TyWinans

Hello I just got my first single speed/fixie. Its gear ratio is 47-17. This feels like an awfully large gear and I think its setup more for a track bike right now. I was wondering if anybody knows of any cogs in the back larger than a 17 or would that not work? I cant find any. Or am I going to have to change the crank.

Just a matter of curiosity what are most riding gear wise for riding hillyish (about 500ft of climbing for every 10 miles) on rural road on a fixie. Or just whats a good standard fixie gearing. Thanks!

seau grateau

That gearing would actually be way too low for track. I usually ride 48-17 on the road. If you feel like it's too high, you can definitely get a bigger cog easily. I've used 18's and 19's in the past when I wanted lower gearing. These are decent: https://www.retro-gression.com/colle...city-track-cog

Bandera

The convention for most road riding on a FG has been for ~70 Gear Inches. 47X18 is 69GI, 19 is 65GI vs the 73GI you are now riding. You may have to add chain but cogs/chains are inexpensive & easy to change to get suitable gearing for your fitness & terrain.

Here's a handy gear calculator to work with:

https://www.sheldonbrown.com/gear-calc.html

TyWinans

Thanks for help. The recommended Gear inches for road riding is extremely helpful. Now I have a starting point that isnt for urban riding. Thanks again!

TenSpeedV2

Checks bike. 86 Gear Inches.

TimothyH

I'm a roadie who discovered fixed gear and so I ride 48-16 (79 GI) on the road.


-Tim-

TejanoTrackie 

Here we go again with another my gear is more inches than your gear.

SquidPuppet

What kinda speeds do you maintain?

TenSpeedV2

Not at all. I was running 36:13 on a bike at one time. That was 72.85 Gear Inches. Didn't like how spinny it was especially since it is flat as a pancake here. Felt very restricted in how uncomfortable it was to spin that out to anywhere near 17 mph.

TenSpeedV2

Without stops like lights or signs? No problem easily maintaining 20 mph or so. Have topped it out at 33 mph I think it was.

TejanoTrackie 

Wait a minute here. Do you consider 80 rpm to be spinning out ?! Because that’s what you get with 36:13 at 17 mph, assuming a 700 x 23c tire. I routinely ride that gear very comfortably at well over 20 mph, and can easily spin over 30 mph on downhills. Oh well, different strokes for different folks.

TenSpeedV2

Nope. 700x37 Continental City Ride tires on a mountain bike turned fixed.

TejanoTrackie 

Well, that’s even a lower cadence of about 75 rpm.

veganbikes

Hahahaha.

OP could go with a Surly Dingle Cog and have like two gears and manually move them if you feel like it is to hard or easy.

seau grateau

Some people like to ride higher gears at lower RPMs. Other people like to ride lower gears at higher RPMs. Both are okay.

79pmooney

Ty, I consider 47-17 to be a very high gear and always have, even when I was a 24 yo road racer. Now I used the bike for winter and bad weather training, not group rides. 42-17 to 42-14 was my usual range back then. You can get much smaller chainring or a bigger cog. They are available up to 24 teeth. The bigger ones a harder to find but are out there. (I have all from 12 to 24 so I can gear my bike for mountain climbs and descents.)

Ben

zubes5280

I ride in similar terrain (500 ft. of climb every 10 miles) and I've found 48/18 (70.22 inches) to be my personal sweet spot. Hills are totally manageable, start/stopping in traffic is easy, and I can still spin a little over 30mph on descents. It's also easier to skid if you're trying to look hella sick on da street. I used to ride 48/16, but gearing down a bit really livened the bike up.

Gresp15C

I've been happy with 46:19 on similar terrain. These are just the gears that I happened to pull out of my bin one day. It seems to be the sweet spot for me. I'm not super athletic, so I can work as hard as I want and not spin out except on long descents. I find myself riding a bit faster than on my geared bikes, just to get into a comfortable cadence, so it helps keep me from getting lazy.

In a sense, single speed means getting used to always being in the wrong gear.

Bandera

If you learn to speak/write in Gear Inches, the default gearing language of track and FG/SS riders for the last century or so, there is no confusion over the wheel size, tires width/height, chain-ring or cog one is using. GI is a clear concise value including all of these variables to express distance per crank revolution.

Here's a handy gear calculator to learn the lingo with:

https://www.sheldonbrown.com/gear-calc.html

-Bandera

FBinNY 

47/17 is very common gearing for street use. As noted above, it's way too low for competition on the track.

I set up my street bike with 47/17 way back in 1968, and never had a reason to reconsider.

However, there are larger rear sprockets, so if the OP wants something lower it wont be an issue, except possibly (but not likely) may call for a longer chain.

joesch

I ride a 46-16 around mostly flat Dallas and find its a nice choice for maintaining higher rpms than I would on my road bike. Its a nice ratio for starting in the city and averaging 16..18 on the longer runs. Not enough gear to keep up with the faster road bike riders in some of the group meetups.

TyWinans

Thanks everybody. This gear inch language is something I definitely have to research more, until this week I never heard of it before. When I rode the 47-17 on a bike trail it felt ok but hard enough I knew Id struggle on the road with hills. I ended up ordering a 20T cog figured that would be a good enough starting point to go from.

Gresp15C

Thanks. It's 66 gear inches.

For the OP, the math isn't hard. Here's how I worked it: My wheel diameter is 27.25 inches, so the gear inches of 46:19 gearing is 27.25*46/19 = 65.9, rounded up to 66 inches.

washer62

i ride a 33-22 SS just over a walking speed. Average 5mph for about 20 miles. Just what I like.
Not in a hurry to go back and sit on the couch

Broctoon

I have a track bike with 49 x 16, which I find I can only really handle on flat terrain (or descents, of course... but any route with descending in it will also have some climbing). I have to hope for no headwinds when I set out on it. It is my lightest and stiffest bike, and the most aero, all of which help a little.

My other fixed gear bike has 46 x 17, which is quite versatile on flat to slightly hilly terrain, just nothing steep. I spin out on even moderate descents, but I find this ratio a good compromise for all-around use.

I have a single speed bike set up for commuting, and have settled on 46 x 18 for it. Because it has a freewheel, the slightly lower ratio is not a disadvantage on descents. It's as heavy as a boat anchor, so climbing hills with it is still a chore. But it's a very comfortable bike, and I can ride it for hours without pain. I'm considering putting a 3-speed internally geared hub on it, to make it more versatile without completely sacrificing the attributes I like about it (simple, durable, low maintenance).

As Bandera said above, somewhere around 70 gear inches is appropriate for most riders. But many factors come into play, including fitness level, riding style, terrain (of course), and others.

When I say I can't handle hills on my track bike, that's not completely true. My favorite place to ride it is at a city park with a 1.3 mile loop that includes two short but fairly steep hills. I love to cruise at a moderate pace on the flats, try to keep up with frantic spinning on the descents, and when I come to the climbs, stand up and sprint as hard as I can. It's a great interval workout. I normally do 10 or 12 laps (13 to 16 miles), and I average about 4:15 per lap: that's an average speed of about 18.5 mph, sustained for 43 minutes or so. The funnest part is smoking roadies on the climbs. They inevitably downshift and lose some speed; I actually accelerate up the hills. When you don't have the option of shifting gears, you learn how to sprint.

The downside to that bike is I have to load it up on the car and drive it to the park, which is quite some distance from my house. I ride there and back on my other bikes sometimes, but never on the 49 x 16.