woodcycl

We have a new carbon tandem coming in the next couple weeks. I am struggling with two important components of spec'g out the bike ...

1. Wheelset options. Mainly, going more aero or lighter weight.
2. Gearing options. Mainly, 2x or 3x.

Wheelset Options
I had been set on going with the Spinergy Stealth Carbon Tandem Wheelset. They seem to have many happy owners and I don't see many if any negative reviews. They look great and their price-point is right at my max for a tandem wheelset. HOWEVER, just noticed today they are 2060 grams in weight. Wow. So, yes, they are aero with the deep rim, but you are paying with their heft. On the other hand, and by comparison, the Spinergy Xaero Light wheelset is only 1673 grams. That is quite the difference in weight. Both sets use the same PBO spokes and can be color matched as desired. I like the looks of the aero Stealth wheelset with the deep rims better.

Thoughts? Input? Anyone had an opportunity to put many miles on both sets and willing to share your experience?

Gearing Options
I did a ton of online research on the Double / 2x vs. the Triple 3x for gearing and overall my take-away was it was about 50/50. I've had the Triple on my Cannondale tandem since 2005 and used to it. However, the ease of the Double that I'm used to on my single/half bike sounds nice too. I was going to go w/ the Triple on the new tandem with a recommendation from Mel and seeing a video he took of the Synch Shifting using the Ultegra Di3. The more people I talk with including my LBS though, makes me question that decision a bit. A big part of me prefers to have a double. And, it seems like my primary concerns of a) Tighter spacing between gear changes and b) plenty of low gear inches for taking really tough (18+ Perc) hills can be accomplished with double as well as a triple.

Thoughts? I'm sure there are folks in both camps. But, which one is the safer route that I won't regret? Tough decision.

Thanks for all the help!

bwebel

Gearing really is a personal choice, and comes down mainly to how closely spaced you like your gears and how hilly your area is. If you get a double with a 34x53 and 11x36 combo, that's going to get you over most climbs that you'll face on the road, but you are looking at pretty big jumps compared to a 30x39x53 combo with an 11x32.

The type of shifting you want can also matter. SRAM doesn't make triple front doubletap shifters, so you need to do something like using a barend shifter for the front derailleur if you want a triple with SRAM.

We get over everything around us with a 39x32, so I have the bike set up with a 39x53 double, but it's a triple crank, so if we ever go to real mountains, I can put the 30 chainring on as needed. If I wanted to leave the triple on, then I could put an 11x25 on the back for regular riding, but I'll put up with the wider shift gaps on the cassette not to deal with the triple in the front.

woodcycl

What about Wheelset options? The Rolf Carbon's are looking decent even though they are around $500 more than the Spinergy Stealth. The Rolf Carbon wheels are also about 500 grams lighter. That is a lot less rolling weight!

Thoughts?

diabloridr

Concerning gearing: We went through a similar exercise when we built our Macchiatto last year. Detailed report here:


https://www.bikeforums.net/tandem-cy...long-post.html


The clear trend in the industry is away from multiple speed chainrings. Mountain bikes and gravel bikes are difficult to find with triples (and some are being built around single chainrings).


The risk of triples becoming unicorns in the not so distant future made the decision to spec a double an easy one for us.

Carbonfiberboy 

Our 2003 Co-Motion triple is still working perfectly for us. Love the 26 X 34 low gear and the close ratios in the granny ring.

We are running Chris King hubs with Kinlin XC279 36H rims and CX-Ray spokes. Light wheels, plenty aero, nice looking, and very durable. 285 lb. team. Hubs are original and get serviced once a year, quite inexpensively.

woodcycl

Diabloridr,

Can you give me your thoughts and experience with the Rolf Carbon Tandem wheels?

woodcycl

I really would like to move to the 2x ... but with the hills we know we will do now and then that exceed 12% (and a few 18% and up to 21%) not having at least the same gear inches as we had before (or now) I am leaning toward the 3x. With the 3x I am able to keep tighter gearing ratios ... with less of a jump or up down when changing gears. Right now on our 9sp ... there is a decent jump between gears even on our triple. And, just knowing that we have the gear inches around 20 to 24 for the tough ascents makes us feel better.

diabloridr

Have you spent time really checking the numbers with a gearing calculator?

We moved from 3x9 to 2x11 and made only minor compromises for top and bottom gearing, while keeping the same or tighter jumps between gears. Eliminating the decision process on when to engage a small ring is a huge plus.

Partially this is due to the fact that a 3x9 setup really only gives you 20 gears (3x9x8) while a 2x11 will usually yield 21 useable gears.

Our 34/50 x 11-36 gearing yields a 25.3 gear-inch low. Switching to a 11-40 would increase the jumps marginally but yield an even lower 22.8 gear-inch low.

Just food for thought.

woodcycl

Diabloridr, yes have used the gear inch calculator online serveral times and have them listed in a excel spreadsheet and have gone over them back and forth several times.

the 34/50 with 11-40 ... giving me a 34 / 40 granny gear is one gear easier than I have now. I was just afraid that the jump between gears on that 11-40 stacked cogset would be too large. But, I have no experience with gearing on a 11sp with that far of a range. My single bike is a 10 sp 12-28 so I'm used to small steps on that and didn't want to take a chance of even wider spacing than what I have now. I do like the 34/50 on my single bike!

I wish this were an easier decision! lol

lichtgrau

...if Rohloff is even an option: I could probobly give some information about adaptation to a derailleur gear dropout...

bwebel

What cranks are you going to use? If you get a triple, you can always just take the granny ring off and use it as a double if you decide you don't like it. Or start out with a double and the put the third ring on if you decide you hate the gaps.

I find that I adapt to larger gaps on the tandem than I do on a single, but I really can't imagine adapting to the gaps in an 11x40 cassette. I think the 11x32 is about as much as I could take.

woodcycl

We are going w/ the Davinci Cranks. So, they would be 52/39/30. And, a 11-36 cassette as long as we have the 30 front chainring.

bwebel

The Davincis are really easy to change, even from 110 BCD to 130 BCD, so stop obsessing at this point, go with your decision, and know it's not too hard to change if you hate it :-)

WRT to the wheels you mentioned, I've never used the new Rolf carbons, but have been happy with the aluminum sets that I have had, so I personally would go with those. (if you'd be interested in a nearly new set of the previous generation Rolf carbons cheap, PM me. I have a barely used set that, sadly, aren't likely to be used much more at this point)

woodcycl

Thanks for all the input everyone!

Looks like I'm going with Triple Chainring / gearing and the Rolf Carbon Wheelset with black decals. Nice knowing that I am able to go to a double chainring without too much trouble and expense.

akexpress 

So are you going with DI2 ? I assume that you are then using either Xt or Xtr derailleurs and pairing with Ultegra road shifters? I will be very curious how the front derailleur handles the 52 or 53 chainrings size. I have the above combo on one of our tandems but the largest chainring we have is a 46 and it handles that well. I have Ultegra road derailleurs and a double chain ring setup to change to when we are not loaded touring so the versatility is a nice option. Please report back when you get the bike and have a few miles on it.

woodcycl

According to Mel at Tandems East, this is the setup he install and sets up primarily on the tandems he sells. I've seen a video he sent me where he displays how the synch shifting works and it was quote smooth. Fingers crossed!

Paul J

A couple we ride with purchased a custom Landshark from Mel last spring with this set-up and it seems to work well. We've ridden with them on several occasions. Here are couple of pictures.

turbozinke

Triple makes the most sense to me. I have 30-39-53 front and 12-28 rear. I basically use the gears just like I do on my single except occasionally, on a really steep hill, we have to drop down to the little ring on the front. With some basic experience, which I'm sure you have since you've been riding a tandem for a long time, you know when you're going to need the little ring. If you have a good setup it should work very well.

We have the spinergy wheels with bladed spokes. Our previous wheels were rolf prima tandem. The spinergys ride like a cadillac compared to the rolfs. I would never go back. I know you're talking carbon so I can't speak to that.

jnbrown

We have 50/39/28 front and 12-32 (10 speed) rear on our Calfee and it has worked out well. When I first built the bike I had Campy Centaur shifters and a J-Tek shiftmate to adapt to a Shimano cassette.
I could never get the rear to shift very well. I eventually changed the rear shifting to SRAM Red shifter and Force WiFli derailleur and it shifts perfectly. I have mismatched shifters but I am very happy with this setup.
There is one gear jump around the middle of the cassette that is bigger than I would like. Sometimes I will put on a 12-28 cassette if we are doing a flatter ride.

oldacura

We have a Calfee Tetra that we bought through Tandems East as well. I wanted the biggest possible range that shifted well. We went with Di2 Ultegra 2 x 11 gears. 52t x 34t in front. The bike came with an 11 speed cassette 11t x 36t. I have since changed the cassette to an 11t x 40t (I like this better). I wanted a big top end and we need a low bottom end. This gearing works well but I would still prefer 3 rings up front - using the smallest ring as a bail-out. Our low gear is pretty low but I'd like a lower one as we age.

My biggest complaint is the drop from the big ring to the small ring. We ride almost exclusively in "Full Synchro" mode. We ride the bike mostly on the big ring and drop to the small ring as we approach climbing. The Di2 will beep twice just before it shifts the front derailleur. This lets me know that the next shift will be a big one and I can warn my stoker to ease up. When the big drop happens, if we have not eased up, the resistance torque drops dramatically.

I like the system pretty well but I'd still like to ride the bike as a 2 ring range and save a little ring as a bail-out.

dragonlord76

I was going to say the same thing. Using 34/52T for front and 11/40T for rear. To me this is a perfect setup.

diabloridr

Our Machiatto was built with 50/34 for the chainrings and 11x36T cassette. I hated to give up the 52T on our old Speedster but since we used the 52x11 for such a miniscule amount of our riding, it was a wise call. We spin out the Machiatto @ 34 MPH, down from 36 MPH on the Speedster.

We're finding we're doing much of our riding in the 34T ring, as we don't spin it out until over 22 MPH. Only when we're on downgrades or have big tailwinds do we have much need for the big ring.

We're not using the "Full Syncro" functionality of Di2, as the gaps in the 11-36 cassette are at best miniscule and at worst manageable for us. That might change if we moved to the 11-40 cassette. I can easily imagine how all those front shifts require good coordination.

YMMV.

Dean V

I can't understand the need for such a big gear range. Surely if you need a 34-40 or similar low gear wouldn't a 52-11 top be rather unnecessary?

Alan_F

That's not a big gear range... (says the DaVinci rider). Whether it is necessary depends on the terrain and the team's abilities.

Warning - lots of numbers ahead: Our current road tandem has 34 tooth timing rings, 18 tooth left side freewheels, 12/18/24/30 rings and a 9 speed 11-34 in the back. Doing the math that means a 22.6 x 34 granny gear (.666 ratio... a 34/40 gives a .85 ratio) and a 56.6 x 11 big gear (5.15 ratio... a 52/11 gives a 4.72 ratio). Our big gear 772% larger than our granny. A 52/11 34/40 yields a 556% range.

Since our new bike will have Di2 we're going down to only a triple. We'll be using 17 tooth freewheels and 13/24/28 rings (equivalent to 26/48/56) and an 11-40 cassette. That retains almost all the range of our current 4 x 9 setup with reasonable gaps between gears.

As for "needing" these gears, we're currently training for a hill challenge ride and we're not particularly great climbers. Tomorrow the first hill on our training ride will be 3 miles long with a maximum 21% grade and an average about 6%, but it has a 1.25 mile stretch that averages 10%. That's just the start of a 65 mile ride with at least 3 more major climbs. We know a local couple that can beat single bikes up the first hill on a 30/32, but we don't have anywhere near the strength-to-weight ratio to do that. Our team needs every bit of the granny gear we have for hills like this. These gears let us spin 80+ rpm up to about a 10% grade, and we can still turn the pedals on the 20% parts. As for the big gear... we use it all the time on slight downhills. I might be willing to give up a little on that end, but with this drivetrain there is no reason to do that.

So while YMMV, count us a fans of very wide range gearing for tandems.

OneIsAllYouNeed