Stem angle suggestion

[vincenz]

I’m looking to get a lower (higher?) angle stem to make it parallel to my top tube. Right now, I have a -7 degree stem on there. How can I calculate what I need?

The head tube is 71.5 degrees. I estimate the top tube to have between a 5 and 6 degree slope (let me know if I’m way off on this).

I found a -12 degree stem from Specialized, but it’s a pig at 200g. Would a -10 degree be close enough? There is the Easton EA90 that looks ok.

[Safepants]

http://yojimg.net/bike/web_tools/stem.php
this site should have you covered with getting the specs.
If you don't have the manufacturers geometry angles available, i've used my iphone with a digital level app to get a nice reading haha.

[tuscanyswe]

Normally with a 73 degree headtube angle you would need a -17 degree (73+17=90 degrees) stem to make the stem parallell with the ground and toptube if level tt-bike.


Since you have 71.5 degree headtube you would need 1.5 degrees more so an 18.5 would make it parallell to the ground. Now you say you want to match your sloping toptube of of circa 5-6 degrees. Subtract those 5-6 and you end up with 18.5 - 5.5 = 13 degree stem. If 10degree is close enough for you to think it matches is hard to determine because thats very subjective and you are not 100% on your tt slope to begin with.

I find however that its better to have the stem slightly less angled than slightly to much as to much is easier somehow for the eyes to pick out (perhaps more true with a level to the ground toptube).

Personally i think both a 10 or even better a 12 would be fine.

[unterhausen]

there are angle finder apps for smartphones. That would be a good start to finding a stem.

[kingpin75s]

Personally i think both a 10 or even better a 12 would be fine.

^ This

[KarlC]

Look on ebay for a -12 degree stem from Specialized SWorks its pretty light.

FSA makes one also

.

[JimmyTango]

Zipp makes 12deg stems, but they are the 2 carbon models and are super pricey

[kppolich]

Zipp makes 12deg stems, but they are the 2 carbon models and are super pricey

I believe the only 12 degree carbon stem that Zipp makes is the Zipp SL Sprint.

The SL Speed is only available in +/- 6 degree

[vincenz]

Normally with a 73 degree headtube angle you would need a -17 degree (73+17=90 degrees) stem to make the stem parallell with the ground and toptube if level tt-bike.


Since you have 71.5 degree headtube you would need 1.5 degrees more so an 18.5 would make it parallell to the ground. Now you say you want to match your sloping toptube of of circa 5-6 degrees. Subtract those 5-6 and you end up with 18.5 - 5.5 = 13 degree stem. If 10degree is close enough for you to think it matches is hard to determine because thats very subjective and you are not 100% on your tt slope to begin with.

I find however that its better to have the stem slightly less angled than slightly to much as to much is easier somehow for the eyes to pick out (perhaps more true with a level to the ground toptube).

Personally i think both a 10 or even better a 12 would be fine.



Thanks! The logic makes sense.

I’m leaning towards the -10 because of the weight (yeh, yeh, weenie) and I don’t mind it being slightly more sloped than the TT— most bikes are like this anyway. I just want to have there be less of a noticeable difference as it is right now with the current setup, i.e. doesn’t have to be perfectly parallel.

I find it funny how the eye can play tricks. I have a Ritchey with less top tube slope (maybe 4 degrees) and the headtube is 1 degree steeper at 72.5. With a -6 degree stem, the difference is not much to the eye.