FSA stem options - confused / advice needed

Discuss light weight issues concerning road bikes & parts.
stevod
Posts: 32
Joined: Tue Aug 18, 2015 8:09 am

by stevod

Hi,

I'm after a stem to match with FSA SL-K Compact 2019 carbon bars for my Cervelo R5. I'd like to use one from FSA to match, as the Cervelo 'Ultralight' alloy stem I already have is 182g! (100mm)

But... the SL-K 2019 is the heaviest one, and the cheapest option is the lightest! So perhaps there's more to this...

- SL-K 2019 ... 141g ... £100ish
- OS-99 CSI ... 126g ... £110
- Energy ... 113g ... £70

Any advice and experience of these much appreciated!

Cheers,

S

jfranci3
Posts: 706
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

Not FSA, but I've found the Scott / Syncros RR1.5 Stem (non-aero, note the non-std cap on both) to be clean/neutral looking and cheap. https://amzn.to/2UMB93Y They're probably 135g at that size, but only $25-50

by Weenie


stevod
Posts: 32
Joined: Tue Aug 18, 2015 8:09 am

by stevod

^thanks - prefer to stick with FSA though

whyamihere
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by whyamihere

The first two are carbon wrapped around alloy, with the alloy stem inside providing most of the strength. The Energy is just alloy, and good alloy stems tend to be lighter than carbon wrapped alloy.

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Dan Gerous
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by Dan Gerous

whyamihere wrote:
Thu Mar 21, 2019 7:31 pm
The first two are carbon wrapped around alloy, with the alloy stem inside providing most of the strength. The Energy is just alloy, and good alloy stems tend to be lighter than carbon wrapped alloy.
The SL-K is not carbon wrapped, it's a chunky piece of forged then machined alloy stem but has a carbon faceplate. Maybe stronger/stiffer than the Energy but, more expensive construction and heavier.

If sticking with FSA is important, I'd take the Energy, or find a discontinued OS-99 (non-CSI), it was 100% alloy, ti bolts, close to 100gr but slightly less stiff in theory than the CSI version (it's basically the same stem without the extra layer of carbon). I can't feel much of a difference personally, might be more important for heavier riders and sprinters.
Last edited by Dan Gerous on Fri Mar 22, 2019 2:44 pm, edited 1 time in total.

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wheelsONfire
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by wheelsONfire

The carbon wrapped alu stems are not a good idea. The aluminium is thinner and the carbon wrap is so thin it easily cracks around bolt holes.
The last nail in the coffin is, they're not all stiffer. Quite the contrary and it have been tested!
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

stevod
Posts: 32
Joined: Tue Aug 18, 2015 8:09 am

by stevod

Dan Gerous wrote:
Thu Mar 21, 2019 7:48 pm
whyamihere wrote:
Thu Mar 21, 2019 7:31 pm
The first two are carbon wrapped around alloy, with the alloy stem inside providing most of the strength. The Energy is just alloy, and good alloy stems tend to be lighter than carbon wrapped alloy.
The SL-K is not carbon wrapped, it's a chunky piece of forged then machined alloy stem but has a carbon faceplate. Maybe stronger/stiffer than the Energy but, more expensive construction and heavier.

If sticking with FSA is important, I'd take the Energy, or find a discontinued OS-99 (non-CSI), it was 100% alloy, ti bolts, close to 100gr but slightly less stiff in theory than the CSI version (it's basically the same stem without the extra layer of carbon). I can't feel much of a difference personally, might be more important for heavier riders and sprinters.
Cheers - I checked out the non-carbon OS 99 though and I wouldn't be able to live with the red graphics (on a black/green frame)!

If the CSI version is the same underneath I might go for that one. Lighter and (arguably) better looking thank the SL-K.

stevod
Posts: 32
Joined: Tue Aug 18, 2015 8:09 am

by stevod

wheelsONfire wrote:
Fri Mar 22, 2019 2:15 pm
The carbon wrapped alu stems are not a good idea. The aluminium is thinner and the carbon wrap is so thin it easily cracks around bolt holes.
The last nail in the coffin is, they're not all stiffer. Quite the contrary and it have been tested!
Thanks - have you tested the FSA one? It was noted above it's the same alu stem underneath, or is that not the case?

It looks like they've been making this stem with carbon layer for over 10 years, so there must be something going for it...

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wheelsONfire
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by wheelsONfire

Not FSA, had Ritchey WCS, the carbon wrapping cracked right away!
I wouldn't buy a second stem with design. Either alu or carbon.
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

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Dan Gerous
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by Dan Gerous

Haaa but FSA and Ritchey are very different companies. I had a Ritchey stem once, threw it in the bin soon after (it was light but had microscopic soft alu bolts with poor tolerances and that oh so dumb 260 degree handlebar clamp), bad designs and executions IMO.

FSA is not the most fancy bling brand but in my experience, they make reliable products and have made carbon wrapped parts for a loooong time, and I have never seen/heard of one delaminating or having it's carbon crack despite being very popular (many OEM bikes came with these). I also have a FSA made seatpost that is carbon wrapped alloy and it's very well made, durable and it's still in use since 2005. I don't think carbon wrapped alloy offers much performance advantage but I wouldn't avoid it.

stevod
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Joined: Tue Aug 18, 2015 8:09 am

by stevod

^thanks both!

S

Karvalo
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Joined: Fri Aug 10, 2018 6:40 pm

by Karvalo

stevod wrote:
Mon Mar 25, 2019 4:52 pm
Cheers - I checked out the non-carbon OS 99 though and I wouldn't be able to live with the red graphics (on a black/green frame)!

If the CSI version is the same underneath I might go for that one. Lighter and (arguably) better looking thank the SL-K.
FSA made a lot of OE stems for Cannondale with green logos, if you hunt around you might be able to find one of those.

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wheelsONfire
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by wheelsONfire

A thinner aluminium wall thickness wrapped with leaf thin carbon fiber, hasn't same stiffness as a solid aluminium stem.
Same goes for a solid wall carbon stem. There's no way around this.
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

Marin
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Location: Vienna Austria

by Marin

Get a Kalloy Uno 7. There's basically no rational reason to get any other type of stem :D

by Weenie


reedplayer
Posts: 511
Joined: Sat Nov 14, 2015 10:10 am

by reedplayer

Marin wrote:
Fri Mar 29, 2019 11:28 am
Get a Kalloy Uno 7. There's basically no rational reason to get any other type of stem :D

....and a good alternative for those, who need it customized for a more expensive bike,
https://www.benobikes.com/de/fahrrad-te ... bau-st-13/

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