Single Speed gear ratios
 

Okay, I've looked around the site a lot and it seems everyone is running a much higher gear than me! I just finished a SS cannondale and it is 39/14 or 16. I live in a hilly/mountainous area and can't go more than 100yards on flat ground anywhere, so i thought my ratio was fine to cruise around on. I'm not doing a time trial or anything haha... Anyway, my quads are gigantic and i don't want any more size, so I don't want to go to a higher gear, though i feel like a hipster with a little chainring and a medium sized cog. Is there a difference in the gear ratio in a SS and a fixed? i guess there would be because with a fixed you've got to be high enough to get down the backside of a hill and a SS you can have a lower gear and then coast down the back.... Any other suggested ratios for a very hilly area? BTW the climb to my house from my job is 1 mi uphill pretty steep and another two with rolling hills, so I need to be able to make it up that first part :p

if you are running SS in a really hilly area like that then run a lower ratio. as you stated, you can more easily get up the hill then just coast down the backside. on a fixed if you run a low gear and you are going downhill, you have to spin your legs furiously.

p.s. don't worry about what everone else is running. it's the hipsters that are running huge gears like they are on the track when they aren't.

gotcha, i always thought the hipsters were running smaller chainrings and larger cogs... whenever i see them they're just cranking away and barely staying upright and moving.

It is pretty hilly here. I run a 42-18 SS. The biggest hills here I can barely do on it, but it is only my city bike, if I go all the way down to the valley, I use my 20 spd road bike.

I live in a really hilly area and I run 46-15 on my fixed.

42-18 would be a lower gear than 39-16, right?

Dayvan: Isn't eastern Ohio like rolling/gentle hills?

42/18= 2.33

39/16=2.44

I use mine for commuting and rock a brake. Chicago 52/16
There is like barely any hills on my commute.

what I did was keep trying different combos until I found one I liked, that felt right to me. I finally ended up with 42/15. no hills here though.

Gear mashing is pointless. Speed gains you nothing but entertainment. The ideal gear for someone in shape riding fixed on rolling highs depends on their ability to climb. I run 39/16 which comes out to 64" or a 4.8 ratio in a relatively flat area. I'd probably run a tooth size smaller in the rear if it was hilly, making those descents a lot easier to manage without a brake.

EDIT: I spin out somewhere in the lower end of the 20's MPH with some absurd cadence rocking 25c Hardcases. Just for reference.

i'm with you here. i changed from 49/17 to 49/19, for about 68 gear inches, and i couldn't be happier. i live in a super flat area too. easier to skid, easier to stop, rpm's closer to 80-90 at normal speeds, which is more efficient. :)

went on a 13 mile ride yesterday and it wasn't that bad...

I was checking out the new white industry's double unos yeasterday. I'm working on an SS and thought this freewheel would be great. I think they run either a 16/18 or 17/19.

Right now I'm working with an old 10-speed style hub converted to SS, but I just ordered a wheel through the local shop that is a cassette-style so I have the option to go fixed with that surly unit or SS with a SS sprocket and some spacers. We'll see how that works out, I've been on plenty of single speeds, but no fixies so I might just do it to try it. I have semi-horizontal dropouts though (1-2mm of play) so it might work better as a SS unless I can work a gear ratio on it that I like a lot.

42/16

Sorry to hear about your huge quads, but in all honesty, mashing a higher gear isn't actually the type of muscular overload that is likely to promote hypertrophy...

Well that's good to know. My lifting routine for rugby has made these babies balloon up in the past few months.

I hate to hijack the thread but I have a similar question and I didn't want to start a new thread. I'm building up a SS and wanted to know what the optimal ratio would be for me. I live in NYC and the biggest hill I'll have to ride is the 59th bridge into Manhattan. It's mainly flat in Queens with some minor hills here and there.

Well, I gave my bike the commute test today.... I pedaled it to church and back this morning (~2 mi each way) and I discovered that the gearing is okay for climbing hills, not bad on long grades or steep short ones either, though I'm certainly not spinning a whole lot, but I am also finding that I am spinning pretty damn fast to keep from coasting in traffic on flats/downhill sections. Overall, I guess it's not bad since I AM riding a SS after all. I think that this will work fine for around town stuff, it cruises fine probably around medium speeds on flat ground, so I'm not too worried.

This is good. I'm in the process of building my first SS and have been nosing around trying to gather as much info as possible BEFORE I order the parts. Started out thinking 44x18 as I'm 56, in shape, but the knees may not hold up. I, also have an old c-dale sr300 w/1x8-48x28-12, barend shifting. So, I did an experiment Friday night on the way home and wouldn't drop my gear under 48x16 for 20 miles of rollers and a couple of killers(though they're short). The last 6 miles is all 5/6% w/about 6/7 'false' crests...very disheartening, mentally. I gutted it out w/panniers loaded(about 20-25lbs extra) and realized I could go to 45-46x17 or 16 w/165mm cranks. The cranks I've got now are 172.5 I think I'll go 45x17x165mm just to be on the safe side. I've seen guys w/60x15 in town(Nashville, Tn) and while I have much respect it's JUST a little stiff for my needs. Good luck, the1amradio. Big ups on the rugby. I played a couple of games in my youth thinking my American football skills would translate, easily...WRONG! The scrum is no joke. BB players think they've got the market cornered for trash talk...10 seconds in a rugby scrum would quiet all that nonsense.

BTW, a friend of mine built up an old Ross w/homade Bullhorns and a Truvative conversion kit. He found the bike abandoned by the interstate and rebuilt it into his #1 commuter. He runs 46x16 w/some pretty stiff hills in his 50 mi rt commute.

It depends on how far your trips are.

On my "fixed gear commuter," which often takes me over 30 miles in a day, I have a 44t ring with 17t and 18t cogs. 90 rpm speed = 18.5 or 17.5 mph.

My Miyata that I use for occasional commuting, but mostly errands around town has 42t ring with 15t and 16t cogs. 90 rpm speed = 19.8 or 18.6 mph.

My ghetto cruiser, which seldom makes trips over a mile, has a 42t ring and a 14t cog. 90 rpm speed = 21.6

As you can see, the basic premise here is that the longer the ride, the smaller the gear you want. My gearing choice for the commuter is based on the gear I'd use on my 27 speed road bike if it was flat and there was no wind and I was riding all day. It's geared just a little higher than that. I'd gear it lower if I was going to use the bike for a century.

on my fixed i ride 42/16 and on my ss (well my girlfriends) theres 46/18. these seem to be perfect for where i live (gentle hills but nothing too steep). i think this is a nice balance of spinning and speed.

MrCjolsen how do you work out speed at 90rpm??

The right gear ratio for you pretty much depends on your overall fitness level. You need to experiment.

I may go fixed in the next month or so, but right now I'm thinking about gearing up a bit more. My cranks are older suntour blaze's and they take specific chain rings which I can't find and nor can my bike shop, so I will probably just buy a whole new set and go from there. I have a few track cogs lying around, but I'm not feeling like suicide style, though I would probably run brakes either way.

Yeah, a scrum is no joke. I used to play 8man, which doesn't get too much into the down-and-dirty of the scrum, but due to some injuries on the team, I'm playing hooker and prop which are front row. Most of the **** talk from front row guys is just hilarious to listen to. It's a good time, lots of beer and parties in rugby culture.

i played prop in better days.
now i just drink.

sounds about right ;)