My mates got a Cannondale F400. We think its about 8 years old.

The front mech is near on impossible to change up due to friction in the system. The mech itself works and moves fine. The gear changer is working fine, and the cable is lubed and clean.

So all I can think it is now is the plastic cable guide that the cable runs around under the bottom bracket. It is deeply grooved, so I assume this is creating the friction ?

What do you call that piece of plastic under the bottom bracket? Ive googled front mech gable guide and nothing is coming up…

Ta

Bottom bracket cable guide.

Cable guide,
Cable Guides

They’re about a quid. LBS should have them.

Why not fit a full length outer and it doesn’t matter as its removed from the equation?

Bb guide

Just get a short bit of plastic tube ( used in sealed cable sets ) and run it through the bb guide
But it might be the shifter

You could even just check by running the cable through a short piece of outer tie wrapped around the bottom of the BB for a bit.

THanks for the advice , I think I might try the bit of outer cable to check.

Are you sure you’ve got the cable routed to the mech correctly? If it’s routed under the BB, it needs to go around the cam before you bolt it in place.

In the trade they are known as frumptons chafe plate or the wifes knatterjack.

Easily replaced with a Thompson half crab shell if needed.

You will not be able to run full length outer on the front mech as you don’t have a stop for the outer.
You could Try the short outer option, but for the sake of a couple of quid you may as well bite the bullet.

This one is the correct one for your bike. Click Here