lortman

Hello,

I have a Calfee Tetra Tandem purchased in 2009. The drivetrain is: FD-Shimano Ultegra 9 speed triple (53,39,28), RD-Shimano XTR(11-34). Shifting the triple has never been easy. It is basically pick the two chainrings you'd like to shift reliably and pray you can get into the other ring. I'd like to replace the triple with either a double (Di2 ?) or something like a Sram 1x. Last year I contacted Calfee and I am due to call them make after our season ends here in Massachusetts. As of our last conversation, aside from internal frame routing modifications there would be issue for me with the rear cassette. I'd need probably a 36 tooth or larger low end so we can get our butts over the hills here in Western Massachusetts. As you know, the Di2 road shifters won't shift a MTB rear derailleur. In summary, this solution would be very expensive. So I'm not sure this is the way to go. Now I just read some articles about Sram's 1x drivetrains with an 11 speed 10x42 and a wide range of front rings. Would this work? Has anyone tried this solution? Would it be less expensive? Thanks for any help.

DubT

If you want to go electronic you might want to wait for SRAM to release their new wireless system for mountain bikes. I am confident that is in their plans. That way you do not have to have your frame modified to receive internally wiring. You will need a rear wheel that will accept an 11 speed cassette and you will probably need new cranks.

merlinextraligh

The 1x system is pretty much intended for mountain biking, and cyclocross, where you don't need a big top end.

For a road tandem, its going to give you much bigger jumps than you currently have, and both a higher low end than you currently have, and a lower high end.

With a 42 front chainring, your top end will be down to 30 mph from 35 mph at 90 rpm on your current setup. Your low end will be up to 7mph at 90 rpm, from a little over 5mph now.

At least as significantly you'll be looking at double digit gear step percentages on every shift, in contrast to the single digit steps you now have for most of your shifts. Basically, most of the gear jumps will be like shifting two gears compared to your current setup.

I think you'll be much happier with Ultegra Di2 for not that much more money.

Dean V

The cheapest and probably best option is to get what you have working properly. I have had an Ultegra 9sp triple on a tandem and it shifted great, front and rear.

oldacura

We have an older (1998) Co-Motion. It is set up as 54/44/30 (I think) in front & 11-32 (8 speed) in the rear. Both derailers are Ultegra. Shifting between the 2 big rings in front & any of the gears on the cassette works great. Maybe better than the Durace 2 x 10 on my single. Shifting down to & up from the small ring in front can be a bit sketchy. The small front ring is our bail-out gear. We rarely use it.

I think the biggest difference between our tandem & my single is that the tandem has bar-end shifters & my single has Durace brifters. Getting a wide range to work on triple front rings may be beyond the capability of the brifters.

Many people wouldn't consider going to bar end shifters but they are smooth & sure.

Leisesturm

t h i s ! !

reburns

We have 2005 T2000 that came with an ultegra FD 6503 front derailleur on a 30/42/53 triple. Rear is 11-34 9 speed. Ultegra brifters. It shifted well for years. I also installed a n-gear jump stop which helped shift down to the inner ring more quickly by allowing the low limit screw to be backed off.

When we wore out the 42T recently I replaced it with a Shimano FC 5603 39T chain ring, thinking there could be an advantage to sticking with Shimano ramps and pins, and being unable to find the 42T middle ring anymore. I could get the FD 6503 to still shift okay, but it was definitely more finicky than before, and one out of every 4-5 shifts to the big ring was grindingly slow.

From this forum I learned that there is a wide range of front derailleur cage designs, and I happened to find a lightly used dura ace FD 7703 triple on eBay for $35. This derailleur was designed specifically for 30/39/53 triples and the inner cage is much deeper than the FD 6503. Wow, what great shifting. Every shift is immediate even under load (I do not announce shifts to the stoker) Trimming when using the middle ring is a bit touchier, but I can't complain about that as it is operating the way it was designed. I'm sure it would still work great if I swapped out the inner ring for a 28, which I will probably do if we ever wear out the 30.

Not trying to talk you out of a DI upgrade, but based on my experience it is possible to get a 9sp ultegra triple to shift really well with the right hardware and adjustment. On this last point, I found Sheldon Brown's article on FD adjustment very useful.

mtseymour

The Sram 1x11 drivetrain is for MTB (and now cyclocross) and won't give you enough range on a road tandem. I use the 1x11 on my full-suspension MTB and have to choose between a 26T or 28T ring depending on the terrain. This is a minor issue because spinning out is not common.

A better option is to upgrade to a Ultegra 2x11 mechanical shifting with 50-34 compact cranks. You should be able to use a long cage RD for the 34T cassette. The front shifting will be better and the 34 x 34 ratio will allow you to do very steep climbs.

If your budget allows, the Ultegra 11sp Di2 is fantastic. The front shifting is extremely precise and reliable. It's much better than the mechanical Ultegra, especially with the long cable run and higher torque on a tandem.

DubT

I am of the opinion that SRAM will have a 2 X 11 system available that will include a long cage rear derailleur. I would give that consideration. Wireless and 15 minute set up. I believe that the OP would have to change out the rear cranks.

That being said our Calfee with 3 X 10 shifts great using 6703 levers and Dura Ace derailleurs. Ultegra cranks 52/39/30, Ultegra cassette 12 X 30.

lortman

Thanks to all who have offered advice. I guess I've concludes that a Sram 1x is probably not the solution. I have one more question. How about a Sram 2x solution. A 50/34 compact crank with a 10x42 rear cassette. I think I'd need a Sram MTB rear derailleur to shift that cassette, so do the Sram road shifters shift a MTB derailleur?

One additional comment on Di2. A member of our Sunday morning riding group just purchased a new ½ bike with Ultegra Di2 groupset. Last Sunday as we were just about to depart she noticed she forgot her battery. How much of an issue is that?

DubT

Do you really need a 10 X 42 cassette?

lortman

DubT, good question, I don't know the answer, I've never had gearing that low. That is certainly lower than my current 28 to 34. But my upper end would also be higher than my current 53 to 11. It would be nice to have such a wide range of gearing. We're certainly not the best climbing team on the planet and having the low end takes the anxiety out of just about any hill around here!

TCW2

I agree the 10x42 cassette might drive you nuts on a road tandem. I have have XX1 on my mountain bike and it's great, but that's because the slower speeds aren't as impacted by big jumps between gears. A friend just added a 44 tooth rear cog to his X01 cassette (OneUp cog) so he'd have lower gearing for Leadville 100 race, but still have some top end with a 32 front ring. He found that he'd spin out around 30 mph, on his 29er. I found that with a 28 ring I would spin out around 28 mph, but my cadence was way over 100.

Some mtb people claim a double front will not play nice with a 10x42 cassette but I think it would work fine with maybe a few issues with chain length.

Our 2007 Trek T2000 has Ultegra level 9-speed components, 105 front der, 11x32 cassette, 52/42/30 rings, XT rear der. With as little friction in the system as possible we found the rear shifting was always a bit iffy. The other day I threw on an old Ultegra rear der and a SRAM 12-26 cassette. The shifting was much better and I think we were a little faster because it was easier finding a more appropriate gear as the jumps were decreased. We noticed the top end was impacted so threw on an Ultegra 53 ring in the front to compensate - shifting was still solid even with the larger ring Shimano 53 ring/SRAM 42 ring.

So, we learned a few things and now have some things to consider. First, smaller gear jumps are nice (especially on fast group rides). Second, it's often difficult to get tandem shifting just right due to long cable runs. Third, 11-speed electronic shifting will likely be the answer for us using a 53/39 double.

SRAM eTAP RED looks pretty awesome. Problem is that the largest cog is a 28. That may work for us but having a little more low-end on a 53/39 would be ideal. I expect SRAM to release Rival/MTB wireless electronic systems soon, hopefully. An 11x32/34/36/40, etc. might be a good solution for tandems.

merlinextraligh

It's the 10 in the 10x42 that's the problem.

It requires a special hub, and limits your flexibility in swapping cassettes

The 10 cog is designed to give you an acceptable high end with one smaller front chain ring.

With a 2X 50/34 setup, the 50x11 should be big enough without going to a 10 small cog.

Using a Sram 2x or Ultegra 2x with an 11-36 would still give you a pretty low gear

waynesulak

If the 28-34 combo they currently have is needed then it sounds like they need or want low gears. With a 34 front ring I think that low of a gear would require something like a 42 rear cog. I can identify with wanting low gears and that is why I have a small ring and the biggest cog is only 28.

Maybe they can loose the really low gears and be happy with a double.

jnbrown

Also agree with this.

We have a Calfee with Campy Centaur 10 speed shifting. Front triple shifts fine, using 50/39/28 rings.
Like Campy much better than Shimano. I have Campy Chorus 11 speed on my single and its awesome.
The newest groups from Shimano and Campy work better than the older ones, so upgrade might be worth while still being much less expensive than Di2 conversion.

mtseymour

With a new bike, the Di2 battery is usually mounted inside the seatpost with the wires threaded through the frame. For retrofit to an older bike, the battery is attached the water bottle cage near the bottom bracket. So I don't understand how she can "forget" the battery if it was installed properly. The battery last a long time, possibly a whole year on one charge.

sch

11spd Di2 batteries are rated for 500-600 miles operating duration. Unless your tandem is a garage queen, a year is unlikely on one charge.
External batteries IME recharge on the charger in 15-30 minutes. Dunnoh about internals with USB connection. Internals assume a particular
seatpost and wiring capacity in the frame, ie the frame has to be relatively open at tube joins so you can snake the wires around.

To the OP, Santana has found that 11spd Di2 road brifters can operate XT Di2 RD, so you can use whatever cassette the XT can handle. Whether
this requires fiddling with the firmware, you need to talk to Calfee or Santana about that. The XT Di2 FD will also run off road Di2 controls but you
may want to stick to road Di2 FD and a suitable crank, there being some question as to the max size of XT FD chainwheel capability and the FD
mounting variants.

justcrankn

They will shift MTB derailleurs but you can't mix MTB and road derailleurs. So you would need to use a MTB front derailleur which can take max 50 to 52 tooth chainring, according to another recent thread.

We have 3 tandem triples that shift flawlessly. I get the best front shifting using matched Shimano chainring sets. A waxed chain slows the rear shifting. The front derailleur should be matched to the size of chainrings.

We have a bike with 26/36/48 chainrings using a DaVinci crankset. This should work with XTR Di2 and road shifters. It currently shifts smoothly using a fd-6503.

If you want to go to 11 speed I think you can put a 11 speed MTB cassette on your 9/10 speed rear wheel. Someone correct me if I'm wrong.

mtseymour

Di2 battery life depends on the shifters, battery pack, weather, and the amount of shifting (esp the front derailleur).

We use the Ultegra 6870 (11sp) Di2 shifters and derailleurs. The older 6770 (10sp) shifters and derailleurs are bigger and apparently use more power.

We use the SM-BTR2 internal battery rated at 500mAh. This battery uses E-Tube wiring and is therefore incompatible with 6770 shifters and derailleurs. The BTR2 weighs 60g and is rated for 1,200 miles between charges. Since we ride in mild weather and out of the city (ie. less shifting), we can go farther between charges.

For tandems using the external SM-BTR1, the rated battery life drops by half to 600 miles. Although it's slightly heavier than the internal battery, the BTR1 has less capacity because the protective case takes up a lot of weight.

For most riders, Di2 battery life is a minor concern because its conservatively rated. It's convenient and easy to charge the batteries, and 1-2 charges should be enough for one season.

CliffordK

As I understood it, at least with early SRAM wireless electronic front derailleurs, it would send a "shift" command without the state, so I believe it only worked with a double chainring.

zonatandem

Have been tandeming since 1975 and have used all kinds of shifting systems, including early version DI-2 .
Di-2 failed us in the middle of a hill climb without any warning after a recharging. Turned around, went downhill and pedaled home in one gear.
Most reliable we've found is barend shifters. Reliable, relatively inexpensive, and lasting over 50,000 miles without failings.
Hi-tech is fine and gets bragging rights and wow-factor.
Currently use a triple and 9-speed cassette (11/34). Reliability and longevity and as a bonus a decent price point are key.
Jus our input/experience.
Pedal on TWOgether!
Rudy and Kay/zonatandem

DrMarkR

Also, be aware that the 2x XTR Di2 front derailleur only has a 10 tooth capacity!!

lortman

To all who offered ideas, I thank you. Once the riding season ends I'll confer with my LBS and Calfee and come up with a plan. I'll let you all know what I decide and how it goes. Again, thanks for taking the time to help out a fellow tandem rider!

On a side note, yesterday we rode the Pedal2Pints ride here in Western Massachusetts, I only saw one other tandem on the ride. It would sure be fun to see some more tandems next year. Check it out: Pedal2Pints.com. There is a Spring version as well.

twocicle

Over the years I have had maybe a half dozen shifter cables break due to bend radius fatigue at the shifters (everything from the latest 11spd Shimano brifters to the old downtubers). So far our 100% Di2 setups have performed 100% without fail and the slim seatpost battery only requires charging once every month or so depending on usage.

Sorry your modified battery setup (not 100% factory Shimano) left such a bad taste, cause the real stuff is truly the best shifting from Shimano.