Ive had a custom guru crono and now a p3 cervelo. Both bikes seem to feel “flat” after about one years time training mostly on the computrainer. Is it just me or is there a measurable data point that can be accounted for the loss of responsiveness? Maybe a decrease in bottom bracket stiffness? I’ve heard this happens when training on the trainer a lot due to all the forces being absorbed by the fixed carbon frame when mounted on a trainer.
I also have a titanium independent fabrication which I haven’t noticed a change but admittedly only ride outside.
This is almost certainly just in your head.
I also have a titanium independent fabrication
My guess is that your carbon bikes have always felt “flat” and that you just prefer the feel of the Ti bike (never ridden one, but I DO notice the difference between my steel bike vs carbon).
Looks like you are right from the lack of responders! Im a bit suprised because I would swear its happened now with two bikes.
I have a ~13 year old Trek OCLV cf bike that I know is more flexy than when it was new, but the change didn’t really start happening until around year 8 or 9. The degree of loss probably depends a lot on how much it is ridden, rider weight and a variety of factors I can’t think of. Mine was ridden about 60,000 km before it lost its stiffness, but even so it is a great ride.
This is almost certainly just in your head.
Not necessarily, there’s a lot of bitching in the archery side of the world about carbon shafts losing there stiffness after a few thousand shots and we can measure that cumulative failure with a spine tester.
I’m open to the idea that the bikes would lose some stiffness.
I’m skeptical that one would notice, on a bike.
One could of course head to the local bike shop, and arrange to blind test themselves!
I wonder if perhaps various cues from drivetrain wear and bearing/lubrication condition create the ‘flat’ feeling you are sensing. Hard to say since…what is “flat” anyway? =)
This is almost certainly just in your head.
Not necessarily, there’s a lot of bitching in the archery side of the world about carbon shafts losing there stiffness after a few thousand shots and we can measure that cumulative failure with a spine tester.
It happens with hockey sticks, too. I have a carbon shaft that’s 5 or five years old. I somehow have managed not to break it in all that time (it’s probably had ten blades in it). The shaft has gotten so noodly that it’s nearly unusable. I couldn’t seem to get a decent shot off anymore and it was starting to play on my mind - picked up a new stick and my shot was right back (back to mediocre!).
I’m not too worried about my AR4, though. I don’t beat on it like I beat on a hockey stick.
The carbon itself really shouldn’t have any fatigue life. I’ve got 20-year-old graphite fishing rods that have gotten the shit yanked out of them countless times on snags so I have a hard time believing the carbon fibers themselves are elongating (like a metal might) or otherwise breaking down. Perhaps there’s some degradation of the epoxy resin that allows the carbon layers to ‘slip’ (the engineers probably have a better term for it) somehow within the layup matrix?
Or, possibly some weakening/loosening of the non-carbon ‘interface’ bits (dropouts, threaded BB shell, head tube & seat tube sleeves) where they’re bonded in? That would seem like it could allow some play at the key contact points w/ wheels, cranks, and/or steering that could contribute to an overall feeling of reduced responsiveness. I had a friend once that had to warranty an old Kestrel cuz the BB sleeve broke loose within the frame so the whole thing turned when you tried to tighten/loosen the BB.