preventec47

I have seen one in use by someone else and they were using a Shimano Ultegra derailleur. I just wondered if they were problematic with chain jumping off etc.

I now have a small 28 gear and I could use the extra leverage for the very steep hills. I dont know for sure if my pedal assembly ( crankset ? ) will hold
that small of a gear. The one I saw was on a RACEFACE crank.

My current lowest ratio is 28-34 and I might also be able to swap the 34 for larger... not entirely sure what is available for Shimano 8 ring cassette

mtreloar

Currently, our set up is 26 front - 36 rear with the Ultegra FD and wide-range long cage XTR RD supplied by Santana on our 2006 TeamTi. I have added an N-gear jump stop to prevent chain dropping on downshifts to the small front gear. This is a 10-gear setup. On a 1990's era Santana Sovereign, we used the same ratios but a 9-gear setup. This also worked.
The 10 spd cassette is Deore XT. The chainrings are FSA currently, but have been Specialties TA. Ramped and pinned are essential. The 26 is the Specialties TA.

Ludkeh

I've got a 24 front 34 rear on one of my tandems which really helps with steep hills here in Central New York. A few downsides with this setup. To make it work you need a relatively small middle chain ring such as a 34 or 36 tooth middle chain ring.Otherwise the jump is to great from the 24 tooth sprocket. . This in itself means your tandems whole gear range is a compromise. Also the "stump puller" small chain ring will only work with three or as most four of the rear cassette rings before chain cross makes the smaller rear sprockets useless.

Leisesturm

It is by no means a 'rule', or it might be but my experience is limited to my own experience. In any case, a triple with a 28T granny is likely to be a 28/38/48 and in a majority of cases it is a unit triple and the rings are not individually addressable. If the granny is a 30T the bolt circle diameter of the crankset is likely 130mm with a 74mm granny carrier and the smallest granny possible is 24T. The only other common triple BCD is 104mm with a granny carrier of 64mm, a 22T granny is possible with these. I always change the 30T granny to a 24T and I recommend it highly. I have a tandem with a 28/38/48 triple with individually addressable rings and I am thinking about dropping the granny to 22T. I have never worried about the capacity of the FD and I am certain I am exceeding posted limits but I haven't seen a downside.

On one tandem where I changed the granny to 24T, the middle ring was 42T. I listened to the group think that 24T to 42T was 'too much' and I lowered the middle ring to 39T. On this bike the FD is not indexed and in actual practice it shifts so damn smooth that it shifts directly from the 24T to the 52T big ring easier than many bikes can shift to ramped and pinned big rings! I need to find some way of providing tactile feedback when the middle ring is found. TL;DR: the opinions on capacities and what not are not always based on real world experience. On paper it looks like a 24/42/52 triple would be impossible. I haven't found that this is true.

What is true about that bike is the rear cluster is 12 - 27. Most clusters these days are 11 - 32 or 34. With that kind of total range the capacity of the RD to wrap chain will be tested. So again, TL;DR. There is the ability of the FD to handle different size chainrings to consider. This can be disregarded more or less with impunity. And there is the capacity of the RD to wrap chain from the big/big combination to the small-small combination this can be exceeded, judiciously. HTH.

preventec47

22 small ring gear !
I just ran across the SALSA POWDERKEG Tandem on the SALSA website and it has (SHOCKINGLY to me) a rear cassette of 11-36 and a front triple ring of 44-33-22

Thats right 22 Twenty Two. Well I guess you pay for it a bit if you are a downhill pavement racer because the large ring gear at 44 is the same as many other tandems middle gear. But still.... a super low "granny gear" 22-36 has to be pretty impressive to ride up a steep hill. There is a point where you go so slow you cannot
balance the bike upright and I wonder if this is getting close ?

10 Wheels

Good gearing for mountain riding.

10 Wheels

I had a 24T on All My Bikes and now Trikes.

Carbonfiberboy 

We run 53-39-26 on our tandem with a 9 and now 10-speed FD. The 10-speed FD works much better on the tandem with this combo, though I have a single with the same rings and a 9-speed FD which works just fine. No shifting issues with either bike. In the back, we now have a 11-40 on the tandem. I've heard that the 24-39 shift is a bit much. Easier to go big in the back using a Wolf Tooth if you want to keep the 53, which is our default ring. I have installed a chain catcher on both bikes. I wouldn't run such a big shift to granny without it.

preventec47

I dont know anything about a "chain catcher" but now I know I want one :-) Please do share some details and where to get and how to install etc..

Carbonfiberboy 

https://fitwerx.com/bicycle-chain-catchers/
Google and look on Amazon for "chain catcher" to see the considerable variety. The one you get needs to work with your front derailleur and your seat tube. Tandems tend to have large seat tubes, so you may have to do a little searching to figure out which one will work for you. I have a K Edge on one bike and a model which isn't made anymore on another. They all probably work fine - it's more a matter of it being installable on your bike.

Andrew R Stewart 

Since the OEM market sets most all the current standards the most common triple inner ring is a 30T. Now for those riders who are savvy (or their shops) on a 110/74 crankset a 24 granny is not at all uncommon. But a lot depends of what you ride.

Years ago I was told by a "big three" sales rep that only CA and NY riders asked for a low/triple/granny geared bike. I then thought this was not quite right. But it explained a lot of what I see in the new bike specs. Andy

79pmooney

I use a 24. 50-38-24. I also use chain watchers as a matter of course. I find it makes little difference which brand I use. (I just wish the makers would put the clamp bolt access on the left rear to make getting to it with a wrench easier. (Especially on a ride which is there you really find out where that catcher is supposed to be.)

preventec47

With the advent of new 10, 11, and 12 cassettes, I am seeing a one or two ring reduction in the front sprocket set at least with road bikes...... and even a little bit with
mountain bikes. I am pretty sure that the smallest ring gear on the front sprocket is always smaller with mountain bikes.

Paul J

We took our Race Face 9 speed crank set from 54/44/30 down to trekking gears of 48/36/24 with out 11x34 cog-set. We have a chain catcher and this shifts very well and had good climbing capability.

hortan

also for us gears downto 22/36
in front 22-34-44 chainwheels
this is what we need, but we never have to walk, even when 15-20%

preventec47

Would you please share what ever special equipment or technique that lets those extreme ratios work ? Did you get the bike that way or did you have to modify it ?

Carbonfiberboy 

22 X 36 at 80 cadence is 3.8 mph with 700c wheels. That's a heckuva lot faster than walking on a steep hill. The Salsa is a 29er MTB.

Leisesturm

I blame the mass market sellers of overgeared production bikes for the thinking that there is anything unusual about a 22T granny. When you have some time look up the "Mountain Tamer" quad crankset. Mountain Tamer quads (and more) modify production cranksets to use rear cogs as front chainrings! This allows FRONT rings as small as 16T. Pick your chin up off the floor and keep reading. My latest bike came stock with a 42/32/22 triple and an 11-34 8sp cassette. That's a low gear of 18.5". If you have reasonable bike handling skills you can indeed pedal this gear. Since I can just about trackstand our tandem with Stoker, ANY gear found on a production crankset is fair game. I can tell you aren't over 60 yet. But I am and the availability of 24T (and 22T) granny rings is a very good thing.

Carbonfiberboy 

Good points. We have a 26T granny. We were using an aluminum granny, but it got messed up fairly quickly because of the few teeth. I bought the last SS 26T rings on the planet, which don't wear. How's the wear on even lower count rings? I hate having to pull the crankset to replace rings, so that's been my hesitancy to go lower. 74 BCD here.

Edit: I found a 24T steel Stronglight, probably not SS though. Buying it anyway.

oldacura

Doesn't using such a small (small) chainring prevent you from using a larger big ring (like 50t - 52t)? Our top gear is 52tx11t and we spin out much above 40mph.

hortan

no special equipment or technique but indeed modified. Originally (1998) Shimano 3x8 34-11, 5x104-64bcd 22-32-42 bought (2nd hand) in 2006 and changed to 3x9 cassette while the front 32-42 were replaced by 34-44 and the largest cog by a 36. Ofcourse, MTB shifters, chain and rear derailleur were replaced by 9spd components. The original front derailleur however is still in place: only some bending of the Outer plate had been applied. In my view my modifications are relatively only minor.

Ludkeh

Everything is a compromise. If you live in the flat lands, probably large chain ring, and spinning out comes in to play. If you live in really hilly country low gear becomes a top priority! For us, spinning out in the large chain ring is a joy because it happens so rarely!

sapporoguy

We're 50/39/24T front and 11-36T cassette. The 24x36 granny gearing is great for our 63/64-year-old team, even on most San Francisco Bay Area hills. Worked great on a fully-loaded self-contained camping tour in the Olympic Peninsula in August.
A 39T FSA was balky, fixed by swapping in a Shimano Deore (I think) 39T from my box of stuff.
Sugino steel 24, the smallest we could fit on 74 bcd. (Kinda wish we could go to 22T!)
Wolf tooth on RD.
Chain length so RD is almost fully taught at 50x36 just in case we forget to shift, which we do. 50x11 is nice to have, but could do without.
That means the smaller four cogs are useless with the 24T, but accidentally shifting into them just makes a clatter to remind us.
Switching to friction shifting bar-ends on front and shifting sloooowly from 24 to 39 eliminated chain drop and works fine, but we also added a chainsaver.

preventec47

Just to clarify., it sounded like you took your 11=34 cassette and replaced the 34 gear with a 36 gear. I did not know that was possible. Do you or not have to swap out
entire cassettes at a time ? I have an 8 speed Shimano cassette with the largest two cogs being 28 and 32 and I would ideally swap those with
30 and 36 if available and I had a good chance of making it work. ( says "Shimano HG Hyperglide" on the cassette. One alternative is possibly using
an 8 speed Shimano CLARIS


cassette that has the tooth count spread out over a wider range but I dont know if is interchangeable on my rear wheel hub.

hortan

After purchase our 2nd hand 8 speed tandem (2006) I switched to 9 speed (including a 9 speed cassette up to '34'). Some time later, when 9 speed became available (because of introduction of 29" wheels), indeed I just 'switched' the '34' for a '36'. This is possible because as far as I know all 8 speed cassettes and most 9 speed Shimano cassette have separate sprockets, this is after removing the three pins (with a "dremel") which group together the largest six (or so) sprockets. This has to be done for the original cassette as well as the new cassette with the '36'. For HG80 and 'above' the largest two sprockets are on a spider and are therefor not suitable for such a switch. My recommandation (in your case) would be, if you stick to your 8 speed system, just buy a 9 speed Shimano cassette with a '36', such as HG400 11-36 or 12-36 (since there is no 8 speed with a '36'). Then switch your current '32' for the new '36' and see if your rear derailleur and chainlength allows this. Yes, this results in a 'giant leap' of 28->36 but a) this is possible and b) in 'emergencies' it is even more convenient. Unfortenately, Shimano, 'very sly', reduced the thickness of their 9 speed sprockets by just 0.02mm (0.0008") comparing to 8 speed, so you can't replace to many sprockets of your current 8 speed cassette so for index reasons.