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maximum stack height?(6 posts)

maximum stack height?RayBan
Mar 22, 2002 6:17 AM
I was searching thru the posts and didn't find an active thread about threadless stems. Sure we all know how aesthetically unappealing too many spacers look on a threadless stem, but what is the practical limit on how much space between the headset and bottom of the stem?
re: maximum stack height?Howard
Mar 22, 2002 11:50 AM
With steel steerers, I believe that there is no limit. With carbon steerers, I believe, the limit is 3 or 4 cm.
re: maximum stack height?MGS
Mar 22, 2002 4:16 PM
Try entering this URL. It's to a thread on this discussion in the past.

This topic has been posted at least a dozen times, with at least a dozen different replies.
People espouse that the stack height should never be more than 2cm and some quote Reynolds at 30mm.

Unfortunately, there is absolutely no evidence that any single person has reported a carbon steerer failure for stacks greater than 2-3cm.

In order to be careful, most manufacturers claim that a height in excess of 2.5-3cm is dangerous. Yet despite this claim, I am unaware of any single steerer failure being reported due to any cause or stack height excess.

I have read about stem failures, despite approved lengths,
seat post failures, handlebar failures, wheel failures, fork failure, crank and frame failures, but no steerer failures.

The question is....
Is this whole stem height paranoia warranted and is the steerer inherently strong enough to take even 3-4 cm stack heights.????

Anyone who is aware of a steerer failure due to stack height excess, please let me know.
re: maximum stack height?bianchi boy
Mar 22, 2002 4:57 PM
As stated, there is no real limit if you have a steel steerer, despite what some fashion-conscious cyclists will tell you. For carbon steerers, the general rule I've heard is about 2.5 cm, but it might depend on the manufacturer. Despite that, there are other options available for raising your bars aside from adding more spacers: a positive rise stem, such as a Salsa SUL 105; or a Serotta stem extender, which effectively raises the headtube about 2 cm. I'm one of those Freds with high bars, and I've got about 3 cm of spacers and a 105 stem. Not crazy about the look, but I'm comfortable.
thanks guysRayBan
Mar 23, 2002 6:07 AM
I also found that other thread. I knew it was talked about before. I'm at 2cm and it feels comfortable (at least on the rollers). Ya got to ask questions when your using exotic steerer tube materials like carbon ya know?!
thanks again
Check with the particular manufacturerdjg
Mar 25, 2002 12:50 PM
I've seen lots of opinions, based on who knows what. Given the differences in fork construction, I'd be inclined to think that there's no definitive answer that applies to, e.g., all carbon steer tubes.

Incidentally, when I checked with the distributor for Colnago about data on this, I was told that one could use up to 3 cm with the Force fork (one Colnago model, with a ti reinforcing sleeve)--this fork has a relatively beefy tube. I still don't have any data or models, just a reply that this is what Colnago says about their forks.