Madone SL 5.2 or Madone 5.5?

[mikehvizdak]

All right, so I have decided that I need a new road bike and i am going to need a little advice here. I could either go with a 2006 Madone SL 5.2 with Ultegra and oclv 110 carbon or a 2006 Madone 5.5 with Dura Ace and oclv 120 carbon. The 5.2 has a lighter frame but a downgrade of components while the 5.5 has a heavier frame but higher end components. I work in a bike shop so i can get everything dirt cheap including these bikes...so i figure if i got the 5.2 i could eventually upgrade to dura ace but the 5.5 already has the dura ace which would cut out the trouble of installing all the upgrades. Man..im just going crazy over this. Can somebody tell me which one of these is lighter and by how much..and which one of these is the better buy? Thanks everybody!

 

[FrankBattle]

All right, so I have decided that I need a new road bike and i am going to need a little advice here. I could either go with a 2006 Madone SL 5.2 with Ultegra and oclv 110 carbon or a 2006 Madone 5.5 with Dura Ace and oclv 120 carbon. The 5.2 has a lighter frame but a downgrade of components while the 5.5 has a heavier frame but higher end components. I work in a bike shop so i can get everything dirt cheap including these bikes...so i figure if i got the 5.2 i could eventually upgrade to dura ace but the 5.5 already has the dura ace which would cut out the trouble of installing all the upgrades. Man..im just going crazy over this. Can somebody tell me which one of these is lighter and by how much..and which one of these is the better buy? Thanks everybody!

At the end of the day, Dura Ace weighs less than Ultegra. It may also be less, well, "Dura"ble. As for the weight, unit for unit, the 110 weighs less than the 120. I think the number is the mass per square units (can't remember if it's inches or cm).

I'll cut through the chase as you will do what you deem "right" in the end; I'll offer my opinion as a non-racer, but aggressive daily & weekend rider. The Ultegra is the better value. The Dura Ace will be lighter, look cooler, but will cost more. If you will race, I suppose you'd want to have about the same equipment as others have (assuming the engine is about the same .. with/without PEDs).

Lighter OCLV 110 frame + Ultegra drivetrain
[Slightly] heavier OCLV 120 frame + Dura Ace drivetrain

You'll probably end up with the Dura Ace bike being lighter by a wee bit. Assuming weight is important here, get the 120 with the Dura Ace. If you don't, even despite the Ultegra being the better value, you will probably feel the need to upgrade to the next best thing, which would obviously be more expensive in the end.

Get the top of the line and be done. Personally, I have 3 (soon to be 2) all ultegra bikes and love them. Never ridden a Dura Ace bike so I can't compare, but these days, the difference is probably not that great. I'm 6'3" & 190 - 195 lbs so a weight difference of a handful of tens of grams will go very much unnoticed.

 

[dhallag]

unless you're a racer, no need to get the dura ace. Both shift exactly the same and the only difference is weight.

 

[RickF]

All else being equal, the OCLV 110 frame is 8.33% lighter than the OCLV 120 frame. I do not know what these frames weigh, but if the 110 weighed 1000 grams, the 120 would weigh 1083 grams. By the time you add the components, this is a small difference in the overall weight of the bike. Any difference in geometry or size of the frames would be bigger than this. By comparison, an ounce of water in the water bottle weighs 30 grams.

The other consideration besides weight is the durability of the frame. The OCLV 120 frame is stronger than the OCLV 110. Durability (or the lack thereof) is the reason Trek does not sell to us mortals the OCLV 55 that is used on the Discovery Channel bikes. Even though Trek will replace cracked frames under waranty, most of us would be very upset if the frame of our $4000 bike cracked every few months.

Theoretically, the 120 should flex less than the 110, but the difference would be so small I am not sure it would be measurable, let alone significant.

BTW, the number refers to grams per square meter.

 

[RickF]

A 58cm Madone OCLV 55 frame weighs 950 grams. Assuming identical size and geometry, the most an OCLV 110 frame should weigh is 1900 grams, and the most an OCLV 120 frame should weigh is 2073 grams. These are the worse case values and probably are not be accurate, since there are other things contributing to the weight of the frame besides the carbon fiber. The OCLV 55 has boron added to the bottom bracket area to increase frame stiffness. This undoubtedly adds to the weight, but I do not know how much.

 

[Lonnie Utah]

The OCLV 55 has boron added to the bottom bracket area to increase frame stiffness. This undoubtedly adds to the weight, but I do not know how much.

Nope. Boron is lighter than carbon.

Atomic Weight
Boron 10.81
Carbon 12.01

http://www.dayah.com/periodic/Images/periodic%20table.png

 

[RickF]

Nope. Boron is lighter than carbon.

Atomic Weight
Boron 10.81
Carbon 12.01

http://www.dayah.com/periodic/Images/periodic%20table.png

True, but unrelated. Atom for atom, boron is lighter than carbon, but we do not know that the boron replaces carbon in a one to one ratio. I may be wrong, but from the description I have seen, it appears that the boron is in addition to the carbon, not instead of the carbon. Also, the crystalline form will determine the weight of the solid. Diamond, coal, graphite, charcoal and carbon fiber are all carbon. Gram for gram, they contain the same amount of carbon, but the weight to volume ratio is not necessarily the same.

 

[rudycyclist]

Get the 5.2 and try to sell the Ultegra right away to upgrade to d/a or better yet Campy, if you're into that. You'll get the lighter frame and probably get face value for the Ultegra. d/a isn't a ton more than Ultegra in price.

 

[rower]

A 58cm Madone OCLV 55 frame weighs 950 grams. Assuming identical size and geometry, the most an OCLV 110 frame should weigh is 1900 grams, and the most an OCLV 120 frame should weigh is 2073 grams. These are the worse case values and probably are not be accurate, since there are other things contributing to the weight of the frame besides the carbon fiber. The OCLV 55 has boron added to the bottom bracket area to increase frame stiffness. This undoubtedly adds to the weight, but I do not know how much.

The Boron actually adds to the weight but increases stiffness an engineer friend informs.