BikingBillVA

We have a Santana Spirit and we'd like to have lower low gears for loaded climbing. This is our current setup:

Front:
Crankset: Santana Octalink Triple Carbon 53-39-30 (BCD 130)
Derailleur: Microsoft R10 Triple

Rear:
Cassette: Shimano 11-36 10-speed
Derailleur: Shimano Deore XT

We tried replacing the small chainring with a 24T but the shifting was unreliable: sometimes we would lose the chain, sometimes the chain would go between two chainrings.

Our shop mechanic (who I trust) thinks we'd get much better results with Shimano crankset, but although we have not priced it out yet, that seems unnecessarily expensive. Other ideas about where to go from here?

Thanks!
Bill and Colette

reburns

You could install a chain catcher along with the smaller inner ring and adjust the front derailleur low limit further inward for faster shifts that direction. Going to a 26T May shift better than the 24 while still lowering gearing by about 15%

TobyGadd

I don't think that a different crankset will help.

You may be able to get away with a 42t cassette by using a Wolf Tooth RoadLink or GoatLink. While the derailleur probably won't be able to pull in all of the chain slack, you shouldn't be riding in the smallest ring and smallest cog at the same time anyway--but nothing bad will happen if you forget. Just make sure that you have enough links in the chain to handle the large ring and large cog, because bad things will happen if you shift into that combination if your chain is too short. With careful derailleur adjustment, the RoadLink doesn't change shifting much at all--just make sure that you adjust the B-screw as necessary.

You may be able to find a 26t chainring, which may improve shifting while still offering a lower gear. Cheap to try, so no reason not to give it a go.

For what it's worth, I've set up my Cannondale R2 with a 24t chainring and 42t cassette with a Roadlink. Shifting from the small ring to the middle ring isn't great, but a chain catcher helps. A 26t chainring has better shifting. I only use this configuration for riding up really steep stuff like Pikes Peak in Colorado. I've got two wheelsets, so I swap out to the one with a narrower cassette (30t) for general riding.

Leisesturm

Yes to chain catcher. The N-Gear is the best I've used but it may not be in production. I would stick with the 24T. 26T isn't enough low by itself to be worth it and you already have the 24T. It can be made to work. Our triple shifts faster between the granny and big ring than it does to the middle. Shifters matter. What shifters are being used? In order from best to worst would be downtube, bar end, brifter. From a shifting standpoint. If you are working with brifters, shift technique has to be flawless. Shift early so there is as little load on the chain as possible. On the tandem we ride most often the front end has a 104 BCD so a 22T granny can be used. Big cog is 32T I think. In any case you want to check the gear inches that result from using a 24T with a 36T. Much below ~18" and it may be too much of a good thing. Mountain Tamer cranksets get into the single digit gear inches and there are competitions to see who can stay upright with those ultra-low gears. They aren't riding tandems. But with practice almost anything can become possible. Just don't want you to shift into that combination unaware.

headasunder

We run the same triple on the front (fsa) and have an 11 speed shimano xt shifter/ derailleur set up . The cassette is 11-42 which has gotten us up all the hills so far loaded and unloaded, We do a lot of hill climbing and descending, the local topography leaves us no choice.

TobyGadd

On one of my wheelsets, I've got a 42t cassette paired with 24t chainring. With an 80-rpm cadence, the bike moves at 3.7 mph. Insanely slow, but it gets us up 20-percent climbs above 12,000 feet in Colorado when we've already got some miles behind us.

RCMoeur 

Still faster than walking a tandem.

TobyGadd

Exactly! And we usually spin closer to 90 rpm, so we're going at 4+ mph. Like a rocket ship!

scycheng

[QUOTE=BikingBillVA;23232989]We have a Santana Spirit and we'd like to have lower low gears for loaded climbing. This is our current setup:

Front:
Crankset: Santana Octalink Triple Carbon 53-39-30 (BCD 130)
Derailleur: Microsoft R10 Triple

Rear:
Cassette: Shimano 11-36 10-speed
Derailleur: Shimano Deore XT

We tried replacing the small chainring with a 24T but the shifting was unreliable: sometimes we would lose the chain, sometimes the chain would go between two chainrings.

Our shop mechanic (who I trust) thinks we'd get much better results with Shimano crankset, but although we have not priced it out yet, that seems unnecessarily expensive. Other ideas about where to go from here?
/QUOTE]

130 BCD crank results in much too high gearing for loaded or credit card touring for mortals. Very few FD are designed for a such a huge range.

When touring, we almost never try to speed down big descents. We coast so we can enjoy the scenery. A loaded tandem goes pretty fast down a big hill even if we coast (~80KPH max). On the flats, you aren't like to be pushing that 53-11.

So my suggestion is to buy a quality 110BCD crank. Doesn't have to be Shimano. SPA Cycle in the UK and various other touring specialists have decent ones pretty cheap. Usually made by Sakae with different brands. TA makes very nice chainrings. My preference is something like 48-36-24 to reduce the gap between the rings which makes the FD's task a little easier. 48T-11T gives you a too high gear already for loaded touring.

I always had problems shifting between the granny and the middle ring. It has never been a slam dunk due to the angle. Maybe Shimano cranks can do better but I haven't had a Shimano triple crank in 20 years. Now days the nicer Shimano cranks are all 2x or 1x.

PromptCritical 

We recently bought a new (to us) 2007 Sovereign which had a 24/42/50 Shimano triple and a 9-speed 11-36 freehub and wornout shifters.

Lots of problems, including the chain jumping into the spoke on a two lane uphill road with traffic, which was not fun. A couple of chain derailments up front.

After much fiddling (straightening out the DR hanger, adding an Origin8 chain catcher), replacing the rear derailleur with a new Deore XT from Santana, the shifters and the front derailleur (I don't recall what I settled on but I can check) and adding a 9-speed 11-42 cassette (microshift), we are finally satisfied with the shifting and gearing.

I'm still thinking about switching the driver on the Hadley hub to a SRAM XDR so I can use a 12-speed 10-51T cassette, but I should probably leave well enough alone.

mtreloar

We have a similar setup to @bikinBillVA. Santana with STI shifters, Octolink and FSA Triple crankset. Our combined age is 150 y. We ride most days in our local hilly terrain, 300 m altitude gain in 1h 10m today for example. Our setup works OK. 24-36 yields 18 gear inches. We get up 12% grades at 4 kph not loaded.

Front: Shimano chainring 52-39 - TA 24; FD Ultegra triple
Rear 11-36 cassette, XT Deore derailleur
A chain catcher is essential. I agree N-Gear is the best. However, what I could get recently is the K-Edge Cross Chain Catcher. It works, but not as well.

I would like a lower gear to allow us to keep biking as we get older. And, the setup on our bike is 18 years old, so needs renewing before it breaks. To that end, I am researching a new drivetrain. I found this article very informative about tandems and triples: https://www.renehersecycles.com/trou...h-sti-triples/.

Has anyone reading this done a compact double with 18 g.i. low and 105 g.i. or more high? Rim brakes and STI style shifters. It seems this is possible. Our bike shop says Shimano Di2 is out of the running because it requires drilling the frame (Titanium) to route wires if we keep rim brakes. That leaves SRAM.

mtreloar

@PromptCritical - Please say more about the SRAM XDR setup you are thinking about.

PromptCritical 

SRAM has an X-Range product line that is a road bike system with a 2x crankset. It comes with various combinations of chainwheels, limited to a 13T difference. Their mtb systems offer a 10-52T cassette. Seems like a combination would be a great solution. SRAM technical support hasn't been helpful. Part of the problem is they are trained to give canned answers, not help find creative solutions. We identified two issues. One is derailleur capacity. While one could typically solve this problem with a Wolf roadlink, that may cause problems with their mtb derailleur as it has a similar (automatic) mechanism built in. The other problem is the mtb derailleurs are not a parallelogram designed so the chain movement from one chainwheel to another may cause problems.

House of Tandems offers a SRAM eTap conversion, but they are using the road system which is limited to a 10-36T cassette. Ric is super knowledgeable, but he hasn't yet tried the 10-52T cassette.

Shimano has a compact crankset with 22/32/42 or 28/38/48 chainwheels (and there are myriads of third party chainwheels using this BCD), so the gear combinations are available.

I've converted both my "daily rider" and tandem to flat bars to help with my arthritis, so I don't have to deal with the additional complication of integrated brake and shifters, and I'm perfectly satisfied with my "Campy/Paul" friction shifter for the front shifting.

We are riding a tour on the tandem in two weeks, so I'm leaving well enough alone until we get back.

When we get back, I'm going to put the SRAM mtb cassette and derailleur on my daily driver and see if it works with the compact triple. If it does, I'll transfer it to the tandem.

Leisesturm

What needs to be kept in mind is that all triples use a separate carrier for the granny ring (74BCD for 5 bolt and 64BCD for 4 bolt) and that is how you can get 18" through 104"+ quite easily with a triple crank but will struggle to achieve it with any kind of double. With a double crank the heavy lifting of a wide range will have to be on the back end and it is truly jaw dropping what has been achieved on that front but at quite a cost in weight and $$$. An 11 - 42 could probably do it and an 11 - 51 certainly should but we are talking three figures just for the cassettes. Triple cranks are mature tech and have plenty of life left.

RCMoeur 

Stronglight 99 (and its SR clone) and TA have entered the chat...

Paul J

We have our touring tandem set-up with triple Race Face 110/74 crank with 48/36/24 chain rings, the cog set is 11-36 9 speed. We also have a chain catcher. This set-up doesn't work large ring-large cog with our current chain length so I have to be careful on that when shifting. We've had this set-up for 4 years and as we age we find ourselves riding this bike more the our tandem with the typical road set-up.

TobyGadd

I might recommend adding some links so that you can shift into big/big without ripping off your derailleur. Better to have some slack in your chain if you happen to shift to small/small (no damage) than too little for big/big (derailleur damage).