It's pretty much flat where I live and for the most of my rides have just a light wind. So a single speed bike might be OK. Sometimes I only use 2 of my 21 speeds (9 of which are redundant), 62 and 70 gear inches. So 66 gear inches would be my choice if I had to lock it in on my 34 lb comfort bike with it's bolt upright riding position.

The gear ratio on my SS's depends on the type of riding I'm doing and what cadence I want to spin that day.

I live in rolling terrain in what the local real estate types have taken to calling The Lakelands of South Carolina. When I rode ss mountain bikes on the area's trails (they're a lot of fun!) I ran 34x18 (edited for accuracy!), yielding around a 48-in gear on the 2.1-in Panaracer Fire tires I used to use.

For fixed-gear I've been primarily running around 70-71 gear inches on the road since 1998 or so. It was 48x18 on my old Bianchi Pista, 45x17 on my beat-but-sweet old Gitane TdF, and 42x16 on the Peugeot PR-10, Falcon San Remo, '71 Raleigh Competition and the custom Mercian. When I started adding fire roads to the equation I fitted a larger cog on the other side of the hub, typically around 63 inches. I think I rode just about every dirt road in this county and a bunch of them in neighboring counties on a 42x18 on 28mm tires.

My current all-road mad scientist bike is a 50-year-old Raleigh Competition with 35mm tires, a Surly Dingle fixed cog and a White Industries Dos Eno freewheel on the other. Combined with 42/44T chainrings, I get 70-in pavement and 60-in gravel fixed gear options, or I can flip the wheel and have a 60-in general noodling and a 52-in mild singletrack option for coasting.

I have family that had a really nice house on lake Murray. Nice area.

I'm about an hour and change west - our local Lake Greenwood is fed by the same Saluda River. What isn't so well known is how well the rolling terrain can work with a fixed-gear. The beauty of Greenwood County is that there are NO major interstates here, lots of quiet-ish roads if you know where to look. The local tourism/Chamber of Commerce types have perhaps mercifully missed exploiting cycle tourism - then again, it gets hotter than the hinges of hell in the summer ....

In the fall and winter, the local mtb guys used to ride all the Parsons Mountain area trails and had strong ties to SORBA. I haven't checked in on that scene since 2008 or so, but there used to be LARGE contingent of ss mtb riders in the area.

There was a time when it was expected that races would come to a stop and everyone would flip their wheels for the upcoming hill. I embraced that concept when I ordered my avatar photo bike. That bike will never be anything but a fix gear but it runs a double sided hub and has a modified road-style horizontal dropout long enough that I can run any available 1/8" cog without messing with chain length. (!2 teeth to 24.) I didn't think this out specifically but the bike is basically what we might have used for a late 1980s road race in a world where gears had never been invented so the rules were - velodrome style nutted rear hub, fix gear, brakes required front and rear.

I received the frame from TiCycles December 2011. That January, Cycle Oregon unveiled their week-long route. To Crater Lake. 6 of the 7 days had big climbs but save for the Crater Lake day, only one. And one big descent. Hmmm. Not many wheel flips! But I gotta have a big gear! So I made the chainwhip you see strapped to the top tube. 22" long so lots of leverage but only 20 ounces. That photo was taken two years later on CO. That was a two mile hill that maxed at 14.5% where the photo was taken. (Credit Cycle Oregon's Dean - a super photographer.)

https://cimg2.ibsrv.net/gimg/bikefor...13d1443e21.jpg

That day I left camp on the 17 with the 23 on the other side. Used the 17 going over a pass earlier and the 12 on the other side. Planned to do the two small hills after lunch on the 17 and flip for the biggie. Oops! I was well into the biggie before I figured out "this is it!". Too steep to stop and start again in hundreds of Cycle Oregon bikes' traffic. So that 14% was done on a 42-17. The tIght muscles on my calf and forearm were not for show. (You can see the 12 tooth cog hanging from the tool bag and the Pedros Trixie tool under the bag. (The spanner on the Trixie is a superior lockring spanner for the bell shaped 12 tooth lockrings. Wide enough that it never slips, unlike the spanners made from plate like most of the Park's.)

The dropout is one of the best parts of the bike. Around 2" long. Angled up at the back 11 degrees, roughly half a regular dropout that maintains constant brake pad location on the rim as you slide the wheel but mine close enough the the pad stays on a deep rim (and is most marginal when the wheel is all the way forward. I am not going to be doing any hardcore descents and doing serious braking in a 42-24 gear. Bottom bracket drop is minimal with the wheel slid all the way back in the 12 tooth cog to keep pedaled 40 mph corners as boring as possible with 175 cranks - my knees insist. (BB height is around 10 7/8". Good and high. Seat tube angle is 75 degrees and a 25c tire nearly hits it with the wheel all the way forward, again to keep the 12 tooth positioning as far forward and bike handling as boring as possible. All a compromise, yes, but a very, very good compromise! Bike is a pure joy to ride. Crate Lake was a blast!

And back to the dropout. Notice the slot is "L" shaped; that it runs forward then opens down like a vertical dropout. Opening forward - makes wheel flips easy. No tight chain you have to wrestle off the cog if you put on a huge one for that hill. And opening down? No clearance between the tire and seat tube with a big cog but opening down, there doesn't have to be. Between that dropout and the chain peg and using the Trixie tool, wheel flips take no more than 2 minutes and my hands stay clean. (Changing a cog with the chainwhip takes about 5 minutes.

And last - a question - why isn't every road fix gear set up like this? Nothing here is rocket science or requires special parts. The dropouts were cut from 1/4" plate. The chain peg is an M5 pan head screwed into a tapped hole in that plate. All perfectly do-able 150 years ago. (I don't know when threaded cogs and lockrings came into being but that was long ago, probably after the first automobile but maybe before the Model T. Track ends on the road? Why?

Alas, in my case I didn't think to specify a forward opening dropout, and wasn't that a mistake! I occasionally flirt with the idea of dismantling my Mercian and sending it to a talented frame builder to have the rear track ends replaced with long forward-opening dropouts perpendicular to the seat stays - but then I remember that the tire clearance is sub-optimal as well. Still pondering it all ...

work harder!
 

switched the 2spd from 42x22 to 44x20.
should be less spinning out. I hope….


https://cimg4.ibsrv.net/gimg/bikefor...eddf6ca40.jpeg
https://cimg6.ibsrv.net/gimg/bikefor...883f80618.jpeg
How far into the drop out is needed anyway…?

You only need enough for good clamping of the nut, A good track nut will have an aggressive pattern on the incorporated washer. If you are not super strong, you don't even need that much. I'm not and I've had washers that ran a little past the end of the dropout.

Now if you have quads of a Mark Gorski or Nelson Vails, my advice night get you in trouble. (I did notice the Vails had just ordinary (probably very high quality) track nuts in a photo I saw. This was back when everybody had to have super chain tensioners on their fix gears to keep from pulling wheels out. (Streetwise Joe just has to have them but Nelson Vails does not? Scratches head.)

I briefly ran tensioners. PITA. Switching back and forth to adjust tension and keep the wheel straight.

It was faster and easier just to do it like when I was a kid. Just enough slack on the chain so it doesn’t bind. Adjust straightness on NDS. Then finish tightening it all down.

You guys push some real big boy gears compared to my SS mountain bikes. I run a 30t oval 18t cog with 27.5x2.6" tires on one and 34/18 on the mixed surface gravel.singletrack/street bike with 29x2.5" Surly Extraterrestrials. I'll take my mountain bike up and down some of the gnarliest terrain available so if I'm not geared real low I wouldn't be able to ride up 1/2 the stuff I do.

44 x 17 gives me a good amount of skid patches and is easy on my knees. Going uphill is is possible and riding in the city I don't need to be going fast, going in to skid is also easier with a lower ratio

The Olympic has a 48/16
The LaJolla has a 48/16
The Rincon is running a 46/17 I believe. It's got those weird half filled dropouts and limited what I could run. I want a 52/16 on it.

it gets hotter than the hinges of hell in the summer

I like that phrase, but I'm in the PNW, so anything nearing that experience is out of my world.

Over the last four years I’ve mostly ridden single speed and most of that time running the MTB about 68 GI and road bike at 71 GI. That is with 42/16. But I just switched the MTB to 42/17 which is about 65 GI.

At times that seems just a tad low, but we are entering the cold, dark, saturated half of the year and our trails will be softer. Also, the leaves will soon drop, leaving all places open to the persistent wind. So that seems to work out well. It also forces me to work more in a slightly higher cadence.

EDIT: Yeah, I did a ride yesterday in very windy conditions and had more than 6% benefit from the 17t versus 16t sprocket. Much easier to stay on top of that gear into a headwind. Also makes the climbs more than 6% less scary. I still managed to work as hard as I wanted to on the flat sections by spinning a bit faster.

It helps that this is an old MTB with touring bars. I normally ride high enough to catch a fair amount of air so I don’t need too high of a gear, but I can reach forward and get a bit lower into headwinds.

Otto

Yeah, man, my ss 29'r MTB was 32x20. It's very steep and rocky where I live so even then I'd be walking at times. My 700c gravel bike is a dinglespeed 34x17/19 and around here that's as tall as I could go and still get up much of this stuff.

There is this tool out there to answer your gearing/cadence questions.
With my failing memory it comes into use frequently.

https://allcitycycles.com/calc

There is this tool out there to answer your gearing/cadence questions.
With my failing memory it comes into use frequently.
I just checked, I thought I was ~68 gi, but was 62.5 gi.
I have a couple more bikes setup at 56.5 gi.
I aging and sliding, just trying to keep up.
Still love the fixed gear!

https://allcitycycles.com/calc

It is always funny when people want to know what single-speed gear ratios others are running, as if anyone is going to be their size, age, genetics, proportions and fitness level and have the exact same grades to climb on their rides every day********************? Even one person, myself as an example, will change gearing throughout each riding season as my fitness level changes and the weather changes etc.. Also it is funny how someone will criticize another rider for pedaling at low-rpm, as if nobody enjoys just beach-cruising along at five or ten mph looking at the sand and waves or the amber fields of grain out in the country? Everyone is supposed to be spinning and speeding at a racing cadence all the time? Ridiculous.

If you are not in a hurry, and you are on level ground or going down-grade going at low speed, then it does not matter what your cadence is, and if you are grunting up a steep grade then of course your cadence will be low. In other words unless you want to go fast and are, your cadence on a single speed will normally be low unless you gear it to need 100rpm at 10mph.

Maybe someone who has little experience on a single-speed wants to know what gear to start with, and that is simple, ride your multi-speed around your usual routes and note what gear you can use to get up the steepest grade on your routes while standing up pedaling, and start with that one on your single speed. If you are willing to walk up your steepest grades then gear for more speed as walking is good exercise too believe it or not.

I am lucky as my local terrain lets me gear my bike fast enough to keep up with a local group-ride I like to join regularly and still be able to easily climb up the steepest grade on my regular riding routes, so I have it all. If I am exceptionally tired I have no problem getting off the bike and walking it up a steep grade, as it can keep your heart rate in the same zone and is good cross-training and also can be a relaxing change.

So you don't need to know what gearing I run or anyone else does because it will never be right for you.