Ok, so, let’s say I had a 15t in the rear, what would you put up front? This is for some poser asphault fixie, not a track machine. What thinks you? 48? 50?
Let’s put it this way, I ride 40k TT’s on 50x15 so you might want to go for a 48, 47 or 46.
Go play here and see what gearing would suit for your type of riding. http://sheldonbrown.com/gears/
wow, i’m 39-16 for commuting. Do you ahve knees of iron? these gear ratios these other guys are suggesting may be a bit much. try it out and see. If you get some of those speed links (kmc, et al) you can experiment. Or, do you have a road bike? Just use only that gear and try it. a fixie will have less drag so may feel a bit easier than the road.
Here in Boulder we ride fixies a bunch in the winter as a low-maintenance way to build strength. The preferred gear up here for rollers is 42x15, so that you don’t spin out under 35mph and you can still climb grades of 5% or more (up to about double that) comfortably and at speed. Some bring slightly easier gears, like a 42x17, some bring slightly harder.
It depends on what you are shooting for, high cadence training or strength. In my opinion, road fixies are for building strength through constant (obligatory) muscle tension. If you want a cadence workout, well, you probably already have the perfect machine for that. I find the urge to shift to a easier gear too strong to do overgearing workouts on my geared bike, and an hour on the fixie is like being on the trainer for an hour – it’s worth perhaps 30% more than the equivalent time on freewheeling bike on the road.
Last summer we put on what we hope will become an annual event, the Boulder Froubaix century. (Fixed-gear roubaix, a road race on mixed road conditions-- in Boulder, that’s dirt roads and some prairie singletrack). There was a cigarette break at mile 80 or so in order to best emulate the old-timey photos. That part is not recommended.
I’m just looking for a starting point. I need a front chainring, but not sure where I should start. Maybe I’ll start with a 46 and see how it goes… Not planning on stop and go riding like you would find on a commute, more of a wintertime diversion as I train for a double century in late April/early May.
Knees of iron - no. I don’t ride my fixie on anything other than rolling TT’s so I’m not doing less than 20mph. Hence the higher gear.
The fixie commuters round her are generally 42 or 44 by 15 or 16.
I was trying to suggest that the 50 might be a bit high, obviously I misjudged that 
can you just try some chainrings you already have? Or borrow some from the shop and tell them you’ll buy the size you need when you decide?
Good luck,
Dan
www.aiatriathlon.com
obviously you are a very experienced fixed gear racer. If I was only doing flat time trials I would use a larger gearing. If they guy is asking I am assuming a low exposure to riding fixed. You’re right that it all depends on your intended usage and fitness.
What’s the terrain you’re planning to ride? I kick around in a 42x17 most of the time, which is enough to get me up and down most of the steep & nasty stuff we have here in Vancouver. Not knowing your strength, experience and location, it’s tough to call.
In wisconsin here, not too hilly and I am trying to build strength. I am riding a 52x18 fixed and a 52x14 free wheel (flip flop rim). Tough at first starting out but it really rips the quads.
Ok, so, let’s say I had a 15t in the rear, what would you put up front? This is for some poser asphault fixie, not a track machine. What thinks you? 48? 50?
That would entirely depend on why you’re using a fixed gear (aside from the poser factor). For example, in the past I’ve used anything between 42x18 (for winter riding) to 55x13 (for TTing).
43x16 for my commuter. Pretty much flat all the time.
Start from a 42x17 or 16… with a 15T rear, that would equate to 37 to 39 chainring.
This since you’re talking about a poser asphalt bike.
I’m in Denver. I normally ride my fixie on the bike paths that are relatively flat. I’m geared at 49 x 17. When I do have to climb and there is a headwind, it is a bit of a push. I’m actually thinking of getting something like a 46 for the winter. I have a whole set of cogs but just one chain ring.
DB
48X17, I ride lots of short-ish power hills. I have it set up as a freewheel. I just don’t enjoy downhills on a fixed gear - E
their are some good riders on this site
I m not one
I ride a 42x16
dirt
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Ok, so, let’s say I had a 15t in the rear, what would you put up front? This is for some poser asphault fixie, not a track machine. What thinks you? 48? 50?
I’ve been riding a 48X16 on mostly flat terrain. It came on the bike and so I kept it. I’m a strong rider but not real strong. Sort of in the middle.
The fixed gear pushes you to ride faster so one option is to find a gear that’s challenging but not too much for you. Use your multi-speed bike to find a suitable gear combination. Use a gear chart or calculator to translate that to gear inches. From that you should be able to determine a size for your big ring given a 15t cog.