#46
|
|||
|
|||
Opposite Effect for me
Quote:
Totally opposite experience for me between the Seven Ti Axiom and Ottott. I believe A LOT has to do with ridder weight and riding style. |
#47
|
||||
|
||||
Quote:
|
#48
|
||||
|
||||
There is a lot of good information here, but there is also some that IMHO can be misleading. In fairness to Serotta, Moots, Litespeed, and all others who make titanium frames, a technical perspective from a different point of view may be helpful to a few.
Regarding what was implied in the original post, we can’t really “see” how beefy (in a stiffness sense) a chainstay is by observation alone. Diameter is a major part of it, but the wall thickness is also important; and that can’t be observed. A wimpy-looking stay can be stiffer than a larger one – which is the case in some designs – in order to make them stronger or to allow for greater tire clearance. Larger stays are probably stiffer, but there is no guarantee that they actually are. As stated above by others, titanium is indeed more flexible than steel, but aluminum is even more so and few complain about aluminum chainstays being too flexible. If designers can work with aluminum, they can do the same with titanium. Other than added weight, a titanium tube can be made as stiff as a steel one without increasing diameter. Judging by looks alone can lead to wrong assumptions. Also as correctly stated by others above, drivetrain loads on the chainstays caused by chain tension are indeed limited to the area between the BBKT and rear axle, so downtube size can’t help the chainstays resist bending due to chain loads. However, many of us lean a bicycle from side to side (some riders more than others) when sprinting and/or climbing, and that action not only places additional loads on the chainstays, but also places the downtube in bending and torsion. That is why a larger and/or ovalized downtube can better resist frame flex under heavy pedaling out of the saddle, which can limit front derailleur rub. When the wall thickness is held constant, an oval stay can be considerably stiffer in bending even when the minor dimension is equal to that of a round tube. Think of a 2X4 which is a lot more flexible in one direction that the other. Even so, it doesn’t change the fact that it is still twice as stiff in its weakest direction as a 2X2 (albeit at a higher weight). The same kind of logic applies to oval versus round stays (again, when WT is held constant). I don’t have a preference in oval versus round stays; I’m just stating a fact. Slight bends in stays can affect the stiffness appreciably in tension or compression, but have insignificant affect in bending or torsion. Unless a buyer actually knows which way a stay is loaded, speculating on its effect is pointless. Just ride the bike and see if you like it. Just a slightly different point of view. |
#49
|
||||
|
||||
Quote:
Additionally, significant vertical compliance provided by seatstays or fork is inherently limited by ability to control the wheels in roll. |
#50
|
||||
|
||||
Quote:
Just more ramblings of a lunatic, -Ray
__________________
Don't buy upgrades - ride up grades |
#51
|
||||
|
||||
Quote:
|
#52
|
||||
|
||||
Quote:
pragmatic i guess. i can't feel shape or guage, or even if the pipe is heat treated. no matter - it's just me. |
#53
|
||||
|
||||
Quote:
Knowing nothing about engineering, but just having ridden a bunch of bikes over the last 4 decades, the bike needs to feel balanced and it needs to fit. I also think you can overdesign stiffness resulting in a harsh ride which is fun for a while but not for long. |
#54
|
|||
|
|||
Quote:
kind of drives me crazy. |
#55
|
||||
|
||||
Quote:
-RS
__________________
Don't buy upgrades - ride up grades |
#56
|
||||
|
||||
Quote:
|
#57
|
||||
|
||||
Quote:
i think i can tell when i have a spoked-from-a-wheelbuilder wheel in my bicycle versus a factory (eurus, etc) wheel, and can feel clinchers versus handmade tubs. when i replace the chain and cassette, my drivetrain makes leads me to believe that i have a near-new bicycle. thes examples are the extent to which i can sense anything rear of the seat tube. if i re-wrap the 'bars with new tape, get outa' my way atmo.
__________________
________________________ the tao of atmo the tao of e-RICHIE©™® ________________________ Campagnolo = The Journey Shimano = Mapquest Last edited by atmo; 03-19-2007 at 12:35 PM. Reason: a puerile typo... |
#58
|
|||
|
|||
Quote:
|
#59
|
||||
|
||||
Quote:
g |
|
|