Geo question.

gabriel959

I am currently riding a 60cm Cannondale SuperSix and an XL Giant SCR 2.0

Geo for the Cannondale SuperSix here (same as CAAD10):


Geo for the Giant SCR 2.0:


So, I am looking at the All-City Macho Man Disc in particular the 58cm and 61cm models:



My SuperSix is quite low and long, good for fast riding, I love the position but I do not think it would be good for riding in traffic or in the woods with it. The Giant feels bigger, I have a 10cm stem on it and I am sitting higher on it. Going by this do you guys think the 61cm would be better seeing as I am going to be using the bike as an all rounder?

In the past I have used the Competitive Cyclist Fit calculator to good use but I am a bit lost as a lot of people say go for a smaller size for a cyclocross bike.

My suggested sizes from Competitive Fit.

The Competitive Fit (cm)

---

Seat tube range c-c: 58.3 - 58.8
Seat tube range c-t: 60.1 - 60.6
Top tube length: 58.8 - 59.2
Stem Length: 12.7 - 13.3
BB-Saddle Position: 77.2 - 79.2
Saddle-Handlebar: 60.1 - 60.7
Saddle Setback: 7.4 - 7.8


The Eddy Fit (cm)

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Seat tube range c-c: 59.5 - 60.0
Seat tube range c-t: 61.3 - 61.8
Top tube length: 58.8 - 59.2
Stem Length: 11.6 - 12.2
BB-Saddle Position: 76.4 - 78.4
Saddle-Handlebar: 60.9 - 61.5
Saddle Setback: 8.6 - 9.0


The French Fit (cm)

---

Seat tube range c-c: 61.2 - 61.7
Seat tube range c-t: 63.0 - 63.5
Top tube length: 60.0 - 60.4
Stem Length: 11.8 - 12.4
BB-Saddle Position: 74.7 - 76.7
Saddle-Handlebar: 62.6 - 63.2
Saddle Setback: 8.1 - 8.5

mfin

10cm stem on your Giant is short for a bike of that size.

The larger of the new bike sizes would be a touch longer again, so I'd say drop down to the 58 on gut instinct based on those tables. But you've got to look at the head tube heights. Your giant's slightly longer than your Dale at the moment, but it has a higher front end too.

BB Drops aren't there in the tables though so it's too difficult to tell. Doesn't sound like your two existing bikes fit the same anyway, so maybe you should get your fit settled first, otherwise it's too difficult to give any real answer.

styxd

Either will be fine I'd imagine, the top tube length on the 61cm All-City is nigh on the same as your other two bikes, not enough difference to worry about. I think the important thing to take note of is the length of the forks, they are about 25mm longer than typical road forks, this will raise the front end height. Im assuming it's an external headset aswell? Therefore you need to add somewhere between 20mm and 30mm to the headtube length to corresponde with an internal headset.

Monty Dog

Things to consider for a CX bike fit:
Increased standover because you never know when you need to put a foot down on rough terrain (e.g. on downhill side) - ride height is higher on CX because of fat tyres/longer forks too
Slightly shorter toptube / more layback because you want to get your weight over the back wheel for grip on deep sand or mud or simply for throwing the bike over drop-offs.
Shorter stem to compensate for a wider handlebar
Bar position a touch higher because you're not going fast enough for aero to matter - control is way more important

gabriel959

mfin wrote:

10cm stem on your Giant is short for a bike of that size.

The larger of the new bike sizes would be a touch longer again, so I'd say drop down to the 58 on gut instinct based on those tables. But you've got to look at the head tube heights. Your giant's slightly longer than your Dale at the moment, but it has a higher front end too.

BB Drops aren't there in the tables though so it's too difficult to tell. Doesn't sound like your two existing bikes fit the same anyway, so maybe you should get your fit settled first, otherwise it's too difficult to give any real answer.

Thanks. I know that, actually it may be at 11cm stem not 10cm. But the large in Giant was far too small even with a very long stem, there was a very large jump in sizes in that generation. The reason they are set different is because I use them differently, one (Giant) is for general riding in town, family, etc the other one (Super6) is for fast riding.

Problem is the head tube on the 58cm is only 17.5cm compared to 19cm on my Dale, which is already low and 21.5cm on my Giant so I am a bit worried about that.

I won't be able to test the bike first as the LBS is getting it ordered and they can order me one or the other but not both

housemunkey

You'll need to add the height of your headset on to that though won't you as it's external?

gabriel959

You are right, it is going to be an external headset so that will add a couple of cm more, going by what Monty has said, I probably should go for the 58cm for the following reasons:

Slightly shorter top tube (59cm on the Dale vs 58.5cm on the Macho Man)
Increased stand over (83cm on dale and giant vs 85cm on the Macho Man)
Shorter Stem (it comes with an 11cm stem as opposed to the 12cm on the Dale)

The BB Drop is 70mm compared to 67mm on my Dale so not much different.

top_bhoy

gabriel959 wrote:

I won't be able to test the bike first as the LBS is getting it ordered and they can order me one or the other but not both

Let the LBS make the decision and if it doesn't fit, then they need to do resolve it. What added value are the LBS offering in this situation? If the LBS aren't going to give expert advice on the bikes they sell and take some responsibility, miss them out and look at the online prices to see if you can get it cheaper. Are you committed to the ordered bikes purchase irrespective if it turns out to be wrong?

holiver

The stack and reach measurements are provided for both the Cannondale and the All-City. Use those first to get the right frame size, then you can muck about with stems etc.

gabriel959

Top_Bhoy wrote:

gabriel959 wrote:

I won't be able to test the bike first as the LBS is getting it ordered and they can order me one or the other but not both

Let the LBS make the decision and if it doesn't fit, then they need to do resolve it. What added value are the LBS offering in this situation? If the LBS aren't going to give expert advice on the bikes they sell and take some responsibility, miss them out and look at the online prices to see if you can get it cheaper. Are you committed to the ordered bikes purchase irrespective if it turns out to be wrong?

In essence, the LBS is offering me a 50% off deal to buy one of the bikes.