Hello,

I’ve seen people write that the headtube on the C456 is quite small compared to other bikes – how true is this?

Unfortunately I only own the 1 MTB so can’t compare it at home. The aim is to cut some steerer tube off but I’d like to avoid making the forks incompatible with any future frames.

Cheers!

how true is this?

fairly.

depends what size frame – I think the 16″ ones had problems with tapered fork steerers (PP will know the details).

If you’re looking to sell a fork then at least 180mm and preferably 200mm seems to be what people are looking for.

rather true it is only 9 cm so much shorter than my orange @12 cm

Why not just leave it long and have spacers above the stem?

They’re very short IME, although recently I reckon a lot of the industry’s gone the same way as longer travel and/or 29ers have become popular as you’ll usualy have the bars in the same/similar place on all your bikes so the headtube usualy compensates by getting shorter.

Something to consider is that if you have a given bar height you’re after then regardless of what frame you have, you’ll be clamping the stem at the same position on the steerer – unless your run the 456 with no spacers and a high rise stem/bar to make up the height.

So… make sure you run spacers under the stem (Slammers be damned!) and keep the steerer relatively long an it’ll then be perfectly easy to swap.

click here

for all sizes, scroll down 1/3 page and click ‘geometry’

Also, FYI, the smoothie headset has a fairly large lower cup which may add up to 15mm over an internal headset (smoothie mixed tapered)

^ what clubber says.

You should be setting your stem/bar height for what is right for you. Not according to your bikes head tube.

I have one of the affected 16″ versions so I use a carbon conical spacer on top of my headset top cap and then normal spacers. Helps avoid the gopping stack of normal spacers.

If you want to use a tapered fork on a 16″ version then speak to on one first.

The lower cup should be external on the C456. Using a low stack bottom will change the geometry from the intended.

Yeah, should have clarified; I meant if you were comparing to a bike which does use an internal headset.

cheers for the reply. mines an 18″. will leave the steerer well alone!

Yeah it’s short, 120mm on my 20, 105mm on the 18 I think. A lot shorter than older bikes, so there’s likely to be chopping involved, I lopped 20mm off mine to about 210mm. Wouldn’t go shorter than that to avoid issues with swapping, but seems a lot of new frames are shorter in the head tube now.

As Nick says, I vaguely remember it was 100ish on my 18″ but by the time you take into account the external cup of the Smoothie headset, it was about the same as my Trek Fuel Ex which had a longer headtube but an internal lower race.

I generally don’t cut my steerer’s any shorter than 185 – 190 and just add or remove spacers depending on the frame. Never had an issue despite multiple frame changes with the same forks. Only some bikes (eg. maybe Giant Trance?) with stupidly tall headtubes might cause you an issue.

For a reference point I used the following…

18inch C456
150mm Sektor RL
Hope spacer kit all were used but the 2nd smallest between top cap and stem.
Hope Intergrated Headset

For use in my GT hardtail the forks required 1 small spacer to fit as the head tube was longer.

Looking at getting another C456 as they are a great frame to be fair.