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Discussion Starter · #1 · (Edited)
What say you - 56 or 54 cm Tarmac for me?

I've been riding a 56cm Roubaix Expert this summer. I thoroughly enjoy this bike but am thinking I might be better served on a Tarmac. I live in the CO Rockies. Typical ride is 40-50 miles, 2-3 hrs with 2-4000k climbing. I'm a strong climber and enjoy the big ascents.

My Roubaix has done a great job but am thinking Tarmac might be the better tool for the job. I particularly like the Roubaix's smoothness and am leery of getting a bike that's "harsh."

I'm also wondering if I'd be better off on the 54. I'm a touch over 5'9" with a 32 7/8" inseam, short torso and long reach. A pro bike fitter fit my 56cm Roubaix with a 90mm stem. I felt a big too stretched out with the stock 100mm. The fit is good but I'm wondering if I'd be better off with the smaller frame and longer stem setup on the Tarmac for more stability.

FWIW, one Speshy dealer says the 56 is right for me, another says 54. I'm thinking that I probably could go with either but am curious what y'all have to say.

If I move to the Tarmac there's a good chance I'll drop the bucks and go SL2. From what I've read and been told, the Tarmac SL2 is at least as compliant as my Roubaix Expert.

All opinions welcome.....
 

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I'm confused. Do you mean a 52 or 54, or 54 or 56? Based on you inseam, I'd say a 52 would perhaps be too small.

Regarding the "harshness." I have a Roubaix Expert and a Tarmac SL. The Tarmac is far from harsh. I ride mine on 100+ mile rides all the time. It's a great ride. The only time I ride my Roubaix is when I need a compact crank, since my Tarmac has a standard double.
 

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Discussion Starter · #3 ·
Dr_John said:
I'm confused. Do you mean a 52 or 54, or 54 or 56? Based on you inseam, I'd say a 52 would perhaps be too small.

Regarding the "harshness." I have a Roubaix Expert and a Tarmac SL. The Tarmac is far from harsh. I ride mine on 100+ mile rides all the time. It's a great ride. The only time I ride my Roubaix is when I need a compact crank, since my Tarmac has a standard double.
Thanks for the reply.

I just reread my post and stated it correctly in the body of the text but mislabeled the thread title 54 v 56 is the question (now edited correctly). I currently have a 56 and am waffling between my current size or the 54.

My 56 has a standard triple (that's what they had in stock at the time) but I've never used my granny - even on the big climbs. I'm thinking I could go either standard double on the lighter bike, or perhaps go compact double for those I-need-to-puke moments.

Cheers.
 

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Ah, OK. Yeah, I'm certainly not a fit guru, but you'd probably do fine on either size. Personally, given a borderline choice, I'd usually go with the smaller. Can you ride both sizes of Tarmacs? Doesn't have to be an SL2 since you're just comparing geometries. Those are pretty popular sizes.
 

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Discussion Starter · #5 ·
Dr_John said:
Ah, OK. Yeah, I'm certainly not a fit guru, but you'd probably do fine on either size. Personally, given a borderline choice, I'd usually go with the smaller. Can you ride both sizes of Tarmacs? Doesn't have to be an SL2 since you're just comparing geometries. Those are pretty popular sizes.
I'm certainly going to try.

In general, are Speshy frame sizes fairly consistent from model to model.

In other words, do most who fit a 56 Roubaix also fit a 56 Tarmac, and vice-versa?
 

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32" inch cycling inseam, 5' 8.5" height. I did have a good fit done on the Roubaix, which I purchased first. Still dialing in the Tarmac (Roubaix has a 110 mm stem, Tarmac, a 100, for instance) a bit, although it's certainly good enough. It's just a great feeling bike. :)
 

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Discussion Starter · #9 ·
Dr_John said:
32" inch cycling inseam, 5' 8.5" height. I did have a good fit done on the Roubaix, which I purchased first. Still dialing in the Tarmac (Roubaix has a 110 mm stem, Tarmac, a 100, for instance) a bit, although it's certainly good enough. It's just a great feeling bike. :)
Thanks. What's the difference between cycling inseam & inseam? Measured in shoes?

My inseam barefoot is just under 33".

I've got long arms, long legs & a short torso.
 

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The Squeaky Wheel said:
Thanks. What's the difference between cycling inseam & inseam? Measured in shoes?

My inseam barefoot is just under 33".

I've got long arms, long legs & a short torso.
Exactly what does your inseam of 33" represent? Is it your cycling inseam, pants inseam....??
 

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Discussion Starter · #11 ·
Just under 33" according to the LBS who measured me in this manner & took the average of 3. This quote comes from CO Cyclist. Interestingly, they recommend the smaller frame if between sizes whereas my shop put me on the larger frame. Again, I am comfortable on the 56 but wonder if I should be on the 54 with a longer stem.

Determine Your Proper Frame Size
To determine your proper frame size, you'll first need to get an accurate inseam measurement . Stand with your back against a wall, your bare feet 6" apart on a hard floor, looking straight ahead. Place a book or carpenter's square between your legs with one edge against the wall, and pull it up firmly into your crotch, simulating the pressure of your saddle while riding. Have a helper measure from the top edge of the book to the floor, in centimeters. (You can convert inches to centimeters by multiplying inches by 2.54.) Repeat two or three times, for consistency, and average the results to get your inseam length.



Thanks for the replies! Keep them coming.
 

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The Squeaky Wheel said:
Just under 33" according to the LBS who measured me in this manner & took the average of 3. This quote comes from CO Cyclist. Interestingly, they recommend the smaller frame if between sizes whereas my shop put me on the larger frame. Again, I am comfortable on the 56 but wonder if I should be on the 54 with a longer stem.

Determine Your Proper Frame Size
To determine your proper frame size, you'll first need to get an accurate inseam measurement . Stand with your back against a wall, your bare feet 6" apart on a hard floor, looking straight ahead. Place a book or carpenter's square between your legs with one edge against the wall, and pull it up firmly into your crotch, simulating the pressure of your saddle while riding. Have a helper measure from the top edge of the book to the floor, in centimeters. (You can convert inches to centimeters by multiplying inches by 2.54.) Repeat two or three times, for consistency, and average the results to get your inseam length.



Thanks for the replies! Keep them coming.
I know how to measure for cycling inseam. I was asking what 33" represented because you didn't specifically say cycling inseam. :)

Without knowing the criteria your fitter used to set you up on the 56 Roubaix, it's impossible to know why they went up a size, but considering they fitted the bike with a 90mm stem, it wasn't to get you a longer TT. It really doesn't matter, though.

I think at this point you'd be best served by having a 54 and a 56 Tarmac set up and test ride both. I know you said you have long reach, but remembering the 90mm stem, keep in mind the Tarmac has a shorter HT, so you're going to feel a little lower and a little more stretched out than you do on your Roubaix. It's not so much the reach that will change, but saddle to bar drop (stack height) will increase. Not to say it can't be adjusted with stem angles/ lengths, but it's something to keep in mind. Going to a smaller size will result in a shorter HT and exacerbate the issue, which may answer the question of why your fitter chose the 56 Roubaix - longer HT.
 

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FWIW, I'm 5'9.5", have 33.5" cycling inseam. I've been riding a 54 Roubaix with 120 stem, no risers. My next bike will be a 56 Tarmac with 110 stem.

Keep in mind Tarmac has shorter headtube so if you size down from your Roubaix (or even keep same size) you will need more spacers or higher angled stem to get same vertical position of bars.
 

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Discussion Starter · #15 ·
PJ352 said:
I know how to measure for cycling inseam. I was asking what 33" represented because you didn't specifically say cycling inseam. :)

Without knowing the criteria your fitter used to set you up on the 56 Roubaix, it's impossible to know why they went up a size, but considering they fitted the bike with a 90mm stem, it wasn't to get you a longer TT. It really doesn't matter, though.

I think at this point you'd be best served by having a 54 and a 56 Tarmac set up and test ride both. I know you said you have long reach, but remembering the 90mm stem, keep in mind the Tarmac has a shorter HT, so you're going to feel a little lower and a little more stretched out than you do on your Roubaix. It's not so much the reach that will change, but saddle to bar drop (stack height) will increase. Not to say it can't be adjusted with stem angles/ lengths, but it's something to keep in mind. Going to a smaller size will result in a shorter HT and exacerbate the issue, which may answer the question of why your fitter chose the 56 Roubaix - longer HT.
great explanation ! :thumbsup:

I just went through the Competitive Cyclist fit calculator. I did all their measurements without a helper so there may be a measurement of error. According to my inputted numbers the results indicate that I size to a 55.1-55.6 for their "competitive fit" and 56.3-56.8 for their "Eddy fit".

Which leads me to believe that my original premise is correct: I probably could fit either the 54 or the 56 :D

I'm going to try & arrange for some test rides.
 

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The Squeaky Wheel said:
great explanation ! :thumbsup:

I just went through the Competitive Cyclist fit calculator. I did all their measurements without a helper so there may be a measurement of error. According to my inputted numbers the results indicate that I size to a 55.1-55.6 for their "competitive fit" and 56.3-56.8 for their "Eddy fit".

Which leads me to believe that my original premise is correct: I probably could fit either the 54 or the 56 :D

I'm going to try & arrange for some test rides.
That's a fine plan, just keep in mind that the CC fit calculator is a guide, not gospel. It doesn't 'know you' like a pro fitter will. Good luck and let us know how the rides go.
 

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I know you said you have long reach, but remembering the 90mm stem, keep in mind the Tarmac has a shorter HT, so you're going to feel a little lower and a little more stretched out than you do on your Roubaix.
Right. That's why I went to a 100 mm stem on my Tarmac, from a 110 mm on my Roubaix.

It really depends on how 'aggressive' of a position you want and are comfortable with. I naturally prefer a more aggressive position. Most of my time on my Roubaix is in the drops. I spend more time on the hoods on my Tarmac.
 

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The Squeaky Wheel said:
Your numbers are almost identical to mine. I'm betting your 54 with 120 puts you in an almost identical position to me on my 56 with a 90.
Assuming for a minute that we have identical saddle positions relative to BB and both have no-rise stems with same # of spacers, then your 56 Roubaix would have a handlebar position about 1.5cm closer to saddle and 2.5 cm higher than mine. i.e. you're probably in a less agressive position.

Here's how I figure that, hopefully my math is right. Your 56 Roubaix has a 56.5 eff TT vs 54.8 for 54 Roubaix (from Spec website). That's a 1.7 cm difference. Then you subtract about 0.2 cm to account for 0.25 deg slacker seat tube angle, leaving you 1.5 net longer. Then subtract 3 cm b/c your stem is 90 not 120 = 1.5 cm net shorter. The 2.5 higher is from the head tube length difference of 19.0 vs 16.5.
 
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