I'm still waffling between a 54cm or 56cm Specialized Roubaix or Roubaix Sport, both of which have the 1.5 future shock system. Various people have told me you can change the fit of a bike by adjusting stem height or changing out stem for longer or shorter versions. I know the Roubaix future shock is not actually part of the stem but is the stem of the Roubaix height adjustable and can the stem itself be changed out for a different model or is it a Roubaix proprietary stem? Thanks.

Yes, but those are relatively minor adjustments. If the 54 v 56 is the question, you need to go sit on some bikes. To illustrate, I have a 56cm Roubaix. I would not really be happy with a 54, regardless of what is done with stem or seat adjustments. Might work to get me from A to B, but it wouldn't be nearly as good as the fit with the 56 frame.

Yeah I posted quite a bit about it in another thread. I'm 5'10" and I tried a 56 cm Roubaix and a 54 cm Roubaix Sport. The 54 put me in a more upright postion which I liked and not that much more aggressive stance meaning the seat adjustment was not that much more higher than the handlebars for the 54 over the 56. I definitely like being more upright. But everyone I talk with seems to think at my height I should go with a 56 cm. I spoke with a professional bike fitter at a different shop and he says no way he would fit me on a 54. But as he mentioned there also is a lot of variances between the different bikes.

If choosing the 56cm Roubaix I'm saving $600 but giving up better wheels and going down to Tiagra vs 105.

I remember your other thread. I still don't understand how you would be sat more upright on a 54 Roubaix vs a 56 Roubaix. The stack height on the latter is 20 mm higher and yet the reach is only 8 mm longer. Last time I mentioned this you were comparing a different bike (Trek I think) against the Roubaix in a 54 v 56. Which is apples vs oranges.
Anyway if you prefer a more upright position and you are in-between sizes, the usual solution is to go for the larger frame and fit a shorter stem. Otherwise you will end up with a load of head spacers on the smaller frame (and the Roubaix is limited on stem height adjusment).

I would go back to the shop and try them both again.

I'm about 1/2" taller than you. I ride a 56 Roubaix. You can definitely change stems, but you need a Specialized "FutureStem".

On my Creo (similar frame with slightly longer wheelbase) I test rode both the 54 (M) and 56 (L). The 54 felt a little twitchy to me. I think I could probably have gotten used to it, but decided to go with the 56.

I previously rode a 56cm Diverge in 56. This was my first road bike. When I got a fit done, we went with a 90mm stem. When I got the Roubaix I assumed I'd end up doing the same, but maybe after a year of riding the bike I got more flexible or something. I never felt the need to shorten the stem on the Roubaix.

I'm not totally sure how you'd be more upright on a 54 vs. 56; handlebar should feel closer and lower on the 54. I'm also 5'10" and ride a 54 with a 110mm stem. However your body is different from mine so YMMV.

To answer the question, the stock stem is a proprietary Specialized one since the diameter of the FutureShock is smaller. You'd need to purchase their stem adaptor to use a standard 1 1/8" threadless stem. The way you adjust the bar/stem height is by removing the FutureShock and adding/removing spacers below the shock boot, then reinstalling; the stem will always sit on top. Its relatively minor and realistically 20-30mm IIRC you can play with before changing the stem angle and headset cap. In my set up below, I use a 0 stack headset cap, 110mm stem at -6 degrees, it's the lowest I can go without going to a different stem with more angle. Obviously you can flip/flop and adjust things to your liking.

Yes, my posts were a bit confusing. At the shop was the 54cm Roubiax Sport along with the 56cm Roubiaix. For whatever reason I definitely felt like I was sitting more upright on the 54 cm Sport. But maybe I need to go back and try them both again.

Since then I have borrowed my friend's 56 cm Trek ALR 5 gravel bike which he has outfitted to be more of a road bike. I felt the reach was uncomfortably long until I looked closer and realized he had a seat post that tilted back along with the saddle being pushed back as far as it can be on the rails. I slid the seat as far forward as it could go and it's better now. Still if I owned the bike, I would reverse the seat post if possible so that it sloped forward, not backwards. I can say the ride is more stable with this bike compared to my wrecked 54cm Synapse 105, I'm assuming because of the longer wheel base.

Guy I spoke with this morning says if looking for a bike now, I have to go with what the shops have in stock. Things it will be a couple of years before things are back to normal and they are just fulfilling orders placed a year ago. If choosing the 56 CM Roubaix should I be concerned about the Tiagra groupset vs 105? It seems like any bike costing $2600 should have 105 but I guess that is the tradeoff at that price point for having a carbon frame. The Roubaix sport is $3200. Neither is light change to me but the alternative is to live with my old but still reliable 25 year old Trek 7500 hybrid.

Your local bike shop is correct, you're up to the whim of whatever is available. My buddy at SRAM noted in June 2021, they're already sold out through 2022 in components.

Something to consider is that Tiagra is 10s while 105 is 11s; Tiagra is also heavier. As far as performance, they're very close. However if you can swing it, I'd go with at least 105 or Ultegra to keep with 11s. If you're a avid enthusiast, I think you'd appreciate the smoothness and reliability of Ultegra. 105 is great as well but I notice it isn't as smooth and light in action.

No, I'm not avid. I'm 58 years old and in really good shape but most rides top out at 30 miles, maybe average speed of 15, 15.5 mph (but hilly riding though). But my past two road bikes, both cheaper than the $2600 asking price of the Roubaix with Tiagra, had 105. However they did not have a carbon frame like the Roubaix and I've never owned a bike with a carbon frame.

If buying new from the shop, they really should swap the stem for you, especially at those prices. My shop swapped the stem and handlebar for me for free, though I supplied my own bars as they don't do exchanges on those.

​​​​​​At 5'9” I was between 54 and 56 on my Roubaix (2019 model year). I picked the 54 to have a lower position on the bike with the stem flipped, and replaced the Specialized Hover bar to lose even more effective stack. I've never regretted the choice, the only issue I've had choosing the smaller frame was toe overlap. I see how 54 could work for you if you leave the spacers maxed out and keep the Hover bar, but only you would know how upright is good enough for the position you're looking for.

I honestly think you'll like the ride quality from a Roubiax, given the FutureShock and carbon frame. You should be definitely fine with Tiagra; my concern in this trim is weight, in stock form I think the bike would be 20 lbs. If you're one to upgrade things, I'd make sure to find some decent lightweight wheels. The stock R470's are bulletproof but feels like a steamroller.

I'm with you that you'd think that anything going up to and past the $3k mark should have better components. However due to the pandemic and supply chain issues, the prices have dramatically increased. All in all, it seems like all bikes had bumped up $1000 vs. the previous year.

Went back to the shop and test rode the 54 cm Roubaix Sport and 56 Roubaix. I also rode a Sirrus 4.0. Both the Roubaix's rode much smoother than the Sirrus 4.0. I can't think the future shock can make that big of a difference, there must be other aspects to the bike design as well. Ended up buying the 56cm Roubaix. The 54cm Roubaix sport felt very quick to me, almost too quick. I could see myself looking down at the bike computer and ending up hitting a telephone pole. The 56 cm Roubaix was more stable.

One complaint is the brakes feel a bit squishy. They work but don't start grubbing until the levers are pressed hallway down. They start grabbing much quicker on my friend's Trek that I borrowed. I know there are hydraulics involved but is this something that can be corrected so the brakes can start grabbing quicker?

That all makes sense. Larger bikes are generally more stable - longer wheelbase etc. So no surprise there.
Smoother ride also makes sense on the Roubaix. 20 mm of front suspension + a flexible seatpost = smooth ride. It was designed specifically to race on cobbles.

Brakes may just need bedding in. I'm not sure if you can adjust the bite point though. You can on some brakes, others not. I suspect probably not in this case.

The brakes need to be bedded in. Take a few laps around the neighborhood and apply the brakes a few times while gradually increasing speed.

https://cyclingtips.com/2018/03/road...brating-noise/