GT Idrive 5 (09 model) vs SRAM X5 front mech?

Northwind

Just gave my Idrive its maiden ride- very nice it is too- but I did run into one unexpected problem- the swingarm fouls the front mech when the suspension tops out. I dropped a couple of steps and THONK, thought "No way did that just bottom out", then tried to pedal and found the mech was knocked halfway round the mounting post, it'd hit the swingarm.

Sooooo... Anyone come across this? I think I could shift the mech down maybe 1 or 2 mm without issues so if it's a just-barely thing then maybe it can be got round, but it doesn't seem like it. Similiarly I could machine a wee bit of metal off the mech but that's not the sort of thing I want to be doing really. A new mech's not the end of the world if I need to, just seems a little odd.

(the mech is a low-mount, dual pull 2008 model- not sure if there are different X5 mechs or not)

supersonic

Not heard of this one! I'd certainly try and tweak the front mech.

Northwind

I was just comparing it with the XT on the Soul and it's pretty bulky by comparison. Hmm. I'll reset it, move it down as far as I can, and see if that works- it got a fair old whack so I don't think it was an "only just" thing.

Ah... it's this exact mech:

http://www.jensonusa.com/product/fd/FD307Z02BLK__31.8_L.jpg

nicklouse

pics of the the up?

Skonk

Never had anything like that happen on my ID5 and it's took some pretty big hits using up all the the travel.

Mine has a Shimano front mech though.

Northwind

Ah, it's the other way round- it's not when it bottoms out, it's when it hits the absolute top of the travel. I had too little rebound damping on at first, which doesn't help, but wouldn't cause the problem.

I'll get the mech back in place tomorrow and get some pics.

Northwind

No, I'm completely wrong in every way apart from the bit where the mech hits the frame. Lets try again.

On closer examination- the mech is of course mounted on the swingarm not the frame. It's not fouling the swingarm, it's fouling the frame. And it's not doing it on top out at all, that's total rubbish, it's doing it on compression.

But apart from that...

Frame showing impact site, mech knocked out of line.



A mech with a dent. Not very clear but just to the right of the pivot, the white spot is where it's hit- it looks like light glare but it's a wee chip in the metal. As you can see, quite a bulky mech.



Total clearance between mech and frame with suspension fully extended:



Total clearance- or lack of- with suspension fully compressed (empty shock). Mech is obviously squint, it won't physically move any further round unless dropped so far down the mounting boss that it won't engage the big ring.



So... Not much discussion here I think, I think it's definately the mech, anyone disagree? (please, do if I'm wrong, because right now I have no working bikes!)

supersonic

The mech gubbins do look quite large! But also tha last pic looks like the mech is just totally in the wrong position, height and angle. Looks ;-)

Skonk

The mech should be mounted much lower on the tube.

On mine, the tube (the small tube put there for the mech to be mounted on), pokes out of the mech mounting bracket by about 8mm.

From the pictures, it looks like yours is only half on with the top half of the mounting bracket haging off of the top of the tube.

stubs

Shouldnt this be a problem for the bike shop where you bought it from

Take it back say It no workee you fixee

Northwind

supersonic wrote:

But also tha last pic looks like the mech is just totally in the wrong position, height and angle. Looks ;-)

The last picture is the "after" showing what happens after it gets whacked- yes it's a bit squint That's as close to straight as it'll go with the suspension compressed.

Skonk wrote:

The mech should be mounted much lower on the tube.

From the pictures, it looks like yours is only half on with the top half of the mounting bracket haging off of the top of the tube.

Like I say, if I move it any further down it fouls the big ring- you can see in the second bottom pic, the cage is only a couple of mm up from the ring . The 2nd pic makes it a bit clearer what's going on with the mech I think, you can see how tall it is, the clamp is much lower and is entirely on the boss.

stubs wrote:

Shouldnt this be a problem for the bike shop where you bought it from

Bought from the classifieds as a frame

supersonic

Buy a deore ;-)

Northwind

Yeah, that's what I'm thinking

Northwind

OK, it seems like more pics are needed just to prove I'm not a cretin

This is just to clarify where the mech was in the last pics, just so you can see the clamp wasn't hanging above the top of the boss, only parts of the mech casting:



But if I move it down 1mm, this happens:



So, definately not too high! But just in case, this is the mech in its absolute lowest position, and the suspension compressed- still touching.:



In that location it can't select the big ring of course.

So, in conclusion- don't try and fit an OEM-spec X5 mech to an Idrive 5, it do not work. Not that this is a particularily likely combination of parts anyway!