can someone explain to me...

[Rockinthecasbah]

I went from a 110 to a 90mm on my "trailbike" because I felt to stretched out, its all about fit, yes it does change the way the bike handles but more or less people change stems to adjust for TT length you will be hurting in certian situations if you go to long or short so try to get somehting comftorble in the middle unless your racing DH or 4x or planning on riding tons of fireroads

[Abui]

Just go ride it. The effects will differ depending on the rake of your fork, the head tube angle, etc.

Don't worry about positioning for power unless you're a sprinter, over time efficiency is more important.

[pastamon]

Originally Posted by Marshall Willanholly

I think Lee presents good information on that topic. Sorry it got you so worked up this morning.

Why are you sorry about me, when you should be sorry for assuming I was "worked up"?

If you haven't read Lee's "blanket endorsements" of 50-70mm stems, you haven't read his site very thoroughly. You also didn't see the thread where I asked him for suggestions on relieving trapezius cramping, and he said my 80mm stem was way too long and I needed to get one that was 50-70mm long.

But hey, if you don't like my being honest and complete, and would prefer to assume I'm "worked up" rather than telling my experiences honestly, that's okay by me. Your being wrong doesn't injure me in the least.

I only want to clarify that I'm not "worked up" and it's pretty danged lame for you to say that I am.

I think Lee has great advice for everyone -- his book w/ Lopes is very good, I own a copy. I'm talking about the limited point of stem length. If you really think that it's not harder for someone to climb on a short stem, you haven't been riding very long and you haven't fooled around with cockpit geometry very much. Lee's perspective is that the bike should be fit for gravity riding because that's his preference.

I share that preference for most situations, but on rides that have steep alpine climbs I don't want a too-short stem, even if the shorter stem makes the descending a bit easier/lazier on those same steep alpine trails. I like to put my climbing energy into pedaling the bike, not into firming up my core and pulling back/down on the handlebar so that the front wheel can stay planted.

[poy]

I've never seen "lee likes bikes" site. I have yet to read the site on long vs short stems and the others that the site may offer. it might be best to try it out and if it does not work out the you'll probably see a 50mm stem in marketplace hopefully someone buys it!

[FoShizzle]

shorter stems, on the average, are shorter than long stems. however, i have seen some pretty long short stems which were longer than some really short long stems. also, given the same design, a shorter stem will weigh less than a longer stem, unless it is a really long short stem.

[poy]

its strange how the thompson 50 is heavier than the 70. maybe its more massive.

[Marshall Willanholly]

Originally Posted by pastamon

Why are you sorry about me, when you should be sorry for assuming I was "worked up"?

If you haven't read Lee's "blanket endorsements" of 50-70mm stems, you haven't read his site very thoroughly. You also didn't see the thread where I asked him for suggestions on relieving trapezius cramping, and he said my 80mm stem was way too long and I needed to get one that was 50-70mm long.

But hey, if you don't like my being honest and complete, and would prefer to assume I'm "worked up" rather than telling my experiences honestly, that's okay by me. Your being wrong doesn't injure me in the least.

I only want to clarify that I'm not "worked up" and it's pretty danged lame for you to say that I am.

Okay, now I really think you're all worked up.

I assumed you were "worked up" in your original post based on your use of ALL CAPS.

I thought the part of your post that was a reply to the OP was an excellent analysis of the effect of stem length change. Much better than I could have done, that's for sure. I'm not sure where you get the idea I don't like you being "honest and complete." The only part of your post I took issue with was when you went off about "50mm stems being STUPID for someone who lives for XC and lives to climb." I simply pointed out that in none of the linked articles is that suggestion made; then went on to quote from some of the linked articles, one of which even mentions that a longer cockpit aids seated pedaling efficiency, and most riders climb more powerfully with a longer cockpit. If I "lived for XC and loved to climb" and read that, I certainly wouldn't run out and get a shorter stem.

I have read Lee's site thoroughly, and I posted up those specific links to give the OP some info to help answer his question, which was:

can someone explain to me what would be effects of shortening the stem on my bike?

Look, I don't run 50mm stems on all my bikes. I have a 90mm on my singlespeed, a 70mm on my trail bike, and a 50mm on my DH. I don't blindly choose my stem length based on what Lee says, nor do I choose my crank length solely based on what Lennard Zinn says, nor set my saddle height at exactly what Greg Lemond tells me to. I don't expect others to do so either. I apologize if my endorsement of Lee seemed excessive in my original post. I was certainly on a high after all I learned in my clinic with him on Monday.

By the way, you should read what Dr. Atkins says about pasta. He really knows what he is talking about..

[RS VR6]

Will I be able to notice a difference by switching from a 100mm/0deg to a 90mm/0deg?

[Bryguy17]

Interestingly, I'm trying to decide on a stem to put on my bike.

Basically, I'm getting very frustrated with the length of my cockpit when descending, but the gains in terms of comfort and efficiency make me not want to get a shorter stem.

Some background:
I'm 6'6", ~34" inseam and a lot of torso/arms.
I'm riding a 21.5" trek fuel EX ('0. That's a 25.4" top tube and it comes spec'd with a 120mm stem with 7* rise. Headtube angle is 69* at full extension, roughly 71* at lowered setting (its a talas 32)

My problem: I really like how the bike feels for most climbing/longer rides. I'm a bit stretched out, but its the good stretch that gives you extra power going up stuff. The only time I dislike the longer cockpit is during really technical climbs, as it makes it difficult to loft the fron over some obstacles, and the slower steering makes quick movements more taxing on my body (more movement needed from body to make a quick steering change)

Problems come when I want to go down. I really like to pin it down hills when I can. This means that I'm usually going a decent bit faster than the average XC racer type. When doing this kind of aggressive descending, though, I really miss the handling/weight placement advantage of a shorter stem. I feel WAY too far over the front of the bike, especially in the steeps, and I don't like the bus-like steering that comes with such a long stem when trying to weave my way around obstacles.

I tried running an 80mm stem on the bike once, but I found myself encountering lower back pain (right around the small of my back) when I was seated for long periods. I figure this is an effect of the shorter cockpit, as I had a similar problem with my old hardtail (a large specialized hardtail with the same stem length). Whenever I was seated for a long amount of time, I would get back pain. That problem dissolved when I switched to the new bike with long stem. I'm also relatively young, so age-related problems are probably not a factor for this (I'm 20).

So I'm wondering if theres any chance that I may be able to get the handling I want out of a short stem, without the back issues I seem to have with such a stem. I would not mind sacrificing a bit of my pedaling efficiency for the extra handling bonus of a short stem.

Perhaps I need to stick with a longer stem for any pedaling rides, and just switch to a shorter stem for when I do more DH-oriented riding, but that gets old fast, having to re-torque stem bolts/reset headsets whenever I want to change riding style.

[Rockinthecasbah]

ad a little rise to the bars or some spacers under the stem it may help out and is low cost

[g-dub]

Originally Posted by poy

what would be effects of shortening the stem on my bike? besides the ride are there also safety issues to be considered? any tips? thanks!!!

My experience: I swapped the stock 120mm stem on my Stumpy for a 90mm and a higher rise bar. I've ridden one particular trail twice ever. On the stock setup I walked a section that I just knew was going to send me OTB. After swapping the cockpit I rode it clean, and wondered what I had gotten so worked up about the first time.

There is a little loss of stability while climbing, but the tradeoff was worth it for me.

Takeoff stems can be had for as little as $10. It's a cheap, worthwhile experiment.

[L8 APEKS]

Originally Posted by mechmann

different effect. now if the steering wheel had a weight (the driver's body weight maybe) hanging off the bottom of it, that would make a better analogy...

Nah....he's spot-on actually. Doesn't explain the effects in all 3 dimensions, but it explains one of them very well.

Picture a wide steering wheel, then mimic a 90 degree turn. Now, reduce the size of the wheel by 50% and make the same turn. The radius of the arc of your upper hand is also reduced by 50%. This means more immediate, sharper steering response...more angle of turn with less steering wheel (or stem and handlebar) input (replace the steering wheel image with a stem and repeat...it follows the same arc).

It doesn't describe the F/R weight ratio or reduced cockpit size, but other people covered that already.

FWIW, I ride 120mm stems with 5 deg. rise on both bikes. I always seem to be in-between frame sizes and I almost always get the smaller size...and I have gotten into the habit of compensating for the shorter top tube by using a slightly longer stem.

[Steven Jackson]

My gurlfriend likes to ride on my short stem.

[L8 APEKS]

Originally Posted by Steven Jackson

My gurlfriend likes to ride on my short stem.

What a coincidence...your girlfriend like to ride on mine too!

[live_in_hilo@yahoo.com]

i changed my specialized rockhopper comp stem for a azonic shorty. it made a world of differance and i felt i was more in control. at the same time i changed my bars to a higher degree of rise also.

[Steven Jackson]

Originally Posted by L8 APEKS

What a coincidence...your girlfriend like to ride on mine too!

She dont do guys who get thare ass kicked by a cholo.

[L8 APEKS]

Originally Posted by Steven Jackson

She dont do guys who get thare ass kicked by a cholo.

She prefers lovers, not fighters. <3

[poy]

i've switched my stem from a 100mm to a 50mm... it works wonderfully. see here is the thing... the day that i tried it i crashed... i dont know if it has anything to do with the stem change...

Originally Posted by Steven Jackson

My gurlfriend likes to ride on my short stem.

o your girlfriend likes riding my 100mm stem...

[DISCO]

In my experience anyone who has tried my 13" stem has come away with a bit of discomfort (like getting hit by a cement truck), and it has fazed some enough to in fact crash later. In your case a weeks worth or hard riding will give you a better picture of how it will hang than a quick "one night stand" so give it some time, a little patience and eventually satisfaction may come.