3T Arx Pro II Stem. Flex?

Hi there! In the quest for perfect bike fit, I've come to realize that I should probably have a shorter stem. Shopping around I found one very good deal on a 3T Arx Pro stem (1st gen at around 40$CAD + shipping) and a wicked crazy deal on a 3T Arx Pro (2nd gen at 35$CAD, local pickup). Pics:

First gen
 


Second gen
 

Now for the second gen they've centered the faceplate screws and converted to a one-screw steerer tube clamp design. All this makes sense on the road (it's a road stem after all), but from a gravel grinding perspective, hardly seems like upgrades. I, checking in at 185lbs and intending to do some singletrack on my Private Jake (featuring oversized everything for stiffness), am worried that the centered bolts might induce some flex in the system, where the first gen stem really is just like an mtb stem.

Anybody got experience with those? Specifically, the second gen stem vs singletrack? Also, anybody got spare Torx keys to lend? The second gen stem has them all over [wtf.]

Thanks guys, cheers.

I have a couple first gen and one second gen. Good stems. I'm not sure I can definitively comment on 'flex' for either one. They get used on my two CX race bikes and I don't feel like there's anything lacking. I'm about 5-10 lbs heavier than you.

I had the same thoughts as you about grabbing a 2nd gen, but I haven't thought once about it since installing it. I *think* the Torx bolts may have been a better idea for their 'team' level stem that uses titanium bolts for weight savings. That's the only difference between the Pro and Team except for color (you probably already knew that). The ti bolts will round out way faster than the steel and the Torx make more sense. I don't like how the pinch bolt is a T30 while the face-plate bolts are T25. Then they probably kept the Torx bolts on the Pro because the Team had them. Personally, I think Torx bolts make more sense on a bike anyhow. If it really was an issue, you could swap out all the bolts with standard M4's for just a couple bucks at the local hardware store...especially since you have the chance to buy these stems at a crazy low price.

Aside from all that, I'm not sure 'stiffness' is a great goal for riding a CX bike on singletrack. That's your decision though.

i have one of those stems and can put out a decent sprint. flex isn't going to be a problem as long as everything is torqued to spec.

hex bolts are less likely to strip, so it is nice that 3t includes them imo.

Thanks for the input guys. I've had it for a couple of weeks and could indeed not notice any flex whatsoever even in road sprinting or technical singletrack situation. Very happy with my acquisition! Ride on, cheers.