Converting Giant Trance to 2x9 Mech Choice

symanoy

In the process of building up a Giant Trance just bought second hand, kept the original raceface crankset and converting 2x9 with a bash, put a 36t chainring on the middle.

I had an XT top swing mech knocking around so I looked at putting that on, however lining the cage up with the top of the middle ring as you would with the big ring on the triple, the suspesnion linkage fouls the bottom of the mech.
I have a top swing on my other bike, so i've put that on and that avoids fouling the linkage, however the cage does foul the chainstays towards the end of the travel.

Its hard to gauge as the rear shock is out having the bushing replaced so its hard to know exactly how far the linkage should be going!

My main question is what mech should I be using? You can get and SLX 2x9 specifically desgined for the SLX 22/36 double which is pretty much the same as what Im running. im guessing the cage is smaller so may avoid fouling the chainstays?

Or do I stick with the top swing but mount it in the same position as if it were a triple as then it should still shift over the first two rings right?? Just set up the limit screws.

The SLX mech comes in top swing and conventional and is only about £25 but I would rather use what I already have if at all possible! any suggestions?

cooldad

Run the mech where you would with a triple, as it was originally set up.

nicklouse

the mech will need to be a little higher mounted for the 36T but you either set it up to work in the outer part of movement(middle to big) or the first part of the movement (granny to middle).

did the frame use a top swing before?

symanoy

The frame came with A Deore top swing and standard 22/32/44 setup which worked fine

I tried setting it up before as if it was middle to big, which caused clearance issues, but i guess if I use small to middle movement of the mech instead it should work fine?

symanoy

This is my attempt at setting up the mech!

Frustratingly I'm still waiting for new gear cables and chain so can't really test it!

But here are some shots of what i've tried! not convinced if the mech is low enough?
Hope they're clear enough!

The Rookie

If anything it looks like it could go higher to me.....

Put a straight edge (yardstick) across 'small small' lower bridge on front mech needs to be only just below that.

symanoy

i put an old chain through as it is in the pictures and it was rubbing on the mech cage for it being too high,
I lowered it enough to solve that! but now the anchor bolt of the mech fouls the linkage, however without the rear shock I don't know if it ever actually moves this far!!

symanoy

I'm at a bit of a loss here! I've set the mech up for a 3 ring setup, using the big ring as a guide, but its just way to high, chain rubs alot, this isn't accounting for suspension sag as its hanging up, but still seems like a lot! But when I lower it enough to remove the rub it fouls the linkage!!

Do I just give in and buy and SLX 2x9??

nicklouse

symanoy wrote:

Do I just give in and buy and SLX 2x9??

will not fix it.

using the big ring as a guide,

what big ring? you have removed it.

if you are trying to set it up as a normal 3 ring you need it at or above where it was if you had the big ring fitted.

cant see the pics here.

symanoy

I held the big ring in position on the cranks in order to set up the mech as if it was a triple, presumably how it was set up before?

i put the back wheel back in and put the chain over small to small, and it was rubbing wayyy too much,

can you see these?

URL=http://imageshack.us/photo/my-images/341/2x91.jpg/][/URL]

nicklouse

Well that mech has not been positioned at all.

How is it on the first click up?

Dirtydog11

If you persevere long enough you may get it working in a rather unsatisfactory manner.

Do it properly!

Just buy an SLX double specific front mech and be done with it. Set it up as per instructions, job done, no faffing about and less chance of the chain jumping off the top of the rings.

Triples don't have the capacity or guide profile to deal with 22 - 36 or 24 - 36. The chain guides(grooves in backlplate)are designed to help shifting between rings of specific size, when asked to perform out of there normal range they can often hinder shifting, SLX double specific mechs don't have these!

nicklouse

not needed.

if you listen to everything on the net the you would know that this could not work with an X9 shifter
http://imageshack.us/f/384/img0088cq0.jpg/

symanoy

That was it without touching the limit screws which were both fully out, is it possible the cage is bent or something?
I'm at a bit of a loss why this is not working!!

Dirtydog11

symanoy wrote:

That was it without touching the limit screws which were both fully out, is it possible the cage is bent or something?
I'm at a bit of a loss why this is not working!!

I'll say it again!

Triple front mechs don't have the capacity or guide profile to deal with 22 - 36 or 24 - 36. The cage guides(grooves in backplate)are designed to help shifting between rings of specific size, typically 22-32 , when asked to perform out of there normal range they can often hinder shifting, SLX double specific mechs don't have these!

No idea why nick is saying x9 shifters wont work with Shimano front mechs because they do, I can only think he's getting mixed up with another post. I wouldn't have thought you even have X9 shifters on a Trance unless you've swapped?

Had/having no problems with this! 8)

symanoy

I think im gonna splash out the £25 or whatever is for a 2x9 mech for peace of mind and simplicity of setup!
Dirtydog, you running a 22/36 on your trance with a slx top swing 2x9? and that works without out ever fouling chainstays or linkage?

nicklouse

Dirtydog11 wrote:

No idea why nick is saying x9 shifters wont work with Shimano front mechs because they do,

I have never said that.

If you looked at the link you would see a 38t ring and a 24t ring and a Sram road mech. The other bike had a 38-26 and mtb mech.

And i have set up many with 22-36 and even 38 yes you may need to add some pressure to the cage bu it is perfectly doable. Might judt have to do it on one of my up coming rebuilds.

Dirtydog11

symanoy wrote:

I think im gonna splash out the £25 or whatever is for a 2x9 mech for peace of mind and simplicity of setup!
Dirtydog, you running a 22/36 on your trance with a slx top swing 2x9? and that works without out ever fouling chainstays or linkage?

Yes 2X9, 22 - 36 with an SLX M665.

It's not mine it's a friends, however I did carry out the conversion for him and I can confirm there are no issues at all.


Sorry nick, misunderstood what you where getting at.

symanoy

This sounds like the way forward, would have been nice to use the XT I had lying around, but hey, will order the M665 on Saturday when I get paid!

desmojen

I've got my Trance X set up like that using the original 3 speed XT front mech and shifter. It takes a bit of setting up in terms of not having too much chain rub in the extremes of gears (which are rarely used in fairness) but it works perfectly shifting form ring to ring, and is nowhere near any of the linkages etc. Cranks are SLX double and bash running 36/22.
Like Nick says, you just have to pick whether you want to run as it as low to middle or middle to high, and set the limit screws to suit.

Jen.

Dirtydog11

desmojen wrote:

I've got my Trance X set up like that using the original 3 speed XT front mech and shifter. It takes a bit of setting up in terms of not having too much chain rub in the extremes of gears (which are rarely used in fairness) but it works perfectly shifting form ring to ring, and is nowhere near any of the linkages etc. Cranks are SLX double and bash running 36/22.
Like Nick says, you just have to pick whether you want to run as it as low to middle or middle to high, and set the limit screws to suit.

Jen.

I just don't understand this!

You pay all that money out for a bike and then compromise over a £25.00 part which is designed specifically to do the job.

desmojen

How is it a compromise if it works perfectly?

And to do it properly, you should use the correct 2 speed shifter and a proper 2x9 crankset as well shouldn't you? I just thought the OP might like to know that what he is trying to do with a bike exactly the same as mine is perfectly possible without spending money on a different mech. It's his choice whether he does or not......

Jen.

Dirtydog11

Because.......

It takes a bit of setting up in terms of not having too much chain rub in the extremes of gears.



So it takes "a bit of setting up" and even then it still "rubs in extreme gears".

Up a bit, down a bit, side a bit, back the other way a bit, down a bit, still getting a bit of rub so up a bit more etc etc etc. Eventually you arrive at a compromise where it doesn't rub "too much".