# Thread: “Single speed gear ratios, what do you find works best”

1. ## “Single speed gear ratios, what do you find works best”

I have asked this question several times and everyone says by extra cogs and test them out to see which is best. So I started looking around and found this website

Thread title “Single speed gear ratios, what do you find works best”
http://www.pinkbike.com/forum/listco...9389&pagenum=1

I copied the following posts and was wondering what all you guys think? Keep in mind I am a novice and just barely ride my bike. Started riding again at age 62 after not riding since I was 16, so take it easy on me fellas;
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use this equation when calculating ratios it really helps...

divide your front chain ring (teeth) by the rear cog (teeth) then multiply by your wheel size.

for example mine is 36/16x26 = 58.5

a 55 is perfect for me... just some equation some brits showed me to calculate it all into a single number...
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aside from personal preference take the size of your sprocket multiply it by your wheel size then divide that by the size of your rear freewheel and you get your gear ratio. Ideal ratio is 55, not sure if this is totally true but I saw it on a bmx website a while back.

Ex. 30t sprocket X 26" ÷ 15t freewheel = 52
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YES. USE THE FORMULA, YALL! IT'S EASY.

The single number is called "gear inches." It means how far your bike rolls with one exact 360 degree rotation of your cranks. So it is essential to factor in wheel size when picking your gears.

The reason 55 gear inches is considered classic is that 44/16 was the classic gear ratio on BMX bikes for like 20 years (which comes out to 55 gear inches).... On race tracks you need it to be spinny enough to get in front of everyone when the gate drops, but still powerful enough to stay fast throughout the track to win the race. People would sometimes do 43/16 or 45/16 but that was pretty much it.

With 26" wheels, 34-16, 32-15, 30-14, 28-13, 26-12 are all optimal all-around single speed gear ratios. Note that it just happens to be double the rear cog plus 2.

2. If your looking for suggestions, you may want to include the type of riding you are doing. I know from reading one of your other posts that you only ride on the road. This obviously makes a huge difference!!

3. Originally Posted by DavidR1
If your looking for suggestions, you may want to include the type of riding you are doing. I know from reading one of your other posts that you only ride on the road. This obviously makes a huge difference!!
You are correct David. So I did the math and the results were 32tX29"/16t= 58 so is the higher the number the harder the ride or vise versa? I like the ride that I have now just wanted to get more speed and less huffandpuff against the wind. The wind I find is the biggest problem with riding on flat roads. Small inclines are to be expected.

4. Wow this gear ratio stuff can get real complicated real fast! Length of cranks makes a difference. I don't even know the length of my crank arm. Its not on the spec sheet of the bicycle, anybody know? 09 Monocog 29er stock?

5. Your Monocog probably has 175mm cranks. Look on the backside of one of the the cranks...it shoud say it on there somewhere.

6. Originally Posted by Blazerwolf
You are correct David. So I did the math and the results were 32tX29"/16t= 58 so is the higher the number the harder the ride or vise versa? I like the ride that I have now just wanted to get more speed and less huffandpuff against the wind. The wind I find is the biggest problem with riding on flat roads. Small inclines are to be expected.
Well, you're not going to get both speed and easy pedaling. Not with a singlespeed.

Don't worry overmuch about gear inches and crank arms and that stuff. Just look at your current gearing: it's 32 x 16. To make pedaling easier (but slower), increase the rear cog in size (for example, to 18t). To make pedaling harder (but faster), decrease the rear cog (to 15t say) I'm suggesting changing the rear cog because it's easier and cheaper than changing the front, but you could change the front instead. It's the opposite direction, though: a bigger chainring = harder/faster, a smaller chainring = easier/slower.

7. Hey thanks a million for all the good info especially that explaination SeatBoy that was what I really wanted to know! Everyone here has really helped me a great deal.

BTW for those that are interested I went to another forum called Two Spokes and tried to ask questions and a person posting by Industry Hack jumped my case and said because my 29er had Big Apples that I wasn't on the same page as mountian bikers. I agree with that but that was not my question, at any rate they started deleting my posts and questions. So a word to the wise stay away from that forum if you don't want to be treated like crap. I sure am glad I came back here where everyone here has went out of their way to be helpful!!

8. Originally Posted by A1an
Your Monocog probably has 175mm cranks. Look on the backside of one of the the cranks...it shoud say it on there somewhere.
You were right! They are 175mm! Thanks for the help.

If you have a geared bike, you have 27 gear ratios you can try. Pick the one you like...

10. He is riding an '09 Monocog 29 if I read correctly, I have a Raleigh SS 29 and when I am smooth pavement riding my gearing is 33 front 16 rear. I find that very good for maintaing a good cruising speed with out spinning yourself out peddling. If tires are factored in with that I was running 47c Kenda hybrid tires (so I dont wear out my knobbies)

11. Only you can really determine what is the right gear. The variables of fitness, and terrain as given are too abstract with the information provided.
Gear inches isn't the rollout either; it's the theoretical diameter of the wheel with a given gear ratio.

12. Unfortunately the internet brings out the worst in some people.

As was already pointed out...best thing to do is experiment with different cogs to find out what works best for you. Some guys will even go so far as to bring their cogs, chain whip, and lockring tool out on the trail with them so they can test out cogs back to back. As for myself...even tough it is easy I am still too lazy to swap my gearing around. I found a "magic ratio" that pretty much works for me on all of the trails in my area. It allows me a mid 11mph avg on the long flat/rooty crap at a reasonable cadence and is still somewhat tolerable on long steep climbs.

You can usually find a multi pack of the stamped steel cogs for pretty cheap. It does not take a ton of cash to tinker around with your gearing. Good luck and have fun!

13. 32-20 on the mountain bike and 50-16 on the fixie.

14. Its really trial and error plus the longer you do this you refine it and as you gain single speed fitness and experience this changes things too.

Here's a little personal history. I started on a 32, 19 and felt it was too tough and went to a 20 and then a 21. Even on the 21 I wasn't making climbs I wanted to so I went to a 33 upfront. Still wasn't making the climbs and went back to the 20 and then I started making some of the climbs some of the time. After giving it some thought I decided the problem was I needed to climb faster so my legs would not fatigue out and stall so I went to 19 still with the 33 up front. Bingo! Not only was I climbing like a mountain goat but I was nailing the climbs almost every time. Now I just went to an 18 in the back and it feels even better. If I could find a Boone 34 104mm chainring I would be all over that too. All of this took place over a year and half of riding a single speed 29er. I do think the 34/18 will be the "magic bullet" for a while.

15. What works best really is dependent on your fitness and your terrain nothing else..

16. It depends on the type of trail, how technical, how fit you are, etc etc.

I find that in Dallas I can clear every trail on a 34x20 29er, sometimes I wish I had a 34x17 or a 34x21. In single speed you are always on the wrong gear.

With my set up, climbs, technical section and twisty single track are my friend, long straight aways are the enemy as I can only go up to 130rpm effectively.

I just moved and find that my single speed set up is to "easy" for Mcallen, so I am going up on the ratio to a 34x18 or 17.

Some people here like the 22x12 or 22x11 set up which is a mechanical aberration...

17. ## In a word ... none. :)

At least in my ~1 month of trying SS'ing out on a 29er. Rode almost exclusively on-road with the standard knobbie tires & started out with the stock 32/18 & eventually ended at 33/12 & still wasn't satisfied. But riding only road certainly make things easier as far as gearing selection goes. Still not for me. I'll stick to gears. IGH to be specific.

But +1 ...
Originally Posted by Leethal
What works best really is dependent on your fitness and your terrain nothing else..

18. Dude, you moved to Mcallen? That's where a UT is, right? No offense but you're going downhill bad. Start moving northwards.

I just started SSing in Colorado and went with a 32x21 based on local input. Two of my friends in flattish Kansas City run 32x16s and 34x16s. It all depends on how strong you are but for my first SS, 32x21 is a good start- I may stick with it. I know guys who run 32x18 here but they also big-ring some pretty steep climbs on their gearies so take it easy till you really feel it is too easy.

Disclaimer: I'm about as much of a SS newbie as one gets, but I stayed at a Holiday Inn Express earlier this year.

19. get yourself 3x consecutive chainrings and 3 - 4 x consecutive cogs and you will be all set.

ie: 32, 33, 34 and 18, 19, 20, 21. that'll give you the perfect spread to play with depending on your terrain. you probably don't even need that much really. see the chart:

20. OK here is what I came up with by using an Excel spreadsheet using the formula above. It also seems to be a relative inexpensive change to make. I currently have a 32/16 gear ratio using the above formula would give me 58". So I plugged in all sprocket sizes from 24 to 42 and I came up with a 34/18 being the closest ratio of 54.78 to the supposedly magic number of 55.

Now the only problem is I'm not sure what size that chainring in on my monocog. I looked it over and could not find the size imprinted in the ring. is it 110mm, 90mm ?? Any ideas. BTW it looks like both those parts are less than \$30 bucks.

21. Originally Posted by jacques_anquetil
get yourself 3x consecutive chainrings and 3 - 4 x consecutive cogs and you will be all set.

ie: 32, 33, 34 and 18, 19, 20, 21. that'll give you the perfect spread to play with depending on your terrain. you probably don't even need that much really. see the chart:

Wow goes to show how great minds work alike! Thanks Jacques!

22. 55" a magic number on the road? That seems awfully short. I ride 78-82" on the road and there are lots of hills here (usually I climb 2500 feet in every 60km of riding).

Off road I ride and race with 51".

23. Originally Posted by serious
55" a magic number on the road? That seems awfully short. I ride 78-82" on the road and there are lots of hills here (usually I climb 2500 feet in every 60km of riding).

Off road I ride and race with 51".
Hey Serious, Those are not my numbers! If you read the thread that was someone else's numbers based on a Penny Farthing I think he said. Whatever that is? Anyway where in hell are you riding that the rise at 2500 feet in 60km? Is that a continuous uphill ride? You must have leg muscles like and elephant! Anyway I admire you for your skills. Like I said at first I am just a novice starting off after 40 years of not riding! Someday I might ride 60 km before I die!

24. I started off with 32/18 and after a while went to 32/20. You don't need to use gear inches unless you are comparing different sized wheels.

25. Blazwewolf,

I ride in Toronto (in a suburb called Richmond Hill) and although there are no sustained climbs here (longest climbs are less than 2 km), there is not much flat riding either.

I race on a singlespeed mtb a lot, so I am in better shape than the average rider.

26. Blazerwolf, only you can tell what the right gear will be - depending on how hilly/flat the terrain is in your neck of the woods will help you choose the gear. You never mentioned how the gear that was on the bike to begin with worked for you... Do you spin out too quickly, or is it too hard to get up a hill? Or have you ridden it for a few weeks and it seems to be OK? That would be my first recommedation - get out and ride it. Give yourself a month (unless it is really obvious that it is too easy or too hard). Remember that with a single speed, there will always be conditions where your gears are not optimum, or may even be way to slow, or you push up a steep hill.

27. Originally Posted by ATBScott
Blazerwolf, only you can tell what the right gear will be - depending on how hilly/flat the terrain is in your neck of the woods will help you choose the gear. You never mentioned how the gear that was on the bike to begin with worked for you... Do you spin out too quickly, or is it too hard to get up a hill? Or have you ridden it for a few weeks and it seems to be OK? That would be my first recommedation - get out and ride it. Give yourself a month (unless it is really obvious that it is too easy or too hard). Remember that with a single speed, there will always be conditions where your gears are not optimum, or may even be way to slow, or you push up a steep hill.

Thanks Scott, That is a damn good anaylis and sorta suits my estimates very well! I ride every other day 10 miles on level streets. The bike came with 32/20 gearing and someone on this forum suggested changing my 20t to a 16t after I took off the Knobbys! I replaced them with Schwalbe Big Apple 29ers. That bike rides like a dream. Been off the pavement just once for about a quater of a mile at the park! All grass hill! With the knobbys no less. That was a thrill so I can imagine the thrill coming down a mountian trail. I believe at my age that probably won't be to smart!

I guess as I get stronger most of my small concerns will disappear. I ride on average between 10-12 MPH, highest speed attained was 18.88 MPH that was with the wind at my back! I only started riding in May since 1963. I started at 280 and am now at 220, that bike has changed my life.

28. Originally Posted by ATBScott
Blazerwolf, only you can tell what the right gear will be - depending on how hilly/flat the terrain is in your neck of the woods will help you choose the gear. You never mentioned how the gear that was on the bike to begin with worked for you... Do you spin out too quickly, or is it too hard to get up a hill? Or have you ridden it for a few weeks and it seems to be OK? That would be my first recommedation - get out and ride it. Give yourself a month (unless it is really obvious that it is too easy or too hard). Remember that with a single speed, there will always be conditions where your gears are not optimum, or may even be way to slow, or you push up a steep hill.

Thank you for that. There are SO many threads asking about this and they always get the same answer - it depends. What really is annoying is when somebody posts what they run (say 32X22) and somebody comes along and says, "Wow, that's really easy... blah blah blah. I run 40X16 and I can climb everything!"

29. Originally Posted by Dion
Thank you for that. There are SO many threads asking about this and they always get the same answer - it depends. What really is annoying is when somebody posts what they run (say 32X22) and somebody comes along and says, "Wow, that's really easy... blah blah blah. I run 40X16 and I can climb everything!"

I run 40 x 16 too (63 GI's),....on the FIXIE side of my flipflop eno eccentric hub, and can get up all the hills in my area pretty well. The freewheel side i run a White Industries Trials version 18T freewheel. The "Angry Bees" sound it makes i use to alert folks i'm coming up on them! (back pedaling REALLY sounds great! :-)

The 40 x 18T freewheel is a bit easier on the hills, of course. But i don't seem to lose any speed on the flats over the 40 x 16 fixed side. (63 GI's).

The reason is i can spin out fast for a clip,.....and then coast! Spin out some more and C O A S T!!! The rest in between "spins" helps me to recover, and i end up just as fast (or a bit faster maybe) than running the steady pedaling higher geared fixed.

This all on one of my Dean Colonial titanium frames converted to a rigid road runner "69er". (in my area it's mostly sidewalk running as i'm not running along with 45 mph traffic and no shoulder).

I like a more upright (see the traffic and some "cute" pedestrians) position. I suspension corrected the frame with a Surly Steamroller 700 wheel size fork, 700x32c wheel/tire, and used the 5mm higher Chris King baseplate/crown race. This all works nicely to get the geometry where it should be.

I used my XL size Dean frame to make use of the long headtube, which pretty much ate up all of the 300mm uncut steerer tube. The frame would be too large as a dedicated MTB perhaps, but as a road conversion is optimum for my needs.

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