MTB Stem, Spacers and Handling

This is the cockpit of a 2022 Specialized Epic Evo S-Works, size Medium. The bike comes stock with a 60mm stem, however that is a bit tight for me so i put on a 90mm stem (I bought this used and they guy had a 90mm stem that he used as well). Not only did i add the 90mm stem i also adjusted the spacers and went from 15mm of spacers above the stem to 15mm of spacers below the stem. I don’t like moving away from manufacturer specs because i assume they make the build with optimized handling. Anyone have any insight as to whether or not this will have a meaningful impact on handling on the trail? Thanks in advance.

Optimized handling for who? For what type of terrain? This is an easy one. You are well within the reasonable limits of how that bike might be set up. Ride it and see if you like. Experiment and find out what works best for you.


Yeah, there is no real “optimized” when you consider the range of rider sizes (overall height along with differences in torso, leg, and arm lengths) along with skills and preferences. One frame size can meet a range of riders and different stem lengths & heights are all part of the adjustment range I expect.

There can be issues if you stray to extremes, but broadly speaking… stem lengths within +/-20mm and anything up or down on a stock steer tube length is acceptable. Things can get interesting once you start looking into more extreme stem angle options, and then add in the ability to alter handlebar rise… so there is a large window in the X/Y coordinate system for where the bars can be in an “acceptable” bike setup.

Some people will deliberately size up or down on a bike to get their particular handling with respect to wheelbase length, weight distribution between wheels and other considerations. So “optimal” is a loaded word to a degree and something I’d ignore unless someone is resorting to rather odd solutions for fit and/or handling.

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Thanks for this, i was just worried that maybe i was going to the extreme with this new setup.

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Without knowing what bike you’ve moved from, I would say that a lot of people don’t try the “optimised” position that the manufacturers/designers intended.

90mm stem isn’t crazy, though getting pretty long for a modern medium.

I would say that it may be worth trying the lower bar position with the saddle further forward.

(This is all massively contextual, and if your previous bike already had a steep STA/you had the saddle forward on the rails there’s not as much change there. Some people can’t deal with the low bars due to core strength and/or arm strength/wrist soreness and these are all legitimate reasons for lifting the bars)

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I think you are well within a functional range. For reference, at one point I got a Trek Fuel EX in the 18.5" M/L size and put on a longer stem (80mm or 90mm) vs getting the “right sized” 19.5" Large with a shorter stem (70mm). Ended up with the same saddle to bar reach & drop so “fit” was identical.

But I wanted the shorter wheelbase and more weight on the front tire for the handling I preferred, so that down frame and up stem was the right move for me.

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Likewise, swapping out my 100mm fork for a 120mm fork rotated my front end, raising and pushing back my body, which had a huge effect on front wheel weighting… I ended up putting on a negative angled stem at a lower position to get my balance back.


Got the same bike and same size. It appears to me that you are trying to make the bike bigger and smaller at the same time! The longer stem will stretch out the cockpit, but the spacers underneath the stem will bring the handle bars back closer to you.

I don’t think there is necessarily an optimum setup here; stem, bars, grips, saddles, spacers, etc are items that a bike fitter will change to dial a bike fit in.

All I would say, is that personally, I would rather go with a wider handlebar, no spacers below, flip the original stem, so that it has a negative rise, before I went with a longer stem. Longer stems like this, has a negative impact on the bike’s off-road handling.


There is wide room for personal preference and bike fit here, but yes the trend since the 90’s has been shorter stem/wider bar for better control in rougher, steeper terrain. Longer stems have a “wallowy” feel IMO, it feels weird to me after a decade of shorter stems, and as a bonus - I can’t remember the last time I have endo’ed with with the shorter stem/wider bar setup.

Frames are being made longer in reach to accommodate a shorter stem. However – I have an Epic Evo and when researching frame geo, noticed that that the Epic’s reach is shorter than other bikes of the same general size, so if you are on the taller range for a medium, it makes sense that you would want a longer stem.

It’s totally fine to experiment - it’s not going to harm the bike in any way. Also, yeah, you might want to lower it a bit if you are looking to lengthen your reach.

Higher bars, or riser bars will make the bike feel more “poppy” - great for manualing or steep downhills, but not as ideal for XC racing and steep climbing.

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I am 5’10” at the top end of Specialized M. The stem that came with it is a 0 degree. You are right I felt the 60mm was short that is why I swapped to a 90mm.

Going from a 60mm to 90mm stem will definitely feel different. The steering won’t be as responsive, it will be harder to get the front up and over obstacles, and steep descents or drops may feel a little more sketchy. Whether you prefer this setup will depend on your preferences and the kinds of trails you ride.

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Pretty sure that the stem does have rise. At least the one that comes stock with the Comp model. I flipped and slammed mine, and went with a wider bar with less rise. That lengthened the cockpit significantly.

Probably right, i bought the bike used and the guy that had it before me used a 60 mm 0 degree stem.