spinachface

I recently acquired a Surly Steamroller, and I'm really looking forward to building it up. It was an eBay purchase, and I was delighted to see when it came that it was from the early 2000s and has a threaded headset. This is great because the intent was to build something similar to a Rivendell Quickbeam. I really like the ability with a Quickbeam to have 4 gears, two on the cranks and two with a flip flop on the rear. Plus, the retrogrouchiness of the bike helps tame my own grouchiness.

That being said, the dropouts on a Surly are not long enough to accommodate this much variance in ratios, but I want to get as close as I can. I feel like the double crankset is out of the question, so I'm resorting to the flip flop hub to try and make up for it. My though is to have a 42t chainring up front, and then a 16t freewheel/22t fixed cog in back. The logic being that the 22t fixed cog is for climbing and the 16t is for flat riding and coming back down the hill. I live on the coast of central California so while there definitely is hills, it's not exactly San Francisco. Will this setup accommodate these things, or should I go smaller up front with a 39t chainring? Will the variance of 16 and 22 be too large for the dropouts? Any help's appreciated and if you have run a similar setup let me know!

ThermionicScott 

Why is a double crank "out of the question"? One way to make a wide gearing difference work would be to use a double crank with two rings that are a couple teeth apart, along with a Surly Dingle cog. The idea would be that you'd use either the inner or outer combos, the same length of chain working for both.

seau grateau

Yeah, I feel like a double crankset would be a good way to go as long as it can clear the chain stays. That way you could run a bigger high gear. 42-16 is super spinny for descending. I have that gearing on my SS, and I usually spin out at under 25mph and wind up coasting down hills.

spinachface

I guess my only concern was in the idea that if I was running smallest chainring and 16t freewheel I wouldn't have enough space in my drop out considering the chain would be long enough to accommodate a 22t cog. For example, if I ran 39/42 upfront, and the 16-22 in back I would have gear inches between 48.4 and 71.7. Do you know if that variance would be too long for the track style dropout that is featured on the frame?

TejanoTrackie 

Each tooth difference results in approximately a 1/8" movement of the wheel axle in the dropout. So in your case you will need about 3/8" adjustment travel in your dropouts. Since you cannot get the chain to exactly fit with the axle fully forward in the dropout, add another 1/4" to that number, or about 5/8" total travel.

TenSpeedV2

Do people really climb a hill, stop at the top, flip the wheel, and then ride down? If I was out riding with someone and they needed to do that, I think that I would get pretty pissed.

Broctoon

Spinachface, you've got yourself a good, versatile bike there. I don't know what the Rivendell Quickbeam is, but here's what I would do in your situation:

Get a Surly Dingle (double cog) with 17 and 20 teeth. Put on a double crank with 42 and 48 teeth. For climbing hills, you use the 42-20 combo, and for flats and descents, switch to 48-17. These ratios are reasonable for moderately steep terrain, if you're in pretty good shape. And your axle will only move 3/4" in the transition, which is easily within the range that your Steamroller frame will allow. (Just be sure to set the chain length so the axle is near the front of the slots when on the big chainring and small cog.)

spinachface

If you're not up for breaks we for sure shouldn't ride together haha

spinachface

That makes so much sense. I think that ThermionicScott was on the same page and I just totally overlooked it. Plus, I could always run the other side as well right? The Dingle goes on the freewheel portion I'd assume?

Broctoon

I believe the dingle goes on the fixed side and uses a lock ring the same as any fixed cog. I have never used one, but I think they're a great idea. The trouble with using a big/big or small/small combo to get an intermediate ratio is you might run out of space in the dropouts. If that didn't happen, you could probably get away with it.

DiabloScott

I actually saw Grant Petersen himself do this on Mount Diablo on his new Quickbeam. He attracted a lot of attention, I don't think anyone thought it was a brilliant idea. And I don't think he had a fix-fix... I think it was free-free.

spinachface

I feel like ever Grant Petersen sighting happens on Mt. Diablo and it always involves him doing something somewhat strange. You must respect a man who is able to do that. It's definitely free/free though, they had some hubs made specially for them that were flip flop single speed.

Broctoon

Correction to my earlier figure...

Going from a 48-17 to 42-20, your axle would only move 3/8"

I was figuring 1/4" for every tooth, but I believe Tejano is correct that it is only 1/8"

kingston 

I wouldn't ride with someone who did that. Makes no sense. If you want to ride a bike with different gears they aren't that tough to find. They come with derailleurs so you can change gears without stopping or needing tools.

ThermionicScott 

The other guys beat me to the math!

The Surly Dingle Cog only comes in a handful of configurations, so consider the 17/21T with a 45/42T crankset. The 45/17 gives you about a 72" gear for flat/downhill, and the 42/21T gives you a respectable 54", while only moving the axle a smidge in the dropouts.

Fixed-gear is (partially) about weaning you off super-low gears anyway.

JeremyLC

Or, you could do what I do and ride a geared bike with a cracked front shifter. It's stuck on the 50t ring. (but! I'm building massive guads for when I drope the hamer!)

Otherwise, on your original topic... The Sturmey-Archer S3X might be of interest to you.

50voltphantom

A dingle setup is meant to swap between two gear ratios with minimal or no fiddling. So something like a 38:19 and a 40:17 would in theory not move the rear wheel at all; you simply move the chain between combinations. Granted it's not a huge jump but it would make the difference between riding and walking certain terrain for sure. In this example I find 40:17 to be excellent for gravel road riding while 38:19 will tackle short, steep climbs on singletrack quite well.

DiabloScott

Well that's probably why the Quickbeam was never a big seller, and has been discontinued. A shame, they don't have any current frames that would make a good SS or FG.

But if your standard ride consists of one big hill where everybody stops at the top anyway, there's really not much of an inconvenience factor for the other people in the group.

kingston 

You might be right @DiabloScott, but I would still make fun of them for being such a sissy.

The other possible example is if you have a long section of road that you need to take before you get to a long section of off-road. I actually ran a 16/18 dual cog for a while and found that for normal up-and-down riding it was totally useless.

DiabloScott

Sheldon Brown's version had a double crank, and a fixed-free - with the free side being a two-speed freewheel.




Yeah, you gotta wonder why.

spinachface

I had a bike with the s3x on it and it just didn't do it for me. There's a lot of play in the cog, so it always feels like you're riding with a bad lockring. Maybe for some, but not for I.

I think my plan is to have a 17:21 dingle cog with a 36:42 up front. There will only be about 2t of difference so it'll move about 1/4" in the dropouts. Thanks for the help y'all, if never heard of the dinglecog before now, seems like it is exactly what I need.

kingston 

Please reply back with a ride report after you've had it for a while.