I am still looking into singlespeeds and by the end of the year (if i'm fit enough) I would like to convert my bike.

It's a 29er, with a shimano 7-speed rear and a typical 44-34-24 front.

The ratio I'm looking for is something decent for offroad riding, but also enough to get me to about 12-15 mph on the road without spinning out. My comfortable cadence is 70rpm or so right now, I might be able to get it up to 75-80 later on in the year but that's about as high as possible for me in sustained riding (not a spinner).

My offroad terrain would be mainly dirt roads, light trails,medium hills, some wind, some potholes, and very occasionally some proper off-roading.

Is it too much to ask for SS or is it reasonable? Also, a question about fixed gear- I like the benefit of trackstands, chain braking, etc, but I do need to coast on freewheel bikes now and again, as well as occasionally off-roading. Does fixed gear sort of lightly move your legs along or does it feel as though you're still pushing pedals?

And finally if I do take the plunge, what's a conversion kit going to cost me? This has to include the tool to remove the freewheel/cassette since i don't have bike-specific tools anymore. And what about a flip-flop hub, one side for road and one for off-road? My rear wheel is quickrelease and has a disc brake which i would like to keep, but I'm open to options.

the easy way to find out which gear ratio you want is to try different combinations on your current geared setup and find a sweet spot. most off-roaders start with roughly 2:1 gear ratio (but with 26" tires) and adjust up or down according to their typical riding terrain. ultimately you'll have to make the decision whether you want to be able to spin at 15mph or have a gear low enough for some serious off-roading.

A ss conversion kit is around $20 online. figure a cassette removal tool will run another 10 bucks or so (been a while since i looked).

My Rig felt great with the stock 34/18, and that was on some fairly hilly singletrack. It spun out fairly easily on the road, but I don't doubt I could do 12mph (never really measured). Riding one ratio both on and offroad is never going to be pretty, but I think the 34/18 made for a decent enough setup.

Fixed gears not being able to coast has always been made a bigger deal than it really is.

When you are on a fixed gear, the only difference between it and a freewheel in terms of coasting is that your feet still move. However, you don't have to be applying force to the pedals. It helps to at least move your legs with the pedals while coasting' on a fixed gear, in order to not sap away some momentum by forcing the bike to push your legs, but it doesn't feel like you're constantly pushing the pedals either.

Of course, it depends on gearing going a decent speed down a hill is different in a shorter gear. In a tall gear your legs must move quick, but not that much out of the realm of your normal spinning technique, but with a gear like 34/18, if you're going down a hill on the road, then you'll be spinning much faster than you'd probably like. Giving the feel that the bike is 'pulling you' down the hill.

Personally, if you want something you can ride on the road and on the trails, I would think it would be better to have a different gearing for each, and carry them with you if you do both on the same ride.

For instance, for road riding using a 46/16 set up, and for mountain riding, use a 44/20. Bring the 20t cog with you, and a chain to accomodate.

Or if you aren't too picky about your chain, just do two master links and remove/add the necessary links as required.

Since you're not changing the chainring in the above example, you only need an axelnut wrench, a lockring tool and a chain whip. Which is something a lot of people already carry. And if you have a fixed/fixed hub, you don't even need the lockring/chainwhip, just the extra bit of chain and 15mm wrench for the axel nuts.

I have a Gary Fisher Rig (29er SS). It came with a 32/18 gearing which I love. When you factor in the 29er wheels that is the same as a 2 to 1 ratio with 26 wheels. I think it is a perfect all around ratio for the 29er.

^really? A 2:1 drive ratio makes me spin out a bit. I had it on the top chainring and 3rd gear today, haven't measured the sprockets yet, but that seems like my area of comfort. It's a bit difficult to offroad with it now but not impossible- I will probably get used to it as i train more. Renewed my love of singlespeed today, promised myself not to shift during the whole ride and suddenly was more aware of the bike and my surroundings- thinking about what gear to shift into really does temper the cycling experience.

Anyway, not much in the coffers right now- I could make a few bucks selling the derailers, shifters, cables, etc but I need the bike to work so that's out. $20 or so for a singlespeed kit doesn't sound bad, what about the chain tensioner for vertical dropouts? Also, does the tensioner have the same friction effect that the jockey pulleys on a derailer have or not as much? Finally what about a fixie conversion kit? Would I need a new hub/wheel or just a lockring and spacers?