This doesn’t seem like a terrible idea but I’d love to know why I’m wrong:
I am currently using one of those on a SS mtb and I’m a little bit scared of it, but I’m not sure if my fear is justified or not.
My current setup has the stem half on the (steel) steerer, half on the extender.
I like that it has enough insertion depth to get some grip. And while it is applying force outward from within the steerer(not meant for it!), the stem is squeezing right back inward against it, sandwiching the top of the steerer in between.
It sure seems solid, but I’m not sure how much I’m willing to reef on these 760mm wide bars and really test it. I’ll probably trim the head tube, get a shorter stack stem, or swap forks.
I’d feel better with some sort of beefier closed-back stem, like this:
(so that the stem flexing and moving doesn’t wiggle the steerer and extender against each other, but rather stays connected as one solid block better).
For a kids bike or something that doesn’t see standing climbing from someone powerful it’s probably fine.
Their pic shows it on a carbon steerer with a stem that has huge cutouts, both of which I would avoid.
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Their guidance recommends (but for some reason doesn’t require) epoxy bonding the insert. Alpha Q forks used to be that way by default, and the Cervelo T1 I have also expects to be bonded. If you do that I imagine it’s mostly fine.
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Cripes. Not cheap.
Shouldn’t there be concerns over manufacturing tolerance between the extender surface/steerer? Otherwise, I’d think it’s fine unless you’re hitting potholes or bumps regularly. Or standing climbing as jimbofly mentioned. Almost anything should be fine on smooth roads anyway.
I think it adds 3 times the material. I would guess it’s stronger
Velobike stuff is nice but def not cheap
Got mine from AMZ, there are a couple length options.
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This brings up something I’ve tried to figure out yesterday - how exactly are carbon steer tubes made as far as the layup goes? I know that generally the fiber for the crown/ST junction runs longitudinally down through the crown and in to the legs, but are the majority of fibers in the steer tube oriented longitudinally along the steering axis?
To your comment about steer tubes not being designed to be loaded in compression from a stem clamping the outside rather than tension from an expander plug from the inside, it seems to my little brain that a tube made from fibers would be able to take more of a load from the inside than a compressive load from the outside.
What kind of cracked me up is they say “yeah you should epoxy it in for best results, but if you ever want the option to remove it just put a little bit of epoxy and you can knock out the expansion wedges with a punch”.
I’d think so. One would think steer tube OD would be consistent between manufacturers but wouldn’t take much to make things weird. Pretty much everything Velobike makes is track focused so while I know there are some rough velodromes out there it’s not going to be like the crap I have to ride on around here.
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i just bought this BBB thing which does the same thing but is way longer and was $20. Steel steerer only though Extender / Headset - BBB Cycling
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I had the BBB one and ended up swapping for a very high rise stem. The extender kept loosening and leading to loose hs which was sketching me out.
I think leverage of a long stem plus it being all aluminium in contact with the steerer meant it didn’t hold over time. From memory going ham torquing it down seemed sketchy as some of the relevant threads were in aluminium.
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dang, so the bbb thing was slipping in the steerer? It seems like such a simple design, i don’t understand how it’s different from a standard quill. I have a clamp on canti hanger so loosening headset isn’t an issue, but obviously i don’t want to lose control if something lets go.
I think part of it was/is that the steer tube contact was all alloy so less bite (cf a steel quill). Also there is potentialy some play under the 25 to 31mm adapter ring things.
I was using it at max height with a long stem fwiw and it didn’t ever fail, I just noped out when it kept having a loosening headset.
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different product imo. one is making your fancy fork work when your new frame follows the trend of taller headtubes and your fork just doesn’t have enough steerer. one is to to get your bars much higher. i have certainly used the latter, but the former is more of a performance minded item
Did you just SharQ?
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The market has definitely been yearning for “DT Star Ratchet but in colors”
These guys got significantly weirder with it though:
- one spring in the freehub with the hubshell ratchet fixed like Hugi from the 90s
- but that nonmoving ratchet sits directly in aluminum teeth in the hubshell
- don’t have to remove threaded steel drivering to service DS bearing
- but have to knock the DS bearing though the hubshell twice to get it out the NDS
- the bearings are is preloaded from the NDS with a cassette lockring
- but that inherently means it’s 6-bolt only
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all measurements for hub are printed on box and etched on the hub.
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