Tandem Cycling - Sorry! its the IRD 11-34 cassette question again

Never did get our new Co-Mo Mocha with Shimano XTR and 11-34 IRD cassette to shift properly. I thought it was me and my mechanic, but then I see a lot of debate here, some of you throwing out the IRD, which is the same suggestion the Co-Mo dealer offered me. I hate to do it, I'd rather live with it till it wears out and then do something else, right now I'd rather spend money on a carbon fork.

My LBS mechanic says that it will improve with Shimano SIS SP cable and housing, replacing the cable and housing that is on the bike which apparently is not Shimano. My Co-Mo dealer does not agree with my LBS mechanic, so what should I do?. I think somebody did change cables and housing and it worked, but I can't find the thread.

Why would Co-Mo not use Shimano cable on housing on a Shimano setup? Why would Co-Mo sell a new bike with a cassette which does not work properly? Should I contact Co-Mo? These last questions are more philosophic, what I really need to know is if I should try changing the housing or not.

Never did get our new Co-Mo Mocha with Shimano XTR and 11-34 IRD cassette to shift properly.

I'm not sure which XTR rear derailleur you're using, but all evidence and indications suggest the latest generation of XTR rear derailleur when used in combination with the 10 speed IRD wide-range cassettes just don't work well. Most fingers seem to be pointed at the XTR rear derailleur as the problems have been solved in one of two ways: 1. Using a smaller, stock Shimano cassette, or 2. changing to an XT or older model XTR rear derailleur.


My LBS mechanic says that it will improve with Shimano SIS SP cable and housing, replacing the cable and housing that is on the bike which apparently is not Shimano. My Co-Mo dealer does not agree with my LBS mechanic, so what should I do?. I think somebody did change cables and housing and it worked, but I can't find the thread.

Here's Shimano's description of it's SP40 and SP41 cable housing. (http://cycle.shimano-eu.com/publish/content/cycle/seh/nl/en/technical_service/faq_s/general_faq_s/what_is_the_difference1.html) I'm not sure that anyone's using the SP41 as OEM housing on tandems and, frankly, while some cable/housing combinations may be a bit more efficient (and more expensive), all of the basic cable/housing sets will yield precise shifting if it's prepped, installed, and maintained properly. For example, I switched over to the Delta Teflon coated cables on our tandem, mostly because of vanity, wanting black cables on the nearly black frame vs. stainless. While the shifting was just fine before the change, I did find the Teflon coated stuff had a lot less drag and made shifting easier. Now, what I don't know is how long it will remain that way. In other words, it's been my experience that a lot of the super-slick cables are very fast coming out of the gates; however, as they become worn-in and collect road grime that slight performance improvement goes away... sending you back to the shop for another 'fix' of the far more pricey cables and/or housing. Again, I tend to agree with your Co-Motion dealer in that the root cause of the problem really lies in the combination of the XTR RD and IRD cassette such that, even if you spent your money on the SP41 cable and housing any perceived resolution of the shifting issues would be short-lived... and Murphy's Law will always cause the problems to re-occur at the worst possible moments, i.e., on tour or mid-way through a challenging ride.


Why would Co-Mo not use Shimano cable on housing on a Shimano setup? Why would Co-Mo sell a new bike with a cassette which does not work properly? Should I contact Co-Mo? These last questions are more philosophic, what I really need to know is if I should try changing the housing or not.

I'm not sure what Co-Motion may ship-out to it's dealers in the build kits, but I suspect like most OEM builders it's not the SP41 cable and housing. Instead, it's on par with SP40 which is about the same as any other reputable brand of housing, e.g., Jagwire, Campy, etc... where stainless steel cable runs through a teflon lined cable housing. Regardless, remember that ultimately each Co-Motion dealer is the one who decides what to actually use when building up the tandem, balancing what the customer has asked for against what their experience tells them works best. So, you're just as likely to end up with what ever Co-Motion shipped out (housing that meets their OEM spec), or what your dealer has decided to buy in bulk and pulls off the spools in their shop. None of this stuff is junk; it's just not the high-end performance stuff which, as noted above, may or may not be the best long-term solution.

Bottom Line: I'd ask both your Co-Motion dealer and Co-Motion's customer support folks for a recommendation so that they are clearly aware of your issue and go from there.

In my experience, you can't know if changing the cable/housing will matter until you change the cable/housing.

I don't use the Shimano 4mm housing: although it works OK at first, I've found it to have a short life expectancy.

So many have reported problems with the IRD cassette that it just seems to make sense to start there.

Thanks.

Though not as many answers as I would have hoped, nobody seems to lead me to trying different cables/housing, everybody includding my Co-Mo dealer suggests dumping the IRD cassette, a tough decission for me, who does not throw anything usable out.

Might be the right answer, but I am not very satisfyed as to why Co-Mo would spec out a bike with a cassette that does not work properly. I understand it is the only 10 speed cassette that goes up to 34 teeth, but if it does not work well enough I should have been warned when I ordered it. If I was not warned I suspect it was an unknown problem at the time, so it it a design error in the specification of the component options. I'll write to Co-Mo's customer service and see what they say.

Thanks.

Though not as many answers as I would have hoped, nobody seems to lead me to trying different cables/housing, everybody includding my Co-Mo dealer suggests dumping the IRD cassette, a tough decission for me, who does not throw anything usable out.

Might be the right answer, but I am not very satisfyed as to why Co-Mo would spec out a bike with a cassette that does not work properly. I understand it is the only 10 speed cassette that goes up to 34 teeth, but if it does not work well enough I should have been warned when I ordered it. If I was not warned I suspect it was an unknown problem at the time, so it it a design error in the specification of the component options. I'll write to Co-Mo's customer service and see what they say.

My Santana 10 speed 11/34 shifts fine. Santana's cassette is manufactured by the same Taiwan company that makes IRD. However, IRD may have to change its cassettes slightly to circumvent patent infringement issues because one would presume that cassettes could be perfectly copied (speculation on my part). However, the difference appears to be that Santana entered into an exclusive deal with Shimano. The Taiwan company makes the cassette for Shimano which in turn provides it to Santana, hence perfect shifting.

I use other Shimano 10 speed cassettes on the Santana and they shift great as well.

One solution is to buy an 11/34 10 speed from Santana and put it on the Co-Motion. I suspect it would work fine.

My Santana 10 speed 11/34 shifts fine.

But I also believe you are using using this derailleur (old XTR):
http://www.bicyclebuys.com/productimages/1010101.jpg

... and not this derailleur (new XTR):
http://bikemag.com/features/onlineexclusive/rear-derailleur.jpg


Xanti Andia.... which one came on your Mocha? One of the XTRs, above, or an XT like one of the ones below (and if so, which one)?

http://kensbikeski.com/images/library/large/shim_rd_m751_sgs_06_m.jpghttp://content.mtbr.com/images/Tradeshow/13/262/prodimg13.jpghttp://www.cyclesuperstore.ie/shop/pc/catalog/medium/RDM770GS.jpg

But I also believe you are using using this derailleur (old XTR):
http://www.bicyclebuys.com/productimages/1010101.jpg

Yes. This one. And your point?

Here is another IRD "it does not work" thread. http://www.bikeforums.net/showthread.php?t=299095&highlight=ird

From a pure engineering point of view, if two cassettes from different manufactures are identical then swapping should not matter. If two cassettes work differently with the same der and setup then they are slightly different even if on the surface they look the same.

Yes. This one. And your point?

Someone can check me if I'm mistaken here, but I believe it's been the new XTR rear derailleur design -- which may have also found it's way down to the XT line -- that doesn't play well with the IRD wide range cassettes.

As noted earlier in the thread, the two solutions that I've heard of for solving crappy shifting with the new XTR and IRD 10 speed cassettes has been to either: 1. change the RD to an older model of the XT or XTR or to use a smaller, stock Shimano cassette.

In fact, I believe IRD may even have something in their FAQs on this:



Q. I am having shifting problems with your cassettes. What can I do?
A. Copy and paste our tech inquiry form into an e-mail, answer the questions and send it to us.

Q: Can I use your wide-range casettes for cyclocross?
A: Yes, of course. The cogs and carriers are plenty strong and durable for the rigors of racing in mud and rain, and the ramps will help make the shifts crisp. Again, and especially, a mountain derailleur with sufficiently long cage (though not ‘07 XTR and '08 XT) is recommended for optimal performance.
{back to top]

Q: Why don’t you recommend using the ’07 XTR/ '08 Deore XT rear derailleur?
A: We do not recommend pairing our cassetttes with the '07 XTR rear derailleur. The XTR derailleur lacks a barrel adjuster and we have concluded that the body flexes to the point that shifts are compromised and overall performance impaired. The XT for '08 also lacks a barrel adjuster.

[QUOTE=TandemGeek;6957944]But I also believe you are using using this derailleur (old XTR):
http://www.bicyclebuys.com/productimages/1010101.jpg

This is it in our Mocha

This is it in our Mocha

Interesting. One last thing to check before taking a flyer with a different cable and/or housing would be the return spring tension on the XTR RD. There's a high and low tension setting and you'll want to be sure it's set for the higher tension for the best performance on a tandem.

Also, make sure your mechanic checks the rear derailleur hanger's alignment, just to eliminate a slightly bent hanger as the cause.

I had the same problem on my Santana and this was the solution:
The Ultegra shift pod requires more movement in the lever to pull the same amount of cable as the Dura-Ace and produce a shift. The amount of cable pulled per a click is still the same but you will need to push the lever further over. If you push and hold the lever over far enough so it is about to make a second click and hold it, it should shift smoothly, however I was not happy with this as it required me to always shift from on top of the hood. My fingers could not reliably reach this point from the drops.

Switching to the Dura-Ace shift pods completely eliminated this problem. How much of a difference there is obvious due to the fact that I can now shift more than one gear while in the drops, where I was unable to even reliably complete a shift with the Ultegra shifter.

Take your bike out for a test ride and try holding the lever over as far as you can to the next shif to see if this makes a difference before you take my word on it. Stop by the LBS and see if you can shift some levers to see the difference in movement that I'm talking about.

I am also now running the Shimano shift cable that came with the levers however I do not think they have made as much of a difference as the shift lever has. It's an expensive fix, but I think it is probably the only way you will be able to make your shifting work without dumping the cassette.

My setup includes the '07 XTR without barrel adjuster, shimano housing that came with the Dura-Ace levers, Torelli tandem cables, and the Dura-Ace 10 speed shifters.

In spite of Shimano's warning "Do not dissassemble as re-assembly may be impossible." I have managed to get hold of "broken" shifters to study. With 8 speed and below, I was able to actually fix many of the shifters as long as they were not Dura-Ace. The Dura-Ace mechanism is much different from the other shifters while the innards of a 105 and Ultgra shifter look fairly identical. I DO NOT reccomend dissasembly.

I had the same shifting problems on my CDale. Ultegra cassette fixed the problem. Shifts 99% as well as my single bikes now.

http://www.bikeforums.net/showthread.php?t=416709&highlight=

I had the same shifting problems on my CDale. Ultegra cassette fixed the problem. Shifts 99% as well as my single bikes now.

The problem with this solution is that it removes the 34 low gear. Sure, if you do some moderate, or maybe even some serious climbing this might be OK, but my plans for the year included the Climb to Kaiser. The first part of the ride my stoker kept asking "Is that all of them?"

The problem with my solution is that it is considerably more expensive, however if you want your shifting to work and you want the low gears then it's the only option now available.

This is one reason (for me anyway) not to make the jump to 10 or 11 speeds. You can mix ,match , customize your gearing from 11 to 34 & it's all Shimano. Everything works & works great! The problem is i spend to much time & money working out all the possible combs....

. and not this derailleur (new XTR):
http://bikemag.com/features/onlineexclusive/rear-derailleur.jpg

We are using this (New XTR) rear derailleur with the Santana stock 11-34 10 spd cassette and whatever cable and housing Santana supplies with no problems at all. Stock Ultegra 10-spd STI brifters. We are kind of hard on bikes too (we ride them in the dirt and wet a lot) and I am somewhat suprised that this set-up has been trouble free for us.

I squirreled away a new set of D/A 9-speed triple brifters just in case the 10 speed sucked. Seems like I wasted the money.

We are using this (New XTR) rear derailleur with the Santana stock 11-34 10 spd cassette and whatever cable and housing Santana supplies with no problems at all.

As I mentioned before, on my Santana the shifters would work if you pushed them to the farthest limit before the next shift. They also seemed to work a little better with the original chain compared to the Dura-Ace chain however not nearly as well as with the Dura-Ace shifters and chain. This is why I think some people do not have an issue with it. It depends on shifting style. Someone who is "hard on his bike" is the person I would most expect to actually get the shifting right in this case.

Greetings All - I am a long time lurker who learned a great deal from this forum and bought a tandem toward the end of last summer. I'll tell that story and show pictures of the bike in a future post. I've been meaning to register and join the forum, but kept putting it off until now. I just wanted to share my experience with the IRD 11-34 cassette.

We had a local builder build a bike for us and I provided him with a list of components we were interested in. Based on research and noting that many bikes were sold with the IRD 11-34 I spec'ed out that cassette with the XTR deraileur. To my surprise my builder strongly steered me away from this combination. I asked him why so many bikes were sold with this gearing system if it was problematic. He responded that he didn't know what other peopl;e were doing but in their experience it did not shift well and he did not recommend it. He said that they continue to test it, but for now they don't use it. He suggested using a J-tek shiftmate if we wanted to go to the lower gearing. He said he usually doesn't like "gadjets" but this one seemed to work well. He also suggested that if we go that route, get two, becuase you never know when he might stop making them.

We ended up going with a 10-speed Ultegra 12-27 and Ultegra RD and Dura-ace FD. Originally he had set it up with a 9 speed 11-32 (I think) rear and XT RD with shift-mate, but we thought that we could get by with the 27 low gear instead of the 32. The Ultegra drivetrain shifts beuatifully for us.

I also had tried an IRD cassette and was never able to get it to work well enough to ride on.
What I did was to return the IRD and then I got a Shimano Ultegra 12-27 and then ordered a single 30 tooth cog from Harris Cyclery and threw out the 12 cog ending up with 13-30 9 speed cassette. Harris Cyclery also sells complete cassettes in various combinations, but it is a little less expensive to buy the cassette and individual cogs and change it yourself. I have bar end shifters and this combination works very well. Using Shimano cable housing could not hurt although it may not help either. The fact is that 100% Shimano systems work well and when you deviate problems can result.

We are using this (New XTR) rear derailleur with the Santana stock 11-34 10 spd cassette and whatever cable and housing Santana supplies with no problems at all. ...

The shifting on our Santana 10-speed 11-34 with the previous model XTR was great when we took delivery in Jan 2006. It has been great nearly all of the time. However I have had some spells of poor shifting in the rear: in hindsight the cause has been friction somewhere in the derailleur cable run.

The first time the shifting to higher gears / smaller cogs deteriorated was when the cable was fraying inside the brifter but it took me a while to figure that out. I was so used to long cable life on my Campagnolo single that it didn't even dawn on me that that was the issue. I even bought another cassette before I figured that out. Another time it deteriorated was when the cable housing got a slight kink / bend right where it entered the rear derailleur. I probably did that when putting the tandem rear-first into the van up between the second row of seats with the housing getting pushed / bent against the seat as it went in. A new piece of housing fixed that.

Yet another time was when I installed new housing and cables just for general maintenance. It had a pre-cut piece of housing for the rear that in hindsight was just not long enough. I could not get the shifting to be clean. When I finally replaced that with a longer piece providing a gentler curve I was able to make it very good again.

On our Santana, the derailleur cables come down under the down tube and then under the boom tube. The bare cables run through pieces of teflon tube under the captain's and stoker's bottom bracket. These are susceptible to getting dirt in them and wearing with repeated shifting. To look at the cable inside these teflon pieces or to look at the housing ends, shift to the large rear cog, then without turning the pedals click the brifter as if shifting to the smallest cog. This puts enough slack in the cable so that one can pull the rear derailleur housing out of the split cable housing stop on the chain stay and then the entire cable / cable housing system is loose enough to slide the cable and or the housing to check and clean.

I have two 11-34 cassettes. I ordered the second one when I was having my previously-mentioned first shifting troubles. The original first generation 10-speed from Santana that came on the bike with all solid cogs and a second generation one from Santana that has the larger cogs on aluminum carriers. These are both made by GIANG in Malaysia as one can read on the lock ring. It would be great to be able to directly compare an IRD 11-34 with the GIANG from Santana. I would imagine that GIANG makes the IRD cassette but I don't know how one could confirm that. GIANG doesn't mention the wide range 10 speed cassettes on their own website but as I said, the lockring identifies the ones from Santana. I had a conversation about the cassette with Bill McCready when IRD began marketing theirs and he said it was very likely that GIANG was also making the IRD but at that time he didn't know.

Counselguy's Calfee has an IRD cassette so maybe he and I can get together and compare / inspect the cassettes.

Also check the "B" screw setting that controls how much chain wrap / how close pulley wheels are to the cogs. Shifting is improved with closer settings (without the pulley wheels interfering with chain movement on the largest cog). In the spring after several sloppy-wet-road-with winter-sand rides I had some sluggish shifting to smaller cogs and I found that my derailleur was not pivoting freely on the bolt that attaches the derailleur to the dropout. I had neglected lubricating that and it kept the derailleur from pivoting to keep the chain wrapped well around the smaller cogs as I shifted to higher gears and the shifting was not so good. Some lubrication quickly restored good shifting.

Finally, I have found that when adjusting the shifting after putting on new cables it can be shifting perfectly in the stand with no load but we go out to ride it isn't good. I have to do some tweaking with the inline cable adjusters while out on the ride to really get it right.

Bloomington, IN
Santana Niobium with over 12,000 miles

I installed a Salsa 24T inner chainring. Now I still have a crisp shifting 10-speed cassette AND lowering gearing than stock. Pick-up a 24T Salsa and just spin and smile no matter what the incline. :thumb:

James

... Someone who is "hard on his bike" is the person I would most expect to actually get the shifting right in this case.

Our success shifting might have to do with the tandem being my only bike with STI. All of my other bikes are either Down Tube shifting or fixed so I don't have a lot of expectations for drive train shifting other than requiring the thing go into the right gear when I want it to. So far we have had no problems at all.

One nice thing that STI gives (although I hate the shape of the levers) is being able to shift out of the saddle-something we do quite a bit.

I installed a Salsa 24T inner chainring. Now I still have a crisp shifting 10-speed cassette AND lowering gearing than stock. Pick-up a 24T Salsa and just spin and smile no matter what the incline. :thumb:

James


What's the rest of your setup? I've got a 53,39,30 FSA crank and D/A 10 speed. I was also thinking about a smaller inner chainring.

The 24 tooth Salsa is compatible with a 10 speed chain? (some references list it as 9 speed compatible, so I was wondering about width.)

How is the jump from the small ring to the middle? Any shifting problems?

I only have about 150 miles on the bike with the new Ultegra cassette and 24T granny, but I have not dropped the chain when going from the middle to inner ring. I have shifted a dozen times or so, and no problems. I can't remember, but I may have taken a link out of the chain to maintain decent tension and with the removal of the IRD cassette, the chain does not need to be as long. So far, I really like. You could even go 22T but that seemed overkill. Having said that, we will probably run into the hill from hell and have to dismount with our 24T. :D

Not that anyone cares, but the one thing I've always attempted to do when faced with the question of "what to do" as the number of cogs have increased is to keep my options open by trying to find the lowest common denominator.

On our '98 Erickson that meant Campy 9 speed shifters & Campy Racing Triple rear derailleur with a Shimano 8 speed cassette, as 9 speed was rumored to be problematic at the time. I was fortunate in that I was already a convert to Campy Ergo and it just so happened that Campy 9 speed Ergo shifters would work with either Shimano 8 or 9 speed cassettes (12x27t & 11x30t w/54-42-28 and then 54-44-32 rings)... no adapters required.

We ran our '98 that way until we took delivery of our '02 Erickson which we spec'd with Campy Ergo 9 shifters & a Record 9/10 long cage rear derailleur and a Shimano 9 speed cassette. It worked just fine right out of the box so we switched the '98 over to 9 speed as well (12x25t, 12x27t & 11x32t w/54-44-32 rings).

When shopping for components to hang on our new tandem we were once again faced with the same dilemma we had back in '98: 10 speed was rumored to be problematic. After doing our homework I found that the solution in 2008 was the similar to what it was back in 1998: Campy Ergo 10 shifters and long cage rear derailleurs could be made to work with either Shimano 9 or 10 speed cassettes (with or without an adapter). I elected to go ahead and use the Jtek #1 shiftmate just to be certain I wouldn't have any shifting issues coming out of the box; experimentation could come later. The Jtek has proven to be a very good solution and we've been able to run Shimano 9 and 10 speed cassettes & chains interchangeably. The significance here is that while 12x27t cassettes are available in either 9 or 10 speed spacing, the tried-and-true Shimano XT 9 speed cassette family includes the 11x32t cassette that we use in the mountains. Now, given that we're 10 years older and wiser, we've reduced our chain rings to 53-42-30 and would even consider going to a 28t for a European tour or any other seriously long, steep ascents.

So, where am I going with all of this? Assuming no one comes up with a silver bullet to solve the poor performance of the IRD 10 speed cassette With your current set-up it, would appear you could use a JTek Shiftmate #2 to retro-grade to Shimano 11x34t wide range 9 speed cassette with your current Shimano 10 speed shifters and XTR RD. Now, I'm not sure if you need the wide range all of the time or only part of the time, but this is just something to consider if you've found that what you have just isn't working well.

Bottom Line: Perfect shifting on a tandem can be ellusive; however, if you're willing to make a few trade-offs here and there, there's usually more than one way to skin that cat.

While at work today, out of curiosity, I shifted Dura-Ace and Ultegra rear shift levers on bikes next to each other exactly one gear. The Dura-Ace lever does travel noticeably less than the Ultegra.

Thanks everybody for your help.

Last LBS adjustment helped, and though suboptimal it works. I'll see what I do. Co-Mo did not answer my e-mail to customer support, not that there is much they can say that has not been said here, but a simple "sorry it did not work out, can we send you a pair of shirts as an apology?" or something like that would be in order to keep up the smile on an otherwise very happy customer.

Thanks everybody.

Co-Mo replied (they did not reply to my mail until I gave them a call, but once I called they were quick), blamed the IRD cassette as well, offered a deep discount on a new SRAM 11-28, and I'll take it. They had known about the problem when they built the bike, but had no alternative gearing solution. IRD claimed to be working on the problem but never solved it. Co-Mo tells me they had made the dealers aware, but I was not advised. We don't need such low gearing in any case, except perhaps sometime in the future if and when we tour fully loaded on mountain roads. We have a 28 chain ring, I think 28 x 28 will be low enough.

Are there different part number on the old and new XTRs?
Thanks,

I don't understand what they were thinking when they put the ratios together for this cassette anyway... the top gears are too close together and then there are HUGE gaps where you need them most:wtf:

The SRAM 11-28 is a much better option IMO, nice spacing and reasonably broad... 11-34 would be nice but not with the ratios IRD uses... yeah lets have a 25, 23, 21, 19... but go from a 15 to a 13 and then to an 11??? :roflmao2:

Last spring we upgraded to a new 10 speed tandem with the 11-34 rear. Even after all the checks of cables, hanger alignment, and normal adjustments the shifting was still sluggish and not as good as our previous 9 speed tandem. We were finally able to get it reasonable by reducing the amount of float on the upper idler pulley on the XTR rear derailleur.

Yup it understood why the upper idler pulley is designed with left-right float. However, reducing the float on our tandem made our shifts much crisper and the stoker is much happier with the shift quality. It would be interesting to know if Shimano changes the upper pulley float between the 9 speed and 10 speed derailleurs.

EnterprizeZ,

How do you go about reducing the float?

Thanks,

We started out using 0.008" shim stock under the idler pulley caps. You have to have the right size hole to go over (not against) the inner bearing race. That took out something under 1/2 of the left-right float. I ran that way for a couple hundred miles and liked the results. I purchased an aftermarket idler once I was sure that's what I wanted and have been running that way for the last 500 miles.

With less float, you do have to have the cables adjusted closer to minimize any noise. However, getting the adjustment right isn't that big a deal and for us the trade-off of faster shifting was well worth it...

I asked the mechanic (who does great work on tandems) at our LBS about the 10 speed on tandems. He said that the derailleur hanger must be perfectly straight for the 10 speed to shift properly. He also said that a rear wheel may be slightly out of true and that he checks the rear wheel in a truing stand before using the derailleur hanger alignment gauge.
I hope that this helps.
Sheldon

Sheldon,

The hanger alignment check is good advice. Before we went the idler pulley float approach, we checked cables, hanger alignment, adjustments (include B tension), chain, etc. With any bike I'd still check all of those first.

BTW - Past experience says derailleur hanger alignment is often one that get's missed when trying to get quality shifting. I purchased the alignment tool a several years back and it really made a big difference on several bikes that I've been asked to work on.

Thanks. Interesting take on this problem. Are you saying that the aftermarket idler had less float, off the shelf?

Take the upper idler pulley off on an XTR rear derailleur and you'll see a fair amount of axial float. So much so, that one if one didn't know better they would think that the bearing was bad. We have 2 singles and one tandem with XTR rear DRs on them and all of them are the same way. If you do some searching you'll find that this is by design and really helps keep things quiet. If there was no float, you would have to adjust the cable more often to keep things quiet.

We've have had very crisp shifting with XTR rear DRs on 9 speeds (2 singles and one previous 9 speed tandem) but the 10 speed tandem could not be tuned-in nearly so crisp (maybe spacing difference between gears with the same idler float?). The aftermarket upper pulley has significantly less float and made a significant difference for us. I believe the XTR rear DR was intended for 9 speed mountain bikes. It would be interesting to know if the Shimano idlers intended for 10 speed rear DRs have any less axial float. Anyone have Shimano specifications for the different idlers?

TandemGeek,

How can I figure out what is the part number of the "old" XTR cassette in long cage (SGS) version? Is it M960?

If I cannot buy one of these will the XT give similar performance? I use a 11-34 ten speed cassette.

Thanks,

EnterpriseZ,

Ah, yes. Now I see your point. So you think that maybe if one just replaced the XTR jockey wheel with eg a 10 speed Ultegra jockey wheel (assuming that would fit) there would be less float and, hence, crisper shifting. Right?

what is the part number of the "old" XTR [derailleur] in long cage (SGS) version?

This one (http://www.bikeparts.com/productinfo/XTR-M952-7-9sp-rear-derail-SGS-long-cage-79923-22908.html)?

will the XT give similar performance? I use a 11-34 ten speed cassette.

I believe the '07 XT (http://wheelworld.com/itemdetails.cfm?ID=4317) will; not sure about the '08 as it seems to now share some similar features with the newer XTR which some in the biz have been disappointed with.

I He said that the derailleur hanger must be perfectly straight for the 10 speed to shift properly. He also said that a rear wheel may be slightly out of true and that he checks the rear wheel in a truing stand before using the derailleur hanger alignment gauge.
I hope that this helps.
Sheldon
If you follow the instructions of the Park tool this is not necessary. They say to use the valve stem as a guide and check using this same point as a reference all the way around. That way an out of true wheel won't be a problem.
That being said your wheel should be true anyways.
Just checked my allignment yesterday and corrected some slight shifting quirks.

TandemGeek,

The XTR M952 is what came as original equipment on our 10 speed tandem. Never tried the XT version so can't comment on that one.

Thanks TandemGeek,

I wonder if anyone has experience using one of the 10 speed Shimano or IRD 11-34 cassettes with DaVinci's modified long cage rear derailleur. I'm still not too clear about this forum; I decided to start another thread asking about the DaVinci rear derailleurs but I am not sure if this is what one is supposed to do.

I wonder if the new 11-28 7900 10sp cassette will work with XTR 2008 or 09 rear derailleur and 28/39/52 on front with Dura-Ace triple front? I'm sure the 7900 rear derailleur doe not have enough capacity for a triple.

The Ultegra 6600 long cage derailleur will certainly work with that combination, and I believe the Dura Ace 7800 long cage would also work. As you say, Dura Ace 7900 currently only has a short cage derailleur that would not work. The 7800 stuff appears to still be widely available, and now cheaper than 7900.

I can say that the Ultegra 6600 long cage will work with confidence because that is what I'm using with 28/39/53 chainrings (FSA Gossamer, with a TA-Specialites 28-tooth inner ring) and an 11-28 cassette (SRAM OG1070). As for using an XTR rear derailleur, I cannot see any reason why it would not be able to handle this combination, but I'd go with a road version if I had the choice.

The Ultegra 6600 long cage derailleur will certainly work with that combination, and I believe the Dura Ace 7800 long cage would also work. As you say, Dura Ace 7900 currently only has a short cage derailleur that would not work. The 7800 stuff appears to still be widely available, and now cheaper than 7900.

I can say that the Ultegra 6600 long cage will work with confidence because that is what I'm using with 28/39/53 chainrings (FSA Gossamer, with a TA-Specialites 28-tooth inner ring) and an 11-28 cassette (SRAM OG1070). As for using an XTR rear derailleur, I cannot see any reason why it would not be able to handle this combination, but I'd go with a road version if I had the choice.

I guess I'm a little befuddled by this whole topic and was wondering what "doesn't work" means. We have a few thousand miles on our speedster with the new xtr and 11/34 and while I wouldn't replace the campy on my single with it, it seems to work ok for us. The shifting is a little vague, but we can get all of the gears and I have no experience with Shimano other than this setup, so I just thought it was how Shimano worked. So if someone could explain what the symptoms are I would appreciate it.

Frank

Symptoms are just sloppy shifting, generally while up-shifting (going to a smaller cog), I shift one click and it does not shift, go two clicks and first it shifts one cog, and then soon after a second cog. I need to go two clicks up, and as soon as I get the first cog shift I do one click downshift and I am stable. Downshift its the same though generally a little better, I don't always need to double shift. Its OK once you are used to it. Also it is slow to respond to a shift input.

I changed to a Shimmano 11-28 and it works much better. It is fine for the terrain here in Buenos Aires, but when we go to the mountains I will need to go back to 11-34.

Symptoms are just sloppy shifting, generally while up-shifting (going to a smaller cog), I shift one click and it does not shift, go two clicks and first it shifts one cog, and then soon after a second cog. I need to go two clicks up, and as soon as I get the first cog shift I do one click downshift and I am stable. Downshift its the same though generally a little better, I don't always need to double shift. Its OK once you are used to it. Also it is slow to respond to a shift input.

I changed to a Shimmano 11-28 and it works much better. It is fine for the terrain here in Buenos Aires, but when we go to the mountains I will need to go back to 11-34.

OK. Thanks. I guess we see some sloppiness as well, but just live with it. It's funny that I wouldn't tolerate this on my single bike, but we are generally pretty laid back on the tandem anyway.

Frank

We recently bought a Cannondale RT2 08' new and after ride two we went back to the dealer and had them replace the bent Ultegra derailleur, locked up the chain up front (who knows why) and the crappy 11-32 IRD cassette. We went with an 12-25 ultegra cassette and new ultegra long cage. While we were at the shop another RT3 rode up and who was on it but a Cannondale factory tech. He said we should fully encase the shift cables as he did, which we then insisted should be done. Connondale paid for the whole upgrade, or should I say proper set up. Shifting is great now with no problems. My buddy just bought an 09 RT2 and had the same upgrade, they let him keep the IRD too.

We have the 3rd XTR in the pictures. We had shifting problems which took a little muscle to correct. We needed to get all the slack out but once we did the shifter works great. Ours cam on an "07 Cannondale.