Just wondering what a shorter stem will bring to the party really, 60mm to 40mm.

What will the advantages / disadvantages be please?

How long are your arms?

I can’t get on with any stem over 60mm apart from on a road bike. It just feels wrong to me, weight is too far forward or something. Long stems look crap as well which is obviously the main reason for a shorter stem.

A blog with some good points here

Also worth pointing out that it helps balance a wider bar.

I run 35mm stem 770 bar and it allows you to rescue you some pretty ridiculous situations on descents. On the ups the front likes to go in random directions.

Modern bikes are often being designed with a bit longer top tube to accommodate the shorter stem. With an older bike you might find your weight shifted too much to the rear.

Depends on the bike really.

It’ll make an XC bike very twitchy indeed, it might make an am bike feel teh awsum

a shorter stem will definitely make your bike cooler. But it might make it uncomfortable, or not.

change your stem to adjust your ‘fit’, not to change handling characteristics.

(yeah, it will make the bike feel a *bit* different, but you will get used to slightly different handling in about 5mins – making the change pointless, but you’ll never get comfy on a bike that’s 30mm too short)

change your stem to adjust your ‘fit’, not to change handling characteristics.

The effect on handling characteristics is at least as important as the effect on fit. A shorter stem increases control by making the steering relationship more direct (your hands follow a more ideal rotation around the steering axis – like on a car steering wheel – rather than being like a narrowboat tiller and swinging out and around). This makes it easier to catch slides and ride on the ragged edge.

There’s also a complex relationship between the self-centring caused by forward pressure on the bars (which decreases with shortening stem length or increased bar backsweep) and the flip-flop caused by slacker head angles. With a steep head angle a longer stem keeps the bike on track uphill but with a slack head angle that longer stem doesn’t give enough self-centring to stop the flip-flop beginning and then doesn’t give you precise enough control to bring it back on line easily. I think a very long stem (like 150mm+) might actually give a slack angled bike much better controlled steering when climbing but that would be horrible the rest of the time.

And I don’t know about everyone else but my arms bend at the elbow so I can happily ride with a shorter stem… You know your stem is too short when your knees frequently hit the bars.

I’m a convert to wide bars and short stems – both my AM and XC bikes have 785mm bars and 50mm stems, I’m pretty happy with the results although I’m pushing the limits of comfort with my AM bike. Any shorter and my knees would hit the bars.

chiefgrooveguru – Member

The effect on handling characteristics is at least as important as the effect on fit.

naah, change a stem by 20mm? – you’ll get used to the small change in handling in a few minutes. But you’ll never get comfy on a bike that’s too short (or long), even 20mm too short (or long).

fitting a 20mm shorter stem is not going to turn an xc race bike into a burly trail bike (or vice versa) if you want to fundamentally change the way your bike handles, get a different bike.

yes, the way a bike handles is important, but you’re not going to change that to any great degree by changing to a stem that’s 20mm shorter/longer.

it might well be that a shorter/longer stem puts you in a position to better handle your bike, but that’s not really the same thing.

I’m running a 90mm on my sultan with 740mm bars. Tried it with a 70mm and hated it.

I don’t particularly seem to have trouble descending.

naah, change a stem by 20mm? – you’ll get used to the small change in handling in a few minutes. But you’ll never get comfy on a bike that’s too short, even 20mm too short.

fitting a 20mm shorter stem is not going to turn an xc race bike into a burly trail bike. if you want to fundamentally change the way your bike handles, get a different bike.

Maybe you ride your bikes in straight lines and are more into pedalling than me? Maybe you buy into roadie-style ‘fit’? I believe that a 20mm change in stem length has more effect on handling than it does on fit, unless your bike is right at the upper or lower limits of reach or top tube length for your size.

The last time I checked I could reach further by bending more at the hips and straightening my arms more, or reach less by sitting/standing more upright and bending my arms a bit – and it only takes a few degrees change to compensate for a 20mm change in reach.

chiefgrooveguru – Member

Maybe you ride your bikes in straight lines and are more into pedalling than me?

i live in Sheffield; the peak district doesn’t really have any corners to ride round, but it does have bloody big hills, so maybe you’ve got a point…

Yep. 70mm stem feels totally different to a 90mm stem. Actually transformed the handling on the first 29er I rode.

Run a 35mm stem – made a massive difference when I dropped from a 50.

Steering is more direct feeling, particularly on tight switchbacks and with a wide (780) bar, stability at speed on rough sections is far greater.

There’s a very good video with Fabien Barel explaining it properly.

As for going for “fit” over handling, maybe that’s ok if you are into road riding or gravel track/smooth XC/marathon style events.

I consider a 90mm a really short stem 😳

Went from 90 to 50, wasn’t impressed.
Went from 50 to 60, was very impressed.

Obviously I was much cooler when running the 50

It looks like ‘normal’ bars vary from 5 to 12 degrees of backsweep. On a 750mm wide bar that equates to almost 30mm variation in effective stem length, so a 750mm wide bar with 12 deg backsweep on a 70mm stem will have the same steering response as a 750mm wide bar with 5 deg backsweep on a 40mm stem.

Obviously the backsweep and upsweep vary with how you angle the bar within the stem so there’s yet more variation possible… Note that with a very short stem and a very wide bar with significant backsweep you could end up running what is effectively a negative stem length – unlikely to feel great!

As for going for “fit” over handling, maybe that’s ok if you are into road riding or gravel track/smooth XC/marathon style events.

Fit is part of handling. A bike that no longer fits you won’t handle well because you will no longer be able to move your weight around properly. Maybe that’s OK if you only ever ride downhill and are happy pushing up because you can’t keep the front down/it wanders all over the place. You used to regularly see people unable to get up the smallest hill because they’d fitted some ‘on trend’ 3″ riser bars and now see people unable to move on the bike as they’re stretched so wide trying to hold onto 750mm bars with their short arms and narrow shoulders.

I’m 6′ 5″ so I’m usually riding the largest size available – to get enough space to move around on the bike I used to have to run 100mm plus stems. As top tubes have got longer I’ve dropped the stem length (and I run wider bars than I used to). I can’t say I’ve noticed a massive difference in steering but having the stem further away giving a bigger cockpit works for me.

andyrm – Member

…As for going for “fit” over handling…

i don’t *think* i’ve suggested that fit is more important than handling, i hope i’ve explained that in my humble opinion, you’ll do more to change the fit of a bike, than the handling of a bike, by changing the stem length by 20mm.

and if the effect upon fit is to make a bike uncomfortable, or to put you in a position where you find it difficult to work the bike, then it might not be worth the change in handling.

‘handling’ is affected by lots of things, most of them are not related to stem length.

example: the wheelbase of a bike is an important factor to determining how nimble/stable a bike feels, you don’t change the wheelbase by changing stem length, but you can give yourself a bad back.

fwiw i’m about to buy a 35mm stem to replace a 50mm. i’ve got a short torso, and i’m riding a 20″ frame with a long top-tube. Using a rule of thumb that i pulled out of thin air a few years ago: if you keep banging your knees into your shifters, then you might like a longer stem, but if you can’t bang your knees into your shifters, then you might like a shorter stem. i can’t reach my shifters with my knees, so i’ll be trying a shorter stem.

(it means i can put my 50mm stem on my wife’s bike, she’s got a 70 and has asked for something shorter. So it means i’ll have a few stems to try us both on)

I think its just best to try a few and see which you prefer.

70mm seems to be my particular sweet spot on both trail and xc bikes I have.

Isn’t the purpose of fit good handling at the end of the day?

But yea, handling is the sum of its parts, 60-40 could be good or bad depending on your bike, where you ride and how you ride it.

Try it and see.

It’ll no doubt give quicker steering, further back position on the bike, too far back, who knows. will make the front end wander more too.

change your stem to adjust your ‘fit’, not to change handling characteristics.

nah – shortening stem and widening bars makes a comparable fit to longer stem and narrower bars

for me it’s 100% about handling and feel, I run a 50mm stem on 785mm bars on a do anything HT. (45 miles of muddy bridleway XC yesterday, it worked fine)

I test rode a buddy’s Inbred with a 35mm stem, loved it, may try one on my Yelli.

also I find a nice side effect of bringing the bars closer is they can go lower

Nothing wrong with a short stem and wide bars but you can take it too far

I remember when going down to 110mm was considered risqué!
I have 45mm on the full sus and it’s great. However, I tried a 50mm stem on the Krampus and it felt really odd, so now have an 80mm Hope with 720 bars. Seems to give a bit more leverage on the big wheels.

Do you have a problem with comfort or handling that you may believe will be remedied by a shorter stem.

Are you looking for an excuse to buy a shorter stem as shorter stems are more fashionable.

Do you have some money mburning a hole in your pocket and you don’t know what to spend it on.

If you like riding up hills you will find it harder to keep the front wheel on the ground as you weight will be moved rearward and less over your front wheel.

If you like to push up and barrel down hills you may feel your weight is too far forward so would benefit from your weight further back so fit a shorter stem.
You may then feel a little cramped and your steering is more twitchy so adding wider bars, will slow down the steering and stretch your arms a bit so a little less cramped.

If you still feel cramped you will need a frame with a longer effective top tube to allow you have the shorter stem that enables you to push your weight back.

You may not be happy with your current bar width and find a wider bar more comfortable but find your steering slow so shorten your stem to try and speed it up.

The whole relationship between bar lengh, stem lengh and ETT should be tailored to suit fit and performance.

If set up is perfect for fit bit causes the bike to misbehave where and how you ride, its wrong.
If you bike handles every thing you throw at it but you feel it does not fit,then something’s wrong.

Stopped to eat my brekkie, now too long to edit.

Feel free to experiment but never suffer poor fit or performance in order to pull off a look.

went from 90 down to 40 just for comfort reasons apart from being cooler apparently I found it helped me old back and neck. steering was a lot sharper front will lift easily on steep climbs.

Going from 50mm/685mm to 35mm/780mm on the cockpit of my Enduro was one of the best changes I’ve ever made to my bike. No compromise in climbing, but so much more assured descending – comfier too

Losing or gaining 20mm off the stem is often the difference between two different sized frames toptubes, so it does have a major impact on fit.

Manufacturers seem very slow in adopting longer top tubes imo with the odd exception of Kona and Mondraker.

Even now, in most cases, if you want a long toptube you have to go a size up which is far from ideal, instead they waste time developing products no one needs (650b).

Still waiting for a proper, affordable 10-40 cassette, its about time they started giving us what we want rather than what they want to sell us.

All this ‘front end wandering’ on climbs with short stems is total rubbish.

Seat tube angle, chainstay length and BB drop are the only factors that effect steep climbing ability

^ yeah moving weight forward over the front wheel has no effect on stopping lifting when you’re climbing.

yeah moving weight forward over the front wheel has no effect on stopping lifting when you’re climbing.

It would make a difference if you were moving your weight forward but the fact is you aren’t.

Course you do.

The more of your body mass you have over the steerer the more of your weight you are going to put through the steerer and front wheel.

In the attack position you have contact with your bike at four points. But by moving you body around you distribute your weight to suit. The more forward your bars are of the steerer the easy it is to shift weight through your arms into the steerer and down through the wheel to the ground.

Think of the steerer top cap as the pivot point on a seesaw and then tell me the more weight you get forward of this point makes no difference .

No matter where your hands are positioned, relative to the wheelbase, it has very little effect on weight distribution, especially on a steep climbs. You can change the angle of your torso regardless of stem length.

It’s all about where 95% of your weight contacts the bike relative to the rear axle, the saddle (predominantly) and pedals.

The dirt bike guys worked this out years ago. It’s all in the mind.

I am not a physicist, frame builder or indeed a dirt bike guy so I readily concede I could be wrong ( wouldn’t be the first time ).

Your argument does make sense and I agree when designing a bike there are many factors with regard to angles and Tube Length that of course would effect a bikes ability to climb.

When setting my saddle fore and aft and indeed height I always set this in relation to the peddles as I have old knees on there way out, so I would not adjust my saddle to get me further or closer to the bars in order to adjust my cockpit.

So in fairness to the op,the question is simply if I took my bike and shortenend the stem would this make it harder to climb and or keep the wheel on the ground, I am sure you could design a bike with a shorter stem to climb better but would simply shortening or lenghening while all else stay the same make a difference.

My brain indeed tells me it does, but their must be a definitive answer and some one on here must be qualified to give it.

The whole ‘difficult to climb with short stem’ thing is probably due to people not modifying their position / technique after going shorter.

With a short stem and pedaling on the flat, you will naturally be in a more upright position. When you come to a climb you have to bend your elbows / put weight forward through the steerer and into the front wheel to negate wandering. This feels wrong at first but you soon get used to it, and the wider bars you should be using with a long stem open out your chest for more efficient breathing on long, sustained climbs.

Going back to the long stem however, pedaling on the flat you are already putting weight on the front wheel so when you get to a climb there is little to no need to change your body position. From my own experience, people going short for the first time seem to approach climbs still in the ‘upright’ position because they are not used to having to bend the elbows in the way required with a short stem.

From my own experience of going from 100-120 stems to 50-70 I’d say that most issues regarding ‘wandering’ front wheels are due to needing to learn a few simple body position changes. The benefits coming down (faster steering, the ability to pump the front of the bike harder) far outweigh this temporary inconvenience.

I 2nd the “just bend your arms a bit more and it’s all the same but better” approach.

This

It’ll make an XC bike very twitchy

in my experience is just plain wrong. Why would anyone like slow steering anyway?

Speeder – Member

Why would anyone like slow steering anyway?

you can be more precise with something that moves slowly?