Possible issue with x7 frat mech?

KevChallis

Hi all, my giant reign 2 turned up this morning, just setting things up, and can't get the front mech right for the life of me, it keeps rubbing on the bottom of the chain, I can't move the mech down any further, as the it hits the big chain ring, it needs twisting slightly as far as I can see, any suggestions?

nicklouse

Bend it.

Or if it is a full suspension bike leave it as it is as it does not matter.

KevChallis

Sorry to be dumb, why does it not matter?

cooldad

Sit on it, then pedal and see.

KevChallis

cooldad wrote:

Sit on it, then pedal and see.

I did, and it still rubs, so just bend it down a bit?

nicklouse

KevChallis wrote:

cooldad wrote:

Sit on it, then pedal and see.

I did, and it still rubs, so just bend it down a bit?

Then it is not rubbing on the bottom bar on the mech cage as the chain lifts way as the sus compresses.

So where is it rubbing?

KevChallis

Still at that point, the rest is all lined up at running straight down the middle, I sat on it, and the chain is still sitting on the bottom

Ouija

Picture of the whole bike might help.

cooldad

And which cog(s) it rubs in.

KevChallis

Every gear on the rear and only the granny cog on the front

bikaholic

The Reign 2 on Giant's website actually shows that the chain is nearly, if not, touching the lower bridge of the FD cage when the rear shock is uncompressed.

Double specific FDs have shorter cages than FDs for triple chainrings.

The Reign 2 (factory setup) is fitted with a 24/38T crankset, and it has been my experience that atleast a 26T granny is needed in order to prevent cage rub fully - a 24T chainring may cause cage rub on low spots where the chainring does not describe a perfect circle (and most don't).

So, three solutions come to mind (assuming that you've double checked everything first - like if the rear wheel has been properly seated etc):

(1) Swap the 24T for a 26T chainring;
(2) Swap the 38T for a smaller chainring (probably a 36T);
(3) Swap the double specific FD for a triple FD (and grind down the inner cage to optimise it for double cranksets).

For (1) and (2), you need to verify if the FD can work with atleast a 12T chainring difference - do this by eyeing the vertical gap between the inner cage plate and the inner ring to ensure that the inner cage plate won't catch on the inner ring when the outer cage is set at the optimum 1-3mm above the outer ring.

KevChallis

Thanks for your reply, very helpful.

I may even change to a single ring up front in future, as I haven't been on the granny ring all day today.

KevChallis

cyd190468 wrote:

In your pic the cage looks bent to me. The curve on the underside of the cage should follow the curve of the big chainring. (roughly) Yours appears to be close at the front and further away at the back of the cage implying that the back of the cage has been bent upward at some stage, so bend it back down a bit.

Don't know when, certainly not when I had it, it was new yesterday

cooldad

As above, and post 2.

KevChallis

cooldad wrote:

As above, and post 2.

I will, bend it that is, until I get the funds to remove it lol