I guess I don't understand this. If you arm/torso angle is over 90 degrees, you would need a shorter stem to get it to 90, not a longer one. Your top tube sounds about right for your height, but I don't have a picture so who knows? I am going to make a wild guess that you are too stretched out now and you are heading in a direction that would make you even more stretched out. Lower back pain he we come. Been there, done that.

Try Franke's rule for stem length. Your tri bike stem length is right if it is just long enough that you don't have to worry about your knees hitting the back of you Syntace aerobars. The rest of the length adjust comes from aerobar size and handlebar selection. If you don't have Syntace aerobars, sorry, can't help you.

Please don't flame me as I am certain there are 83 body types for which Franke's rule gives the wrong answer.

Sorry - Had my angles backwards. My arm/torso angle is about 80 degrees (not 100).

You really should post a picture. 13 cm sounds a little long, but it is not absurd. I don't think you will have a lot of trouble just from having too long a stem. The trouble would come from being too far forward on the bike. Too much weight on the front wheel gets exciting when you descend. Yes, been there, done that too.

I am not familiar with your bike, but if you are riding at a much steeper angle than the bike was designed to accomodate, your effective top tube gets shorter and you might compensate for the fit problem with a longer stem.

I don't know if you are in that cycle, but it is something to watch out for. I would just buy both a 12 and 13 cm stem and try them. It will take a little while, but you will figure out if you have a problem. Just go to the top of a big hill with curves.

Seems to me I read somewhere that a stem over 12cm is not recommended for tri bikes due to placing too much weight forward (as the esteemed Mr. Franke states). Where is your saddle positioned? Too far forward perhaps?

BTW, how do you like the Caliente? I am close to pulling the trigger on one but am having a tough time finding one locally in my size to try out.

Mike

I wouldn't recommend anything over a 120 mm stem in most cases as it could cause some handling problems. It sounds like you're trying to get that theoretically perfect 90 degree angle but remember that the stem is just one part of the cockpit length equation. The bikes top tube length and the fore/aft position of your seat are the other parts. You can't change the bike top tube length so that means that you have only the stem length and seat to play with. Maybe you could max out to a 120 stem and slide your seat back on the rails slightly. If you're a long femur person the steep aggressive position may not be optimim for you anyways so sliding your seat back slightly and loosing a degree or so of seat angle won't mean anything.

It's hard to tell without a posted picture so I'm just guessing, but that's all I can think of at the moment.

The longer the stem , the less twitchy your steering will be, so if you go from a 110mm to a 130mm you will probably have MORE control... not less... And 130mm on a 57cm does not sound TOO large to me...



PS : just dont stretch yourself out TOO much...

Thanks, all, for your input. To answer a few questions: I love the Caliente, so far (only been on it about 60 miles over 3 rides). For tris, I went from adapting my 2002 Ciocc steel-frame road bike with aero bars to the Caliente. So far it's been a joy and I would recommend it. For the gentleman interested in a Caliente: What size do you need, and where do you live?

As for my position - sorry for not posting a pic. Perhaps later this A.M. I can do that. My saddle position is pretty much centered, which makes it 76.5 degrees. My femur is about 1" shorter than my lower leg, and the steep position feels great, and I'd like to keep it if possible. My only problem is discomfort in my upper body - namely my triceps (get really tired, fast). I noticed that if I slid my forearms forward about 2 cm (which put my elbows just barely on the edge of my aero bar pads, that my upper body felt perfect. I've taken some digital pics of me on the trainer, and angle-wise the move forward seems reasonable. Thanks for your input on the riding characteristic changes. I ordered an inexpensive 130mm stem to check it out...

As I glance over this thread again, I can't believe I didn't make clear the obvious alternative. Maybe you just need longer aerobars. Duh. That will slide your arms forward in the aero position as well. Duh. I generally like the aerobars as long as possible since I like my elbows rather than forearm on the pad. I am 5' 8", with a long torso. I took a shot at the large C2s, but they were a little too long, so I use the mediums.

Your seat angle can be determined by giving your saddle height as measured from the middle of the bottom bracket to the top of the saddle at the center and the position of the tip of the saddle to the center of the BB. Pass this along. You may not be at the seat angle you think.

"The longer the stem , the less twitchy your steering will be,"

That's only true to a point. A stem that is too short will give twitchy handling, but a stem too long will have the opposite effect and make the bike feel lethargic and unresponsive. The trick is to find that perfect balance.

Stems generally come in standard sizes of 70 to 140 mm. I tend to think that if you're using one at either end it it could likely be that you're on a frame that's either too large or small.

"Maybe you just need longer aerobars. Duh."

Make that double duh! Should have thought of it myself.

I don't need longer aero bars. Could I use longer aero bars? Probably, but I'd rather not ride with my elbows in the middle of the forearm pad.

You shouldn't discount that approach without trying it. It won't ccost much since you can resell the aerobars on ebay for basically 90 cents on the doller. I like my elbows on the pads. You might too. I would think it would be much better than a 13 cm stem.