Front derailleur mods?

I have a stock trials bike I want to put a front derailleur on.

The chainstays are short (15.5"), the tire is fat, and I'm using an 8 speed chain.

There isn't much clearance between the seat tube and the tire, and the derailleur cage rubs the
rubber when in the granny.

Since I am only running a granny and middle, I have thought of modifying the cage, short enough to
prevent rub.

Anyone come up against this and have any suggestions?

- Chris.

 

Go to Cambria Bicycle Outfitters and order a SRAM 5.0 derailleur. Get this 10 bucks. I've got a few
of them with no problems and one on order for the same thing your looking at plus the Shimano gets
adjusted and next time I shift into the small chain ring it won't go and needs adjustment again. I
love SRAM front derailleurs but their getting hard to find since they don't make them anymore. I run
a 9.0 on a ACCESS frame with a IRC 2.35 CUJO tire.

Fire up MTB 03

 

"Chris Snell" <[email protected]> wrote in message
news:[email protected]...
> I have a stock trials bike I want to put a front derailleur on.
>
> The chainstays are short (15.5"), the tire is fat, and I'm using an 8 speed chain.
>
> There isn't much clearance between the seat tube and the tire, and the derailleur cage rubs the
> rubber when in the granny.
>
> Since I am only running a granny and middle, I have thought of modifying the cage, short enough to
> prevent rub.
>
> Anyone come up against this and have any suggestions?
>
> - Chris.

I was having this problem after a crash - fd cage rubbing rear tire when in the granny ring. I
noticed my cage was tweaked, so I took off the derailleur and untweaked it with judicious use of
ViseGrips and ChannelLocks. Keep the inner and outer plates of the cage parallel, and work in small
easy increments.

Chris

 

Chris Snell <[email protected]> wrote in message
news:[email protected]...
> I have a stock trials bike I want to put a front derailleur on.
>
> The chainstays are short (15.5"), the tire is fat, and I'm using an 8 speed chain.
>
> There isn't much clearance between the seat tube and the tire, and the derailleur cage rubs the
> rubber when in the granny.
>
> Since I am only running a granny and middle, I have thought of modifying the cage, short enough to
> prevent rub.
>
> Anyone come up against this and have any suggestions?

Yes - I'm running a Nokian Gazzaloddi 2.6 on the rear, and the bottom end of the front mech cage
rubbed terribly on the tyre when in the granny ring.

I took the mech off and cut a section out of the inside end of the cage, then welded a small right
angled piece of steel over the breach to maintain its rigidity. Now, the mech cage clears the tyre
by enough to even cope with a slight buckled wheel, but still has full range.

Looks like this (if the text wrap doesn't skew it):
____
| |
| |
| |
|_ | __|

Hope this helps!

Shaun aRe