How long is this stem?

[Simon Q]

http://www.cyclingnews.com/photos.php?id=/photos/2007/sep07/kvv07/kampioenschapvanvlaanderen0004

This stem looks crazy long to me. 160mm maybe? Anyone else think the same? If it is abnormally long who makes these stems - are they short runs for the pros?

[imp25rs]

The seat was crazy high too. It looks like he just needs a bigger bike. :confused:

[David Kirk]

The mold is paid for so it's one size fits all from here on out.

Dave

[fstrthnu]

http://www.cyclingnews.com/photos.php?id=/photos/2007/sep07/kvv07/kampioenschapvanvlaanderen0004

This stem looks crazy long to me. 160mm maybe? Anyone else think the same? If it is abnormally long who makes these stems - are they short runs for the pros?

That is a 160 iirc.

[R2D2]

The mold is paid for so it's one size fits all from here on out.

Dave

It probably has more to do with Astana can't get "free" bikes from BMC anymore.

[Sandy]

Won't such a long stem put too much weight too far in front of the front wheel and outward and not downward, or will the great drop from seat to handlebar overcome that? Couldn't such a long stem upset the geometry designed into the bike and optimal weight distribution. Just wondering.


Sandy

[obtuse]

it's a deda newton in 150mm. if he got a bigger bike he couldn't the bars low enough. nothing really weird there.

jerk

[fstrthnu]

it's a deda newton in 150mm. if he got a bigger bike he couldn't the bars low enough. nothing really weird there.

jerk

Nope. That's a 160 Rotor.

[stevep]

its 2 75mm fsas attached.
if his bars were higher he could go better.

cause then he could get into the drops.

[fstrthnu]

http://weightweenies.starbike.com/phpBB2/viewtopic.php?t=32705&highlight=160mm+stems

[Dave]

The idea that a longer stem alone puts significantly more weight on the front of the bike is a misconception. The biggest contributors are the bike's front-center, chainstays length, saddle fore/aft position and the rider's torso angle.

Generally a rider would have the same saddle to BB relationship, regardless of the frame size. A smaller frame may have a shorter TT, requiring a longer stem, but not always a shorter F-C. The chainstay length is often the same on all frames sizes these days.

If you want to se the effect of torso angle on a bike's weight balance, place your bike in a trainer with a scale under the front wheel. The weight will be significantly less, if you ride with your hands on the top section of the bar, is the most upright position. Moving the hands forward to the brake hoods will lower the torso angle and increase the weight on the front. Move down to the hooks, where the hands should be during critical cornering and the weight will increase more. From there, you can lower your torso angle even more and increase the weight some more.

If you think that adding a longer stem alone really changes the weight balance, move just your hands forward or back without altering your torso angle and you'll see no significant change in the weight on the front. It's torso angle that's the big contributor to a change in the weight balance.

As for the change to the steering, it takes a large length change, like from 80 to 120mm (or 120 to 160mm) to change the steering arm length about 15%. High speed turning is done by applying pressure to the bars in the opposite direction of the turn (push on the rightside of the bars to lean the bike to the right and turn right). The amount the bars actually turn might only be a couple of degrees. Whatever change the longer stem creates will be small and quickly accustomed to.

I judge a stem to be long enough if my knees and arms don't touch when I pedal in the descending position. I've got my hands in the hooks, with my fingers in reach of the brake levers. My upper back is nearly horizontal. Since I use a large 9-10cm drop, I don't need to bend my arms much at all to achieve this upper back position. If you ride with only a 5cm drop, you'll be forced to bend your arms and that may create knee to arm interference. Then you either flare the elbows or ride more upright to eliminate the knee to arm interference.

[zap]

snipped


cause then he could get into the drops.

+1.