Adjusting Front Derailler?



B

Bill Henry

Guest
I'm installing a front derailler on my bike, and my book has left me a
little lost. The rear derailler works fine.

I've got a top-pull Shimano Alivio on my mountain bike. The book says
to first put the chain on the lowest gear (before installing the cable)
and then spin the crank to make sure nothing rubs. Then I adjust the
low gear screw so that the inside part of the chain cage is about .5 mm
of the inside chainwheel (Note - Rear derailler is working well by this
point.)

Okay. Done.

Now it says to shift the derailler BY HAND to the highest gear point,
and put the chain on the largest chainwheel and adjust the high gear
screw so it's close, too. Problem is - I don't see how the hell I'm
supposed to do this. I can pull the derailler over, but it's very
awkward because the springs inside tend to keep the derailler pulling
back towards the frame. In short, I can't adjust the screw with one
hand while pulling the derailler with the other. Also, the derailler
goes WAY past where it would need to be to shift into high gear, and I
don't think tightening the screw is the answer.

What do I do?

Is is possible to install the cable FIRST, and then shift into high gear
while adjusting the screws accordingly? I already had some serious
cable tension issues that I was dealing with before...

It's a triple chainring (42/32/22 I think) and a standard Shimano Alivio
derailler. If I can't get the damn thing to work, I'm wondering if now
might be a good time to upgrade to a better front derailler. However, I
think it's probably just my technique that's lacking.

And yes, I'm trying to avoid taking it to a shop. The LBS only wants to
do a full setup for somethign like $40 and my bike doesn't need all
that.

Sorry for the long post. Thanks for any ideas.
 
Bill Henry wrote:
> I'm installing a front derailler on my bike, and my book has left me a
> little lost. The rear derailler works fine.
>
> I've got a top-pull Shimano Alivio on my mountain bike. The book says
> to first put the chain on the lowest gear (before installing the cable)
> and then spin the crank to make sure nothing rubs. Then I adjust the
> low gear screw so that the inside part of the chain cage is about .5 mm
> of the inside chainwheel (Note - Rear derailler is working well by this
> point.)
>
> Okay. Done.
>
> Now it says to shift the derailler BY HAND to the highest gear point,
> and put the chain on the largest chainwheel and adjust the high gear
> screw so it's close, too. Problem is - I don't see how the hell I'm
> supposed to do this. I can pull the derailler over, but it's very
> awkward because the springs inside tend to keep the derailler pulling
> back towards the frame. In short, I can't adjust the screw with one
> hand while pulling the derailler with the other. Also, the derailler
> goes WAY past where it would need to be to shift into high gear, and I
> don't think tightening the screw is the answer.
>
> What do I do?
>
> Is is possible to install the cable FIRST, and then shift into high gear
> while adjusting the screws accordingly? I already had some serious
> cable tension issues that I was dealing with before...
>
> It's a triple chainring (42/32/22 I think) and a standard Shimano Alivio
> derailler. If I can't get the damn thing to work, I'm wondering if now
> might be a good time to upgrade to a better front derailler. However, I
> think it's probably just my technique that's lacking.
>
> And yes, I'm trying to avoid taking it to a shop. The LBS only wants to
> do a full setup for somethign like $40 and my bike doesn't need all that.
>
> Sorry for the long post. Thanks for any ideas.


It's not that complicated. Just push the derailer out by hand jam a
screwdriver to hold it open. Set the clamp height and angle to where the
outside edge is parallel to the big ring and a mm or 2 above the teeth.
Remove screwdriver.

Cable it up with the shifter at lowest setting and cable just slack.
Tweak the high & low limits from there by shifting slowly between rings
and only allowing as much derailer travel as necessary.