|Skewers: Steel really better than Ti?||5ive|
Dec 3, 2002 8:33 PM
|I always just automatically assumed that QR skewers with Steel rods will be stiffer, more secure than Ti. But aren't the wheels really contacting the dropouts at hub axels and not the skewer rods? If so, does it really matter that Steel rod is stiffer than Ti rods on the skewers? Does anyone have any personal experience to contradict this? Just curious...|
|steel's less elastic.||jw25|
Dec 4, 2002 5:49 AM
|Yes, the main contact is between the axle and dropout, but the QR needs to be tight, and stay tight, to keep the axle in the same location in the dropouts.
Up front, it makes little difference, as cornering doesn't generate enough force to stretch a ti skewer, but in the back, pedaling torque can cause movement of the axle. It's an uncommon situation, and depends on skewer tightness.
For mountain bikes, where the front axle is used to stiffen a suspension fork, ti skewers are not at all recommended, hence the "suspension" skewers from Salsa and others. They use a steel rod up front, and a ti in back, for the best combination of performance and light weight.
|steel's less elastic.||eddie m|
Dec 4, 2002 12:42 PM
|Ti is stronger but steel results in greater clamping force because it is less elastic. For modern road bikes with vertical dropouts, it doesn't make much difference, but steel will hold better on bikes with horizontal dropouts.|
Dec 4, 2002 1:32 PM
|Better start covering your bases with broad statements like that. What it all comes down to is what particular alloy of ti or steel you're talking about and exactly what heat treament process has been used. The question is what's typically used in bicycle skewers not cutting surfaces of machine tools. In this application the ti skewers are noodles and it really does matter as many of us can attest to having wheels move around when ti skewers have been used. Ti has a superior strength to weight ratio over steel, however one is severely limited in cross sectional area for a skewer and you need all the strength and stiffness you can muster into a few millimeters of the skewer diameter and the relatively long length. Most people, even self proclaimed weight weenies like myself, come to the conclusion that ti skewers aren't worth it. I've got a perfectly good set sitting in a coffee can that I never use.|
Dec 4, 2002 5:33 PM
|Actually, strength and elasticity are two different things. All steels have nearly the same modulus (elasticity), just as all Ti alloys have the same modulus (about 1/4 of steel), and heat treatment has no effect on the modulus. That's why steel QR's are better than Ti, regardless of their strength. Cheap steel skewers are as good as costly ones (unless of course they are so weak that they fail) although the hardness and finish on the nuts has an effect on retention.|
Dec 4, 2002 4:48 PM
|I had a problem with my back wheel - when I firmly locked the rear scewer, my wheel was fine until I rode the bike - then the wheel would scew to the non drive side a few mm - enough to notice. The Trek rep picked that the cro moly scewers were to blame (i though it was incorrect dish) - when we replaced them with cheapy steel ones the wheel stayed put. Trek are trying to decide between replacing my original scewer with either their Ti one or a steel Dura Ace - I know which I'd prefer!|| |