# Sizing/Handling Question; 56 cm w/ 90 mm stem OR 54 cm with 110mm stem.



## Brentos (Jul 16, 2006)

Choosing between the following on a Cannondale Super X. How will they handle differently, which would you choose and why?

54 cm frame
110 mm stem
72 deg head tube.

56 cm frame
90 mm stem
72.5 deg head tube.

Stack and reach to the bar are nearly identical.


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## jmoote (Nov 29, 2007)

A 56 cm frame with 90 mm stem is a massive compromise that is best avoided. As long as you don't need a ridiculous number of spacers on the 54 cm frame, a more normal stem length of 110 mm will ride much better.


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## pigpen (Sep 28, 2005)

I have always consided 100mm stem to be neutral.
90 would be a little quicker, 110 a little slower.

But I think you might be looking at this wrong.
Get the/a frame that fits. Stem is just fine tuning the fit.


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## pretender (Sep 18, 2007)

jmoote said:


> a more normal stem length of 110 mm will ride much better.


Why is that?


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## Brentos (Jul 16, 2006)

With the stems listed, they will have a nearly identical fit. So it really is a question of handling.

I've been racing pro cross country on mountain bikes, and I always tend toward short stem/long top tube as it offers better stability at speed (among other handling benefits). I wasn't sure how that translates over to 'cross. I was on a M/L Giant TCX last year w/ a 110 stem, but was never quite comfortable with the handling of the bike.

Thanks for the responses. Leaning toward the 54.


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## jmoote (Nov 29, 2007)

pretender said:


> Why is that?


More neutral weight distribution. Stem size needs to scale roughly with frame size to maintain an optimal balance (as the setback generally grows with saddle height) and you might go up or down one stem length to fine tune fit.

"as a rule" cross tends to prefer a stem about 10 mm shorter for a given size, though I hesitate to say this.

In any case, a 90 mm stem on a 56 cm frame is pretty extreme. For a road bike of that size you'd expect to see 110 mm +/- 10.

As the OP points out, either is going to work (fit) but the best handling will be achieved when they can place their weight where it needs to be.


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## Local Hero (Jul 8, 2010)

54 w/110


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## pretender (Sep 18, 2007)

jmoote said:


> More neutral weight distribution.


Wheelbase for the 54 is 101.7, for the 56 is 102.6. HTA for the 56 is half a degree steeper than the 54.

So we're talking about moving the front wheel forward by 0.9cm, which I'd hardly consider a "massive compromise". Especially since the steeper HTA counteracts the longer wheelbase. I say the OP would do fine on either bike. Hell, he could split the difference by running a 100mm stem on the 56 and moving his saddle forward by 1cm.

There seems to be a Freudian attachment to longer stems.


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## m_s (Nov 20, 2007)

I tend to prefer shorter stems in cross where turning is a priority but getting your weight forward for climbs is not. But if the 90mm puts you at the limit of the reach you want, 80mm might feel too short. So the 54cm size may give you more wiggle room


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## jmoote (Nov 29, 2007)

pretender said:


> Wheelbase for the 54 is 101.7, for the 56 is 102.6. HTA for the 56 is half a degree steeper than the 54.
> 
> So we're talking about moving the front wheel forward by 0.9cm, which I'd hardly consider a "massive compromise".


The wheelbase change is compounded by the stem length though - you put the wheel further out and then move the hands back relative to that, and now the front wheel has no weight on it. How can you steer the bike without weight on the front wheel? This is not a mountain bike.



> I say the OP would do fine on either bike. Hell, he could split the difference by running a 100mm stem on the 56 and moving his saddle forward by 1cm.


This should not even be said it's so wrong. You do not get to move the saddle to adjust reach - saddle position is set relative to the pedals by leg geometry only. From there you can dial in the front end to get the hands where they need to be.


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## pretender (Sep 18, 2007)

jmoote said:


> The wheelbase change is compounded by the stem length


No, it's not. (Think about it for a sec. Hint: steeper HTA.) Because the chainstays remain the same, the front wheel moves forward in relationship to the bars by exactly 9mm.


jmoote said:


> This should not even be said it's so wrong. You do not get to move the saddle to adjust reach - saddle position is set relative to the pedals by leg geometry only.


If you're devoted to KOPS or such. A lot of people aren't.


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## JeffS (Oct 3, 2006)

pretender said:


> If you're devoted to KOPS or such. A lot of people aren't.


Regardless of KOPS or not, you should still have a preferred setback. I can't believe that anyone with tens of thousands of miles on a bike wouldn't have a problem moving their saddle to any ole' position.


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## m_s (Nov 20, 2007)

I have my saddles set up differently fore-aft on a number of different bikes, and even move them around depending on use. It's not a big deal. Roadies seem to get so uptight about THE ONE EXACT FIT that they forget most of us are quite adaptable and can get used to a number of different positions. Besides, over the course of a 45 minute cross race I'm in the saddle maybe 30 minutes, and a lot of that time I'm just hovering or shifting my weight around. So why does it matter if the saddle is a centimeter farther forward or backwards? Are people seriously so sensitive that its going to wreck their races if their KOPS relationship isn't perfect?


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