Carbon Steerer And Stem Compatibility


So, I’ve started putting pieces together on a new frame, steel pursuit geo with a recently acquired pinarello vola carbon fork, with carbon steerer.

Something I didnt think about was how the carbon steerer would handle the stem I have chosen. I like the aesthetics and short reach of square BMX stems, as well as using 22.2mm bars. I know this obviously seems like an odd choice/combination, but I’m riding it, not you. It, for the record, is a superstar revolte stem. It tightens by a single bolt internal ‘wedge’.

What I want to know is if this is tightened to an appropriate tension (will be heading into an LBS for this) will there be any potential drama with these two?

Am I better off ditching the carbon fork (which I got for a remarkably low price) and simply finding a nice steel fork?

Any help is useful!

could have issues with this if the wedge pushes into the fork tube as opposed to clamping around the stearer tube it could damage the tube and cause a weak/stress point…
just looked at the stem it is designed to pinch the stearer tube i wouldn’t use it on a full carbon fork, it will pinch the tube and could set you up for a catastrophic failure… plenty of blood and sparks

Without knowing what the the wedge system in your stem is like it sounds a bit iffy to me. I’d be a bit concerned about the wedge creating an unsafe point load on the carbon.

Righto - will ditch that idea for now. Anyone want a carbon fork for $20 bucks?

Might just stick with a AL steerer or go for a full steel, just looking to save some grams on the build.

^+1. probably agree, however doesn’t Crank Brothers use a wedge system for their stems - which they sell as carbon compatible? I’d be asking a bike mechanic…Whatever the case may be I wouldn’t install any stem onto a carbon stearer without a torque wrench. Saw a guy on the trails last weekend whose carbon handlebar had neatly sheared off at the brake clamp. Slinky was quick to point out overtightening as the cause.

Yep, there’d be no chance of me touching it without a torque wrench. Too many years of engineering studies has made me a bit wary of carbon fibre and fucking it up, so I think I might just go with a steel fork and save the 500 grams somewhere else, maybe by drinking less beer.

torque wrench and carbon paste then you can getaway with only 4nm with bars and stems!

All of my carbon stearers have a special expanding nut that goes in the riser, torques up to 6 nm with the stem ‘pinching’ onto where the expanded nut goes. I would be nervous about doing anything different.

What size is the stearer on the carbon forks?