Small People don't like Stiff Frames ..

[JohnO]

Just to toss in an alternte viewpoint...

Of the bikes in my growing stable, the smoothest riding is an aluminum framed Cannondale. The harshest riding bike I have sports a carbon beam frame. This tends to be the opposite of what the 'frame material' debates around here tend to indicate, that carbon rides easy (especially a beam frame) while aluminum rides rough.

Of course, the Cannondale is a tandem, with 4 cross laced wheels and my wife on the back, while the carbon beam bike is a Trek Y-Foil with tightly torqued Rolf Vector Pro wheels and very stiff Cinelli Integralter bars. Fast as a thief, but definitely a rough rider.

Point being, frame material has an impact on ride quality and efficiency, but it's not the only factor. Components like wheels and handlebars also contribute to the package, as well as rider weight. I would imagine that the weight of two riders on one set of wheels (albeit very stout tandem wheels) is a primary reason for the 'Dales velvet smooth ride.

Which gets back to the original question - do bikes ride harsher for lighter riders? Based on what I've seen with the tandem, I'd have to say yes, rider weight is definitely a factor in ride quality.

 

[nickwill]

I was recently told that aluminium frames under 54 cm size should be avoided . The weght difference between a small aluminium frame and one made of steel is minimal. Once one gets into the larger sizes they are likely to be structurally less stiff. Also the larger the frame, the greater the weight differences between materials.
So steel or titanium for small frames, and consider aluminium for larger sizes.

 

[boudreaux]

Originally posted by JohnO
Just to toss in an alternte viewpoint...

Of the bikes in my growing stable, the smoothest riding is an aluminum framed Cannondale. The harshest riding bike I have sports a carbon beam frame. This tends to be the opposite of what the 'frame material' debates around here tend to indicate, that carbon rides easy (especially a beam frame) while aluminum rides rough.

Of course, the Cannondale is a tandem, with 4 cross laced wheels and my wife on the back, while the carbon beam bike is a Trek Y-Foil with tightly torqued Rolf Vector Pro wheels and very stiff Cinelli Integralter bars. Fast as a thief, but definitely a rough rider.

Well, that's gotta be the most inane, obtuse, lemons to watermellos comparison I ever heard. At a minimum,consider the tire sizes and the fact the trek really isn't a true 'beam' in the Softride sense.

 

[dhk]

Originally posted by Mario Jr.
No, you will not have as much, if any, filtering from the CF rear, as you will from a fork. The fork can move freely back and forth, whereas the rear is part of a fixed triangle. The difference between an alu and a CF rear is very very little in that manner.
I own a bikeshop, and I have had the opportunity to ride two completely similar bikes, with one having a CF rearstay. The difference was much smaller, than a different tire choice would show.

Could you share what bikes these were? I've heard the italian CF rear frames tend to be pretty stiff, but have no experience with them. I've only test-ridden the Trek 2300 vs 1000. Would like to know your riding impressions of the new Trek 2300, or any bike with a Reynolds or Carve carbon rear stay. I know the label CF itself doesn't tell you much, but I believe a CF rear seatstay can be designed to absorb a good bit of road buzz....if that's the type of ride someone is looking for.

Dan

 

[Mario Jr.]

Originally posted by dhk
Could you share what bikes these were? I've heard the italian CF rear frames tend to be pretty stiff, but have no experience with them. I've only test-ridden the Trek 2300 vs 1000. Would like to know your riding impressions of the new Trek 2300, or any bike with a Reynolds or Carve carbon rear stay. I know the label CF itself doesn't tell you much, but I believe a CF rear seatstay can be designed to absorb a good bit of road buzz....if that's the type of ride someone is looking for.

Dan

Yep, is was a danish bike called Boreas. look for the Ignis and the Ignis Carbon models: http://www.boreas-bikes.com
It is quite a stiff bike with or without CF rearstays. Their inventor is the former head engineer from Principia. http://www.principiabikes.com
Again I can tell you about the german "Tour" magazine. When they test bikes, they have a fixture with weights, that very precisely shows the stiffness in a frame. They measue both the BB stiffness and the front/headtube stiffness.
They also masures the amount of vibrations in every frame they test, using a special seat with sensors.
It amuses me to read some of the replys here, stating that their bike is super stiff and comfy, when I can read the objective results in my magazine.
The difference between any diamond-shaped frame is very little. They proved that tire choice, fork choice and seat choice had a 10 times larger effect on the experience of vibration damping.

 

[chr]

German Tour magazine conducted a test while ago, which ended up showing that the carbon rear ends have close to nothing to do with comfort. They don't really take away the road buzz or anything like that. Dropping your tire pressure by 2 psi will do more.

A nice marketing gimmic though, I've bought into it myself...

 

[dhk]

Originally posted by Mario Jr.
Yep, is was a danish bike called Boreas. look for the Ignis and the Ignis Carbon models: http://www.boreas-bikes.com
It is quite a stiff bike with or without CF rearstays. Their inventor is the former head engineer from Principia. http://www.principiabikes.com
Again I can tell you about the german "Tour" magazine. When they test bikes, they have a fixture with weights, that very precisely shows the stiffness in a frame. They measue both the BB stiffness and the front/headtube stiffness.
They also masures the amount of vibrations in every frame they test, using a special seat with sensors.
It amuses me to read some of the replys here, stating that their bike is super stiff and comfy, when I can read the objective results in my magazine.
The difference between any diamond-shaped frame is very little. They proved that tire choice, fork choice and seat choice had a 10 times larger effect on the experience of vibration damping.

Can I review that Tour article on line? I've seen the EFBe fatigue tests on their website, but have read nothing about any vibration testing or measurements. I'm skeptical when you say there is very little difference in any frame, but would like to learn more.

Agree that tire pressures make a big difference. At 76 kg, I prefer 95-100 psi vs running the 120 psi max.

Based on my own experience of test-riding the Trek 2300 and 1000 back-to-back, at the same tire pressures on the same roads, I definitely felt a difference in ride quality. Perhaps I mistakenly attributed that to the CF rear stay, when of course the Zr9000 Al is a thinner-wall tubeset, and the forks and tires are different as well.

Dan

 

[boudreaux]

Originally posted by dhk


Based on my own experience of test-riding the Trek 2300 and 1000 back-to-back, at the same tire pressures on the same roads, I definitely felt a difference in ride quality. Perhaps I mistakenly attributed that to the CF rear stay, when of course the Zr9000 Al is a thinner-wall tubeset, and the forks and tires are different as well.

Dan

Well,yeah there is too much that's different.Only way to even get close is to try the current 2300 and last years without the CF stays,and even that assumes the various other contributing parts are the same.

 

[telrad]

Originally posted by dhk

Agree that tire pressures make a big difference. At 76 kg, I prefer 95-100 psi vs running the 120 psi max.

Based on my own experience of test-riding the Trek 2300 and 1000 back-to-back, at the same tire pressures on the same roads, I definitely felt a difference in ride quality. Perhaps I mistakenly attributed that to the CF rear stay, when of course the Zr9000 Al is a thinner-wall tubeset, and the forks and tires are different as well.

Dan

Tire pressure is another whole debate isnt it.

Personally I ride at 110psi .. a compromise between outright performance and feeling like your wheels are 6inches under the tar.

 

[drewski]

Originally posted by dhk
Can I review that Tour article on line? I've seen the EFBe fatigue tests on their website, but have read nothing about any vibration testing or measurements. I'm skeptical when you say there is very little difference in any frame, but would like to learn more.

i'd love to see that as well, if there is a link.

Originally posted by dhk
Agree that tire pressures make a big difference. At 76 kg, I prefer 95-100 psi vs running the 120 psi max.

i'm 73kg and ride @ 120psi. i guess i'm a glutton for punishment . . . maybe from my racing days a decade ago? back then i'd pump the tubulars up to 130-140psi! and i was just 62kg too.

of course, that was with my steel frame and now i have these great CF stays absorbing the vibes!! it seems like a CF rear triangle can be designed to be more vertically compliant and absorb some vibration.

ok, i admit it. i'm a lemming for slick marketing!

 

[dhk]

Originally posted by drewski
i'd love to see that as well, if there is a link.



i'm 73kg and ride @ 120psi. i guess i'm a glutton for punishment . . . maybe from my racing days a decade ago? back then i'd pump the tubulars up to 130-140psi! and i was just 62kg too.

of course, that was with my steel frame and now i have these great CF stays absorbing the vibes!! it seems like a CF rear triangle can be designed to be more vertically compliant and absorb some vibration.

ok, i admit it. i'm a lemming for slick marketing!

I always used the max too, until I noticed many of the faster guys in the club running 95-100 psi for better roadholding and comfort. Seems to work better for me too.

And good to hear your reaction to the CF rear. I'll be switching from steel also to CF rear, so I'll find out for myself. It doesn't surprise me at all that CF rear will absorb some vibrations.

Dan

 

[dhk]

Here's one link to the EFBe testing: http://damonrinard.com/EFBe/frame_fatigue_test.htm

Note they were a little surprised by the early failure of the Merlin.

There is also an 11/03 update which has the great results for the Cannondale CAAD 7 posted.

Dan