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"Slamming" the Stem Concerns?

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Tri Slow Poke

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Discussion starter · #1 ·
Hello,

I'm thinking of lowering the bars on my road bike, possibly all the way down to the headset. What should I be concerned with before I start cutting the steerer tube? Should I leave a little room above and/or below the stem for safety reasons? I don't care about resale value as I plan on keeping the bike forever. It's an Easton EC90 fork with a Chris King headset if that makes any difference.
 
#3 ·
Before you bust out that hack saw with the shiny sharp n' new carbon blade, slow down a bit. You say you're 'thinking' of lowering your stem, why not ride it for a while with a few too many spacers above to be certain you don't want to put it back where you presently have it or somewhere in between? You can always cut it, right? If you're compelled to cut it, I would suggest leaving 10mm above. I feel your pain though, I hate those spacers above the stem...and below for that matter as well!
Also, don't forget, as you lower the stem, your cockpit dimension will change and you're more stretched out. How much lowering are you doing anyway?
 
#4 ·
Tri Slow Poke said:
Hello,

I'm thinking of lowering the bars on my road bike, possibly all the way down to the headset. What should I be concerned with before I start cutting the steerer tube? Should I leave a little room above and/or below the stem for safety reasons? I don't care about resale value as I plan on keeping the bike forever. It's an Easton EC90 fork with a Chris King headset if that makes any difference.
Click to expand...
Of course, the first concern is whether that's really the most efficient, comfortable positioning for you. There are a lot of incorrect assumptions made in that regard, even among the pro ranks.

IMO, a 'perfect' bike would have a couple of cm's below the stem and one above (on a 'down' stem), to allow for positional adjustments up and down. If you think about what it takes to hit any given position within an adjustment range, there's usually a gap unless the stem is allowed to be flipped up and dropped.

But, that's not really your question. Where you are really looking depends a bit on the stem manufacturer's recommendations and the type of compression plug / star nut / stem cap used. The most common for a carbon steerer is probably to allow for a small spacer (3-5mm) above the stem.
 
Discussion starter · #5 ·
RK250 said:
Before you bust out that hack saw with the shiny sharp n' new carbon blade, slow down a bit. You say you're 'thinking' of lowering your stem, why not ride it for a while with a few too many spacers above to be certain you don't want to put it back where you presently have it or somewhere in between? You can always cut it, right? If you're compelled to cut it, I would suggest leaving 10mm above. I feel your pain though, I hate those spacers above the stem...and below for that matter as well!
Also, don't forget, as you lower the stem, your cockpit dimension will change and you're more stretched out. How much lowering are you doing anyway?
Click to expand...
I agree with you 100% My plan is to ride through the summer with it it slammed, but nothing cut, and make a final decision in the fall/winter.

I currently have 2 cm below the bars.
 
#6 ·
To further RK250's post, and I hope this doesn't happen to you, but here is my experience. I once decided to lower my stem so I cut the steerer and lowered the stem. Fast forward a few months to where I herniate a disc in my back really, really badly. Now I want to raise my bars and the only option was to flip my stem which looks far worse than a few spacers below looked, doh! Definitely ride it for awhile like RK250 said.
 
#8 ·
See what the bike/fork manufacturer has to say about it. Some advise against it. I'm not sure if they are being over cautious or if it really matters but......

A different stem is probably a better/safer way to go if you can do that especially if the bike maker advises having spacers below.
 
Discussion starter · #9 ·
VCRC Bike said:
To further RK250's post, and I hope this doesn't happen to you, but here is my experience. I once decided to lower my stem so I cut the steerer and lowered the stem. Fast forward a few months to where I herniate a disc in my back really, really badly. Now I want to raise my bars and the only option was to flip my stem which looks far worse than a few spacers below looked, doh! Definitely ride it for awhile like RK250 said.
Click to expand...
Get well soon!

My question wasn't really about whether I should do it or not. My plan is to lower the bars to get "longer and lower", but not cut the steerer until I'm sure that the position will work for me. I'm more concerned about the safety involved with having the stem rest directly on the headset.
 
#10 ·
Tri Slow Poke said:
Get well soon!

My question wasn't really about whether I should do it or not. My plan is to lower the bars to get "longer and lower", but not cut the steerer until I'm sure that the position will work for me. I'm more concerned about the safety involved with having the stem rest directly on the headset.
Click to expand...
That part will depend on the headset / stem interface. If the headset cap is narrow enough, and the base of the stem clamp wide enough, no worries. But if the neck of the stem touches the cap, you risk pushing bearings out of alignment.

slipping a thin spacer under there is cheap insurance.
 
#11 ·
I rode my bike for 2 years with a LOT of steer tube poking up. It bugged me. I wanted to cut it. I joked that it was to protect my Garmin. Last year, I went back to the shop for a refit. A lot changed since the first fit - I started as a new roadie, long-time mountain biker, etc. I got very comfortable riding lower and lower. Over those 2 years, I moved the stem down a spacer at at time. I was comfortable with the stem "slammed". Even on centuries.

The fitter put the stem back at/near the top of the stack. We moved the saddle, up, forward... lots of changes. Would not have been possible if I cut that steer tube.

Punchline: To danl1's point: Make certain you are in that optimal position - not just comfortable, but the most efficient/powerful position - before cutting.
 
#17 ·
A lot depends on if you have a 73 degree or an 84 degree stem.

If you're going to slam a 73 degree stem, you're going to be "Real Low".

My bike has an 84, with a 2mm spacer under the stem, and a 3mm spacer above it. (the frame has a slightly longer head tube than some racing frames.
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#18 ·
Ventruck said:
Otherwise, slamming the stem is the best thing you can do a bike. Don't let anyone tell you otherwise.
Click to expand...
Making sure your bike fits is the best thing you can do with a bike. The above advice is either sarcasm or nonsense.

Tri Slow Poke said:
What should I be concerned with before I start cutting the steerer tube? Should I leave a little room above and/or below the stem for safety reasons? .
Click to expand...
What should you be concerned with? That it fits right. If you slam your stem for fashion you are a Fred. Nothing says poseur like a bike fit that was obviously fashion driven and not function driven. If it's wrong then it will be obvious to everyone. Now that you've been sufficiently berated about this (I meant this tongue in cheek, please don't take it too seriously), make sure it fits, even if that means the stem is flipped up (which from an engineering/performance standpoint is actually the correct way to set up any bike) and set yourself up for success on the road.

As for safety, make sure you leave 5mm of spacer between the top of the headset and the stem. If you have a carbon steerer then you need 5mm above the stem too. Most bike brands agree that having no spacer between the stem and top-cover increases steerer tube fatigue which means if you plan to keep the bike forever, you'll want to consider.
 
#19 ·
I had the stem on a bike I built up a few years ago sitting right on the top bearing cover. I couldn't figure out why the bike kept developing play in the headset. It turned out the stem was sliding inside the internal diameter of the bearing cover. My excuse is that that was the first bike I had built with a threadless headset, so I had a bit to learn. I put a 2mm spacer under the stem and it has been fine.
 
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Mahatma Kane
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