Road Fan

That sounds like some sharp thinking!

bulgie 

Is it even still possible to get S3? I would have guessed stocks were depleted by now.

I semi-doubt it's possible to build a frame too flexible for a 115 lb woman, with commercially-available bike frame tubes. I would steer away from anything oversized. Unless you're a believer in "stiffer is better, any flex wastes energy" -- I obviously am not, I think there's a "right" amount of flex for each rider, that you should not go under. Stiffer frames are easy and cheap to make, so they boost the profits of the manufacturers. Then magazines, bloggers and other self-appointed experts repeat the "stiffer is better" mantra because they know which side their bread is buttered on. It's an easy sell to inexperienced cyclists. "17% stiffer than last year's model!" – as if that's a good thing.

My wife weighed 115 when she was racing. Won medals at district championships, road and track, so she definitely pedals hard. I made her frame with trad diameter (1" TT, 1-1/8" DT) and .6/.3/.6 walls. Frame weight a bit under 2.5 lb. She loved it. I tried to get her to complain about the flex but she said she wasn't sure if she was feeling any. When she did notice the flex was when she got on a crabon frame, a Madone -- she definitely noticed and hated the lack of flex on that one.

Back when pros raced on steel, a lot of them rode with a .8/.5/.8 TT in 1", even sometimes lighter, like Reynolds 753. Most of us can hardly imagine how much harder your typical pro can pedal, compared to us mortals. If I listed some of the guys who won TdF, World Championships etc on a frame with 1" .7/.5/.7 TT, you probably wouldn't recognize the names unless you're old like me, but suffice it to say they would have paid the weight penalty for a stiffer frame if they thought it would make them faster.

So basically, at 115 lb, 1" TT *is* oversized. I say just use the smallest thinnest tubes you can find. Of what's still made, I think Reynolds 853 still comes in a 1" TT, 1-1/8" DT and thinwall.

I'm an ex-framebuilder, a bit out of touch with current offerings, but someone here will know what the lightest available small tubes are.

Mark B in Seattle

unterhausen

I assume people still have S3 because TT gave builders a year to make a last order. But it's in private stashes. I agree though, superlight frames are fine for a 115 pound rider.

I also assume the OP got their bike since it has been 4 years

vespasianus

Tommasini's Fire Gravel is made with Spirit tubing and at 115 lbs (not kg, right?), that should be more than strong enough. In fact if you go to a good custom builder, ask them to make you a bike with good old fashioned "regular" tubing - basically not the over-sized stuff that is used everywhere now. Smaller diameter steel tubing is plenty strong (especially at your weight) and gives a nicer ride.

unterhausen

I feel confident the OP has moved on

vespasianus

Holy crap, I did not notice the date of the OP. Yeah, gone and we are forgotten.

guy153

Ain't that the truth. And now they've made the frames too stiff they're selling everyone on fat tyres and really long seatposts.