mikemelbrooks

I have a 50 38 30 triple chainset and a 11 36 cassette fitted at the moment and find the change down to the 30 is very hit and miss and triple brifters are getting rare. So I have found a double chainset 110 BCD that will allow me to go down to a 34 on the front. So I am thinking a 50 34 front with a 11 40 cassette, is anyone using a similar set up? if so what derailleur? Shimano preferably?

JoeShellharbour

Hi, we have a group of Cannondale tandems (in Australia our group is exsight) and are having chain drops on a few of them from the little ring so are also considering the change to 2 rings and a MTB group set and shifter similar to you
So will watch with interest your post
Regards
Joe

Leisesturm

A double is no insurance against chain drop. My 50/34 roadbike single drops the chain if there is any forward motion of the cranks during the shift. I've taken it to the LBS repeatedly and they can't fix it. Once upon a time I could have fixed it myself but my eyesight is to the point where bike wrenching is out of the question. To the o.p. however: Since 2005 I have chain catchers on all my tandem triples. The first one was an n-gear chain catcher and it's probably the best if it is still available. But any old chain catcher is WAY, WAY cheaper than a drivetrain overhaul and more effective. A no brainer IMO.

mikemelbrooks

Hi, ours is also a Cannondale, at the moment we have cable disc brakes and I would like to try changing to hydraulic but hydraulic triple brifters are unobtainable.
Hi I have the opposite problem it seems if we put the slightest of pressure while changing down to the smallest front ring the chain will stay put with the front derailleur pushing hard against the chain. I have fitted a chain catcher already.

scycheng

I did the conversion from 3x8 to 2x11 with 48-32 (I think) and 11-42 cassette using a mix of Ultegra and GRX parts. Have not had a chance to ride it a lot but seems to work well. Shifting is better than the 15 year old Campy+Shimano combo.

In the same conversion, I converted the drivetrain to run the timing chain on the right as well.

mikemelbrooks

Thanks that was just what I was hoping to hear, I have a timing belt so it's staying that way. The original crankset are FSA Gossamer megaexo 130bcd I have bought the same Crankset but 110bcd and a double. I think I should be able to use the original left crank for the cross over.

scycheng

You should be able to. I went with new cranks to get a better length for my stoker. Now I can use any run-of-the-mill triple crank for the back and a double/single ring crank for the front.

bobh123

My Comotion Speedster came with 50/34 chainrings and a 11-40 cassette. Ultegra shifters front and back. It worked fine, though like all derailleurs it needs to be adjusted properly. I think the rear derailleur had a Comotion-branded extension similar to a Roadlink to be able to handle the larger cassette.

As an aside, this past summer I installed a larger 11-46 cassette to be able to ride the bike loaded up hills when we rode across the country.

CaliTexan

I've always ridden all Shimano 3X tandems. We all know that getting the drive-train adjustments right and keeping them right was a bit of work, and the shifting was never quite as good as on my similar single bikes.

So, in 2019, when we ordered a new Co-Motion, we switched two things about the drive-train - we switched from 52-42-30 rings to the very common 50-34 compact chainring combination, along with a similarly common 11-34 cassette (and a second 11-42 cassette + Wolf tooth Roadlink for mountain tours). The downside of these double chainring configurations is the large jumps in teeth. And shifting the chainring up or down almost always requires a double shift. But, the Shimano components are tried and true and work just fine - no chain drop issues.

The biggest change, however, for both initial adjustment and for smooth operation, was switching from mechanical to Di2 Ultegra shifters and derailleurs. They are a lot better than mechanical for a tandem. So, switching to a double won't be that big an adjustment for you, but if you can incorporate the change to Di2 in your upgrade, you'll likely find a big improvement, perhaps including fewer chain drops.

Chilepines

Our old tandem had the same gearing as the OP, and the same problem getting it to drop into the small ring. We are now running 46/30 and 10-42 11speed cassette. All with GRX di2 shifting. This is a massive 647% range. And we use all of it! And we still spin out the 125 gear inch top gear as soon as the road tips downhill.
The 46/30 is FSA modular on an SL-K crank, but should fit other of their modular cranks.

merlinextraligh

We are running di2 with 50/34 f chain rings, and put an 11-36 for climbing. Bought a wolf tooth adapter to fit an 11-40, but we have t had to use it.

based on how well the 11-36 shifts, and the accounts others running 11-40 and bigger with the wolf tooth, I pretty confident it would work well.

Carbonfiberboy 

We've been riding our 2003 CoMotion since 2007. It's a triple of course. I had a chain catcher on it for several years, but finally took it off. It seemed easier to me to properly adjust the FD than to mess with a chain catcher. Our current experience is that was a good decision. We are running 53-39-26 in front and an 11-40 in back. We have some steep hills and we're a 151 y.o. team.

The front end has been an issue. It has been our practice to ride in the rain a lot, we being in the PNW. That has meant a fair bit of chainring wear and we started having trouble getting 42T triple rings. We changed our left brifter and FD to 10-speed and our middle and big rings to 10-speed rings. The 53 is actually for a double, but there's no difference there and of course the granny doesn't care either. That change solved our front shifting problems and we stocked up on 39T triple rings. We don't drop the chain on the granny shifts.

I have triples on all my bikes. I prefer them because the gear-inch numbers are much closer on a triple than they can be on a double, plus I get to use 26T grannies on all my bikes which makes an even larger difference on my singles. Interestingly, my singles work fine with the 9-speed FD and brifter and 10-speed chainrings, but our tandem wasn't happy that way. There is a small difference in ring width between 9 and 10 speed chainrings. I do have a chain catcher on my most-used single which is running 10-speed rings. Of course shifting is easier on a single.