
Quoted message said:This is
the same principle used in impact wrenches for automotive work.
Maybe he should use an impact wrench.
Quoted message said:This is not based on armchair theorizing. I've used this technique
many times on recalcitrant freewheels that wouldn't respond to the
usual bench vise approach.
You're the one who talked about how much trouble you had getting
freewheels off in your defense of cassettes, and it didn't work for the
OP.