Road Bike Stem Length effects on Handling

hi there,

i am looking at a shorter stem for my road bike.

on my MTB i am well aware of shorter stems making handling more twitchy, however, as one does not really turn bars as much or at all on road bike does it have the same effect in users’ experience?

i am looking at going from a 100mm to a 90mm or preferably 80mm but wanted to seek some advice on handling characteristic changes 1st

many thanks in advance !

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Yes, it’s the same impact generally speaking. It’s all about the rider hand position relative to the center pivot (headset). Hands closer to the pivot means it will take less arc length of hand movement to apply a a given steering angle. This is what makes it feel more lively to the rider. Less input to output ratio connection.

The effect may differ between Road & MTB due to the changes in actual bike motion, but shorter stems still lead to more “fast” steering. Whether that’s a problem or not is individual to the rider, the bike in use, and the actual use case.

Another impact here (assuming same bars in use, pulling the rider’s hands rearward) is the fact that weight distribution to the tires is also affected. Having a proper amount of weight on the front tire is necessary for general balance, but also the feel and control when cornering closer to the limits of speed and traction. Shift too far rearward with shorter cockpit, and you may lack weight on front tire compared to a longer setup.

80mm works and I have used for some riders, but that is usually on 56cm bikes or smaller and I note the handling concerns with the rider. Often, we are using these shorter stems with a comfort focus, and they are fine accepting the handling changes.

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Just adding to Chad’s excellent feedback that it might also impact the pressure points on your body (more weight on the saddle or hands, for example) so be on the lookout for sudden changes that lead to knee, hand, elbow, butt, or neck pain.

Whenever I change stems, I find that at first my turns can be a bit choppy, as I learn how to apply pressure to the bars and smooth my turns out.

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Hi Chad - you’re such a founatin of knowledge

Steve at specialized recommended a shorter stem (post bike fit ) for my 56cm tarmac sl6 as i sitting on the nose of my saddle with out it all the way forward - i feel way better when climbing with hands-on bars close to stem and can produce way more power - i feel 100 to 90 would not be quite enough of change but am concerned 80mm is quite drastic - or do you think 80mm is acceptable for 56cm frame ?

i have much longer legs than torso which creates the issue

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  • So, when you slide your hands back on the bars, you are sliding back to a proper position on the saddle?

  • If so, and you are happy with that precise saddle location (what I call the “motor” part of the fit from the hips to the pedals), then shortening the effective reach can make sense to get the right upper body position and feel.

  • An 80mm stem on a 56 race bike like the SL6 is not typical, but can work. Keep in mind that talking about just the stem ignores 2 other factors in functional reach. Handlebar reach and hoods both add up with the stem. Not all bars have the same reach, and presumably the stock SL6 bars have a reach in the 90-110mm range. And I have no idea what the functional values for any of the various hoods actually are, just that they vary and even models within a brand may have a different “hood reach”.

  • All that said, 80mm might be ok, and I tend to use a 90mm for my 56cm bike since I have long legs and short torso. You can probably make the 80 work fine, just know it will feel different than the 100mm generally speaking.

  • But despite the shorter than optimal stem in theory, the reality that you will more likely now be more comfortable and have a proper grip on the hoods, along with proper position on the saddle is a win in my eyes.

  • Totally anecdotal, but for the many times I’ve put a relatively short stem on a road bike to meet a fit preference, I’ve never had someone come back and say the bike was sketchy or scary to ride. Might be that I warned them sufficiently that they knew what to expect OR there is not that much functional difference in the end for some people to notice / ignore.

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This is the case for me. I switched from a 100mm to 90mm and there’s no difference I can tell. I will say my Lauf is a pretty long bike anyway so it’s pretty stable so I’m not sure 10mm would make a dramatic difference.

I wonder if it’s dependent also on a rider’s riding style. I can’t say I’m a particularly aggressive rider so I’m not sure where I would notice any sort of twitchiness from a 10mm switch.

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10mm down from 100mm is a relatively minor change. 100>80 as above is greater from a percentage standpoint.

Add in the difference in what I presume is a slacker head tube angle and longer wheelbase on your Lauf vs a steeper and shorter race bike like the SL6, and there would likely be a “feel” difference even if the stem length change was identical. One is a very “stable” bike in general while the other is more “lively” from the geos.

And as you mention, how the rider actually uses each matters. If someone is railing descents with harder corners at high speeds and dealing with crit-like direction changes, it might be a bigger deal to cut a stem like this. But for those with a more casual and less “racy” use, I know my customers have had no complaints on the handling side. Most are more than happy with the fit change for comfort that the handling is either a non-issue or something acceptable for the ride improvement.

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Agree. My bike is definitely about stability. Somebody described some of the modern MTB geometry making the bike like a limo. Long and stable. But turning not exactly snappy. I think that applies to my gravel bike as well. But for much gravel one doesn’t need snappy turning. But I can understand it more for road

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hi chad thank you!

1 - yes - when i have my hands on the bars not hoods things feel right power production wise
2 - i have upgraded to easten ea90 aero bars but they have same reach on hoods
3. i might try 90 and go from there in which case - TY
4 & 5 good to know - worst case i might order both sizes to try and return one - thank you ! i was just UNSURE if 90mm from 100m would make that much difference or not

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For whatever it’s worth, a quick Google search shows a reach on the Easton bars of 80mm. You could go for a bar like the Zipp SL 70 with a 70mm reach, and avoid shortening the stem to bring the bars back.

Also, BikeFitJames on Francis Cade’s YouTube Channel has some good tips about setting initial bar rotation and hood position on the bars in order to maximally reduce or mitigate a slightly-too-long reach without changing much of the components.

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  • Six to one, half dozen to the other. Meaning, the end result of the rider position will be essentially the same with your proposal (shorter bar reach with existing stem).

  • I find a bar swap to be more of a hassle since moving controls and wrap is more work than a simple stem swap that takes mere minutes. A stem (or two) may also be less expensive but it depends on the ones compared.

  • And considering that he already swapped to a new set of bars vs stock, I’d be inclined to keep those and just do a stem change.

All good points, and from a source more knowledgeable than myself. In all honesty, I sometimes feel that my tendency to favor a longer stem over a longer-reach bar is likely typical cyclist’s vanity… :thinking:

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Dude… you are so right on the vanity side. I get plenty of people coming in asking for a more comfortable road position, but it’s funny when some of them scrunch their noses as I show them upturned and shorter stems to meet their request :stuck_out_tongue:

Some want the slammed pro look with cruiser bike comfort… this is in the “you can’t have both” type of scenario. But you are totally right in that some people will prefer the newer solution of short reach bars with a longer stem. As I said, the final position can be identical, but the looks can sure differ.

I get a fair number of people that bring in older bikes, with the REALLY long reach bars of old. I am super into changing those as a first step in cases like this as opposed to a stem swap. There can be issues though, as the hoods from that era had shape and mounting setup different from more modern stuff. So mixing old and new can lead to some interesting results as well.

I am not the hard sale person like my boss, but there are times when I have to honestly tell the customer they are better off abandoning the current bike for something new and more appropriate. Some bite, while others insist on tweaking what we have already. I do whatever they want within reason, so there are MANY ways to get it done :wink:

thanks so much for all the wisdom - its such a joy to learn from you all

went for a 90mm stem and will see how i go - i might consider 0 offset seatpost but seems a lot $$$ for 2mm !

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  • That is a whole 'nother can-o-worms. You never mentioned considering changing saddle position.

    • Are you really talking 2mm or 2cm (20mm) delta?

    • Are you currently maxed out on forward position of the saddle rails in the seatpost clamp (presumably a 20mm rearward offset?) , and wanting more forward saddle position?

    • What is driving this consideration? Power over the pedals or rider reach to bar issues?

Sorry for the new questions, but saddle position is a new factor you didn’t mention above.

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more position over pedals - saddle is already all the way forward

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OK, then in my person fitting process order, you have the cart before the horse.

  1. Get the rider position on the saddle dialed. Do this to whatever preference is appropriate, but essentially lock this down to “set the motor” like I referenced above.

  2. Then and only then, start addressing reach to the bars. Adjust bar and stem setup to reach the desired goal.

IMO, chasing a front end setup before dialing in the saddle is a bit out of order. If you are really only talking 2mm as the desired change to move forward, a new post sure is spendy. But if you are looking for more than 2mm change, I’d consider that change more essential and address that first, then do bars/stem.

In reality, there is a bit of give and take here where sometimes we hit bar stuff first, especially if we anticipate major changes, but getting saddle position close first is usually best.

hi chad - in my fit we got the saddle position dialed - my issue was that in my new position - sitting in middle of saddle - reach of the hoods was a touch too far thus the need for a shorter stem - hope that makes sense

OK, then if the saddle is dialed, I don’t understand the mention of a possible swap to a zero offset post.

I have an 80mm stem on both my road bike and gravel bike. I’ve never ridden either with a longer stem, so can’t contrast on handling characteristics.

But I’ve never once had the feeling on either bike that my steering is twitchy or sketchy. And I feel perfectly comfortable descending all the paved and gravel roads in the area around me.

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