jyl

I have a derailleur bike for commuting, usually am in the 64" to 73" range including the modest hills I ride. But the steep ramp out of the underground parking garage has me down in my lowest 42" (42 x 26).

kingston 

I do believe I can tell the difference between 1 tooth plus or minus on the front, especially going downhill and into a headwind, but you are right, the differences are slight and could just be in my head. I'll just have to continue with the experimentation

noglider 

In general, I would say a 5% difference is the smallest perceptible difference, but maybe it's smaller. 1.4%? No, I don't think so. If you do a double blind test, then I'll be impressed that you even conducted it.

FBinNY 

I don't know the limits of gear sensitivity, but can say from experience that I've often found myself wishing for a gear between two rear sprockets different by only one tooth. That would mean that I'm looking to split a roughly 5% difference. Of course, we're probably most sensitive when in that sweet spot of gearing on flat roads. It's less meaningful when we have the ability to shift.

On a single speed, there's no option to change, so riders need to find their own sweet spot for the conditions they see the most often. Their legs then need to have the latitude to accommodate less than ideal gearing to either side of that sweet spot as speed, wind or grade changes. Since "normal" or perfect conditions aren't going to be duplicated every day, because if nothing else we can count on the wind changing, the exact sweet spot isn't as critical as being in the right ball park.

Some 45 years ago, I set up my fixed wheel street bike based on the gear combination that saw the most use on my road bike, figuring it would be right more of the time than any other. I've never changed is since because I tend to be less focused of micro adjustments, and more focused on being in the right ballpark.

noglider 

You raise an interesting point. There is the difference between two gears where you can shift between them. Then there is the difference between two gears where you have to stop and change your equipment and then get on the bike again. I have no proof, but I'd say the former can be smaller than the latter for it to be perceptible. If you're riding a SS, you're going to be riding in conditions where, if you could shift, you would shift but can't. So a percent here or there can't make a practical difference in my mind.

FBinNY 

I don't claim that 1-2% would make a difference, but my point is the flip side of yours. Since I can't shift, I'd want a combination where the chances that I wish I could to be reduced to the lowest possibility.

I don't know how long the OP has been riding, but anyone with many miles under their belts should have a sense of what gear (inches) he spends the most time in. That's what the single speed should duplicate, with possibly an adjustment lower so hills aren't a barrier.

But that's only a starting place. For example, if the distances aren't going to be too long, and there aren't hills to consider, the OP might set the gearing slightly higher than normal, forcing him to ride slightly faster to stay in his cadence sweet spot. This has penalties if kept up too long, but can be an effective training device.

Gearing selection isn't a science where there's one right answer. It's a matter of finding the right ball park then adjusting within it based on experience and ones goals. IMO, nobody can ever answer the question of "correct" gearing except one's own legs.

noglider 

I agree in full. I recently had my Viscount set up with a 3-speed fixed gear hub. Knowing that 66 is nice as a fixed gear, I set it up that way with 66 in the middle, 55 at the bottom and 88 at the top. It turned out that 66 was too low, because my legs seem to find their favorite cadence, and I went more slowly (slowlier?) than I wanted to. 88 was too high for cruising around town. Now the bike is a single speed with 52/19, which works out to 74 inches. Much better for me, though I may lower it in the winter. BUT (there had to be a but) I took it out to NJ and hit a couple of monster hills. It was the first time in decades I had to get off the bike and walk. Perfection might be worth pursuing, but you never attain it.

LesterOfPuppets

I'd go with 70". I ride 72 but there is stomping up the hills and no panniers.

LesterOfPuppets

For MTBs I'm in the 50-55" range, depending on expected terrain. About 60" for street cruiser MTB.

Carbonfiberboy 

Just for the fun of it . . . I've ridden with a guy in the mountains, though only up to 7% grades, who rides a 90" fixie. I am not in his category, but we have a social ride together occasionally. That ride was a 115 mile, 7000' social ride, a low intensity training ride for him. So it just depends on how strong you are. Don't ride the gears of someone else. I ride as close to 70" as I can get.

noglider 

Holy cow.

LesterOfPuppets

90"? So burly!!!!

I'm not man enough for that even on the flattest of roads. Maybe with a 15 kt tailwind.

kingston 

I would do it, but then I would have to teach my wife how to change a chainring blindfolded

jyl

So his fixie is geared like 53 x 15 or 42 x12? Hard to imagine.

yipyipyip

Depends on terrain and fitness level. I'm on 46x16 (77'') fixed, riding mostly flat terrain, and I was thinking of going higher. <65'' would be far too low in my opinion. Ultimately, you'll just have to try it out for yourself. Track cogs aren't that expensive.

LesterOfPuppets

Freewheels, for the OP.

yipyipyip

Oh OK, sorry. Freewheels are kinda more expensive of course. Still, OP will have to try for himself for optimum gearing. That sounds like a truism, but it really is accurate IMHO. Most "enthusiast" riders would probably agree that most "casual" riders ride too high a gear. That does not imply that everybody rides too high a gear.

Ultimately, SS/FG riding is also about building the ability to broaden one's power band, i.e., increasing power at high as well as low RPM.

DiabloScott

I've been riding fixed gears for over ten years and that has never even been a tertiary objective for me. Most people ride them because they're fun and use a different set of skills. OK, I say "most" but I have only anecdotal evidence from people I talk to and correspond with.

Carbonfiberboy 

He and his girlfriend are national tandem champions. Not so hard to imagine, really. Probably any pro could ride that with a little practice.

yipyipyip

Note I say "also" in my original post .

For me, too, it's all about having fun. I ride a flip-flop hub with 46/16 gearing on each side, one side freewheel the oder side fixed. I ride fixed. Why? Fun. So ride whatever you like.