I am considering switching tri bikes and had some fit questions. I have been Fitted by both shops (different dealers) and there seems to be at, least to me, a large discrepancy in size. I am currently on a size 56. The sizing sheet that they gave me doesn’t really have a stack and reach on it. Its just the measurements that they used to build it. So I pulled this up from the ST database. I just wanted a sanity check from a third party that doesn’t have a dog in this fight.
There are the specs for my current bike (56) and the new frame (ML-H).
Size Stack Reach Wheel HS HT Stem Hbars SA Ft/Ctr 56 52.5 42.5 700C int 125 100x0 Low 78/76 612 ML- H 543 413 700C int 140
75-80
Am I worrying about nothing or does this seem like a large difference?
Thanks!
I am considering switching tri bikes and had some fit questions. I have been Fitted by both shops (different dealers) and there seems to be at, least to me, a large discrepancy in size. I am currently on a size 56. The sizing sheet that they gave me doesn’t really have a stack and reach on it. Its just the measurements that they used to build it. So I pulled this up from the ST database. I just wanted a sanity check from a third party that doesn’t have a dog in this fight.
There are the specs for my current bike (56) and the new frame (ML-H).
Size Stack Reach Wheel HS HT Stem Hbars SA Ft/Ctr 56 52.5 42.5 700C int 125 100x0 Low 78/76 612 ML- H 543 413 700C int 140
75-80
Am I worrying about nothing or does this seem like a large difference?
Thanks!
So if I read your list correctly the new bike you’re considering drops your pads a bit over one cm (525 - 413) and is shorter so requires a 140mm stem to achieve the same pad position vs the 125mm stem on your current bike?
Do the setups you have listed actually achieve the same position or are do the two fits result in different fits in terms of angles, especially in terms of cockpit length and how open or cramped you are there or how much shoulder angle you have in either riding position?
Personally I’d avoid a frame that forces me to a 140mm stem to achieve what seems to be a good fit. That’s pushing the limits on stem length so going longer won’t really be an option. But it’s hard to say if for instance the front end setups are very different and the 140mm stem compensates for your aerobar and pad setup or you’ve been fitted to very different seat angles or the 140mm stem is already a very long cockpit position that is more likely to be tightened up than stretched over time.
The stack difference doesn’t seem like a big deal as it’s easy to add a centimeter or more to pad height with simple things like thicker comfort pads or short tower spacers under the pads if you need to be higher and it sounds like you could go lower on either frame with a drop stem angle.
The big question is whether the resulting fits are actually the same fit or whether you’re comparing apples to oranges in terms of the final position achieved on these bikes. Hard to say since two fitters from two different shops, neither of whom seem to use a FIST system(or they would have likely given you the stack/reach info directly) may very well arrive at different fits.
-Dave