Lower the stem height???

[BlueJersey]

I am trying to work out some fit issue. Just built up a caad8 frame and the frame is one size larger than my old one. My old one is a bit smaller. The caad8 feels just roomly enough. The caad8 has a higher head tube height and a bit longer top tube. I am using the same 110mm stem. My mind tells me that I feel the stem isn't low enough on the new frame considering that my old frame has a shorter head tube height. On the new frame, I don't use any spacers. I can switch to a headset with a lower stack height to compensate for the higher head tube. Now, but the top tube lenght is 1cm longer. In theory, I shouldn't need to lower the stem because I am 1cm more stretched out (more flatter back) on the new frame. Isn't right?

I test rode the bike today and I rode much harder (more power output) but I wasn't going faster. It was very, very windy today and cold. I am thinking maybe I wasn't aero enough as before with the extra higher head tube height???

 

[PeterF]

I am trying to work out some fit issue. Just built up a caad8 frame and the frame is one size larger than my old one. My old one is a bit smaller. The caad8 feels just roomly enough. The caad8 has a higher head tube height and a bit longer top tube. I am using the same 110mm stem. My mind tells me that I feel the stem isn't low enough on the new frame considering that my old frame has a shorter head tube height. On the new frame, I don't use any spacers. I can switch to a headset with a lower stack height to compensate for the higher head tube. Now, but the top tube lenght is 1cm longer. In theory, I shouldn't need to lower the stem because I am 1cm more stretched out (more flatter back) on the new frame. Isn't right?

I test rode the bike today and I rode much harder (more power output) but I wasn't going faster. It was very, very windy today and cold. I am thinking maybe I wasn't aero enough as before with the extra higher head tube height???

You might try a stem with a 73 deg angle which will be parallel to the gound. If the head tube is longer (check the stack height of the headset too) even though the top tube is longer, the stem might be closer to you than you realize.

 

[BlueJersey]

I am already using a 74 degree stem. Went out today and did a 2 hours and 30 minutes tempo ride. While in the drops I certainly felt more comfortable and flatter than before. I mean, hitting 24 mph only using 220w to 240w. I think the setup is aero enough. I also checked my positon with a mirror too.

You might try a stem with a 73 deg angle which will be parallel to the gound. If the head tube is longer (check the stack height of the headset too) even though the top tube is longer, the stem might be closer to you than you realize.

 

[John M]

I'd try a few more rides before changing anything. A single days power ratings can't tell you too much, particularly if the weather was extreme. Sounds to me like the fit is pretty close.

One other option is to get an adjustable stem to use temporarily while you dial in your fit and then get a fixed position stem (lighter than the adjustable) that puts you in the position that best balances comfort and power.