If you were to change your bike stem from a 100mm stem to 90mm stem, would you also slide your seat back 10mm assuming that the prior fit you had was dead on perfect?
Or would getting the smaller stem ruin the bike fit?
**Just a hypothetical question, assuming you don’t move your aerobar setup down or up, or adjust seat height…
I would say it is relative to your upper body position .
If your saddle is centered where you want it , whether thats behind the bottom bracket or in front of the bottom bracket I would say leave the saddle as is
shorter stem is usually to get less stretched out which depending on your fit your seat may be slammed way forward to compensate for the longer length stem
If your prior fit was dead-on perfect, why would you switch stems to go a single cm shorter?
the question is not entirely coherent.
if the fit you had prior was perfect, you would not change the stem.
if you did change the stem, your fit is no longer perfect, whether or not you move the seat back.
if your fit is perfect and you found a good deal on a super cool, lightweight stem but it is shorter.
pass
If you were to change your bike stem from a 100mm stem to 90mm stem, would you also slide your seat back 10mm assuming that the prior fit you had was dead on perfect?
Or would getting the smaller stem ruin the bike fit?
**Just a hypothetical question, assuming you don’t move your aerobar setup down or up, or adjust seat height…
A. It would disrupt your fit.
B. Don’t move your saddle back (this changes your effective saddle height and a lot of other fit variables). Road bike fit is much more forgiving on the front end (ex. there are lots of positions that the fit supports: hoods, tops, drops, etc.).
I found a great integrated aerobar, visiontech’s, but the stems shorter by 10mm… I didn’t know if it would ruin my fit on the bike, thanks for the input…
so the thing that makes that new integrated front end “great” is what exactly? the look? the weight? Do tell, I’m curious.
Ian
I found a great integrated aerobar, visiontech’s, but the stems shorter by 10mm… I didn’t know if it would ruin my fit on the bike, thanks for the input…
Just keep the aerobar position the same. The stem is irrelevant. If you maintain your pad position and width, forearm position and angle and hand position, you’re good.
Are you using Vision (non integrated) aerobars now? I would be more concerned with the changes that would be significant. For example, if you went from Medium Syntace C3 bends to uncut 290mm Vision R-bends, the stem length would be the least of your concerns.
-SD
I found a great integrated aerobar, visiontech’s, but the stems shorter by 10mm… I didn’t know if it would ruin my fit on the bike, thanks for the input…
Well in that case, the stem length isn’t the issue anyway. It’s the reach to the armrests and shifters (and maybe also to the brake handles out on the basebar is you spend too much time there). If you can set them up where the distances from the tip of your saddle to a given point on your armrests and to the shifter/hand position you want are the same, the stem difference is irrelevant.
might not
measure how far the elbow pads are away from the head tube
i think the vision elbow pads are swappable for a bit of adjustment fore-aft
I found a great integrated aerobar, visiontech’s, but the stems shorter by 10mm… I didn’t know if it would ruin my fit on the bike, thanks for the input…
if they fit you perfect the benefit is less adjustment hardware in the wind and nifty aero stem
so the thing that makes that new integrated front end “great” is what exactly? the look? the weight? Do tell, I’m curious.
Ian
SUPERDave … faster than a silver comet (or a Jackmott). 
Now I have a standard profile aluminum base bar and t2 extensions, they fit great, no complaints, but on my old tri bike I had visiontechs, with a 100mm stem, I liked them, and they’re more aero I assume, and I know that they fit, which is what I guess makes them “great.” I have a chance to buy a visiontech aerobar now but with a 90mm stem, can’t decide if I should get them or not. I was fitted for my bike and it fits great so I don’t want to ruin the fit, but I know the visiontechs feel good, and if they’re more aero then why not get them? unless the 10mm difference throws off my fit, in which case I’ll keep shopping around.
yeah, like the others have said in this case then you’re not simply swapping stems but the bars too, and since the different bar combos don’t necessarily position the pads the same then you can’t isolate the difference to the stem length. More variables at play here.
I’m not saying anyone is right or wrong here…this just highlights a situation that I see many in the triathlon community (and way too many here on ST) get themselves into: prioritizing something that seems more aero over something that fits perfectly. The OPer says he’s now perfectly fit but wants to change. I suspected that he wanted to change to a bar that looks cooler or may appear to have less drag - I still want to believe that position takes precedence over something that reduces drag by a very small amount and this seems to fall into that category.
Ian
I agree completely. I had one of the old vision integrated bars myself and the inability rotate the extensions up or down turned out to be a dealbreaker for me.
you’re right, I think I got excited about the opportunity for a great deal. i was thinking that since I used to own a set of visiontech’s before that they’d also fit my current set up. Thanks for the input, I’ve always valued comfort over looks, and will stick to that motto in the future.