# How do you choose gearing?



## Skorp (Jul 20, 2009)

Hi, 

How do you choose your gearing?


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## Cotharyus (Jun 21, 2012)

I choose based on climbing hills. The gearing I run I can climb all my hills locally on a good day. On a not good day, I may find myself walking some.


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## edubfromktown (Sep 7, 2010)

+1 for making single speed gear selection based on the hills along the route. If I can pedal >95% of the climbs, then I chose well.


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## mack_turtle (Jan 6, 2009)

BikeCalc.com - Bicycle Gear Inches Chart

Input your tir size. Start with 45-50 gear-inches. Change your cog by a tooth or two if the gear is too easy or too hard.

Most people I know ride a 29er with a 32 front and 20 rear.


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## asphaltdude (Sep 17, 2008)

If you don't throw up at the top of a climb from time to time, you should increase your gear inches and/or beer consumption.


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## jestep (Jul 23, 2004)

asphaltdude said:


> If you don't throw up at the top of a climb from time to time, you should increase your gear inches and/or beer consumption.


Sounds like a fairly good baseline...

It was somewhat of a guess for me when I switched, but just rode without switching gears on another bike to get an idea. Running 32/18 on 26x2.25's, which is fairly pedestrian compared to some of the SS's I've seen, but works for most riding around here and it's still usable when I'm back up in Colorado.


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## Skorp (Jul 20, 2009)

Yeah, i have been trying out some gears lately. 
On my other SS builds that i've been commuting on 32/16 has been my only gear. 

But now i have started some trail riding on a 29" with 2.25 Ardents. 
At first i had 32/16. Waayy to tall of a gear for me, even the smallest climb made me struggle. 
30/16 was really good on gravel and road, struggled on some of the gravel climbs but it's part of the game. 
30/17 was good allround, not too slow on the flat, and i could ride some trail.
30/18 is really fun, the bike feels quick and i have only pushed one climb that i know i could do with gears. Soo slow on the flats though, but you get to enjoy the scenery!  

Cotharyus and edubfromktown what gears did you end on then? 

If i need to throw up on some climbs i guess i should go with 30/17


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## JoePAz (May 7, 2012)

Depends on mileage, climbing total, steepness of climbs and length, technical climbing or smooth, racing or just riding, where do I spin out. 

All those go into the gearing I run, but I run 34x19 most of the time. 34x18 for occasional flater course were I might spin out the 19 and 34x20 for more rocks, longer distances and longer sustained climbs.


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## Impetus (Aug 10, 2014)

JoePAz said:


> Depends on mileage, climbing total, steepness of climbs and length, technical climbing or smooth, racing or just riding, where do I spin out.
> 
> All those go into the gearing I run, but I run 34x19 most of the time. 34x18 for occasional flater course were I might spin out the 19 and 34x20 for more rocks, longer distances and longer sustained climbs.


I've chosen 32x18,19,20 on a 29+ for many of the same reasons- balancing the penalty for spinning out vs suffering, stalling and walking.

Joe is a beast. He buries me every time we're on the same group ride.


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## Cotharyus (Jun 21, 2012)

Skorp said:


> Cotharyus and edubfromktown what gears did you end on then?


29x2.25 Ikon/Crossmark combo on the bike, I'm running 32/18 with an oval wolftooth front ring. I've run the same with a 32 tooth round ring. Most climbs in my area are short punch climbs rather than long grinders.


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## chazpat (Sep 23, 2006)

I don't have a choice as my SS uses the magic gear ratio so it's 36:18, 26er with 2.3s. My climbs are also mostly short punchy climbs, and I very often have to stand up and pedal to make it to the top. I've been thinking about getting a 29er with sliding dropouts so I could make it a bit easier on myself.


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## mtnbikej (Sep 6, 2001)

I find the most hardcore SS rider on my local trails....see what they are riding...call them a wuss and run 2 teeth more on the chainring. 













Actually, first time out is a guesstimate. Pick a gear and try it out. Where and how far you ride is most important. For me personally, I gwar mine for hours 6-10, where mileage is in the 50-80 mile area and climbing in the 7-10k’. I can run a harder gear for shorter rides....but I don’t believe in constantly changing gearing for different rides.


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## edubfromktown (Sep 7, 2010)

chazpat said:


> I don't have a choice as my SS uses the magic gear ratio so it's 36:18, 26er with 2.3s. My climbs are also mostly short punchy climbs, and I very often have to stand up and pedal to make it to the top. I've been thinking about getting a 29er with sliding dropouts so I could make it a bit easier on myself.


Glad that works but you do have "a choice". Some believe in mystical magic of chain stay length and a particular gear ratio. I just try different gearing to find optimal all around for the terrain that minimizes bailing on climbs. For the past couple of years, I run 36 x 18 on one of my 29er's and 36 x 17 on the other while others run something more spinny (34 or 32 up front).

Keep in mind that the ratios change with a larger wheel size- typically the "recommended" single speed starting point of 32:18 on a 29er is equivalent to 32:16 on a 26″ bike.


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## LonelyDwarfProd. (Jul 22, 2015)

When I was running 29" x 2.2" tires I was running 32:16 or 34:18. Now that I'm running a 29+ Krampus I'm running 35:21. Those seem to be good gears for XC/trail riding that doesn't have a lot of vertical but lots of quick up and downs, which is what I get in the Albany, NY area. 

When I head to areas with more climbing (NH, VT, ME), I will run a slightly smaller gear for the longer climbs, usually a 34:22.


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## chazpat (Sep 23, 2006)

edubfromktown said:


> Glad that works but you do have "a choice". Some believe in mystical magic of chain stay length and a particular gear ratio. I just try different gearing to find optimal all around for the terrain that minimizes bailing on climbs. For the past couple of years, I run 36 x 18 on one of my 29er's and 36 x 17 on the other while others run something more spinny (34 or 32 up front).
> 
> Keep in mind that the ratios change with a larger wheel size- typically the "recommended" single speed starting point of 32:18 on a 29er is equivalent to 32:16 on a 26″ bike.


I'm not sure we're talking about the same thing, my SS is a converted geared frame, vertical dropouts and I don't run a tensioner. This is the ratio that works without a tensioner, eccentric bb, half link, etc.; there is no way to adjust chain tension.


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## inclinelongboards (Jun 10, 2015)

I generally try to pick something that I can sit and pedal on a moderate grade and stand and mash on a steep grade. Currently that is a 34 tooth oval and 22 tooth cog on 27.5" wheels with 2.4" tires. I'm not weak, but I am pretty out of shape so I error on the easy side.


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## Raybum (Apr 16, 2009)

I've tried over time to quantify this choice...here's what I've come up with...all as a function of climbing ft/mile
50ft/mile = 34-18
100ft/mile = 34-18 sub 2 hour rides, 34-19 for recovery or over 2 hour rides
150ft/mile = 34-19 for sub 2 hour rides, 34-20 for over 2 hour rides
200ft/mile = 34-20 for sub 2 hour rides, 34-21 for over 2 hour rides

All on a 29r...
Those are my general rule that fits my current fitness. The ONLY exception to that is in a place like Sedona (for those that have been there)...the ups are often steep and techy, as are the downs... Seems you go from coasting to zone 7 power many many times.... And no where to really take advantage of a tall gear...


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## Raybum (Apr 16, 2009)

I should also add...if your goal is to get stronger, gear a bit taller for a few weeks and suffer a bit...then add one tooth in back for a week and you'll be amazed how much faster you are.


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## Drider85 (Jan 12, 2009)

I pick the average speed and cadence I hope to run and find the gear that matches off of one of those charts. 

The formula off elevation seem quite close to my experience. 

Races over 3 hours get 2 extra teeth in the rear.

Sent from my MotoG3 using Tapatalk


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## Shinkers (Feb 5, 2014)

Raybum said:


> I've tried over time to quantify this choice...here's what I've come up with...all as a function of climbing ft/mile
> 50ft/mile = 34-18
> 100ft/mile = 34-18 sub 2 hour rides, 34-19 for recovery or over 2 hour rides
> 150ft/mile = 34-19 for sub 2 hour rides, 34-20 for over 2 hour rides
> ...


I was poo-pooing these numbers in my head until I did the math.

I'm running your 200ft/mile ratio and that appears to be my typical ride after looking through my Strava.

Go figure! Nice work!


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## Skorp (Jul 20, 2009)

Raybum, ft/mile ratio is a PITA if you are using metric units!
Converted my last rides to ft/mile, and it seems like this could fit me when i get a month or soo more on my SS. 


Also, im using a really easy gear to have fun on tech trails, then the next ride on gravel i just run my trail gears spinning out at 23km/t


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## erichwic (Mar 3, 2004)

All depends on where you live too. I live in the northeast and ride a 32x19/20. My ride to the trails is pretty short so I just spin out. Some of the pitches are really steep and don't think I'd be able to go much taller than a 19.


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## j102 (Jan 14, 2018)

You guys are strong. But for a regular guy, what would make the climbs easier? Go smaller on the front gear or bigger on the back?
I do well with what I have now, only trying to understand which gear (front or back) makes the biggest difference for climbing.


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## Impetus (Aug 10, 2014)

j102 said:


> You guys are strong. But for a regular guy, what would make the climbs easier? Go smaller on the front gear or bigger on the back?
> I do well with what I have now, only trying to understand which gear (front or back) makes the biggest difference for climbing.


general rough rule of thumb is: 1 tooth on the back is similar to 2 teeth on the front. maybe the 'gear inch' numbers are different, but it's close enough for 'feet in pedals' comparison.

e.g from 32x20, you can go harder to 32x19, or 34x20, which will feel similar to each other.

Most folks don't swap front. pulling cranks sucks.
Buy a range of basic steel Surly cogs and pick what you think is best for that ride.

I personally keep a 32 oval full time, and have a range of cogs from 22 to 17.


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## mack_turtle (Jan 6, 2009)

Yeah, many of us use a 32 or 34t front and just change the rear cog occasionally. 32/20 just happens to be a good gear for me to push everywhere and it allows me to slide my axle all the way foward, so I have the shortest effective chainstay possible.


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## j102 (Jan 14, 2018)

ARandomBiker said:


> general rough rule of thumb is: 1 tooth on the back is similar to 2 teeth on the front. maybe the 'gear inch' numbers are different, but it's close enough for 'feet in pedals' comparison.
> 
> e.g from 32x20, you can go harder to 32x19, or 34x20, which will feel similar to each other.
> 
> ...


Thanks. It makes sense. If one had the choice to do one or the other, I thought that it would be better to install a smaller front gear (instead of going larger on the back) to make climbing easier.
We in South Florida don't have that problem. Even a 36T on the front could work for us. Other than the advanced sections in the parks, it is mainly flat everywhere.


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## Impetus (Aug 10, 2014)

j102 said:


> Thanks. It makes sense. If one had the choice to do one or the other, I thought that it would be better to install a smaller front gear (instead of going larger on the back) to make climbing easier.
> We in South Florida don't have that problem. Even a 36T on the front could work for us. Other than the advanced sections in the parks, it is mainly flat everywhere.


That's the point. Larger in the back will make it easier, the same as smaller in the front. 
The actual size of the front ring is irrelevant. It's the RATIO. But cogs are cheaper and easier to swap than chainrings. 
36x20 is so close to 32x18.... they're 1/2 gear inch different, few people could tell the difference by feel. 
36x18 and 32x16 are dead identical.

Play with this a while. 
https://www.sheldonbrown.com/gear-calc.html


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## eri (Sep 4, 2012)

Gosh. I just broke my crank, old one had a 34t chainring so I had a 23t in the back, I adapted and was pretty comfortable with that ratio. New one has 32t chainring. Well. I got to experience the rubbish experience of having a ratio that is just too low. Normally I can sprint and sort of fling myself at root sections while riding and sort of jump them. Jeese 32x23 just sucked, I kept skidding out and couldn't get enough momentum for the stuff I couldn't pedal up.

My other cog is a 20t, I'd never used it, now I have a reason. Well... what do you know... it feels like I'm riding ss again for the first time. Legs toasted. My old cadence is not possible, I'm blowing out my lungs. Today I... walked... a steep section that I haven't walked since the first week that I rode ss. But even walking I was only about 1:30 slower than my best over a 30 minute climb, and I set personal bests on other parts of my ride, that taller ratio is way more fun on the more rolling terrain.

I think another 5-8 days I'll have acclimatized and can do full rides again without feeling hamburger'd.

So, in conclusion: I think all the advice above seems good. If you aren't sometimes walking you should reach for a taller gear. I think I'd forgotten how the difficulty keeps things fresh and alive.

[edit]:

With the 34x23 I was good to 450-500 feet/mile for 90 minutes, past 500ft/mile I gassed out pretty quick and needed to walk.
The climb I quoted above is 500ft/mile and I bet I could make it if I had something to prove.


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## OldHouseMan (Dec 7, 2006)

Trial and error. This is something you will need to experiment with. Nobody will know your fitness, terrain or style of riding other than you.


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## j102 (Jan 14, 2018)

ARandomBiker said:


> That's the point. Larger in the back will make it easier, the same as smaller in the front.
> The actual size of the front ring is irrelevant. It's the RATIO. But cogs are cheaper and easier to swap than chainrings.
> 36x20 is so close to 32x18.... they're 1/2 gear inch different, few people could tell the difference by feel.
> 36x18 and 32x16 are dead identical.
> ...


Thanks.


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## waltaz (Oct 14, 2004)

OldHouseMan said:


> Trial and error. This is something you will need to experiment with. Nobody will know your fitness, terrain or style of riding other than you.


^^Only this

Sent from my iPad using Tapatalk


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## mr_chrome (Jan 17, 2005)

- I try to focus my gearing so that I can keep a reasonable cadence on the flats and slight uphill, after that, I try to stay seated on moderate hills and like to be able to climb steep hills without walking........I'm 55 so I use a 32/22 and it works for me........


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## Raybum (Apr 16, 2009)

I think the answer to the original question is "it depends"... my post above where list my gear choice in terms of ride ft/mile is based on my goal of covering ground as fast as possible. Sometimes that means HAB on steep stuff but overall, still faster. If you goal is having fun and cleaning all obstacles, those recommendations are not gonna work.


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## slowpoker (Jun 4, 2008)

Nm...


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## Pauldotcom (Aug 15, 2010)

I invite any of you folks running 32x18 to come ride with me at Bachelor Street in MA. You wont make it 1 mile without walking.


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## slowpoker (Jun 4, 2008)

Pauldotcom said:


> I invite any of you folks running 32x18 to come ride with me at Bachelor Street in MA. You wont make it 1 mile without walking.


And why would anyone want to take the wrong gearing for the terrain?


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## Pauldotcom (Aug 15, 2010)

Just seems like gearing is a "macho" fest in the land of SS. I ride 34x22 most or 32x21... No way some of you guys talking lower are riding in the North East.


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## slowpoker (Jun 4, 2008)

Pauldotcom said:


> Just seems like gearing is a "macho" fest in the land of SS. I ride 34x22 most or 32x21... No way some of you guys talking lower are riding in the North East.


I'm riding 34/18, daily. Nothing to do with being macho. I'm in southeast Alabama, not in the mountains. No....I wouldn't take this bike to your place.


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## Cotharyus (Jun 21, 2012)

Pauldotcom said:


> I invite any of you folks running 32x18 to come ride with me at Bachelor Street in MA. You wont make it 1 mile without walking.


I'd come ride with you there, but I'd try to bring gearing appropriate to the trails as well. Where I am I could run a 34 18 at a couple places, but I'd like a 32 20 at a couple places, and 32 18 works well at most places, so I suck it up where I could run something different, and there are a couple places I push, because I'm not to proud to do that instead of taking the time to change gearing all the time. See, we simply don't have mountains in middle Tennessee. Only hills.


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## J.B. Weld (Aug 13, 2012)

I live in the mountains and my friend crushes it with a 34/18, I guess he is kind of a macho man.


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## scottg (Mar 30, 2004)

Pauldotcom said:


> Just seems like gearing is a "macho" fest in the land of SS. I ride 34x22 most or 32x21... No way some of you guys talking lower are riding in the North East.


No Macho-Fest for me - I run a 30-20 (on a 29er). I do live in a place where the climbs get pretty steep, and the trailheads are very close though. I like to run a gear where I'm varying between spinning and mashing and have almost no walking. There are some climbs here that I'd never attempt though, as I'd be walking almost all of it. Whatever the gearing is, it's not appropriate for everyone - pedaling style and fitness are big variables.


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## JoePAz (May 7, 2012)

Pauldotcom said:


> I invite any of you folks running 32x18 to come ride with me at Bachelor Street in MA. You wont make it 1 mile without walking.


This year I ran 34x19 most of year. It is my standard gearing. I am in fact faster on smooth climbs on 34x19 vs 34x20. 24 miles and 2100ft of climbing at 5000ft 34x19. 22 miles and 2000 feet of climbing at 7500ft 34x19.

There is alot that goes into gearing selection including things like average speed, max speed, distance, terrain condition, elevation gain, base elevation, and profile. All of this are things to consider at any fitness/skill level. Of course the fitter and more skilled the bigger gear you can often run.


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## maximo (Nov 2, 2011)

Pauldotcom said:


> I invite any of you folks running 32x18 to come ride with me at Bachelor Street in MA. You wont make it 1 mile without walking.


Why so skeptical of others abilities?


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## milehi (Nov 2, 1997)

I run 34/20 everywhere. I never change it. I work for the climbs but flipping fly on rolling twisty singletrack.


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## Cotharyus (Jun 21, 2012)

Vader said:


> I run 34/20 everywhere. I never change it. I work for the climbs but flipping fly on rolling twisty singletrack.


Interesting. I've though about running a 34/20 because it's so close to (actually a little lower than) 32/18 to get the chain on more teeth.


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## BrianU (Feb 4, 2004)

Vader said:


> I run 34/20 everywhere. I never change it. I work for the climbs but flipping fly on rolling twisty singletrack.


Same here. I can hit a local trail 2 miles from where I work that is flat and twisty or drive 30 minutes to my favorite local trail, which has plenty of relatively short, steep climbs. For me, 34/20 works fine on both.


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## NordieBoy (Sep 26, 2004)

Tried from 34/20 to 32/22 in the hills here..
Flatter races might get me to 34/18 or 19.

Normally running 32/22 on a rigid 29er.
Shifted back into town and now a 10min warmup to the trails (was 20min).
Still struggling up climbs at max HR.


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## CObiker123 (Oct 13, 2014)

Running 32/20 on my 29er and can manage that everywhere I ride (with the occasional walk). To answer the question though I did two things, asked people that rode SS around here what they were running but also paid attention on a geared bike to where I felt I could stick with a combo. While not apples to apples, it got me in a good starting place.


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## arphaxhad (Apr 17, 2008)

When I was setting up my SS almost 10 years ago, i went out on my geared bike to where I do 95% of my riding, chose the gear where i could barely make the longest, steepest hill, and then chose the next hardest ratio. Settled on a 34x20. happy to say the today I can clear that hill lots easier:thumbsup:


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## OldSkoolMark (Jun 8, 2006)

scottg said:


> No Macho-Fest for me - I run a 30-20 (on a 29er). I do live in a place where the climbs get pretty steep, and the trailheads are very close though. I like to run a gear where I'm varying between spinning and mashing and have almost no walking. There are some climbs here that I'd never attempt though, as I'd be walking almost all of it. Whatever the gearing is, it's not appropriate for everyone - pedaling style and fitness are big variables.


30x20 29 inch wheels for me too.


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## OldSkoolMark (Jun 8, 2006)

Echoes of my other thread ... This one would be a lot more interesting if we didn't have to guess whether 32x20 etc is on 26" 27.5" or 29" wheels.


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## Jefflinde (Mar 26, 2015)

I made a choice to live in a state with basically no elevation change (MN) so i dont really have to make this decision. at most you have to struggle for a minute and then even the longest climbs are over. 

But this is what i am running with a 34 oval chain-ring
29x3 - 20T
29x2.1 - 16T - this is mostly for gravel and bike path
27.5x3 - 18T
26x4.8 - 22T - sometimes 20T if i ride really flat trails along the river.


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## rockychrysler (Aug 9, 2003)

Skorp said:


> Hi,
> 
> How do you choose your gearing?


Experience has taught me that, given the elevation and topography of my local terrain, I am happiest on a bike with gear-inches in the 44-46" range, depending on wheelsize (smaller wheels = slightly smaller gear inches... for reasons I am nonetheless hard-pressed to explain but which probably has something to do with gain-ratio (leverage) that one can achieve with a larger drive "gear" (rear wheel), or something like that).


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## KevinGT (Dec 25, 2012)

If the climbing is less than 125' per mile, I run 32x18. If it's more, I run 32x20. This is on a 29er and driven primarily by laziness.


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## Tom23133 (Nov 5, 2018)

Hi, right now I have a single speed bike for the street - a one like this 
https://locabikes.pl/kategoria/ostre-kolo 
and I use 46/16. I now want to buy a MTB bike annd turn it to MTB single speed and want to ride across fields and forrests. I think I'd go for 40/18. This should give enough speed on flat surface but also allow climbing some not very steep hills.


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## chazpat (Sep 23, 2006)

Tom23133 said:


> Hi, right now I have a single speed bike for the street - a one like this
> https://locabikes.pl/kategoria/ostre-kolo
> and I use 46/16. I now want to buy a MTB bike annd turn it to MTB single speed and want to ride across fields and forrests. I think I'd go for 40/18. This should give enough speed on flat surface but also allow climbing some not very steep hills.


40/18 would be extremely aggressive for a mountain bike. Realize that off road you will have a lot more rolling resistance unless your trails are just really, really hardpack with no loose at all or soft spots or roots or rocks. But it's impossible for us to tell you what ratio you need without seeing your trails. If your trails are that smooth, try riding your current bike and see how it does on the trails and try to get a feel for how much more help you need.


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## mack_turtle (Jan 6, 2009)

Tom23133 said:


> Hi, right now I have a single speed bike for the street - a one like this
> https://locabikes.pl/kategoria/ostre-kolo
> and I use 46/16. I now want to buy a MTB bike annd turn it to MTB single speed and want to ride across fields and forrests. I think I'd go for 40/18. This should give enough speed on flat surface but also allow climbing some not very steep hills.


40/18 is much harder than you think when you get on trails. I would shoot for something like 32/18 on a 29er to start and go from there. i know 40/18 sounds low, but when you're trying to pick your way through a rock garden or get a sudden burst of speed to attack a punchy climb, it's going to be way too hard a gear to work and you will end up walking a lot of trail.

I use a 39/16 gear on my cyclocross bike with a 32mm rear tire, which is mostly used on roads, some mellow singletrack, and gravel road races. I sometimes wish for a slightly lower gear.


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## BLUFF (Dec 23, 2013)

arphaxhad said:


> When I was setting up my SS almost 10 years ago, i went out on my geared bike to where I do 95% of my riding, chose the gear where i could barely make the longest, steepest hill, and then chose the next hardest ratio. Settled on a 34x20. happy to say the today I can clear that hill lots easier:thumbsup:


+1 I set the stop screws so that I couldn't absent mindedly change gear from 32 X 18 and rode for a week or two. As I got fitter I changed to 16 at the back. For me this was the magic gear on a 26er. Only then did I convert to SS.


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