Singlespeed & Fixed Gear - Lighter Bike, raise gear inches?

a friend of mine just put his Major Taylor together this week. i took it for a ride yesterday and i must say that it is a world of difference from my road conversion. at a little over 14 lbs, the MT is a fast smooth ride. i was expecting a bumpy, sketchy ride because of its aluminum frame and track geometry. i found it to ride smoother than my road conversion but i didnt really notice all the negative quirks people say about riding track geometry (it does have track geometry, right?)
im building up my soma rush now with choice parts, being a bit of a weight weenie here and there. im thinking about increasing my gears to 44x15 because the bike is going to be a lot lighter than my centurion fixie. i currently ride 43x16 fixed. that major taylor was geared at like 46x16 and it was a sinch on hills.
does anyone do the same with their lighter bikes? i commute on my bikes, so im wondering if i should just stay in the low 70's...

the centurion will be my winter bike.

according to cannondale's website, the major taylor has a headtube angle of 72.5 degrees for the smaller sizes (48/50), and 73 for the larger ones. compared to my older cannondale's head angle of (i think) 74 degrees for a 48cm frame, i'd have to say it's kinda slack. depending on the size of yr soma, it's gonna have 74 to 75 degree head angle (i'm assuming you aren't riding a 49).

a friend of mine just put his Major Taylor together this week. i took it for a ride yesterday and i must say that it is a world of difference from my road conversion. at a little over 14 lbs, the MT is a fast smooth ride. i was expecting a bumpy, sketchy ride because of its aluminum frame and track geometry. i found it to ride smoother than my road conversion but i didnt really notice all the negative quirks people say about riding track geometry (it does have track geometry, right?)
im building up my soma rush now with choice parts, being a bit of a weight weenie here and there. im thinking about increasing my gears to 44x15 because the bike is going to be a lot lighter than my centurion fixie. i currently ride 43x16 fixed. that major taylor was geared at like 46x16 and it was a sinch on hills.
does anyone do the same with their lighter bikes? i commute on my bikes, so im wondering if i should just stay in the low 70's...

the centurion will be my winter bike.

I just came back from test riding a bianchi pista in 57cm (my size). I did not go to LBS to buy one, but to test out the bianchi geometry. I am considering a Soma rush and it has the same geometry (head angle, seat angle, fork rake etc) as the bianchi. What I found today was quite comforting. The bianchi ride was quite comfortable (at 74.5 degree head angle and 28mm fork offset). I did not notice any of the 'quirks' people talk about even though I was actively looking for any hints of instability. I rode slow, fast, made sharp turns etc. The only thing that concerned me a little was the toe overalp of about 5-10mm. Not a big deal. I made tight circles just to make sure it is not an issue. I am pretty much decided on soma rush. Modmon, what color did you get? Anyway, sorry for going on a tangent. As far as increasing the gear ratio is concerned, you can establish how much you want to increase by doing a little math. You should be increasing the gear ration in proportion to the reduction in the weight of you+bicycle. If you and your bike together weigh 180 lbs and you reduce the combined weight by 9 lbs then you can very well increase the gear ratio by about 5%, so that you will be applying the same effort while pedalling. If you are using different lenght cranks etc then instead of gear ration you want to concentrate on gain ratio, gear inches etc. (see sheldon's site). There is an assumption here that you did not buy any super aerodynamic parts (like wheels) which drastically reduce the drag, which justifies increasing the gear ratio even more. Also, notice that tires affect rolling resistance which has to accounted for.

thanks for that response, CTaco. i didnt even think about the tires he was running on the major taylor... they were probably stock, low resistance tires. when the rush is finally built up, it will probably have armadillos which ive heard are rather slow. im running a gatorskin on the rear wheel and a ultra 3000 on the front of my converted fix. it probably weighs 23lbs or something. i doubt that the soma will weigh 14lbs but im still thinking that 44x15 will work for commuting. i think ive kind of plateaued on my leg strength recently so a change might be good. hills will be fun...
on the soma, i got the black frame, 49cm. its a nice looking frame. headtube is really short. itll be another month or so till its finished. i bought the frame from a guy who has a shop that does online sales. found him on ebay, where the frame was up for auction. i got a good deal on it, imo, for what i could get at the time. in the end it was $375, matching frame and fork, shipping included. PM me if youd like information on the seller.

on the soma, i got the black frame, 49cm

heh. everything i just said about the soma is irrelevant, then (as usual). fwiw, i'm riding a 48cm (approx) 90's cannondale with a 46/13 gear and 23mm tires. dunno how much it weighs, tho...

heh. everything i just said about the soma is irrelevant, then (as usual). fwiw, i'm riding a 48cm (approx) 90's cannondale with a 46/13 gear and 23mm tires. dunno how much it weighs, tho...

my bad, its a 48cm, not a 49...