Advice on Stem length

[vl1016]

i am posting because it seems my current bike is too small for me (though the original lbs that sold it to me doesn't agree)-I have checked out various fit calculators, that say I need a 56-57cm frame size, with a combined stem and top tube length of 69cm. My current frame is a 55cm, and my tt length is also 55 with a 12cm stem, or total of 67cm. My lbs agreed that I need a longer reach, and also came up with the 69cm "ideal" measurement. They want me to put a 130mm stem on the bike. I am wary of putting a 130mm stem on the bike, because it seems like an extreme size for a stem...will it drastically change the handling? Will it be too flexy? If the seat tube and head tube are 1cm short for me, could having a +tilt on a stem make up for this? I really can't afford to buy another bike (though I'm happy with my components and could maybe just buy another frame), and I like my bike. The rationale for a stem change is that my upper shoulders, neck, and midback have been hurting if I go on rides for any decent duration. Ideas??

 

[artmichalek]

You probably won't notice any extra flex in the longer stem. It will make the steering a bit less responsive. Increasing the reach probably won't help your neck/shoulder pain though. This is usually caused by the bars being too low. How much is the drop from your saddle to the bars?

 

[vl1016]

You probably won't notice any extra flex in the longer stem. It will make the steering a bit less responsive. Increasing the reach probably won't help your neck/shoulder pain though. This is usually caused by the bars being too low. How much is the drop from your saddle to the bars?

I would say approx 3 inches.

 

[Hypnospin]

some stem and bar combos are flexy, if you can grab and flex test at a shop you can compare. when it comes to longer stem, do take into consideration your saddle setback relative to the bb with your tt recommedation.

i personally like the handling characteristics of a neutral 73/73ish 56ish square bike with a 13 stem. but you gotta go with what fits.

 

[vl1016]

some stem and bar combos are flexy, if you can grab and flex test at a shop you can compare. when it comes to longer stem, do take into consideration your saddle setback relative to the bb with your tt recommedation.

i personally like the handling characteristics of a neutral 73/73ish 56ish square bike with a 13 stem. but you gotta go with what fits.

But isn't saddle setback only relative to knee over pedal placement, and not a function of reach? Or is there another reason to consider this?

 

[artmichalek]

But isn't saddle setback only relative to knee over pedal placement, and not a function of reach? Or is there another reason to consider this?

What Hypnospin meant is that the reach should be measured from the bars to the saddle, not to the post. You want to figure out the right saddle setback first, then work out the tt/stem length from there. Also, more so than any other number that you get out of a fit calculator, reach is very subjective. The number is a decent starting point, but it's not to be taken too seriously.

 

[el Ingles]

But isn't saddle setback only relative to knee over pedal placement, and not a function of reach? Or is there another reason to consider this?

This seems to be one of those urban myth things : if you want high cadence then a forward saddle will aid that ( track pursuit , timetrial and triathlon ) but there is another side to this in that for races on rougher surfaces then a more rearward seating position and lower cadence works better ( opinion of Sean Kelly the last great sprinter/roadman , winner of paris-nice 6 times , tour of spain , milan-sanremo ,5 or is it 6x winner of the green jersey in the tour de france , paris-roubaux etc .......... )
The trouble is who ever is " the best " at the time , be it Indurain , Armstrong or whoever somebody want´s to "explain" they´re a success with biomechanics but the best are always freaks and what work´s for them will not work for everybody else with anything like the same success .


re the stem : 130 mm stems are fine , the steering is a touch slower than 11cm but you´ll only get " noticable " flexing as you go for lighter and lighter components . As a measurement I was told that your nose should be over the bars when on the drops - use a plumbline - but it´s all about feel in the end and there are plenty of reversable stems inthe 6/8 +/- range though remember that inverted the stem will be at least 5mm shorter - so if you need the rise a 135mm will convert into a 130mm and a 130mm will convert into 125mm etc - checkout models by ritchey and pazzaz ( nb do remember that you can fit a mtb stem to a road bike but not vice-versa , though it´s probably not a good idea if used in conjuction with an extra-light or a carbon handlebar - all stems are now sold as 11/8 with a shim included to come down to 1inch so there´s a lot of variety out there to experiment with at resonable prices then buy a better one if / when your sure of your needs )

 

[Hypnospin]

the effective tt length, along with the reach would move with the saddle if setback is changed from the fit prescribed for you.
i know this sounds like approximate science but even the best fit is a series of compromises...

But isn't saddle setback only relative to knee over pedal placement, and not a function of reach? Or is there another reason to consider this?

 

[Hypnospin]

i did not read this post, so excuse my previous redundant reply...

What Hypnospin meant is that the reach should be measured from the bars to the saddle, not to the post.