brons2

I had this idea when I got my tandem and converted it from the freewheel it has now to a modern freehub that I would want to set up some super low gears, like one might do on a touring bike. It seemed perfectly logical to me that I might acquire a casette with a 34 or 36 tooth bailout gear, along with something in the mid-20s up front.

Now that I have actually ridden the tandem, I am starting to re-evaluate what I was thinking before. Touring bikes do not have the complication of an extra rider, so it's possible to ride at super slow speeds going up steep hills when required, so something like a low gear of 24 in the front and 34 in the back can actually be useful. However riding the tandem I have found that using the lowest gear of 28:28 that the tandem is equipped with currently produces feelings like we're on the edge of stability. If I had some sort of extreme low gear that enabled operation at say 75 cadence resulting in a speed of 3.5-4 mph, the bike might actually be so unstable as to risk a fall. Or so it feels like, anyway.

So I'm wondering what you guys think the lower limit of usable gears on a tandem would be, or what you're currently riding.

I did go ahead and buy a 12-36 9 speed cassette for my conversion. My original plan was to change the chainrings to 52-39-26. However with my new thought that 26:36 probably wouldn't be ridable, I may just go 52-40-28 and leave the existing granny in place. Having a 40:36 available in the middle ring would just about eliminate the need to use the granny anyway on all but the very steepest of hills.

B. Carfree

We use a 26/34 as our lowest gear. While we're not exactly burning up the roadway on the few occasions we use it. We're not unstable at all in such a gear. In fact, we have considered going even lower for our next trip down the Lost Coast. We often go thousands of miles at a stretch without using the small ring. It takes a bit of a hill for us to want anything lower than 42/34, but it does happen on occasion.

Perhaps our oddities are in play here: large stoker, small captain. Stoker rarely stands (prefers to sit and spin hills), captain sometimes stands on hills. 90 degree out of phase, so no rocking back and forth when one or both of us stands.

Edit: Oh yeah, we also roll on 26" wheels, so we're a bit lower for a given gear ratio than you folks on big wheels.

SuperJETT

We're a new team and on our first ride used the 28/30 combination up a hill just fine. However, I mountain bike a lot (and she does some also) and use the 22/34 combination on it sometimes so I'm used to going slow and spinning if needed so maybe that helped?

bikeinxs

Our dirt road tandem has a 26/32 and 26" wheels, which probably makes it more like a 26/34 or even a 26/36 if it had 700c wheels. When we get into really steep stuff (20% or more) we are climbing as slow as 5 km/hr. Sometimes on very loose climbs that may not be really steep we have to drop to granny because in a bigger gear we don't have enough traction and the rear wheel spins out. Of course our bike (an Ibis Cousin It) is absolutely rock solid. We are a 300 pound team with a 170 lb captain. Even in the lowest gear one or the other or both of us can stand.

So it's absolutely possible and works great with the right bike. Whether you need gearing like that depends on what sort of riding you do.

Tandems

Used 20/34 for years.

2 years ago switched to 20/36

Last week went to 18/36

It is nice being able to spin at 80 cadence doing 3.1mph

DCwom

Off hand I don't know our gearing but the lowest 4 gears are virtually useless on our tandem, the slow speed and high cadence is so unstable it's tough to stay upright. I find that around 4mph is my limit to hang on and still feel in control, but as with most things its probably going to vary based on the team.

waynesulak

Standard modern tandem front end geometry used by Santana, CoMotion, Calfee and others is a 73 degree head tube angle and fork rake of about 43-50 mm. This geometry lets the bike fall into a corner naturally like a single bike but makes handling the big bike challenging at very low speeds. You can't change the head tube angle of your tandem but changing the fork to one with a 60mm fork rake makes slow speeds much more stable. Very noticeably more stable at 10mph and lower.

The longer rake fork makes the tandem react quicker at higher speeds so the bike needs to be driven with a light touch on the bars. Captains that use a death grip on the handle bars will not like a 60mm fork. I love it but it is not for everyone. The handling at speed takes a period of time to adapt to because it feels so different than a single. The bike does not fall as quickly into a corner and more steering is required. At first this feels sluggish but once the captain adapts it allows for very responsive steering.

Bilenky uses this geometry as their standard and will make just a steel a steel fork for reasonable price. If you spend a lot of time grinding up hills it is worth a try. We can ride in a low gear spinning at 90-95 cadence while I have one or two fingers on the handlebars. I can ride our tandem in circles in our standard two car garage with the door closed until I get dizzy. Can't get my stoker to ride with me when I do it though.

CGinOhio

When touring we use a 36t cassette and 26t small chainring and a 35mm tire on a Co-Mo Speedster. I think our low speed is around 5- 6 mph. Working hard on a steep grade at these low speeds with a touring load requires a lot of small handlebar corrections to keep us pointed straight. But certainly not uncontrollable.

Non-touring and unloaded we run 27t cassette with 26t chainring and 28 mm tires.

p2templin

We started with a 24/32, and three weeks after we bought the tandem we got surprised by a rough hill on an event. We just figured it out, spinning away at 80rpm doing 3.4mph. It was tough to handle but we survived, and we've been glad we had it. This season we had to put on a new cassette, so now we're running a 24/36 for Seattle hills, and I'm liking it.

Sprout97 

Anything steeper than a 20 degree grade translates into -- for me -- trouble at 6 mph. I'm already weaving, and nearing total instability. We're running a 52-42-30 with 9 sp 12/25 on our Speedster. But hey, we live in costal FL, not the Rockies. Our "climbs" around here generally involve bridges. On a related side note, Georgia Tandem Rally at Athens was really tough on us. And we'll face that again.

brons2

OK, sounds like what I was originally thinking was pretty much in line with what other people were running! So maybe when I get my position sorted out, I'll be more comfortable at super-slow speeds.

Wayne, the bit about the low-trail fork is interesting, but I definitely do not want the handling to be jumpy at high speeds. If I had to choose one or the other it would be more stability at higher speeds.

Tom Spohn

We are using a 36/34 combo with good results on steep hills. Secret is remember to spin the pedals at a fairly high cadence (75-100) and avoid pumping up and down.

waynesulak

There is always a problem with which words to use when talking about handling because it is so subjective. I assure you it is not jumpy in my mind anyway because no hands riding is stable and the bike tracks well up to the 40 mph that we have taken it (I was full aero with hands next to stem). On the other hand I have found that some riders feel the need to constantly steer the bike and are uncomfortable with it.

Below is a Quote by Sixtycycles (Pateka Tandems) extracted from long and "spirited" thread comparing Cafee and Pateka racing tandems. The conversation started with stiffness and then turned to steering geometry.

Link to above quote:
https://www.bikeforums.net/showthread...tiffness/page8

In my mind higher trail requires more countersteering to start the turn. The lower trail lets me start a turn with less countersteering and adjust my line easily in mid turn. It is different than most commercially available tandems and some people miss the rock solid in the groove feeling of high trail at 20 mph.

Steering is in large part a personal thing but I decided to carry an extra pound+ of weight to get low trail with a steel fork vs high trail with a carbon fork.

StephenH

Try riding your single bike as slowly as possible & take up unicycling and that seems to help a bit at riding at slow speeds. I think I've got 30 front, 32 rear, no problems on stability, but we could use lower gearing on occasion. Normally don't get below about 5 mph, but stability isn't really the issue, either. On my single bike, I can ride under 3 mph okay. I was riding with a recumbent lady one time, and when she went to walk a hill, she was surprised that I could ride at her walking pace.

diabloridr

This reminds me of the old gag where a reporter asks a pro "Do you prefer big gears or a high cadence on the steep mountain climbs?"

His response was "I prefer to push a big gear at a high cadence."

Chris_W

I switch our gearing around depending on the type of riding. For regular day rides, we typically have a low gear of 28-32. When touring, we have 26-34. Even when touring with an extra 30 kg of luggage in the panniers, it's not too hard to keep the ship steady when doing above 5 mph (8 kph); if the speed drops to 6-7 kph (4 mph), which is pretty rate, then I do start to struggle, but we've never gone down (yet).

brons2

I don't honestly know what the trail is on my Rivendell but that is my favorite bike for making high speed descents. It really feels very stable and almost like an extension of my body. Steering effort is high(er) so that it keeps you in a straight line really well, but yet still allows you carve tight corners very nicely.

I hit my all time high of 55.1 on the Rivendell while riding Wolf Creek Pass in Colorado. There's no doubt I could go faster on the tandem, if I really wanted to. I'm not sure that I do, though. Actually, I probably could have gone faster on Wolf Creek, but the cars were holding me up! No joke, there was line of cars behind an RV that was doing about 35 and that was the end of my screaming descent.

waynesulak

I understand that Grant believes in high trail (about 60mm) so I would bet that your bike is close to that. That feeling of "cornering on rails" is what high trail bike lovers love to say. I rode a single like that for years and liked the feeling that I could set up a for high speed tight corner and once started down the line the bike held the chosen line on its own and I came out the other side just as planned every time. It was a set and forget feeling. Set the corner up and you knew with confidence you would stay on that line.

That is a great stable feeling except over time I have found that for me if I wished to change the line in mid-corner the bike still cornered on rails and adjustments to the original line are very difficult. There are always tradeoffs.

zonatandem

We currently run 52/42/30 with 11/34 cassette.
We live in Arizona, so yes there are hills/mountains.
We are ages 80/78 and still manage to do OK.
Way-back-when in the 1970s, we ran 56/42/28 with 13/28 freewheel. Front cage was customized (brazed-on extra length to cage) to handle the front der.
Gear needs vary greatly between couples

Krenovian

We run 53/39/30 with 11/34 cassette for most of our local riding here in Utah. On a trip to the Dolomites this summer I swapped the 30 tooth ring for a 26 and was very glad to have it on there for some of the climbs we did. Two days ago we rode up the Empire Pass/Guardsman Pass section of stage 5 of the Tour of Utah out of Park City. The GPS registered up to 13% grades. At times we were barely going 4+ mph with the 26/34 combo. I didn't find it difficult to steer or balance the bike here or in Italy. As slow as we were going, we were still able to pass some of the folks riding the Ultimate Challenge because they weren't geared low enough and couldn't spin up through some of the steeper sections like we were able to. (Of course it may have helped that we had only ridden 19 miles to get to the base of the climb and they had already done 80+ miles.) I prefer the 30 tooth inner chain ring to the 26 tooth because I can use more of the cassette without the chain pinging on the 39 tooth ring, but there are climbs that we've done with the 26 tooth inner ring that we might not have gotten up with the 30 tooth ring. As others have mentioned things like terrain, the bike you ride, team weight and experience plus conditioning all go into determining what gearing works for who and whether you'll feel in control at low speeds.

2592

Don't remember what our gearing is (standard Santana), but I have found changing to OOP from IP has greatly helped our low speed stability when climbing.

Clarabelle

Had some trouble with low speeds at first, but like so many things, it got better with time.

Carbonfiberboy 

Another 26/34 on our Speedster with WoundUp fork. Been down to 55 cadence when touring. At low speeds a lot depends on a quiet stoker. Comes with experience.

zonatandem

Rode IP from 1975-77;
Been riding OOP since 1977 . . .
Yup, there is a huge difference, especially when climbing.

JanMM

Not shy about getting down into the lowest gear, which is now 28/32. Replaced the original 30T inner ring with a 28. We have found our Screamer to be very stable down to 3 mph. Thankfully, getting stronger/working together better and 4-5 mph is our more-common uphill grinding-it-out speed.