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Light(est) 35mm clamp, 50mm length stem?

Udi

Udi

RM Chief Ornithologist
Mar 14, 2005
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What's out there?
Please keep in mind most brands weigh the shortest/lightest size (not what I want) so please only suggest something if you can link or provide a verified weight / scale pic of the 35mm-clamp 50mm-length specifically.

Things I'd like:
- 7075 alloy (will settle for 2014)
- Sub-140g, ideally 130g in specified size
- Wide-ish clamp with 4 bolts
- Full contact on steerer would be nice, no huge cutaway

I know there's plenty of decent options out there, but finding the weights is a pain.
 
toodles

toodles

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Aug 24, 2004
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If you don't mind a bit of rise (they don't do a 0º), the RF Turbine (http://www.chainreactioncycles.com/au/en/race-face-turbine-35-stem/rp-prod113265). I've got the newer Turbine R, but its 6061.

The Renthal Apex is 136g in 50mm x 35mm clamp and 2014 body with 7075 clamps.

If you can find a verified weight on the KS Ether it might be ok, comes with ti bolts and stuff but info on its weight is conflicting and dunno what alloy is used.

The Hope 35mm option is 136g and 2014 T6.
 
Udi

Udi

RM Chief Ornithologist
Mar 14, 2005
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- Pretty sure that Hope weight is for the 35x35mm, not 35x50mm
- Raceface also provide weights for the lightest length only, kinda misleading
- No dice on Renthal (seen too many broken)
- KS Ether is 149g in 35x50mm, even with Ti bolts, kinda heavy

If anyone's wondering, Syntace doesn't seem to make their stem in 35-clamp either, shame as it's a light option in 31.8.

Edit - Raceface Turbine R 35x50mm is 138g, though 6061 (thanks toodles).
 
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Jm_

Jm_

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https://ritcheylogic.com/wcs-trail-stem-35mm

I have this one in the 31.8 version on my AM bike. It's 2014 alloy. 130g for 70mm, so should be a few g less at 45mm.

It works well, I also have their WCS super-light XC one on my XC race bike, but that one is a bitch because of the tiny torx screws T20, not the usual 25, and how they are mounted, it's a b*tch to get your bar off, but the WCS trail suffers from none of that.

Haven't weighed it.
 
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troy

troy

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Dec 3, 2008
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Intend makes super light, and well tested stems. Not sure about 4bolt clamps and 35/50mm dimensions. Grace Trail is 31.8/50mm iirc, and all the 35mm ones has 35mm length as well. They are a bit pricey too (~150eur). Send them a msg, and ask, iirc they will introduce some more options in april.

 
iRider

iRider

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Apr 5, 2008
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troy said:
Intend makes super light, and well tested stems. Not sure about 4bolt clamps and 35/50mm dimensions. Grace Trail is 31.8/50mm iirc, and all the 35mm ones has 35mm length as well. They are a bit pricey too (~150eur). Send them a msg, and ask, iirc they will introduce some more options in april.

Click to expand...
These are for sure cool stems, but miss 3 out of the 5 criteria Udi was asking for: has a cutaway at steerer, not available in 35/50 mm (and won't be according to Cornelius on another forum) and is 2 bolt.
Cornelius/Intend was also asked if he would be making a Cannondale stem (1.5, 70 or 90 mm) and he was positive if he gets enough preorders for it that offset the costs of the testing. If I remember right it was somewhere between 30-50 units. So if you guys rally the troops and get that many together he might go for it.
 
troy

troy

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iRider said:
These are for sure cool stems, but miss 3 out of the 5 criteria Udi was asking for: has a cutaway at steerer, not available in 35/50 mm (and won't be according to Cornelius on another forum) and is 2 bolt.
Cornelius/Intend was also asked if he would be making a Cannondale stem (1.5, 70 or 90 mm) and he was positive if he gets enough preorders for it that offset the costs of the testing. If I remember right it was somewhere between 30-50 units. So if you guys rally the troops and get that many together he might go for it.
Click to expand...
Yeah, I know, that's why I wrote, to ask him directly, as he will introduce some new stuff in april. He does the fatigue testing at the same facility as I do, so it is a well tested product for sure. Those Grace stems were like sub 100g as well.
 
chris_f

chris_f

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Jun 20, 2007
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Intend is a sweet little company. If I had the coin, I'd probably run his DH fork just to test something different.
 
iRider

iRider

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I have two of his chain guides that predate his company. He was making and selling them on the side to fund university. Full carbon and wicked light. Not mine:
 
Udi

Udi

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Mar 14, 2005
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Unfortunately those single-bolt faceplate clamps are a total dealbreaker for me since I run pretty high rise bars (35mm rise SIXC) and it's annoying enough getting them through my similar design DM stem (which splits into left / right halves - I still have to hold the clamps expanded with a screwdriver to get them past the bends). Pretty sure using my bar with that stem would be impossible.

I really did put down criteria for a reason, most of them are non-negotiable, thanks iRider for paying attention to them. I know there are lighter stems out there but not many that meet all my criteria.

I also really need to see a specific weight in my chosen size (35 clamp x 50 length) for these suggestions to be useful - because for example most stem models that are available in both 31.8 and 35 clamp, the 35 is significantly heavier. The aforementioned Truvativ stem is 160g in the configuration I listed, and Hope is over 150g also. Both no good.

It's still good to see what's out there though, so thanks for sharing.
I found www.r2-bike.com is also great for seeing verified weights.

I've only found one stem that meets all my criteria:

Syncros XM1.5
137g in 35x50mm
Forged 2014
4-bolt faceplate, closed steerer clamp, cheap


Also shortlisted:

Raceface Turbine R
138g in 35x50mm
Machined 6061 (typo? regular turbine is 7075, emailed RF)
4-bolt faceplate, but open steerer clamp (fail)

Acros Popular
135g in 35x50mm
???? material (emailed Acros)
4-bolt faceplate, but open steerer clamp (fail)

I'd still consider those two since they're not total dealbreakers. I think I might have to give the closed steerer clamp a miss, just prefer them as less likely to twist on steerer in crash, but not many stems do that anymore.

I know nukeproof has a cool option in the works so I'm inclined to wait for that before deciding (plus waiting to see anything I missed).
 
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troy

troy

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Ritchey WCS Trail has an open steerer clamp and is 45mmlong, but it is much lighter too (60mm one weights 134g exactly - confirmed weight), so the shorter one would be even lighter):
 
Mo(n)arch

Mo(n)arch

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Dec 27, 2010
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The germans have a rather nice database for weights:
https://gewichte.mtb-news.de/
Eidt: irider was faster.


Raceface Turbine seems to be heavier then the weight you posted: 168grams
https://gewichte.mtb-news.de/product-13823/race-face-vorbau-turbine-basic
Or is there a difference between the „basic“ and the „normal“ model?

Raceface Atlas: 161g
https://gewichte.mtb-news.de/product-11459/race-face-vorbau-atlas-vorbau

Raceface Turbine 6 degree version: 144g
https://gewichte.mtb-news.de/product-9916/race-face-vorbau-turbine-35

What is the weight of the Sram Descendant stems? Shockingly, they are made out of 7075.
Just found it. Too heavy, about 160g
 
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troy

troy

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Dec 3, 2008
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Also, Thomson Elite X4 stem should be now available with 35/50mm option as well. Although I cannot find them in that spec on their website yet.
 
Gary

Gary

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@slimshady What brand is that?

Looks awfully similar to the RSP stem I run on my 4X bike. But that only comes in 31.8 as far as I'm aware.


It's nicely made, easy on the eye and stiff enough considering the (110g) weight. The thing I don't like about lighter stems like these is the small bolts they all use and the lack of gripping strength from all that material in the clamping areas they don't have. I'm using carbon paste on my steerer and bars to help with this.

While I'm here posting in a 35mm stem thread. Has anyone seen a shim (or other decent solution) that could be used to run a 35mm bar mounted light bracket on a 31.8mm bar?
 
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M

marshalolson

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May 25, 2006
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Jm_ said:
https://ritcheylogic.com/wcs-trail-stem-35mm

I have this one in the 31.8 version on my AM bike. It's 2014 alloy. 130g for 70mm, so should be a few g less at 45mm.

It works well, I also have their WCS super-light XC one on my XC race bike, but that one is a bitch because of the tiny torx screws T20, not the usual 25, and how they are mounted, it's a b*tch to get your bar off, but the WCS trail suffers from none of that.

Haven't weighed it.
Click to expand...
Running the 35mm clamp x 60mm length on my trail bike, and really dig it, fwiw
 
slimshady

slimshady

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Gary said:
@slimshady What brand is that?

Looks awfully similar to the RSP stem I run on my 4X bike. But that only comes in 31.8 as far as I'm aware.


It's nicely made, easy on the eye and stiff enough considering the (110g) weight. The thing I don't like about lighter stems like these is the small bolts they all use and the lack of gripping strength from all that material in the clamping areas they don't have. I'm using carbon paste on my steerer and bars to help with this.

While I'm here posting in a 35mm stem thread. Has anyone seen a shim (or other decent solution) that could be used to run a 35mm bar mounted light bracket on a 31.8mm bar?
Click to expand...
It's Daigoro, a local brand. I know the owner and I'm currently reviewing their 35mm cockpit kit. It's a generic stem he took from a generic factory in Taiwan. So far, digging it. It's affordable, plenty stiff, and I haven't had any issues once I clamped it hard enough to the steerer and bar.

The story on how he started the brand is funny: the guy wanted to buy two Surly bike touring frames and they refused to send them to Argentina, so he went to Taiwan to order some Moto stuff and ended up creating a bike brand.
 
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Udi

Udi

RM Chief Ornithologist
Mar 14, 2005
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Thanks, few more cool options being thrown around and great to see the weights for specific configs being looked up.

@Mo(n)arch there's a "Turbine" and a "Turbine R", and the regular Turbine came in a 31.8mm version in the past as well (that one broke, but I think all the new 35mm clamp ones are good). The one I gave a weight for is the "R", my buddy owns one and weighed it which matches the r2-bike claim.

I like that 6deg one you posted actually, for an extra 5-6g it'd let me ditch some spacing. I'm running a huge conical spacer at the moment (short headtube) and the whole point of this purchase is to switch to a higher rise bar and have a less ridiculous amount of spacing.

For the same reasom the AMS OM (and similar designs) won't work well for me, because they lower the bar height or need additional spacing to get to zero height.

The WCS Trail looks like a great option but I do wanna stick to my guns on the 50mm, bike is already a touch small for me. Shame they don't make that length.
 
Gary

Gary

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slimshady said:
The story on how he started the brand is funny: the guy wanted to buy two Surly bike touring frames and they refused to send them to Argentina, so he went to Taiwan to order some Moto stuff and ended up creating a bike brand.
Click to expand...
Those Surly guys are a bit out there. I met them outside a pub over here once. They'd flown their fatbikes from the States to take part in an 8 mile ride along a local beach to get ice creams. Sounds like they'd have got along great if they'd actually met your mate. :D
 
iRider

iRider

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Funny that nobody complained about the useless 35 mm standard that does nothing what 31.8 can't do besides creating incompatibilities. Further it came from the roadies, so even worse. Guess it was not SRAM that introduced it.
 
Gary

Gary

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iRider said:
Funny that nobody complained about the useless 35 mm standard that does nothing what 31.8 can't do besides creating incompatibilities.
Click to expand...
iRider said:
Funny that nobody complained about the useless 31.8 mm standard that does nothing what 25.4 can't do besides creating incompatibilities.
Click to expand...
iRider said:
Funny that nobody complained about the useless 25.4 mm standard that does nothing what 22.2 can't do besides creating incompatibilities.
Click to expand...
If only somewhere there were a place to complain about such serious concerns as these.
 
Sandwich

Sandwich

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May 23, 2002
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stems and bars are two places I don't care to save much weight. Have a thomson 50mm on my evil and outside of the stupid 2.5mm bolts, it's sturdy and I doubt it's going to fail. I appreciate your quest though.

FWIW I have a 35mm stem and bar on my road bike to try and reduce twisting, and the 35mm bar and stem on my diamondback HT is the flexiest bar I own. I'd stick with 31.8 until I'm forced otherwise, I guess.
 
Udi

Udi

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Mar 14, 2005
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Sandwich said:
stems and bars are two places I don't care to save much weight. Have a thomson 50mm on my evil and outside of the stupid 2.5mm bolts, it's sturdy and I doubt it's going to fail. I appreciate your quest though. FWIW I have a 35mm stem and bar on my road bike to try and reduce twisting, and the 35mm bar and stem on my diamondback HT is the flexiest bar I own. I'd stick with 31.8 until I'm forced otherwise, I guess.
Click to expand...
My weight target (130-140) isn't actually all that light, there are way lighter stems out there, some are posted here - but virtually all of them fail to fit my criteria, which I suspect puts us closer to the same goals than you think. My thread title is a bit misleading.

I didn't have a problem with 31.8mm either, but I switched to carbon on both trail and DH bikes a while ago, and it seems to make good 800mm carbon bars they need to use the larger 35mm clamp. I have broad shoulders and feel uncomfortable on less than 800. I use SIXC and it maxes out at 785mm in 31.8, to get 800 you need to go 35 (own both atm). They're super stiff though - maybe too much by some people's standards - no complaints there. I think you might just have a particularly flexy 35mm example?

Just for a laugh, @toodles here did break his Thomson X4 (31.8) stem, just from normal riding I think. But he used it for quite a few years so I don't think it was a fault of the stem. I guess everything can break.

I do have some heavier choices on my trailbike though (coil both ends, switching to 203mm rotors both ends) hence it'd be nice to keep the weight down where it's not needed. If anyone is interested, the SIXC 800x35x35rise bar is actually lighter than the 785x31.8x19rise bar (~220g vs ~230g), so that's kinda handy. I'm mostly changing for the extra rise.

Happymtb.fr said:
What does open vs close steerer clamp change?
Click to expand...
More surface area clamping the steerer so less chance of twisting stem on steerer in minor crashes. Probably not a huge deal on a trailbike (without a dual crown to "stop"), I just have bad memories of running Thomson stems on my DH bike back in the day (before integrated) that would twist on the steerer no matter how hard you did them up. I know this will go against troy's classic friction theory (friction shouldn't have proportionality to surface area, only the normal force), but it's my experience anyway.

I think some opening is okay but some stems have very little surface area against the steerer and I don't really like that. It's probably not a big deal though so I'm flexible on it.
 
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slimshady

slimshady

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jonKranked said:
The Paul Components boxcar stem would check your requirements except it's only available for 31.8 clamp. Paul is one of those companies they always have something in the works, might be worth emailing them to see if they've explored a version of their stem with a 35mm clamp.

https://paulcomp.com/shop/components/boxcar-stem/
Click to expand...
They announced the Boxcar in 35mm bar diameter a while ago, but it fails the rise requirement for @Udi :

http://reviews.mtbr.com/paul-component-35mm-boxcar-stem-is-a-beauty
 
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