[centurionomega]

I am building up a new bike and am wondering about flipping the stem. It is aluminum with 120mm length and +/- 6 degrees of tilt. On my other road bike I have the same stem length, but it is flipped to the -6. Sometimes on long rides my lower back feels kind of "stiff" but not really hurting, and I was wondering if my years require me to go more slack on my new build. Also, this is my first bike with a carbon steer tube.
My question is, will the +6 tilt drastically change handling, and will it cause the carbon steer tube to flex more over the -6 tilt.
Less importantly, I like the way the -6 looks over the alternative; it looks more like a road bike vs. a mountain bike.
I use my bikes for recreation/fitness only so a deeply aero stance isn't really needed.
Any input from each camp will be greatly appreciated!

 

[boarder1995]

I've got a 100mm +/-6 stem on my road bike. I don't race - just ride charity rides, etc. So, most of the year I leave the stem in the -6 position, but when I start "training" for the annual big 2 day ride, I flip it up. May not look as cool, but on that second day I'm thinking less about being cool and more about finishing in whatever small amount of comfort I can garner. Not only does the flipping up raise you, it shortens your reach as the head tube is angled back.

So, the up position doesn't negatively affect handling or add stress to the steerer tube as far as I can tell. It'll just make you look like a dork - just like me part of the year! I agree, I like the look of the down low position, but with a 6 degree stem, even in the down position, it'll still be at a slight angle up.

I just flipped my stem down this week and even lowered it one 3mm spacer down additionally to try out and will go out on a ride tonight for the first time down low in about 3 months.

 

[MerlinAma]

I've read where the stack height limit for a carbon steerer tube is 1". You should probably check the recommendations for your fork.

That being said, I'd try to achieve the desired bar height with the -6 position if you can get there within the stack height limit. Why not?

If you can't get the desired bar height this way, then you don't really have a choice. You have to go to the +6.

When I build up a new bike, that's the choice I've been faced with.

I think that's why some bikes (Specialized Roubaix models) have longer head tubes. You can get your bars higher without the stem having a rise.

 

[boarder1995]

I should correct something I said about flipping up and not only going up, but also having a shorter reach. This would also be the case if you leave the stem in the -6 position and use spacers to bring it up as Merlin has suggested. Nothing special really happens by flipping a stem other than going up along the angle of the steerer/head tube, just as spacers will do.

 

[centurionomega]

Thanks for the responses.
I definitely need to check on that stack height limitation. The fork is a Look HSC4, which goes with my Look 555 frame. I got the 57cm frame with a 180mm headtube. On my other aluminum bike I have all the spacers that I could manage; I only cut about 1" off of the aluminum steertube. So if 1" is the case with carbon steerers, it looks like I will have to go with the +6 for the stem.

 

[C-40]

spacer limit..

LOOK frames come with 30mm of spacers in addition to the 15mm tall headset top section. They don't recommend adding more. Looks stupid if you do.