I think my SFN is edging up the steerer and i can’t seem to tighten it enough. Some juddering from the forks when i break.

How far down steerer should it be/need to be? and, does it need to be dead straight in? I don’t have the correct tool and have no access to LBS.

Cheers

About 5-10mm below the end of the steerer tube should be far enough. It does need to be straight though.

Consider buying an insertion tool, I’ve had loads of use out of mine and it’s very satisfying to get the job done right very easily.

If it’s too far up it’s a fair chance the top cap on the stem is actually tightening up onto the SFN and not pulling the stem tight onto the headset – might be causing the juddering.

If there is already a SFN in then maybe tap it down again, should slide straight down if you’re careful. Then see if it starts creeping up again.

Personally I think SFN height makes no difference so long as you’re not contacting the top cap. I got sick of SFNs moving so I went and bought one of these:

Never had to touch anything since.

I’ve had SFNs slipping inside the steerer a couple of times now, especially when they get a little old & rusty.

I’m running Hed Doctors now and I think they’re the future. No special tool required, no arsing about hammering stuff into my expensive forks.

Whoever thought jamming a spikey bit of metal into a tube was a clever idea or “the solution” to the problem of headset compression should have been removed from the engineering gene pool early on.

Once you have adjusted it correctly and tightened the stem bolts the star nut is redundant and you can even take the top cap off if you want. If its moving while you are riding then you havent got the headset/steerer tube set up correctly.

I had that problem when I put my new fork on. It turned out that I’d knocked it in a little bent, and when I tapped it straight I bent one of the fangles. Fortunately, it was easy to remove, so I replaced it and had no further trouble.

coffeeking – why? It’s simple, cheap and works.

I fitted an Azonic headlock when I had a similar problem no probs since!

What rockhopper says – the SFN moving will not affect the headbearing once the stem is tightened. all the sfn and top cap and bolt do is the the correct bearing clearance / preload. I have run bikes without a top can or sfn quite happily.

I find that when I’m breaking its not the fork shuddering that I worry about.

glenh – because it requires a tool to insert (properly), isn’t overly user friendly, damages the inside of alloy steerers and is a one-time-programmable brute-force answer to something that 20p worth of alu and a blob of rubber can do without the need for tools, without the need for any skill on inserting it and without ever damaging steerers and is re-usable on as many bikes and forks as you fancy trying it on.

is even simpler