what are they like?

not very grippy

Exactly like a star-fangled doohicky, except that you can remove it easily and it's absolutely guaranteed to go in straight.

Used them on all my bikes, never had any problems, always had to remove the rubber 'O' ring to insert them tho'

Far more civilized that those damned wonky SFN's 😀

wet the 'o' ring before insertion to act as a temp lube but found them to be ace 🙂 BTW they should not "loosen" if you have done the stem up tight also the headset will bed in a bit and may need a 1/4 turn after a few rides 🙂

check the vid on hope tech website. shows where so many people have gone wrong in the past!

Won't expand enough to grip a thinner walled steel steerer tube.
Needs the burrs cleaning off the cut edge of the steerer thoroughly, ideally with a tapered leading edge.

They work, but are a lot more expesive than a star nut

but some people are thick and can't understand them, just as other thick people can't fit a starnut either 😉

Annoyingly there doesn't seem to be a 1.5 version..

Won't expand enough to grip a thinner walled steel steerer tube.

yer i have steel steerer…

Used them on all my bikes, never had any problems, always had to remove the rubber 'O' ring to insert them tho'

I found exactly the same thing – I didn't lube the O ring, so it got knackered as I tried to ram the head doctor in, so I just took the O ring off.
Works a treat for me now.

I have fitted 3 now – I have not had any problems to note so maybe that make me intelligent then 🙂

They are a solution for a problem that doesn't exist.

ohh dear – Rockhopper – I don't like scoring the inside of my steerers so I opt for the head doctor which is the same as most bungs in carbon tubes. I can also take it out when I want and pop it into a new one etc etc. Yeh fine use a SFN if you like – its an alternative not a fix for a problem.

BTW you get one with a hope headset which is the main reason I have use them in the past!

I have used a few and much prefer them to SFN. If I was a serial fork changer and used SFNs then I would invest in (or make up) a tool to drift them in square. The only when I treid ended up a bit skew and so fitting the cap was a bit dodgy.

I do feel that I have reasonable self taught mech skills and so didn't find fitting too hard. Admittedly first insertion wasn't right but thought about what had gone wrong and refitted no problem.

As someone said not really an answer to a problem, just a useful (IMHO) alternative. And now with carbon steerers appearing, who would use a SFN?

They are a solution for a problem that doesn't exist.

A friend of mines steerer sheared across the SFN. The steel/ally interface had developed some nice bi-metallic corrosion and landed him on his face on his first day in Morzine.
Admittedly it was a few years old, but it wouldn't have happened with a head doctor. I'd happily put a SFN in a steel steerer, but they're a bit iffy in ally…

I split a steerer tube with a Head Doctor. My fault I should think, but I was just trying to get the damned thing to not slip when trying to tighten the bearings. Which is _all_ it's for (Once your stem's tight you don't need the top-pressure). This is like 7 years ago. So, I put the damned thing in thinking it's complicated therefore good (idiot). Tighten with 8mm Allen key (I think I had to buy one). Put on stem, try to tighten bearings – slips. *think*. Aha! Tighten stem. Loosen HD and push down. Tighten HD. Loosen stem. Tighten bearings a bit. Repeat. All is well!

Much later: Remove stem. Boof! steerer cracks as over-tightened HD bursts out, Alien-style.

Oh, crap.

a.

Sorry I would agree prob user error there AK – I can't believe you needed to tighten up the headset that tight the HD would slip – You dont need to tighten the HD that much either so? I hope you didn;t grease the inside of the tube?

It's all academic now anyway as I've ordered one. 🙂

The bike shop at Glentress told us that they have a drawer-full cos they don't use them when they fit a Hope headset. So, ask them if you want one.

al.

It's all academic now anyway as I've ordered one.

It's all academic now; he's ordered one.