Another boring Supersix sizing thread. 48 or 50.

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sanrensho
Posts: 433
Joined: Tue Aug 02, 2011 5:54 pm

by sanrensho

Judging by the photo, although you would be able to make the 50cm work, it would look a little large.

You don't have much seatpost extension as is.

nemeseri
Posts: 794
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

sanrensho wrote:Judging by the photo, although you would be able to make the 50cm work, it would look a little large.

You don't have much seatpost extension as is.


Yep. That's a problem that's more visible if someone has such short legs like me. And it's also a problem with saddle - bar drop. You can see that it's the smallest caad10 available, the stem is already on the conical spacer and still the drop is quite small. And I'm a 5'6.5". That's not extremely short. (At least I know a few guys who shorter than me. *sigh*)

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numberSix
Posts: 124
Joined: Sun Sep 23, 2012 1:53 pm

by numberSix

Drop: ?? Did you look at the stem comparator? http://www.yojimg.net/bike/web_tools/stem.php

the comparison for 100mm, -6*, 25mm spacers(the cone) vs. 100mm, -17, 2mm (a slam cap)
is 41mm lower, and 9mm more reach. From the photo I'd say you can get to 100mm drop this way.
Of course your hip angle preference, saddle preference, etc come into play.

HTA: the slackest bike I have is my Evo @72.5*. It's just enough more stable that when tired I'm still a steady wheel in a tight pace line. I prefer the way my CAAD9 turns ( 73* and a heavier, stiffer fork). But the Evo is more comfortable. Having never ridden a frame smaller than a 52cm, my concern is the slacker head angles of the 48cm are more for toe clearance than handling.

Ordinarily, riding a size down gets you a short wheelbase and thus a faster turning bike. For Cannondale's small sizes, there isn't much difference. Another random thing to consider; are you a stand-up-climber, and do you throw the bike from side to side? a smaller frame or sloped top tube gets you more leg clearance.

Fiery
Posts: 420
Joined: Sat Mar 16, 2013 9:21 am

by Fiery

CAAD10 48 front center is within 1mm of SuperSix 50. Trail is identical, chainstay length is identical. They will handle the same once you get used to the slightly more sensitive shorter stem.

Now, SuperSix 48 has a shorter front center and more trail. More trail will make it hold the line better when going straight. Shorter wheelbase will put more weight on the front wheel, making feel more solid when I cornering hard. The shorter wheelbase will make it more nimble in tight corners and quick direction changes. The wheelbase somewhat offsets the trail.

If you have good weight distribution on your current bike, and if you are pleased with how it handles, I think you should go with SuperSix size 50. Otherwise, go for 48.

If course, this is just theory from behind the keyboard. Ideally, you should test ride both before making a decision.

jeffy
Posts: 1325
Joined: Sun Oct 05, 2014 11:51 pm

by jeffy

Fiery, what are you refering to as "front center"?

nemeseri
Posts: 794
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

numberSix wrote:Drop: ?? Did you look at the stem comparator? http://www.yojimg.net/bike/web_tools/stem.php

the comparison for 100mm, -6*, 25mm spacers(the cone) vs. 100mm, -17, 2mm (a slam cap)
is 41mm lower, and 9mm more reach. From the photo I'd say you can get to 100mm drop this way.
Of course your hip angle preference, saddle preference, etc come into play.


Sorry, I wasn't clear. I meant that with the factory setup this is the maximum drop if you have short legs. If you go up a couple of sizes you can get much more drop without using a -17 or a special dust cap. I know that I have plenty of room to go down.

numberSix wrote:HTA: the slackest bike I have is my Evo @72.5*. It's just enough more stable that when tired I'm still a steady wheel in a tight pace line. I prefer the way my CAAD9 turns ( 73* and a heavier, stiffer fork). But the Evo is more comfortable. Having never ridden a frame smaller than a 52cm, my concern is the slacker head angles of the 48cm are more for toe clearance than handling.

Ordinarily, riding a size down gets you a short wheelbase and thus a faster turning bike. For Cannondale's small sizes, there isn't much difference. Another random thing to consider; are you a stand-up-climber, and do you throw the bike from side to side? a smaller frame or sloped top tube gets you more leg clearance.


Great info here again. I have toe overlap on every bike I have and I think it's just fine. I can't avoid it.

Fiery wrote:CAAD10 48 front center is within 1mm of SuperSix 50. Trail is identical, chainstay length is identical. They will handle the same once you get used to the slightly more sensitive shorter stem.

Now, SuperSix 48 has a shorter front center and more trail. More trail will make it hold the line better when going straight. Shorter wheelbase will put more weight on the front wheel, making feel more solid when I cornering hard. The shorter wheelbase will make it more nimble in tight corners and quick direction changes. The wheelbase somewhat offsets the trail.

If you have good weight distribution on your current bike, and if you are pleased with how it handles, I think you should go with SuperSix size 50. Otherwise, go for 48.

If course, this is just theory from behind the keyboard. Ideally, you should test ride both before making a decision.


Thanks for the explanation how the wheelbase, trail effects handling. This is great info! That's why I'm so torn between the to bikes. The 50 SS is closer to the 48 caad in handling, but the longer reach scares me a bit. Also using a longer stem / bigger drop also affects the weight distribution between the front and back. Ultimately I will end up in the same position, the only question is which one affect handling more? The slightly different trail, wheelbase, front center and HTA of the SS in 48, or the shorter stem in the case of size 50.

jeffy wrote:Fiery, what are you refering to as "front center"?


The front-center is the distance between the center of the bottom bracket and the axle of the front wheel.

Fiery
Posts: 420
Joined: Sat Mar 16, 2013 9:21 am

by Fiery

jeffy wrote:Fiery, what are you refering to as "front center"?

Distance from center of bottom bracket to center of front hub. Comparing front centers and chainstay lengths of two bikes gives you an idea of how weight distribution over the wheels will compare.

pdmtong
Posts: 34
Joined: Tue Mar 02, 2010 10:31 am

by pdmtong

there is a lot going on here but IMHO I would choose the frame that allows me to run a 110 or 120 stem with the bar drop I like. the comments above regarding weight distribution absolutely nail it.

pro riders have smaller frame because the amount of bar drop they want cannot be obtained in a stock frame with eTT that is correct for them. they want lower, so go smaller to get a shorter headtube and offset the now shorter top tube with a longer stem.

Fiery
Posts: 420
Joined: Sat Mar 16, 2013 9:21 am

by Fiery

nemeseri wrote:Thanks for the explanation how the wheelbase, trail effects handling. This is great info! That's why I'm so torn between the to bikes. The 50 SS is closer to the 48 caad in handling, but the longer reach scares me a bit. Also using a longer stem / bigger drop also affects the weight distribution between the front and back. Ultimately I will end up in the same position, the only question is which one affect handling more? The slightly different trail, wheelbase, front center and HTA of the SS in 48, or the shorter stem in the case of size 50.

Stem length and height doesn't affect the weight distribution between the wheels as much as it changes the pressure felt on the hands (to a point, i.e. changing reach/drop by 10mm). Regarding the effect of stem length vs. geometry, in my experience you'll feel the different stem when rolling out of the driveway, but you'll feel the geometry when pushing the bike through a variable radius curve on a fast descent.

Again, I don't know whether the changes in geometry between the CAAD10 48 and the SuperSix 48 would be an improvement for you - it is also possible to have too much weight on the front wheel, or too short of a wheelbase.

DeLuz
Posts: 405
Joined: Fri Dec 04, 2009 2:30 am

by DeLuz

If it helps at all I am 5'8", short legs 30" and ride a 52cm with 100mm stem.
I highly recommend the EVO, best bike I have ever had.
The larger frame might be a bit more compliant and ride smoother.

nemeseri
Posts: 794
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

DeLuz wrote:If it helps at all I am 5'8", short legs 30" and ride a 52cm with 100mm stem.
I highly recommend the EVO, best bike I have ever had.
The larger frame might be a bit more compliant and ride smoother.


I'd love to be that flexible. :) What's your saddle height?
I rode a 52 caad10 before and while it was fine, I know that I need a smaller frame. Also I almost had to push the seatpost all the way down. That wasn't that cool. :)

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