Road Bike Size 54 to 56...i there a difference

[biserker1]

I have been currently riding a size 54 for the past three years (trek 2.1). I am 5'11" 165lb

Looking to upgrade my frame to a carbon fiber. I found a very nice 5.9 madone size 56. Looking over the measurements there doesn't seem to be a big difference. Any insight to moving up a size? feel of the bike, feel of the ride?

Thanks

 

[Look 566 Rider]

First stand over the Trek 5.9 to make sure the top bar is not in your crotch. You know, can you lift the bike and have an inch or more clearance before the family jewels provide interference. I am 5'10.5" with 31 inseam. I tend to have 54 be the top of my size range. If your reach, pedal stroke etc. is good then go for it. Ride the bike.

You don't say in your post if this 5.9 is frame only, is it?

Going from aluminum to carbon will feel different. Less buzz, chatter or whatever you want to call it. The larger frame may feel ever so slightly less responsive, but probably not since you are changing frame material. I think the handling will also be a wash for the same reason.

If you want to upgrade and really like your current bike, I suggest upgrading your wheelset and tires. Lighter stiffer wheels can make a big difference. Then maybe other parts like the seat post, seat, stem and bars. switch them out for CF parts.

Good luck,

Mike

 

[biserker1]

Thanks. It is just a frame, i would transfer my current group over.

Would love to buy a new carbon new, the money is just too much. If i can expand my search to include 56, there are many more options.

 

[danfoz]

2 noticeable changes:
1. taller head tube. Solution - remove corresponding # of spacers under stem.
2. longer top tube. Solution - may need a slightly shorter stem.

If your contact point triangle stays the same, i.e. the relationship between your seat, pedals and handlebars, the feel of the bike over smooth pavement should not change all that much.

Seat tube diameter may be different and would therefore need a new seatpost.

I am 5'8" and ride a 54cm. Smaller sizes (with their shorter head tubes) usually have me too low on the bars unless I flip the stem.

 

[Mark George]

You can buy compact frames now that have longer headtubes and shorter top tubes. I put together a Raleigh Revino that has the same length head tube as my old Litespeed 55cm, but a shorter top tube. End result is I can use a 52cm frame instead of a 55cm just go to a longer stem. Feels alot different to me and handles better. My "triangle" remains the same on a smaller more nimble bike.

 

[danfoz]

Getting better handling on a new bike is a nice thing. Many things can make a bike feel more (or less) nimble when changing sizes between different brands. Wheelbase length, seat and head tube angles, fork rake, rider's center of gravity, position of weight over the steering axis. Smaller can be more nimble, or not.

 

[vspa]

Originally Posted by biserker1 .

I have been currently riding a size 54 for the past three years (trek 2.1). I am 5'11" 165lb

Looking to upgrade my frame to a carbon fiber. I found a very nice 5.9 madone size 56. Looking over the measurements there doesn't seem to be a big difference. Any insight to moving up a size? feel of the bike, feel of the ride?

Thanks

for your height a 54 is already big, in classical frame geometry at least,

 

[danfoz]

Here are a couple sizing charts which can be useful for establishing a baseline. These were some of the first charts in my search, there are other charts as well. These are a little different from each other. Those more familiar with sizing and riding have their own baselines and have a preference for sizing one way or the other. 54cm, or something with a top tube around 54.5 is on the smaller side for someone 5'11" (180cm). Edit: and since I've successfully gotten away with riding a 52cm c-c as well as a 55 for a period way back when I'm the last one who should be pointing to any charts /img/vbsmilies/smilies/wink.gif

 

[biserker1]

Thanks for all the advice - Some charts say 54 and some say 56. When i looked at the TREK chart the difference between the 54 and 56 was subtle. I feel comfortable on the 54 and will stick with that size!

 

[danfoz]

That's as good a baseline as any. Good luck with any upgrades.

 

[alienator]

Screw the generic baselines and just get on the bike to see how it fits and rides. Some folks have short torso's or long torso's. Some folks have short legs or long legs. Trying a bike, short of knowing exactly what you need, is the best way to find out what fits. Since there's a Trek dealership in loads of cities, it shouldn't be hard to find a place to try said bike.

Going from aluminum to carbon will feel different. Less buzz, chatter or whatever you want to call it. The larger frame may feel ever so slightly less responsive, but probably not since you are changing frame material. I think the handling will also be a wash for the same reason.

Not. Generalizations about ride character based on material alone are bad generalizations. Ride is a function of design, construction, QC, and fit. Full stop. There are, for example, loads of CF bikes that are "buzzy" or display "chatter". Likewise, there are loads of aluminum bikes that don't.