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Just swapped a beefy Nukeproof Neutron 50mm for an On One El Guapo 35mm, which has a narrower clamp and looks a little weedy compared to the original.
Does anyone notice stiff stems with wider clamps?
Depends on use case, I guess.
I'm sure Chris Hoy probably cared when he was churning out 2200 watts, not so sure your average weedy climbing roadies, with no upper body strength to trouble even the flimsiest stem, would care ...
Yes, although off-road it's more of a binary stiff-enough decision. I had an old 50mm specialized "enduro" stem that was just awful, swapping that made more difference than going from 32mm Sektors to Lyriks. It's odd because unlike the fork twisting it's hard to put your finger on what's actually wrong, just that you keep making 'mistakes' and crashing into things.
On road it's just a feel thing for most people, like the "vertically compliant laterally stiff" mantra, some stems are better at absorbing a bit of shock without being a twisty mess. Same with bars, you want a bit of comfort, but not so much that the drops move around while sprinting.
If you want an unnerving experience, fit a pannier rack and carry luggage that comes up to the bars. You can then see quite how much movement there is between the grips and the fork axle.
I do Molgrips.
I have had to send two well known UK stems back as they flexed too much which made the bars creak or marked them.
If you are a big guy with powerful shoulders and wish to ride hard, then flex matters. Too much flex and you loose control - some is good but when things get too noodley you have to go to 35mm bars and wide stems or even better braced bars like the Surly Sunrise.
I did on a 100mm carbon road stem when honking up 20% steeps, but not anywhere else.
I'll admit I rather like the look of the chunky Nukeproof one too!
I didn’t until I swapped from the skinny Specialized stem that came on my Levo, to a RaceFace Atlas which I already had.
From this:
to this:
Huge difference, even when riding flat turns in the wet! Bars were changed at the same time but I could really feel how the old stem had been twisting as I loaded up the bars.
I have had to send two well known UK stems back as they flexed too much which made the bars creak or marked them.
Which ones please so the big people amongst us can avoid?
What bars have you got clamped in there? I'll bet they flex and bend waaay more than the lump they're bolted into...
“What bars have you got clamped in there? I’ll bet they flex and bend waaay more than the lump they’re bolted into…”
It’s pretty easy to tell the difference between a stem twisting and a bar flexing - load both ends of the bar in the same direction and the bar flexes and a short stem won’t move. You can do this just riding along. To make a stem twist, push one end of a bar down whilst you pull the other end up. If it feels softer like this then the stem is twisting.
Not been an issue for me but I've haven't owned any really weedy stems. Most of mine are built similar to the Atlas above. Chromag Ranger (narrowest clamp I've had) Funn Strippa and Kore Cubix (narrow but forged box section the lightest/weediest I've owned). Even the Crank Brothers one I had was pretty solid with a wide clamp, the included bolts were toffee though so I'd steer well clear of them! The heaviest one (Truvative DH) was like a stock brick and just overbuilt for the sake of it.
Your bars can be pretty flexy though depends what you have got and how much flex feels right to you. I can imagine a weedy stem in combination with a flexy bars would be pretty weird/bad feeling and you'd know about it pretty sharpish on any decent trail!
I’ll bet they flex and bend waaay more than the lump they’re bolted into…
That's where the clamp width comes in too.
New stem a fair bit narrower than the previous.
Keep in mind that 20 years ago, 700 mm was considered a wide handlebar. Bars are now 100 mm wider than back then. It's also possible that the average user of this forum is a bit beefier than back then too.
Yes, i've had too stiff and too flexy, with the same bars, on the mtb, much less of an issue now with forks that actually work, and big rubber at low pressure. I'm also significantly heavier, so that changes things.
Had issues on the road bike with noodly stems in the past. But everything i've had lately has been fine. Never had too stiff, though most of what i ride is proper road stem length, 110-130mm, so that'll help.
It’s also possible that the average user of this forum is a bit beefier than back then too.
Why yes, I have been working out. Thanks for noticing 😀
To make a stem twist, push one end of a bar down whilst you pull the other end up. If it feels softer like this then the stem is twisting.
I'm not sure that's 100% accurate. The fork steerer, csu, bushings and tyre also play into twist along that axis as well, and are likely to contriubte a lot more flex than a stubby stem
I could only find one test, of roadie stems..
https://blog.fairwheelbikes.com/reviews-and-testing/stem-review/
that suggests a good stem flexes ~2mm (I think at the hand position) and a bad one ~4mm. A mtb bar is wider, so you might be getting more deflection, but an mtb stem is way shorter so will give much less deflection overall. My suspicion is a lot of this is placebo rather than any significant measurable difference
I love a wide faceplate, anything narrow just looks awful to me now, my Horizon stems just inspire confidence and you can feel the difference more when you revert back to narrower stem with same or similar bar, unnervingly so in some cases.
Another fan of the Nukeproof stems with wide faceplates. Had the Neutrons on 3 bikes until I found cheap Horizons. Original Neutron stem I used was originally on my 2018 Mega 290 I think.
Only negative is the bolts are so far apart I couldn't use the Exposure 'out front' light mount that puts the light central on your bars.
I didnt think it would make a difference, then swapped from a stock specialized stem on my stumpy evo to a Unite co one and the stiffness was absolutely noticeable. Especially so when I swapped back to the specialized one due to a warranty issue on the Unite stem (which they were awesome about and sorted quicky).
Those Nukeproof stems with the extra wide front? Gawd they is ugly.
I've got a 40mm Pro Tharsis, it looks sooo feeble (100g!), but really can't tell any difference myself. 31.8 too! What is wrong with me?? But then do I notice a 2.5mm Q Factor difference..? nope, 5mm extra length on cranks.. nope... 1/2 degree head angle.. nope... gawd I should give up and take up golf I am so crap.
Gawd they is ugly.
Incorrect. They're cool. I suspect the clamp width is a big factor in how well it holds the bars and perceived stiffness. I'll let you know when I've ridden the narrower one.
Renthal Apex - are those still classed as flexy? Ran a 70mm one on an XC bike a few years ago and didn't notice much flex.
Currently using a 50mm Race Race Turbine R 35mm and combined with the matching bars that setup was stiff enough to stop a speeding train. Had to buy some of those "compliant" carbon bars to take the sting out of things.
I don't thinkclamp width makes a meaningful difference. As long as the bar is not moving within the clamp, all a wider clamp is doing is reducing the leverage from the end of the bar to the point where the clamp starts. That does make a difference, but reducing the gap from 370mm to 360mm isn't massive in percentage terms
As long as the bar is not moving within the clamp
I think it will though, a bit - these things aren't machined perfectly and the metal flexes. That's why your bar/stem interface can creak - it's moving slightly. A wider clamp will make a significant difference there, because the lever applying the force is a fair bit longer. Old clamp was 63mm wide, new one is 48mm, so the same immobilising force on the bar is basically 50% more. Of course any deflection there is small but the leverage ratio applied by my arms is greatly magnified because the bars are so wide.
Incorrect. They’re cool
Nah, was such a moose, I only got £14 for mine on Ebay!
Well, 35mm is definitely the right length for me - transformed the bike, it's ace. But could I tell a difference in stiffness? No, not at all.
Quite possible that both stems are equally stiff though. Back in the day I had a Syncros F99 105mm stem that was alarmingly flexible torsionally even for the time when nice bikes were under 10kg. I could twist the bars several cm up and down just standing over the bike. No way I'd ride that now!
Does anyone notice stiff stems with wider clamps?
Loic Bruni does... hence why despite being sponsored by Renthal who started the whole trend off he refuses to use 35mm bars
“Renthal who started the whole trend off he refuses to use 35mm bars”
I’m fairly certain they didn’t - I think it was Easton who started the whole thing, and Renthal (like many others) were pushed to do 35mm to hold onto their OEM sales.
My patchy memory suggests it was Easton/Race Face (was it the same company then?) who started that nonsense.
Proud to say I've never had one on my bike - #31.8forlife
I think it was Easton who started the whole thing
The first 35mm bar/stem combo was launched by Deda Elementi in 2011.
I've been servicing my bikes ahead of riding again (I broke, not the bike this time!) And just replaced stem/bars on one bike. A stubby 7050 DH stem and some 35mm diameter carbon DH bars for my AM full-suss. This stem is 50mm across the front. A lot wider than my other stems, apart from the dual crown direct mount one on my Trail bike (68mm width)
The original, skinnier, 31.8mm 6061 stem on it had cracked (from twisting?) at one corner, around the stem bolt. Didn't trust the bars either after pressure there. All fit for the bin. Not like I'd been doing anything too silly on that bike, and I religiously use a torque wrench for virtually all of my bolts so doubt it was from overtightening. It ran a 130mm RS Revelation boost fork up front, that can take a 220mm rotor, and the stem was definitely exhibiting flex I could feel up front.
Theres no NHS where I currently am. I rely on Commercial Insurance and my current accident was a road accident, a pothole, riding to the shops and back. I think they'd have turned down coughing up (£3800 hospital bill!) as I was asked direct questions about how I was riding at the time. I'm staying clear of narrow 6061 stems from now on because I don't want to cough up for the medical bills and salary loss whilst off work.
Username checks out. Was the flex due to the crack perhaps?
I think clamp width could be important. You can see from this pic that the anodising has rubbed away already where the edge of old clamp was, so that's clearly where all the force was going.
"The first 35mm bar/stem combo was launched by Deda Elementi in 2011."
On a mountain bike?