Carbon Fibre Forks max stack height.

[hondated]

To try and increase my comfort on my Focus Cayo I have brought a pair of new forks and I would like to ask if anyone knows the maximum spacer height I can use under the stem.Would 50mm be too much.
Can someone also tell me why the forks stems are made so long when a big part of it needs to be cut off. Thanks

 

[black'n'yellow]

About 30mm for a carbon steerer, longer for an aluminium steerer - 50mm would probably be ok, although at that kind of height I would think about flipping the stem instead, if you haven't already. The steerers are long so they can fit anything from 45cm frames, right up to 60cm+. You can cut them shorter, but you can't cut them longer...

 

[jowwy]

my planet x forks say 40mm of spacers max - i think specialized state the same too

 

[fossyant]

I'd have just bought an adjustable stem. Or trained your back to be more flexible.

 

[fossyant]

I'd have just bought an adjustable stem. Or trained your back to be more flexible.

On road bikes it's ar$e up, head down, so slam the stem.

 

[hondated]

black'n'yellow thanks for your advice and yes I can see your point about not being able to cut them longer.
jowwy thank you I think I might just push it to 45mm.
fossyant your first point is a good one but I think they look so ugly and your second point is sooooo right but as much as I would like to my old back cannot take it.

 

[Malaconotus]

jowwy thank you I think I might just push it to 45mm.
fossyant your first point is a good one but I think they look so ugly and your second point is sooooo right but as much as I would like to my old back cannot take it.

Don't 'push' the recommendations on a carbon fork steerer, where failure can be fatal. (Chap in the US died a couple of weeks ago due to carbon steerer failure... http://www.tauntongazette.com/news/...mpany-comments-on-cyclist-s-death-in-Rehoboth) I'd ask Focus what they advise (assuming you have a new Focus fork?)

If your back won't take it, use a more upright stem. Any LBS can order these... http://www.extrauk.co.uk/product/detail/SystemEX/MTB_Stems/2049/ Use this calculator to work out what impact angle and length have on hand position... http://alex.phred.org/stemchart/Default.aspx

If the stem alone won't solve the issue and a longer spacer stack is needed, get a steel fork with a steel steerer and add as many spacers as you like.

And, as suggested above, it is a road bike, and backside-up, head-down is what makes it fast. With time, your core strength will improve and it will get easier. I am currently training my corpulent front and ailing back to withstand a more aerodynamic position, one 5mm spacer a month, on a very long steel steerer.

Can someone also tell me why the forks stems are made so long when a big part of it needs to be cut off. Thanks

Manufacturing costs. Same fork for all size bikes. It was a very big factor in the adoption of the Ahead standard over the threaded quill standard, which required different forks for different size frames.