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I am wondering if it is better to start to ride a fixie with a relatively low gear, and as experience comes, switch to a higher gear, or if the advised practice would be to start with a higher gear, and then perhaps change it to a lower gear.

I know you need to be strong to go uphill with a high gear, but you also need experience to go downhill fast with a low gear, so which would be considered more "expert"?

EDIT: I am not planning to ride on a track, rather on open road with rolling terrain and possibility of hills (not extra-steep, I care about my knees).

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  • Welcome to the site! Information about the terrain you ride might help folks give you a better answer. Sep 13, 2011 at 3:22
  • I'm wondering how there can be more than two answers to this.
    – user2410
    Sep 15, 2011 at 19:46
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    @rancidious - Because the why component of the answer changes, depending on who's writing the answer. Sep 15, 2011 at 19:48
  • There is no single rule, I ride 52/16 every day in central London. Each to his own...
    – user2518
    Oct 2, 2011 at 21:17

6 Answers 6

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As you've surmised, optimizing a fixed gear for either uphill or downhill has its disadvantages. If you're going to be riding a fixed gear on the street, you're likely best off starting with a medium gear. 70" is pretty common, though you can go a bit higher if you're in a predominately flat region. For climbing, get used to bailing out from pedaling to walking when you lose your momentum. For descending, use a front brake to control your speed to a point where your cadence is still smooth and not throwing you all over the road. With experience and training you'll be able to climb steeper and further before you walk and descend faster without having to lean on the brake as much. If you want to work on those skills separately, consider a freewheel singlespeed bike, where you can dial in a lower climbing gear and still coast while descending.

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  • Chosen answer for giving strategy to evolve while riding. I would also specially thank @Unsliced for recommending starting low and then going up. Sep 13, 2011 at 15:04
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In general I would recommend starting low. Your legs will go through an adjustment period and you may find that your knees get sore from a larger gear. After you've ridden for a few weeks pay attention to how you're riding. If you're in a hilly area are you struggling to get up the hills? Do you find that your cadence is regularly high enough that your hips are bouncing on the saddle? There are both indications that you should adjust your gearing high or low respectively.

It's can be cheaper to replace a track cog than a front chain ring so start with 16T in the back and then pick a chainring that gets you into the gear you're looking for. With any luck, if you do need to make an adjustment up or down switching the rear cog won't force you to change your chain length.

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If you have a normal derailleur geared bike you can use it to work out what gear would work out best for you if you only had one gear to use. Simply ride your commute in one gear without changing gear. Pedal on the downhills rather than coast and see if you can keep up. After this experiment is over you will know what size chainring and sprocket works for you.

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  • Good tips, I've already done this, although I think the weight difference of the bikes might influence a lot. Sep 13, 2011 at 15:00
  • Why do you think the weight difference would have much of an effect? It's not that substantial, and weight really only affects acceleration and climbing, not level rolling resistance. Nov 30, 2011 at 12:46
  • This approach worked well for me. My hybrid is significantly heavier than my fixie with gears/rack/fenders but still I but found that the top gear I found comfortable for commuting gave me a pretty spot on ratio to ride fixed.
    – Twelve47
    Apr 3, 2013 at 10:59
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Just to provide a little perspective, track bikes on velodrome run 81" (=48x16) at a minimum. This is used as a "warm-up" gear ratio and is considered very light. After the warm-up the gears go into the 90's for specific work-outs or competition. Generally speaking, higher gear ratios are used for solo time-trial events like the flying 200m where riders wind-up and max-out at a particular cadence. Lower gears are used for points races where riders need to accelerate often and modulate their speed.

81" is borderline miserable on the road if there are any hills or stop-and-go traffic. Anything higher is not practical on the road unless you're a dare-devil and are willing to ride through intersections without stopping or have legs like the incredible hulk.

I have a utility bike set-up as a fixed and it is 40x16 (=67.5"). This is low enough for hills and for trails but decidedly NOT a work-out bike.

A good practical range for the street would be high-60's to high-70's depending on your terrain and what you're willing to push. If you're new to this I recommend a high-60's ratio and set it up so that the rear axle is near the front limit of the drop-out. You can then get smaller cogs and experiment with higher gear ratios as needed. Swapping out cogs should be easy with a little practice.

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Which you choose will be affected by your physiology and the terrain that you'll mostly be using the machine on. If you've a smaller build, the more natural climber or the terrain is more hilly, you'll probably tend towards a lighter gear.

I tend towards the fast twitch end of the spectrum so I generally ride a heavier gear, but my terrain is pretty flat with only the occasional hill, so those two things match quite nicely.

If you're not sure, then I would suggest that you start light and get heavier - it's generally easier to spin your cadence up then to hammer your knees crunching along in a gear that's too low.

What you can do is have two cogs on the same rear hub, with different rings on so you could start on something quite light and then switch it to something heavier, e.g assuming you've something like a 46 on the front, you might have an 18 on one side and a 17 (or 16) on the rear.

If you do think that you're likely to end up with a heavier gearing then you would probably want to go with a larger front cog, e.g. a 48. It's a lot easier to change the rear than the front.

With due respect to @lantius I wouldn't start with a single speed and gravitate to a fixed, they are quite a different experience. If you want to ride fixed, just ride fixed. (To be honest, I've never really seen the point of singlespeeds, but that's not really an answer to a question, just an opinion!)

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  • +1 for "easier to spin your cadence up than hammer the knees in a too low gear". And thanks to everyone, you've been very insightful! Sep 13, 2011 at 15:03
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Answering my own question:

I have settled with 44 x 16, I can ride very slowly in moderate uphills and reasonably fast downhill. I'll keep using 700x23C tires, so that the bike is relatively light for slow uphill.

I think I would much rather go with a higher gear even having to walk uphill, because it feels dangerous to spin too much going down, and I always will have a front brake and I don't plan to skid.

It is important to mention that my other commuting bike is much heavier, so that I feel fine going slowly uphill with a high gear, because it is still easier than muscle my heavy bike up, even in proper gears: I end up arriving less tired with the fixie, because of its lightweight.

Thanks to everybody who answered!

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