Does Stem Angle Matter if Bar is in the Same Place?
 

I put 40 mm wider bars on my bike (400 to 440). Therefore, I am switching to a shorter stem to bring the bars back closer to me to account for the wider hand spacing. There are currently 25 mm of spacers beneath the existing stem. Using an online stem comparison calculator, if I use a 70mm 7 degree stem with the current 25mm spacers or a 70mm 17 degree stem with 10 mm of spacers, the bar will be in almost the same place. Since this is a bit of trial & error on my part, I'm not concerned about the couple of millimeter difference. For my current purposes, that's close enough.

My question is, if the bar ends up in essentially the same place is there any reason to use the 7 degree angle over the 17 degree, or vice versa? I'll be borrowing or buying a used/inexpensive stem to confirm fit first so if there's no preference between the angles, that will open up more inventory for me to look through.

Thanks!


https://cimg1.ibsrv.net/gimg/bikefor...00932eb97f.jpg

Your body will never know what stem you used. Getting your bars in the right place is all-important. How they got there isn't (unless strength or stiffness is compromised. (And in general, right location is far more important than stiffness unless you happen to be a track sprinter or the like.)

To me, aesthetically, a shallower stem angle combined with more spacers is more attractive.

As far as your position on the bike, either will work.

It doesn't matter but also depends on what sort of compression plug is in your steerer.
15mm + of spacers on top might mean the steerer isn't internally supported as well as it could be without cutting the steerer.
Then you obviously can't go back.
But I also can't see the need in changing the reach because of the extra 4cm bar width.

I'm still trying to get my head around what the OP is trying to do. He's attempting to get his new bar to sit in the exact same place as the old bar, for some reason related to reach. And to get his bar to be in the same place as the old bar was, he's changing his stem angle and spacers?

The flaw in this analysis is the stem reach changes when the angle is changed. Most stems are measured along a line through the center of the steering tube clamp and the center of the handlebar clamp. A 100mm stem in the -17 position should be 100mm long, but when flipped up, the horizontal length becomes 829mm. There are other stem calculators that show the change in reach and height, when a stem is flipped.

That said, most people just change one thing at a time. Change the bars, but leave the stem alone, since any change in reach is very small.

Except, if I'm reading the OP's graphic, what you're talking about is mentioned in the calculator graphic he posted (2mm less reach and 4mm lower stack) and he's already aware of this.

I do agree though that a change in bar width (assuming the bar itself's reach is identical between the wider and narrower bars) isn't worth worrying about. In fact, OP may have it backwards, IF the wider bar he's installing more closely matches his shoulder width, then the distance would be shortened from shoulder to bar, not made greater.

I'm curious what length stem he has at the moment (guessing an 80mm)?

Thanks for the answers regarding stem angle having no effect on handling, etc if the bar ends up in the same spot.

Good comment about the number of spacers above the stem. It currently has a single 5 mm spacer there. So if I were to lower it by 15mm there would just be 20 mm above the stem. This is an aluminum steerer & stem. It has a star nut inside, not compression plug. I don't see any issues there.

As for the questions above about why I want this, it's simply because I sat on the bike and know that I need it. While 40 mm greater width may not sound like much, and I agree in theory, the hoods/levers are now farther apart from each other which means in order for my hands to grasp them I am leaning farther forward. On some bikes that might not be a big deal; on this bike it was clearly noticeable. For test rides, I nudged the saddle forward a little bit and raised the post to keep the saddle-to-cranks distance approximately the same. That was fine for test riding. But since this is a gravel bike*, in the long term that saddle position makes it difficult to get my butt off the back for descending or light single track. And how do I know that? Because I test rode the bike on the roads & trails that I use.

I do agree about the aesthetics of a shallow vs. steeper angle. In a perfect world all stems would be parallel to the ground. But at the end of the day I'm just more interested in riding my bike. If a 17 degree stem angle keeps my bike from getting a Super Nice on GCN, then so be it. :D

* why post about a gravel bike in the Road Cycling forum? Because gravel roads are still roads, the answer to the question I asked has nothing to do with the road surface, and there's a heck of a lot more traffic in here than the CX/Gravel forum and figured I'd get a quicker response.

Thanks again!! :thumb:

Assuming that shoulders were 400mm wide, moving each hand out 20mm

would increase the reach about .4mm- about the thickness of a business card.

Might have to go custom for that stem.

truth

Again, I have a general idea of what I need because I actually got on the bike, made some adjustments, rode the bike, tweaked some adjustments, rode the bike, etc. I have no idea what the measurement difference is between the old and new set up because, like you, I assumed it wouldn't make much of a difference. I was wrong; it did make a difference. I did some general play with Pythagorean theorem, but in the end it's about getting on the bike and riding. But my measurements are probably no better or worse than your assumption that my shoulders were 400mm wide to begin with. I have no clue, so how would you?

No need whatsoever for a custom stem. Between length, angle and spacers you can get pretty much whatever you need (see my screen shot above from the stem calculator). I have never had a problem dialing in a good fit on my bikes - road, gravel, CX, mountain, owned/borrowed/rented. I've averaged 4000 miles a year since 2013, and was probably in the 2400-2600 mile range starting in 2007 (pre-Strava/RidewithGPS). I've never had issues on single day rides up to 200 miles, or multi-day rides in the 350 mile range. I have no doubt there are certain people and bikes that might require a custom stem (similar example: a friend had a custom bar made for his flat-bar gravel/monsterX bike because he couldn't find what he wanted; but even he will admit that had as much to do with "want" as it did "need"), but the rest of us can do just fine with off-the-shelf products.

The current stem is some generic thing (the bike is a house-brand from Performance Bike, the only visible printing on the stem is the torque spec). Using a tape measure with inches, I think the current stem is 85 mm which I know is an uncommon length. It's shorter than several 90mm stems I have lying around, but the tape measure has it longer than 80mm. But I could be wrong. It's a little tough to get a 100% accurate measurement while the stem is on the bike clamping a bar in place.

Anywhoo, you all can continue to armchair quarterback my measurements, wants, needs, and decisions. That's what we often do here. I do it too. In the mean time, I'm going to go play bikes.

Apparently I failed to select the irony typeface for my comment.

Good luck getting your fit dialed in.:)

Step angle doesn't matter. But as noted, reach will differ between two stems of same length but different angle. Go with whichever stem puts you where you need to be, regardless of looks.

Yes, you did. :o

In which case I apologize for my lengthy post. I just do find it funny when a simple question is asked (does stem angle matter if bar is in the same place?), that people will start telling the poster what they need/don't need far beyond the original question without giving the original poster a bit of credit for knowing what they are doing, and giving solutions without having all the data necessary to find a solution. (BTW, I see the same thing on music forums all the time).

Again, my fault for not catching the tongue-in-cheek nature of your reply.

This is Bike Forums. If you have to ask, clearly your basic assumptions/knowledge/experience is wrong. There are posters who step up regularly to point this out. Your diagram? Well that's in the category of your assumptions and knowledge so hence clearly wrong and to be ignored. (I'm a big fan of such sketches, being a ret. engineer.)

I sometimes post about things I've known work well for me and have for decades and observe the posts that will tell me how wrong I am. (A favorite - I never set my seats up level. Always nose down. Funny I never knew I had all the problems posters here tell me I have.)

Hmm.. you should probably seek out a fitter or see a doctor. Or you just are likely on the wrong bike.

:P

Thank you for the example. I rest my case.

Curious what site you were looking at? Looks like a handy tool.

Dave

If it was me, I'd simply try a new cheap stem with your current spacer situation and see how it works. You have a pretty good idea about what you want to accomplish. You realize that the stem calculator for angle and length that you've used probably won't hit your fit/comfort need exactly. So, why not just get a stem that you think will accomplish it? Like, same or similar angle but 5mm shorter or longer if you can find it? I'd do it while keeping the spacers below the stem, but that's my sense of aesthetics.

PS: I have used that stem calculator and found it a great way to visualize and approximate what I was trying to accomplish. But in the end, I just had to find a commonly available stem that got me close, but not exact.

I have also used the Specialized stem that can adjust angles with shims in the steer tube clamp hole. That opens up some subtle tweaking.