? for all you bike handling gurus.

[Len J]

I'm trying to learn more about bike handling and I'vebeen rereading threads about optimal stem length.....some say 11 some say 12, jerk says 13.........but it seems to me that more info is needed, What about reach?

I currently use an 11 cm stem with 10.0 reach bars, a total reach of 21 to get me weight distribution over the bike in the perfect place. So my question is.........What difference in bike handling would I notice if, instead of an 11 stem with bars with a 10 cm reach, I used a 13 stem with 8 cm reach bars? My weight would still be over the bike in the same place.

Any ideas?

Len

[Smiley]

Len , I let the reach be dictated by hand size as well as where you like to placed said hands when decending cause that where it counts anyway .

[dirtdigger88]

I think comfort would be effected before handeling. You will streatch your back in odd ways to make up for the longer/shorter reach of the stem.

Jason

[Matt Barkley]

Bike handling has to do with bike handling not stem length and bar reach combos.

Bars a fairly standard in terms of reach. Smiley is correct with hand size, etc. With what you are talking about your weight distribution should be set up properly with a correct front to center as well as appropriate stem length for overall reach.

Bike fit comes first in terms of your saddle set back and then in terms of overall reach. Just palying around with stem length adding or subtracting based on bar reach ain't gonna do anything real for your bike handling.Matt :beer:

[Peter]

I'm actually experimenting right now with something similar to what you're pondering.

In your case, you will see NO change in position or handling because your hands wind up in the same location. The only reason I can imagine you would want to do this is because of some feature of the bars you would swap to.

In my case, what I'm doing is installing a longer stem and sliding the seat forward to keep the reach the same. If you don't follow the "knees over the pedal spindle" philosophy it's no big deal, but I expect to feel a difference in steering, force application to the pedals, and weight distribution on the wheels.

[Len J]

Len , I let the reach be dictated by hand size as well as where you like to placed said hands when decending cause that where it counts anyway .


Then that there is no difference in handling as a result of stem length, assuming the reach of the bars compensates for the difference (i.e. the hands end up in the same position?

Len

[Len J]

Bars a fairly standard in terms of reach. :

This is not my experience. Ritchey bars have a reach of around 8 cm....my Nitto bars have a reach of 10 cm. I have bontager bars that are around 9 cm. Reach can vary by up to 2 cm.........consequently, shouldn't this reach difference affect the stem length selected if the aim is to get the hands in the right position?

As to starting with seat setback........My question assumes that everything else is static. If everything else is the same, what differences would be detected with a shorter stem/longer reach combination compared to a longer stem shorter reach combination, assuming the result puts the hands in the same position?

Len

[soulspinner]

My perception is that a longer stem seems to slow the steering and a shorter one makes it quicker..I had an old Colnago and went to an 8 stem (the bike was given to me) from an 11 and turn in seemed to be quicker.
My question is does bottom bracket height in and of itself,ie all other variables being equal, affect handling? Or only the the angle at which your pedal strikes the ground in a corner?

[Smiley]

The combo of stem length and bar reach is kind of misleading since some bars have flat spots on the bends like Deda and allow for a higher brister mount hence a shorter reach . But the general answer is if the combo of stem and reach as measure from tip of saddle nose to brister knob or anywhere else you chose is the same then NO change in handling will be percieved. Again I have used the Poco Bars especially for women with small hands to effect reach to the brake hoods with using a tad longer stem to balance the HELM (a sailing term I know you are familar with ) of the bike . I tend to have smaller hands so I don't like to use a bar with any reach longer than 8.2 cm . Now depending on the shape of the bend and the type of hoods you pick things can change or how high you mount the hoods on the bends . Its all eronomics after all . The new Shimano 10 speeds brake hood can mount higher on the bend versus the old 9 speed stuff since the clamp is angled , The Campy 10 speed hoods are best for flat transitions and shorter reach . Best of luck Len J.

[Len J]

My instincts told me exactly that, I just wasn't sure i wasn't missing something.

Len

[SPOKE]

now here's something to think about. if all other fit dimensions remain the same. switching from a shorter stem to a longer stem the bike will feel less "twichy". why?? the radius of the arc created by the handle bars when turning will increase. this increase in radius actually makes the steering inputs slow down a bit. put another way, in order to turn the bike a given amount (X degrees) with a short stem the arc length required is less than would be required with a longer stem.

[Ken Robb]

while we are on this topic let's remember that the angle of the stem affects the virtual length. For instance, a 12cm stem with an upslope with be effectively shorter than a 12cm stem that is a 90 degree or zero slope stem. Downward slopers are effectively shorter.

[Len J]

now here's something to think about. if all other fit dimensions remain the same. switching from a shorter stem to a longer stem the bike will feel less "twichy". why?? the radius of the arc created by the handle bars when turning will increase. this increase in radius actually makes the steering inputs slow down a bit. put another way, in order to turn the bike a given amount (X degrees) with a short stem the arc length required is less than would be required with a longer stem.

if the bar reach is adjusted to give the same overall reach?

lrn

[zap]

Len, If the hand position stays the same as you originaly posted, no. It's the distance from the steering axis and your hand. But good luck keeping all the hand positions the same when changing bars/stems.

But as SPOKE says, same bar but longer stem will make the bike feel less twichy. I just switched one bike from a 13 to 12 using the same bar and the bike feels more twichy. Not a big deal for me, now it feels like I have a 74 head tube angle, but the shorter reach sucks.

[Len J]

Len, If the hand position stays the same as you originaly posted, no. It's the distance from the steering axis and your hand. But good luck keeping all the hand positions the same when changing bars/stems.

But as SPOKE says, same bar but longer stem will make the bike feel less twichy. I just switched one bike from a 13 to 12 using the same bar and the bike feels more twichy. Not a big deal for me, now it feels like I have a 74 head tube angle, but the shorter reach sucks.

axsks

Len