# How much above the steerer tube can the stem be?



## mtb2road (Jun 23, 2007)

Sorry if this is a repeat question, but I couldn't find anything specific using search.

As part of a pro fit, I had to change my stem to a shorter one with a steeper rise, which brought me much closer to being comfortable on the bike. The fitter wanted to put a 5mm spacer below the stem to bring the bars up to the correct position (currently below the minimum), but another shop employee insisted he could not. Currently the stem is 1mm above the top of the aluminum steer tube, so another 5mm will still put the stem screws below the top of the stem. Is this safe to do or do I need to look at a new fork? 

Thanks,


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## Dave Hickey (Jan 27, 2002)

Most recommend 2mm on the top of the steerer tube...That being said, If the bolt is below the top of the tube, I'd do it but that is me....

Another option is to find a shorter stack stem that still has the rise you need. Not all stems have the same stack height


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## cxwrench (Nov 9, 2004)

even though you have an alloy steerer tube, i wouldn't do it either. i always cut the steerer tube just above the stem and put a 2.5mm or 5mm spacer on top of the stem. easton actually require this in their instruction booklet.


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## FBinNY (Jan 24, 2009)

If it'll improve your position, go ahead and add the spacer. It's a judgment call, but I think in this case position trumps the technical worry. 

1-2mm recess is a *minimum* clearance to prevent the top cap from bottoming out on the steerer when adjusting he headset. There's no firm maximum but with a metal steerer, and typical stem 7mm isn't at all unreasonable. Though as *Dave H* posted you definitely want the steerer to go higher than the stems clamp bolt.

Some folks insist that the steerer go beyond the stem with a spacer on top to ensure that the stem won't cam against the end of the steerer when flexed, though I've never seen any evidence that it's a problem.

BTW- one nice thing is that with the top cap back in place, no one will know, so you won't have to listen to lectures from know-it-alls on your rides.


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## mtb2road (Jun 23, 2007)

Thanks everyone for your replies. I appreciate your input. Unfortunately, i misunderstood the fitter and heard millimeters instead of centimeters, so there isn't much I can do, except to buy a new fork, or get a different bike to fit me better.


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## laffeaux (Dec 12, 2001)

Yes, having the top of the steerer tube below the stem bolts is a very bad idea. 1 to 3mm is fine. You're describing 6mm which is quite a bit of stem clamping air instead of aluminum.


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## suprcivic (Apr 10, 2009)

if weight isn't a concern, you might try this...

http://www.nashbar.com/bikes/Product_10053_10052_175545_-1_201521_10000_200459


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## Dinosaur (Jan 29, 2004)

It sounds like you need a stem with a different stack height. That would solve the problem with no need to add a spacer.


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## Amfoto1 (Feb 16, 2010)

Yes, a stem with a different stack height would help.... but might be hard to find.

Depending upon the stem... most particularly, precisely where the clamping bolts are located... you might be able to have the stack height reduced by machining some off the top and bottom. This would have to be done very carefully, but might gain some additional space, if needed.


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## Dinosaur (Jan 29, 2004)

Well. thinking about this while on a ride today. You could add a 5mm spacer and the gap between the top of the steerer tube and the top of the stem clamp would depend on the stack height. I can pull out or add a 5mm spacer depending on which stem I am using. The most common stack height now me thinks is 40mm. I think the Deda Newton is 37, FSA's are 35, 3T's and Ritcheys are 40. The clearance on my steerer tube and the stem clamp is 3mm. I am using a Deda Magic (45mm stack). Zinn says distance should be between 3-6mm.


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## mtb2road (Jun 23, 2007)

suprcivic said:


> if weight isn't a concern, you might try this...
> 
> http://www.nashbar.com/bikes/Product_10053_10052_175545_-1_201521_10000_200459


I was thinking about that, but not ever sure about adapters. I suppose it's safe enough and definitely would get the job done in the short term, until I can get a better fitting bike down the road.


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## merlinluvr (Feb 6, 2010)

What is the consensus on this scenario: carbon steerer tube with the stem flat(-17*). The steerer tube is uncut from the factory: Reynolds Ouzo. I have 1.5cm spacer under and 1cm spacer above stem. 

So, my stem clamp is below the cap.....but don't know anything regarding conventional wisdom on this.....thanks.


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## Dinosaur (Jan 29, 2004)

*Two camps on this*

I think there are two camps about placement of spacers with carbon steerers. The O.P. was referring to aluminum one's (which I have also). Since yours and already done and you've had no problems, I wouldn't worry about it. But I've never had a carbon steerer.


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