Single chainring - why not?

[thejen12]

I'm so happy with my new custom bike (Mango Passion!, in the image gallery), that I'm going to order another one because I can't live with just one bike. I gave away my stock commuter/backup-bike recently because it still causes me pain, whereas my custom doesn't.

So I'm going to order a titanium bike with the same geo as my new S&S coupled steel steed. It will have a rack and full fenders and will primarily be a commuter, and a backup-bike for when the steel one is in the shop or it looks like rain. I've been trying to decide what drive train to put on it. The steel bike has Ultegra 9-speed triple, and I've always been happy with that. However, I ran my previous commute bike with only one chainring up front for a short time and really liked the simplicity of it. It also allows a narrower Q-factor, which I will want on this bike because I want to run mtb shoes and pedals on it instead of road shoes and pedals.

If this bike is also going to be a backup-bike, it needs to be able to climb hills. (Notice how I put that responsibility on the bike, not the engine! ;) ) I debated and debated and finally came up with a plan to put one 41-tooth chainring on the front, and an 11-34 XTR 9-speed cassette on the back. This will give me an equivalent of the triple's 30/25 low gear for the climbs and 52/14 high gear for the descents. It means fairly big jumps in between, but while I'm commuting I can just pretend it's a single-speed and stay in one gear if I don't like the jumps.

I think the pros to this plan are that it keeps things simple, quiet, light, narrow, and easier to clean for a rain bike. (I also think it sounds like fun, something different to try.) The cons are that it has big jumps between the different gears, and I'll lose some gearing on the high end. Are there other cons that I have missed? It seems like I don't hear of many (any?) people doing something like this, although single speeds are all the rage now.

By the way, my old commute bike was a 7-speed with a 12-28 cassette, so I had kinda big jumps there, as well. It wasn't quite as nice as my 9-speed 12-27, but it wasn't all that bad. Also, I prefer 167.5 cranks, but will use 165s if I have to. I don't know if a compact crank set would come in either of those, but somehow compact cranks just don't turn me on anyway. I would definitely go with the Ultegra 9-speed triple if not the single chainring - I spend most of my time in the 42-ring of the triple.

Comments welcome, thanks!

Jenn

[PBWrench]

I recently added a single speed to the stable: 42 in front and 16 in the back. I'm managing reasonable hills and couldn't be happier. Good luck.

[mosca]

My old town bike had an 8 speed cassette with single ring. One downside was that the chain would occasionally bounce off the ring due to lack of front derailler. Also, the chainline was not usually as good as with a double ring, if you're the type to be bothered by such things.

I'd focus on maximizing function for a commuter bike. If you want simplicity, the best solution is a custom fixed gear ;)

[RPS]

My old town bike had an 8 speed cassette with single ring. One downside was that the chain would occasionally bounce off the ring due to lack of front derailler.I had the same problem a few times with a single ring. A fixed front derailleur solved my problem but after a while decided to reinstall the cable and small ring.

[Waldo]

Jen,
Another Rex, then? I'm off to see Steve for a fit next week.

[thejen12]

Jen,
Another Rex, then? I'm off to see Steve for a fit next week.
I couldn't be happier with my Rex! I'll be scheduling some time with him as soon as I get back from my tour, in a couple of weeks. Mostly to discuss braze-ons and such, I don't think I need much of a fitting for this second one. :)

I'm sure you'll love your new Rex!

Jenn

[thejen12]

My old town bike had an 8 speed cassette with single ring. One downside was that the chain would occasionally bounce off the ring due to lack of front derailler.
I was wondering about that! What about a bolt-on chain-guard thingy that I see on some bikes? I think it bolts on outside the chainring - I'm not sure if it's for single-speeds, or something else.

Thanks, Jenn

[stackie]

Why not consider an internally geared hub? The Shimano Alfine grouppo is supposedly the bomb. Then, you will be able to tension the chain such that chain hop will not be a problem. Hub is supposedly bombproof and you get generator run lights.

Jon

[rpm]

Jen--

Here's another option. I'm going to refit one of my bikes that has an Ultegra 30-42-52 and 12-27 triple with a Ritchey cyclocross 38-48 double crankset and the same cassette. This will give me the gears that I really use with a simpler setup and fairly small jumps. This setup would give you pretty much the same high and low as you're planning without the pie plate cassette, big jumps, and chain loss issues.

[justinf]

I ran my Surly commuter as a 1x9 for over a year and loved it. It's a singlespeed now which is also cool but I may take it back at some point.

Honestly in Charlotte I could ride with a 50T ring in front everywhere on every road bike. I literally never use the small ring, it's just too flat.

[mosca]

I had the same problem a few times with a single ring. A fixed front derailleur solved my problem but after a while decided to reinstall the cable and small ring.Yeah, there's a point at which the single chainring option loses its elegance and you might as well have the extra gears, imho.

[11.4]

What you describe makes it a bit easier to maintain, especially after bad weather. And I'd definitely recommend you install cyclocross chainring guards (see www.cyclocrossworld.com for a good selection, as well as all kinds of intermediate-sized chainrings). You can install a ring guard on each side (with longer chainring bolts) or just install one on the outside and then put a chain-catcher (dogfang) on the seat tube to catch a chain that falls off inwards. Frankly, I've never lost a chain yet on the road -- you may occasionally lose one carrying the bike up stairs or whatever, but not on the road. The chainring guard on the outside for road use is really just to keep grease away from you a bit and to dress up a standard double-chainring crankarm.

You can definitely do a close-ratio front (39/46 is my own favorite with a standard crankarm). Getting rid of that front shifter, however, gets rid of a cable routing to the front shifter plus all the hardware associated with it. You can use a top-tube routing for the rear derailleur (across the top tube and down the right seatstay) which keeps the down tube clear of cables. It makes cleanup easier.

As for gearing, you're commuting and you can always use the cadence training, right? You could do something closer than what you describe and probably be just fine. Figure out the lowest gear you need and don't worry about pushing it too far on the high end -- you can coast, you can spin, or you won't be in the gear anyway. When you ride a fixed gear you really end up learning this one in a hurry. (You say you want to take it easy on hills or I'd simply suggest a fixie or a single rear freewheel -- not for aesthetics but because it is the easiest to maintain as a commuter.) If you pick up a compact front crankset, you can put a smaller chainring on such as a 34 or 36 and then work with a closer-ratio cassette. This might give you the better shifting intervals you're looking for.

You could conceivably consider the approach Rivendell came up with: two chainrings on front, two side-by-side White Industries cogs on a single freewheel in the rear, and be able to mix and match them at will. You might check out their site just to see what they do. The limitation is of course gearing range. The advantage of not having a rear shifter is that you don't have anything there to get knocked around, and of course it's easier to keep clean. But while I ride fixies a lot of the winter, I don't push them on people who have other ideas about how to ride.

[gdw]

I used a 34t front ring with an 11-30 8 speed cassette and short caged derailleur on an old Bridgestone MB-3 for a couple years without problems on or off road. I shortened the chain and fitted an outer guard made from an old 42t ring to keep from dropping the chain to the outside. I just cut off the teeth with a hacksaw and ground the outer edge till it was smooth. It worked great. You can use one of those chain deflectors/guards to prevent the chain from dropping to the inside although it wasn't an issue with a short caged derailleur. Pay attention to the chainline, a 9mm shorter bb spindle was ideal for the Ritchey crankset used, and it will work great.

[thejen12]

Jen--

Here's another option. I'm going to refit one of my bikes that has an Ultegra 30-42-52 and 12-27 triple with a Ritchey cyclocross 38-48 double crankset and the same cassette. This will give me the gears that I really use with a simpler setup and fairly small jumps. This setup would give you pretty much the same high and low as you're planning without the pie plate cassette, big jumps, and chain loss issues.
Yes, but I really like riding in the 42 on my triple. I think if I had a 38-48, I'd be wanting to switch between the small and the large chainring all the time. The 42 on my triple is one reason I like it so much better than when I had a 39-52 double.

Jenn

[thejen12]

As for gearing, you're commuting and you can always use the cadence training, right? You could do something closer than what you describe and probably be just fine. Figure out the lowest gear you need and don't worry about pushing it too far on the high end -- you can coast, you can spin, or you won't be in the gear anyway. When you ride a fixed gear you really end up learning this one in a hurry. (You say you want to take it easy on hills or I'd simply suggest a fixie or a single rear freewheel -- not for aesthetics but because it is the easiest to maintain as a commuter.) If you pick up a compact front crankset, you can put a smaller chainring on such as a 34 or 36 and then work with a closer-ratio cassette. This might give you the better shifting intervals you're looking for.

Thanks for the ideas. I love cadence training on my commute! But, as a backup bike, I'd still like to be able to ride in the hills - I'm talking hills that are 5-8 miles of 6% to 8% steady grade, climbing 2000+ feet per hill. I know a lot of you cats can do that with smaller gears (I used to, myself), but I'm not there yet. I make liberal use of my 30/27 now! As I get stronger, I can downsize the cassette or upsize the chainring....

I'll check out the website you posted, too - thanks!

Jenn

[Ken Robb]

Why not consider an internally geared hub? The Shimano Alfine grouppo is supposedly the bomb. Then, you will be able to tension the chain such that chain hop will not be a problem. Hub is supposedly bombproof and you get generator run lights.

Jon
yep, and you will always have a perfect chainline. If you run the set-up you suggested originally it seems like you will frequently be in the extreme ends of the cassette. Another nice touch for a bike with one ring: you can use a chainring guard to keep your pants from catching in the chain.

My Bike Friday has a 3 speed Sachs hub with 7 spd. twiist-grip rear deraileur and its pretty slick.

[thejen12]

An internally geared hub sounds interesting, but I already have wheels - that was one of my cost savings, using my old-but-nice wheelset. Still, it's something I could research. Do the gears span the range that I'd need?

Jenn

[11.4]

Thanks for the ideas. I love cadence training on my commute! But, as a backup bike, I'd still like to be able to ride in the hills - I'm talking hills that are 5-8 miles of 6% to 8% steady grade, climbing 2000+ feet per hill. I know a lot of you cats can do that with smaller gears (I used to, myself), but I'm not there yet. I make liberal use of my 30/27 now! As I get stronger, I can downsize the cassette or upsize the chainring....

I'll check out the website you posted, too - thanks!

Jenn

When you ask about gearing it helps to indicate just how much in hills you have. You sound like you're right on target. Just put on your 42 as a single and get that wide-range cassette. You can always change cassettes later. When I was talking about cadence training I was really referring to your not needing really high gears. I've been riding junior Ultegra cassettes in the winter and like them even for a lot of racing. You can keep your ratios closer together if you don't worry about your highest gear.

Though you really like that 42, note that your hills and gearing preferences suggest that you might actually try a lower chainring. It can give you more comfortable gearing for those climbs. But in the end it's all about what you're comfortable with. Nobody can tell you what works for you. You've heard enough alternatives but you seem to be on the right track already.

[dwightskin]

1 Ring up front is great. I occasionally drop the chain to the outside so I'm considering installing a chainguard, but no hurry.

Another +1 about single ring is not worrying about ramped and pin chainrings and shifting in between them.

I run a bar end shifter.

In the winter I've got a 1x7 drivetrain but that's a whole different story (commute in the snow and down to -20F).

Dwight

[rpm]

Yes, but I really like riding in the 42 on my triple. I think if I had a 38-48, I'd be wanting to switch between the small and the large chainring all the time. The 42 on my triple is one reason I like it so much better than when I had a 39-52 double.

Jenn

I live a lot on my 42, too. What the 48 does is basically move everything down a cog, so that you'll then live on the 48 most of the time, with the bottom gears on the 38 to extend your range:

30 42 52 38 48
12 66 92.3 114.3 12 83.5 105.5
13 60.9 85.2 105.5 13 77.1 97.4
14 56.5 79.1 98.0 14 71.6 90.4
15 52.8 73.9 91.5 15 66.8 84.4
17 46.6 65.2 80.7 17 59.0 74.5
19 41.7 58.3 72.2 19 52.8 66.6
21 37.7 52.8 65.3 21 47.7 60.3
24 33.0 46.2 57.2 24 41.8 52.8
27 29.3 41.0 50.8 27 37.1 46.9

The one gear that you'd have to double shift for is the one in the high 70's, going from the 48-15 to the 38-13. But a 10-speed cog solves this problem:

38 48
12 83.5 105.5
13 77.1 97.4
14 71.6 90.4
15 66.8 84.4
16 62.7 79.1
17 59 74.5
19 52.8 66.6
21 47.7 60.3
24 41.8 52.8
27 37.1 46.9

Don't be so sure that your new ti bike will be just your errand bike. You might find that you'll like it for longer distances, too. :) A double makes it more versatile for that. And you can always get a Sheldon Brown "Century Special" cog with a 30 bottom.

[vandeda]

I shortened the chain and fitted an outer guard made from an old 42t ring to keep from dropping the chain to the outside. I just cut off the teeth.

Oh my gosh dude, how long did that take? You know you can buy them for like 40 bucks, right? I've personally loved my Blackspire Ring God as it's taken quite a beating and is quite beefy.

[stackie]

An internally geared hub will definitely have the gear range you are looking for. It is greater than the range provided by a typical 2 x 9 or 10 setup.

It will cost more, however, especially since you already have wheels for a derailleur setup.

Jon

[gdw]

It took all of 10 minutes. A vise, a hacksaw with a new blade, and a file were all that was needed. It's amazing what you can accomplish with the right tools, although a bench grinder would have been quicker, and common sense.

[vandeda]

It took all of 10 minutes. A vise, a hacksaw with a new blade, and a file were all that was needed. It's amazing what you can accomplish with the right tools, although a bench grinder would have been quicker, and common sense.

Wow ... that's a lot faster that I would have thought .... a *lot* faster.

But suckers? Maybe on a road bike ... I decided to get the Ring God after bending my big chainring over so far going over a log that I could only use my little gear up front. My ring guard gets lots of use over logs & rocks on my mountain bike, so I'd destroy a big ring that was filed down.

Since people are talking about internally geared hubs which intrigue me some ... how well are they sealed from water and grime if you were to ride one year round in places that see lots of salt/sand/etc. from snow in the winter?

[gdw]

The ring I cut down was strictly there to keep the chain from being dropped and wouldn't have survived very long if it had been used as a bash guard. I was also surprised at how easy it was to cut off the teeth on the old chainring. The aluminum was much softer than I expected.

[RPS]

By the way, my old commute bike was a 7-speed with a 12-28 cassette, so I had kinda big jumps there, as well. It wasn't quite as nice as my 9-speed 12-27, but it wasn't all that bad. Also, I prefer 167.5 cranks, but will use 165s if I have to. I don't know if a compact crank set would come in either of those, but somehow compact cranks just don't turn me on anyway. I would definitely go with the Ultegra 9-speed triple if not the single chainring - I spend most of my time in the 42-ring of the triple.

Comments welcome, thanks!

JennJenn, I've ridden my Ultegra 9-speed triple with a 12-27 a few times to handle steep grades, and found that I stayed in the 42 most of the time also during casual rides. I personally don't like it because I miss the 16-tooth between the 15 and 17 cogs, but I'd guess from your comments above that that is not a problem for you since you've been doing it successfully -- which brings me to a comment about another option if you are set on a single chainring.

Santana Tandems recently introduced a 10-speed 11-34 cassette for their tandems that has uneven spacing of the gears but in a way that minimizes the jumps in the most commonly-ridden gears. You may want to ask them about it and see if it would work for you. In the center of the cassette the jumps are 2-teeth apart; the same as on your present 12-27. You'd have 15-17-19-21 just like at present.

My take from their magazine is that it has the following: 11-13-15-17-19-21-23-25-?-34.

The mid range is better than a MTB 9-speed 11-34 cassette but you'd pay for it occassionally at the very low extreme. The largest two gear jumps are not specified in the magazine but must be a little wider -- strictly for serious climbing and/or bail-out. Personally I wouldn't have a problem with that as long as they shifted well since they would get very little use. I'd take the tighter gearing where I ride the most.

[thejen12]

Santana Tandems recently introduced a 10-speed 11-34 cassette for their tandems that has uneven spacing of the gears but in a way that minimizes the jumps in the most commonly-ridden gears. You may want to ask them about it and see if it would work for you. In the center of the cassette the jumps are 2-teeth apart; the same as on your present 12-27. You'd have 15-17-19-21 just like at present.

My take from their magazine is that it has the following: 11-13-15-17-19-21-23-25-?-34.

Hey, that sounds great! Thanks for the info, I'll check it out. Speaking of that, my bike shop can also make me a custom cassette, so that's something else I can explore.

Jenn