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I Have Gnarly Potential
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Discussion Starter #1
Just wondering, is there any standard means of figuring out whats a good stem length without going to some guy at your LBS who is gonna charge some stupid $75+ for a fitting?

I have a 120mm 0deg rise stem on my XC bike and just wondered if there was any normal way to find if its puttin me in the right position (goin by feel is hard, cause id just sorta adapt to whatever, 110mm, 120mm, 130m,, so just wonderin if there was another way to find whats "best")
 

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conjoinicorned
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i'm a big believer that we don't give ourselves enough credit for adapting. if you aren't uncomfortable with your current stem, it's probably just fine.

i've found over the years that i tend to prefer between 60-75mm on all my bikes, from XC to DH to SS.
 

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Old man on a bike
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Some bike shops have stems for you to test with, some don't. Proper stem length and rise for you and your bike is a pretty subjective thing, so even if you find a "formula" it still may not work for you. I have some Syntace VRO stem/bar combos and they're somewhat adjustable for height and length, which when switching from one bike to another can be pretty handy. Trial and error I think is what most of us end up doing to fine tune...
 

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A longer stem will have your weight further forward on the downhills but be good for the uphills (if your not having any back pain from tension on the spine) If you have a long stem then you're at a disadvantage on the downhills - and it weighs more too! LOL!
 

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you go ahead
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Thomas Anderson said:
A longer stem will have your weight further forward on the downhills but be good for the uphills (if your not having any back pain from tension on the spine) If you have a long stem then you're at a disadvantage on the downhills - and it weighs more too! LOL!
So longer stems can cause lower back pain?
I switched my short stem for a 120mm one and on the climbs i felt it in my lower back. Untill now I thought it had nothing to do with the new stem.
 

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Its the overall bike geometry not jsut the stem - not everyone fits into a S,M,L etc.
Say you have average legs and long arms then a M frame and long stem would be fine. However if you are normally proportioned then with a long stem you are less upright which puts tension on your spine (imagine bending a bamboo cane) after an hour or so this starts to hurt. 120mm is pretty long. I'd try a 100 or a 90 - it'll make big diff going up (less pain) and you'll be able to get your weight further back going down. Hope this helps
 

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Try a 110 first..

Thomas Anderson said:
Its the overall bike geometry not jsut the stem - not everyone fits into a S,M,L etc.
Say you have average legs and long arms then a M frame and long stem would be fine. However if you are normally proportioned then with a long stem you are less upright which puts tension on your spine (imagine bending a bamboo cane) after an hour or so this starts to hurt. 120mm is pretty long. I'd try a 100 or a 90 - it'll make big diff going up (less pain) and you'll be able to get your weight further back going down. Hope this helps
120 to 100 or 90 is a big jump...unless you know for sure..
 

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Try before u buy if you have a friendly LBS. If not then take the bars out of the stem and hold them where your arms have a slight bend in them and note where the centre line of the bars are along side your existing stem to get a good idea of where you're at.
 

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I Have Gnarly Potential
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Discussion Starter #9
Thats completely dependent on how much your leaning forward and any SLIGHT change in back angle will easily skew the difference between 100, 110, 120mm, etc :p

My arms and legs are really long (longer then normal for my height) and im 6'3 so I need to get XL (21ish inch) Frames and still have a very high seatpost and stem length.

It seems people really can adapt to just about any length though, difference in any position usually causses a bit of pain, many people mistake muscle soreness for actual pain, if you lean more forward your lower back is being used more, and most standard peoples lower backs are pretty outta shape (only really gets worked out from lifting things "the wrong way" or targeting it with workouts, its a very hard area to develop).

1 thing that may be a plus to a longer stem on taller people is that it places you lower down instead of a wind sail and branch clipping height.
 

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110

110 is deffinatlly the way to go. I was at 120 6 dgree rise and found my proper fit 110 10 degree rise. I tried 100, 105, and 90 and all i needed was a little more lift and short. I'm 5'11 with a 30 inch inseam and ride a medium frame because a large feels to big for me.
 

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my guideline.. is

I usually buy a frame size that in order for me to get a good fit will requie a stem no longe then 100mm. But thats just me. However its worked so far..
 

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I Have Gnarly Potential
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Discussion Starter #12
JediSith said:
110 is deffinatlly the way to go. I was at 120 6 dgree rise and found my proper fit 110 10 degree rise. I tried 100, 105, and 90 and all i needed was a little more lift and short. I'm 5'11 with a 30 inch inseam and ride a medium frame because a large feels to big for me.
I got like a 36 inseam :/
 

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Mantis, Paramount, Campy
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Opposite Here

I don't think I've owned a stem less than 120.... with most of them in the 140-150 range.
Its all personal preference. I come from a roadie background so I like to be low and stretched out.

But as the others have said....try before you buy. If experimenting at the LBS isnt an option buy a couple $5 stems off eBay and try them out before dropping a bunch of cash on a good stem.
 

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The stem length that will work for you is a combination of what kind of riding you want to optimize for, plus the overall fit of your bike.

I used to run a 120mm stem with 23" flat bars and bar ends. It was perfect for climbing steep fire roads, (Mission Peak in Fremont CA) but was suicide on steep technical descents (Soquel Demo).

I Changed to a 90mm stem with 26" x 1.5" riser bars, and pushed my saddle back 1.5 inches. Now it’s MUCH better on steep technical descents, but so-so on steep fire road climbs.

The 26” bars increase to stability on technical descents (better leverage). But on the other hand, not having bar ends reduces climbing comfort and efficiency, and therefore endurance.

The hand grip position on bar ends is generally 2” farther forward than the normal grip position, and lets you get low and stretch out on the climbs. Too bad it is a fashion no-no to put them on riser bars.

In addition, if your bike frame is a little small for you, you will need a longer stem, and push back your seat to give you more room in the cockpit. The opposite applies if your frame is a bit large for you.
 

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I Have Gnarly Potential
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Discussion Starter #15
Im just afraid that sinc I use a 120mm Stem and ride a gary Fisher (which usses longer then normal top tubes alwready) that i may sorta be screwed if I get use to this since i wont get that reach on any other frame i may go to in the future. I mean Thompson makes a 130mm Stem i guess, but that 10mm wont make up the difference that the GF top tube makes, any anythin longer is a bit nuts.
 

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Well Trek...Gary Fisher...pretty much the same...I have trek i beleive 19.5 inch frame. I found I was way too layed out....its always had good XC geo tho....so it climbs like a goat.......I chose to go with an 80mm stem...this was a huge jump from the 140+ stem that was on there stock. I had no trouble adjusting.....and suddenly I had doubled my speed on the tight cross country downhills.....well worth the slight decrease in uphill leverage.

Keep in mind this was one of many choices i made to make the bike more "all mountain" ish...if thats not your goal than think twice about going under 100mm....
 

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Ride Instigator
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Ebay...

You can find MSRP $80 stems on ebay for half that price, do the fitting yourself and eliminate the middle man. Once you find the "right" stem, you can toss the stems you don't use back on ebay and get practicially the same $$ as you paid for them.

'Dats what I done and I'm happy now:thumbsup: .
 
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