Road Cycling - Im stuck with a stem discision

I have a 140mm stem right now on my 58cm Bianchi. Now if I have measured everything right (which I think I have..I have been measuring and researching for 3 weeks) then I need a 115mm stem. Now I have found a couple of stems and they all seem to be either 110mm or 120mm. My question has 2 parts. 1. Which stem length should I go with 110mm or 120mm. Is it better to be a tiny bit longer or tiny bit shorter. 2. Are quill stems and threadless stems measured the same way? I would most likely be getting a quill stem with 0 rise. Or I might get a quill-to-threadless adapter and going with a threadless stem. I haven't decided. Thanks for the input.

How are you measuring your overall reach - from the point of the saddle, the center of the seatpost or the top of the seat tube? Reason I ask is because your ultimate decision could be effected by the fore/aft position of your seat or whether or not you have a setback seat post.

55/Rad

You kinda lost me there. When I'm on the saddle and I look down the handlebars do not block the front hub. It sits infront of it. I have measured for the distance I need to bring it back. My fore/aft position is my knee over the pedal right? or am I totally off.

The whole "blocking the view of the hub" is but guideline, not a rule per se. You may be more comfortable ahead of it, or behind it. Everyone is different.

The fore aft position 55/Rad is talking about is, how far back your seat it.

The whole "knee over the pedal spindle" is but a guideline, not a rule per se. You may be more comfortable ahead of it, or behind it. Everyone is different.

Have you been through a fitting with a LBS? If not, go to www.wrenchscience.com and proceed through the fitting program on their site. When you measure yourself, make sure to double check for accuracy. After you've entered your information, the site will instruct you with some basic guidelines for how to measure your overall reach, saddle height and other things.

I have found their program to be fairly accurate in regard to overall reach though not so much on saddle height. So, I make adjustments according to how I feel. At the least, this program is good for getting you close to optimal and makes for good reference. Good luck.

55/Rad

I find if im doing alot of climbing I like to be waaaaay back, with the handlebars waaay in front of the hub....whereas if I am TTing with aerobars I like to be very forwards with the bars behind the hub. Everyone is different

Brendon

Yeah I have used wrenchscience.com and they came up with the same stem measurement as I did. a 115mm. But then they only come or I have only foound them in 110mm and 120mm. Which one should it be?

Hi

If cash is no object I would get a custom made 115. However, if your current knee position is exactly right then the stem length will not change it at all, it will just change the angle of your back and shift your centre of gravity forward slightly. 5mm will not make too much difference so I would go for the 120 as it will make a more aerodynamic position. There is a slight chance that this could be a bit uncomfortable if you have a very high saddle postiton with the bars down super low, then too much weight might be shifted on to the bars.
TT riders often have their knees in a more forward position as do those that climb a lot out of the saddle rather than sitting down.
Are you taking your critical measurement as the distance from the back of the saddle to the centre of the handlebar tube?

Cliff

2cm is a lot of adjustment, I would'nt change any more than that. I went from 120 to 100 on my bike and it made a huge difference. Now that it is late in the season I wish I went to 110 but doubt I'll go back to the 120 because I felt like a monkey swinging from the bars.

If you want to get as close to 115mm then I see two options.

The first is a custom stem that was already mentioned above.

The second is going 120mm with enough positive angle in rise instead of the 0 degree rise so that the horizontal length gets closer to 115. In the second case you'll need to remove steerer tube risers to account for the added rise of the stem.

Do you have risers between the stem and headset? If not, is there any steerer tube above the stem or is it already cut flush? What is the drop between the saddle and the handle bar? If you have too much drop (personal opinion here ... more than 4 cm is too much drop unless its a TT specific bike) then you might want to address that first and then correct the stem length.