Mountain Biking - Shimano XT 760 vs. SRAM X.9

i currently have an shimano xt for my rear derrailleur and deore rapid fire with orginal shifter cables and housing. Recently i have had problems with ghost shifting and it sucks up during my ride. i wanted to upgrade to sram x.9 rd and trigger shifter or upgrade my shifter with xt also... any recommendations....

No experience with the XT drivetrain but I am using a X9 RD with X0 trigger shifters and they are flawless.

i would prefer shimano over sram ... just because i kno shimano is way more durable

You said you still have the original cable and housing...if that is the case, I would replace/upgrade that before you do anything else. Then give the derailleur a good tune up and most of your problems should be solved.

Yup, I agree with never. It'll make a world of difference for less than 8 bucks. My XT/XTR combo shifts like crap when the housing is full of mud. My last bike had Deore shifters & RD and it shifted flawlessly when set correctly. The difference between Deore & XT are minimal.

However, if you really want to drop a load of cash on something less durable.....

T.J.

i would prefer shimano over sram ... just because i kno shimano is way more durable

and you "kno" this how?

i currently have an shimano xt for my rear derrailleur and deore rapid fire with orginal shifter cables and housing. Recently i have had problems with ghost shifting and it sucks up during my ride. i wanted to upgrade to sram x.9 rd and trigger shifter or upgrade my shifter with xt also... any recommendations....


how old is the bike? have you had it tuned up since you purchased it? sounds like your cables have stretched and the slack needs to be taken out. when the cable stretches, the shifter pulls up that slack in the first shift, and that in turn throws off the rest of the shifts. the derailleur isn't getting all of the "information" from the shifter that it needs to do it's job.

a good way to tell if the cables have stretched is to shift the bike into the small/small combination (or if you've got one of those wretched rapid rise RDs, the small/big) and tug on the cables. if they feel loose, they have stretched and you simply loosen the cable anchor bolts (5mm allen key) and pull the cable tight (it doesn't have to be tight like a guitar string, hand tight will do), and tighten the cable anchor bolt. don't mess with the limit scews at all. then shift through the gears and make minute adjustments with the barrel adjusters on the derailleurs and the shifters.

the chain suck could be due to a dirty drivetrain, or a heavily worn chain/chainring. clean the chain with a citrus degreaser, and the rings and cassette with something like simple green, or hot soapy water. sheldon brown has an excellent article about chains and chain wear, including a section devoted to measuring chain wear. (http://www.sheldonbrown.com/chains.html)

and you "kno" this how?

Through my experience with both, I would agree with gmoney.

Here is a recent thread that outlines why I believe so....
http://www.bikeforums.net/showthread.php?t=168914

T.J.

i think, based on the video you linked, i would take the sram over the shimano, because it doesn't move. the steady sram RD keeps the same number of links in contact with the cogs at all times, while the shimano RD moves around and causes fewer links, and more links to contact at different times. which could cause skipping...it's not likely to, but it could. i don't really see any advantage to having the RD swing around all willy-nilly like that.

i know there are a lot of people out there using SRAM stuff who have never experienced the problems you've had, and there are also a lot of people who've had their shimano parts fail on them. a direct impact to any RD is going to result in a jacked up RD and hanger. there are plenty of people experiencing problems with both brands of components, but i've never seen any of the issues you described in that thread.

i "kno" shimano is stronger than sram because of past knowledge... basically the sram x9 dies and the xtr survives.. with scratches but they just dont break...

and the way shimano bobs helps in shock absorbsion obviously and as for more chain on the rings.. doesnt matter go chek your bike out and itll be clear that it doesnt matter to have 1 extra link on a ring

i want to know what your past knowledge is. i work in a shop and i see people put their equipment through hell and both shimano and sram hold up just fine through all riding conditions. i own both, and i honestly prefer the sram over shimano. until someone shows me something credible and repeatable, i will continue to use sram.

i don't think specialized would put sram X0 derailleurs on their S-Works bikes with XTR brakes and cranks if the sram stuff didn't hold up.

i think, based on the video you linked, i would take the sram over the shimano, because it doesn't move. the steady sram RD keeps the same number of links in contact with the cogs at all times, while the shimano RD moves around and causes fewer links, and more links to contact at different times. which could cause skipping...it's not likely to, but it could. i don't really see any advantage to having the RD swing around all willy-nilly like that.
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Hi OneTinSloth

I beleive that the weight and gravitational forces on the chain is causing the rear deraileur to bounce up and down. In the side view, the chain bounces up and down the same amount on both deraileurs. The Shimano deraileur is keeping up with the chain and absorbing /dissipating more of the forces on the derailer due to the movement of the chain. The SRAM absorbs the bouncing forces of the chain with only one pivot point, the cage. The Shimano has two pivots points to absorbe chain forces, the cage and deraileur body.

I've never experienced any skipping as you've mentioned. As long as the chain is tight coming into and over the cassette, which both deraileurs do, and it is aligned properly, there will be no skipping.

Anyway, I know this board has a lot of dedicated SRAM users. (Some very rude with no intelligent input) Other boards have a thier share dedicated Shimano users. Everyone should use what works for them and feels right. This Old Cat is just sharing what he has experienced.

Cheers.
T.J.

You said you still have the original cable and housing...if that is the case, I would replace/upgrade that before you do anything else. Then give the derailleur a good tune up and most of your problems should be solved.

+1 - clean, lube or replace the cables. You never know how much gunk and junk is inside the housing.

Dirty, cruddy cables will make any drivetrain regardless of manufacturer shift like crap.

A great way to improve your shifting and keep it shifting well (by keeping the mud, dirt, and water out of the housing) is to go with a quality sealed set of shifter cables. I'm using Avid Flak Jackets and have had no problems with shifting. They're a bit pricy for a set of cables (~$30-35), but considering you're thinking of shelling out for a whole new derailleur/shifter set-up, you'd be getting great shifting performance for about 20% of the cost simply by replacing your cables with a quality sealed set.

Greenfish has them for $25 here (http://www.greenfishsports.com/index.asp?PageAction=VIEWPROD&ProdID=1003).

There's nothing wrong with an XT r.d./Deore shifter setup. When connected by good, clean and lubed cables, and shifting a clean and lubed chain over a relatively clean cassette, you should have no problems in shifting - at all. After you replace your cables, go to Park Tool's website and follow their procedure for re-adjusting your rear derailleur; it's very comprehensive and if followed, will have your drivetrain shifting like butter.

Save the cash and get new cables.

Hi OneTinSloth

I beleive that the weight and gravitational forces on the chain is causing the rear deraileur to bounce up and down. In the side view, the chain bounces up and down the same amount on both deraileurs. The Shimano deraileur is keeping up with the chain and absorbing /dissipating more of the forces on the derailer due to the movement of the chain. The SRAM absorbs the bouncing forces of the chain with only one pivot point, the cage. The Shimano has two pivots points to absorbe chain forces, the cage and deraileur body.

I've never experienced any skipping as you've mentioned. As long as the chain is tight coming into and over the cassette, which both deraileurs do, and it is aligned properly, there will be no skipping.

Anyway, I know this board has a lot of dedicated SRAM users. (Some very rude with no intelligent input) Other boards have a thier share dedicated Shimano users. Everyone should use what works for them and feels right. This Old Cat is just sharing what he has experienced.

Cheers.
T.J.

well, i'm honestly not trying to argue that one is objectively better than the other. just that i haven't seen that particular failure, ever. they're two different systems, each with their own strengths and weaknesses that will work better for different people. in fact, i posted not too long ago that SRAM RDs use plastic inserts that the limit screws thread into. these inserts can come loose, causing the derailleur to shift into the spokes. i've seen it happen on a brand new X0 RD. shimano's issues seem to come more from their shifters (specifically with the integrated shifters not functioning as well with dirty cables than their predecessors) than from the derailleurs, while SRAM's shifters seem to work flawlessly.

either way, i don't think the OP's problem is best solved by switching to SRAM or upgrading anything. a clean drivetrain, and fresh cables and housing are probably the best solutions.