Disadvantage of a bigger road bike?

[Saudiq]

It's unlikely you will find a 54cm bike with a top tube as short as 53,7cm. Perhaps you should be looking at a size 52. Anyway, my top tube is 2cm bigger than it should be. I put on a shorter stem too and it does help.

Thanks Eugene. The specialized that I currently have is a 52 with a 53.7cm top tube and the one I'm looking at is 54 with a 54.8 cm top tube

[Saudiq]

Why go for Ergo Fit then?

 

I used to use a Large Scott....and then I went to buy a medium Fondriest with a top tube of 55.7.....according to ergofit I need a 55.7 which was spot on, then your stem gets added to that according to the measurements the program gives as your flexibility, etc. Speak to Renay Groustra, he did my ErgoMax setup, he will be able to explain better to you and since he is a pro mountainbiker I am sure he knows what he talks about.

 

Rather get a frame that fits you as mentioned by ErgoFit....your whole setup is worked out according to that system.

 

If you want I can send you his number?

I had the Ergofit done and according to the Ergofit measurements I should have a 53.7cm top tube which is exactly I currently have. I've sent Renay an email and he replied saying that I can get a shorter stem. Its not as ideal as sticking to my current bike size but it shouldn't hinder my performance.

 

My current stem is 100 and I should have a 105 according to the Ergofit measurement; I'm therefore assuming that the bigger top tube shouldn't be a problem? I'm also reasonably flexible, I can reach about 10cm past my toes

Edited August 26, 2011 by Saudiq

[Saudiq]

I am curious as to which frames these are? The 54.8cm is probably being sold as a 55cm right? And the 53.7cm you have now probably a 54cm?

 

You are measuring centre to centre?

 

It's the specialized tarmac geometry: http://www.specializ...09&sid=09Tarmac

[AndreZA]

Ja I mean horizontal, but what is the word (help the afrikaaner out here)

You have to draw in imaginary line because the top tube is sloped?

 

Know what I mean?

 

Virtual top tube

 

[Tankman]

Virtual top tube

 

Ja that's the word that was missing from my Friday vocabulary, thanks!

[Bike Mob]

What size stem did the Ergofit reccomend?

 

The Spesh Tarmac 54 has a sloping TT so even in a 54 it's pretty compact, you wont have any issues with standover height.

 

I gather you have seen a 54 the\at is a good deal making you want to move from a 52, which would maybe be your choice if you were buying new.

 

I am 180 and ride a 54, but with a huge seatpost extension and 110mm stem. My brother is 175cm and rides a 54 as well with a 100mm stem and medium extension..

 

My feeling is that a 54 will work for you with either a 100 or 90 stem and low saddle height. The tarmac is a quick steering bike but is not going to suffer with a 90mm stem - some bikes handling changes dramatically with stem choice - but the specialized in my experience does not

Edited August 26, 2011 by Tarmac-SL3

[Bike Mob]

You can ride either just like I can ride a 56...I am on the border, but chose a smaller frame.

 

1) More options on stem length for tuning, rather than playing with short stems.

2) Shorter wheelbase for tighter steering

3) Lower frame weight

4) shorter chain stays for climbing

5) less flex on shorter joining tubes

6) Lower overall height affects frontal wind and drafting possibilities.

 

Disadvantages:

 

1) long stems may be more flexy

2) stems heavier

3) running out of available standard seatpost and having to get longer ones

4) longer seatposts are heavier

[Fitter]

It's hard to beat working with good bikefitter. That being said, good bikefitters are very, very few and far between.

 

The problem with measure-and-calculate bike fitting is that it relies on average assumptions. Bell curves suggest most of us are anything but average. Any system that uses physical measurements to calculate a bike sizing (including guarantees of decimal-point accuracy) has to be viewed with complete skepticism.

 

But worse is that, even when a proper pre-purchase physical assessment and functional assessment has been performed, by a good fitter, most people display widely diverse biomechanical responses during a dynamic fitting on a bike. In addition these diverse responses change depending on the load, fatigue and neural stresses on the rider.

 

What I'm saying is that you can feel free to plug-and-play bikefit measurements - the web is full of different "systems", each guaranteed to give you a different result, but you are ballparking about as accurately as a new salesman in a bike shop using "rule of thumb".

 

The minimum requirement is to get a flexibility and functional physical assessment done, then factor in your riding style, requisites, goals and limitations. This will get you close to a good approximation based on your overall height . Then it is down to the fitter and his ability to take you through a dynamic fitting to achieve the desired result. And, yes, I've heard all the arguments about how you can do this at home with your ex-pro buddy, but really, you can't - at least not any better than the new salesman in a shop with some internet reading behind him.

 

To the OP - are you young or old, flexible or stiff, muscled or slim, chunky or skinny? Are you trying to podium or are you riding to win age-group or just have some fun and stay healthy? A bigger frame will increase head-tube height but also increase reach. The stay lengths/wheelbase/saddle height are generally irrelevant. What is important is your ability to get proper saddle setback (and NOT the calculated kind) and a useable saddle height that lets you keep control of the pedal throughout the pedal stroke, and most importantly, a comfortable front-of-bike position that permits some option for anterior pelvic rotation and lessening of load on the hands and arms. This means, contrary to some of the popular myths being bandied about, a raised bar height with properly assessed balance and reach.

 

If you are having lower back or hand pain, the larger frame might be a solution. Frankly, stem reach adjustments down to 60mm are absolutely fine and won't materially affect bike handling for our purposes. But slammed stems and the pro-wannabe long reach look are just guarantees of overuse injuries lying in wait.

[MTB_Roadie]

It's hard to beat working with good bikefitter. That being said, good bikefitters are very, very few and far between.

 

The problem with measure-and-calculate bike fitting is that it relies on average assumptions. Bell curves suggest most of us are anything but average. Any system that uses physical measurements to calculate a bike sizing (including guarantees of decimal-point accuracy) has to be viewed with complete skepticism.

 

But worse is that, even when a proper pre-purchase physical assessment and functional assessment has been performed, by a good fitter, most people display widely diverse biomechanical responses during a dynamic fitting on a bike. In addition these diverse responses change depending on the load, fatigue and neural stresses on the rider.

 

What I'm saying is that you can feel free to plug-and-play bikefit measurements - the web is full of different "systems", each guaranteed to give you a different result, but you are ballparking about as accurately as a new salesman in a bike shop using "rule of thumb".

 

The minimum requirement is to get a flexibility and functional physical assessment done, then factor in your riding style, requisites, goals and limitations. This will get you close to a good approximation based on your overall height . Then it is down to the fitter and his ability to take you through a dynamic fitting to achieve the desired result. And, yes, I've heard all the arguments about how you can do this at home with your ex-pro buddy, but really, you can't - at least not any better than the new salesman in a shop with some internet reading behind him.

 

To the OP - are you young or old, flexible or stiff, muscled or slim, chunky or skinny? Are you trying to podium or are you riding to win age-group or just have some fun and stay healthy? A bigger frame will increase head-tube height but also increase reach. The stay lengths/wheelbase/saddle height are generally irrelevant. What is important is your ability to get proper saddle setback (and NOT the calculated kind) and a useable saddle height that lets you keep control of the pedal throughout the pedal stroke, and most importantly, a comfortable front-of-bike position that permits some option for anterior pelvic rotation and lessening of load on the hands and arms. This means, contrary to some of the popular myths being bandied about, a raised bar height with properly assessed balance and reach.

 

If you are having lower back or hand pain, the larger frame might be a solution. Frankly, stem reach adjustments down to 60mm are absolutely fine and won't materially affect bike handling for our purposes. But slammed stems and the pro-wannabe long reach look are just guarantees of overuse injuries lying in wait.

 

And you are?

[Bike Mob]

It's hard to beat working with good bikefitter. That being said, good bikefitters are very, very few and far between.

 

The problem with measure-and-calculate bike fitting is that it relies on average assumptions. Bell curves suggest most of us are anything but average. Any system that uses physical measurements to calculate a bike sizing (including guarantees of decimal-point accuracy) has to be viewed with complete skepticism.

 

But worse is that, even when a proper pre-purchase physical assessment and functional assessment has been performed, by a good fitter, most people display widely diverse biomechanical responses during a dynamic fitting on a bike. In addition these diverse responses change depending on the load, fatigue and neural stresses on the rider.

 

What I'm saying is that you can feel free to plug-and-play bikefit measurements - the web is full of different "systems", each guaranteed to give you a different result, but you are ballparking about as accurately as a new salesman in a bike shop using "rule of thumb".

 

The minimum requirement is to get a flexibility and functional physical assessment done, then factor in your riding style, requisites, goals and limitations. This will get you close to a good approximation based on your overall height . Then it is down to the fitter and his ability to take you through a dynamic fitting to achieve the desired result. And, yes, I've heard all the arguments about how you can do this at home with your ex-pro buddy, but really, you can't - at least not any better than the new salesman in a shop with some internet reading behind him.

 

To the OP - are you young or old, flexible or stiff, muscled or slim, chunky or skinny? Are you trying to podium or are you riding to win age-group or just have some fun and stay healthy? A bigger frame will increase head-tube height but also increase reach. The stay lengths/wheelbase/saddle height are generally irrelevant. What is important is your ability to get proper saddle setback (and NOT the calculated kind) and a useable saddle height that lets you keep control of the pedal throughout the pedal stroke, and most importantly, a comfortable front-of-bike position that permits some option for anterior pelvic rotation and lessening of load on the hands and arms. This means, contrary to some of the popular myths being bandied about, a raised bar height with properly assessed balance and reach.

 

If you are having lower back or hand pain, the larger frame might be a solution. Frankly, stem reach adjustments down to 60mm are absolutely fine and won't materially affect bike handling for our purposes. But slammed stems and the pro-wannabe long reach look are just guarantees of overuse injuries lying in wait.

 

Interesting read, where are you based and what service do you offer?

[Saudiq]

What size stem did the Ergofit reccomend?

 

The Spesh Tarmac 54 has a sloping TT so even in a 54 it's pretty compact, you wont have any issues with standover height.

 

I gather you have seen a 54 the\at is a good deal making you want to move from a 52, which would maybe be your choice if you were buying new.

 

I am 180 and ride a 54, but with a huge seatpost extension and 110mm stem. My brother is 175cm and rides a 54 as well with a 100mm stem and medium extension..

 

My feeling is that a 54 will work for you with either a 100 or 90 stem and low saddle height. The tarmac is a quick steering bike but is not going to suffer with a 90mm stem - some bikes handling changes dramatically with stem choice - but the specialized in my experience does not

 

They recommended a 105mm stem. Yes, my buddy bought a 54 and when I got on it, it felt very comfy. It really didn't feel much bigger than mine.

[Saudiq]

It's hard to beat working with good bikefitter. That being said, good bikefitters are very, very few and far between.

 

The problem with measure-and-calculate bike fitting is that it relies on average assumptions. Bell curves suggest most of us are anything but average. Any system that uses physical measurements to calculate a bike sizing (including guarantees of decimal-point accuracy) has to be viewed with complete skepticism.

 

But worse is that, even when a proper pre-purchase physical assessment and functional assessment has been performed, by a good fitter, most people display widely diverse biomechanical responses during a dynamic fitting on a bike. In addition these diverse responses change depending on the load, fatigue and neural stresses on the rider.

 

What I'm saying is that you can feel free to plug-and-play bikefit measurements - the web is full of different "systems", each guaranteed to give you a different result, but you are ballparking about as accurately as a new salesman in a bike shop using "rule of thumb".

 

The minimum requirement is to get a flexibility and functional physical assessment done, then factor in your riding style, requisites, goals and limitations. This will get you close to a good approximation based on your overall height . Then it is down to the fitter and his ability to take you through a dynamic fitting to achieve the desired result. And, yes, I've heard all the arguments about how you can do this at home with your ex-pro buddy, but really, you can't - at least not any better than the new salesman in a shop with some internet reading behind him.

 

To the OP - are you young or old, flexible or stiff, muscled or slim, chunky or skinny? Are you trying to podium or are you riding to win age-group or just have some fun and stay healthy? A bigger frame will increase head-tube height but also increase reach. The stay lengths/wheelbase/saddle height are generally irrelevant. What is important is your ability to get proper saddle setback (and NOT the calculated kind) and a useable saddle height that lets you keep control of the pedal throughout the pedal stroke, and most importantly, a comfortable front-of-bike position that permits some option for anterior pelvic rotation and lessening of load on the hands and arms. This means, contrary to some of the popular myths being bandied about, a raised bar height with properly assessed balance and reach.

 

If you are having lower back or hand pain, the larger frame might be a solution. Frankly, stem reach adjustments down to 60mm are absolutely fine and won't materially affect bike handling for our purposes. But slammed stems and the pro-wannabe long reach look are just guarantees of overuse injuries lying in wait.

 

I had the ErgofitMax done with Renay which included using flexibility testing where my riding style, etc was taken into account. What he then did was stick me on the bike and checked the angles at the hip and knee as well as elbows. I can't complain about the results, I'm very comfortable on my current bike. The reason for this post however was to find out if I did switch to a bike with a slightly longer top tube, would I be able to get the same results, i.e., be just as comfortable on the bigger bike.

 

I do however agree with you that the 'plug and play' methods are not always accurate, my dad also had the Ergofit done with Renay and his seat always looked to low and also felt to low for him. he recently raised his saddle 2cm and now is very happy with the bike.

 

To answer some of your questions above, I'm a healthy 31 year old male with a blend of chunky and muscled but working on getting lean. I used to ride just for fun but now I ride to try and win my group so I can improve my seedings.

Edited August 26, 2011 by Saudiq

[Fitter]

I had the ErgofitMax done with Renay which included using flexibility testing where my riding style, etc was taken into account. What he then did was stick me on the bike and checked the angles at the hip and knee as well as elbows. I can't complain about the results, I'm very comfortable on my current bike. The reason for this post however was to find out if I did switch to a bike with a slightly longer top tube, would I be able to get the same results, i.e., be just as comfortable on the bigger bike.

 

I do however agree with you that the 'plug and play' methods are not always accurate, my dad also had the Ergofit done with Renay and his seat always looked to low and also felt to low for him. he recently raised his saddle 2cm and now is very happy with the bike.

 

To answer some of your questions above, I'm a healthy 31 year old male with a blend of chunky and muscled but working on getting lean. I used to ride just for fun but now I ride to try and win my group so I can improve my seedings.

 

Changing frame sizes changes a lot more than just tt length. Even on the same model bike. Fit is not about angles at knee or hip or elbow. PM me and i will refer you to a trained and certified fitter in CT who can help if you get stuck.

Edited August 26, 2011 by Fitter

[Cippo]

Pm me your bike fitters details kanalla

Edited August 28, 2011 by Super Mario