|Frameset Questions - materials & design||JBF|
Aug 2, 2002 12:36 PM
|I am concidering a new frameset and would like opinions on how steel vs. titanium compare given similar frame design. Will one ride different from another? It seems that some new steel frames are as light as Ti these days. |
My other question is if there is any difference in straight vs. curved chainstays & seatstays. Is there any downside to one versus the other?
All input is appreciated
|re: Frameset Questions - Ti and steel||Eric_H|
Aug 2, 2002 2:26 PM
|I'm sure many will say it is difficult to compare different materials objectively and this is true. I will give you my impressions, as I currently ride a Merlin XL and before that I was riding a Marinoni built from Columbus Foco. The frames are very similar in geometry and the components used are nearly identical, except the Merlin has a Reynolds Ouzo Pro fork and the Marinoni had a unicrown Columbus Genius steel fork.
First off, the Merlin is lighter. I've never weighed the two frames on a scale, but in an unbuilt state and hefted by hand, the Merlin was definitely lighter. The claimed weight for a Merlin XL (size 58) is around 3 lbs. Obviously, this weight transfers into a lighter bike. In terms of BB stiffness, I find both frames to be about the same. There is definitely some flex (I'm 6' and 167 lbs), but I cannot say one was worse than the other. Compared to aluminium or scandium frames I have owned both the steel and Ti are more flexible at the BB. In terms of the mystical "ride quality", my impression would be that the Ti frame dampens road vibration a little more. But of course the forks are different and this will greatly influence ride quality perception.
Another consideration is durability. While steel has an excellent fatigue life, it is still not equal to Ti. Plus, the lightweight steels (Foco, UltraFoco, EOM 16.0.5) are drawn VERY thin. This can be problematic if the builder does not have experience working with the tubing, in terms of fatigue induced failure from overheating. Plus, the thin steel tubes are likely much less dent-resistant than Ti.
Finally, regarding curved stays versus straight. The builders of Ti bikes would like to have us believe bending and cold-working of the stays increases the stiffness of the tube. It very well may be so. However, changes in geometry (ie. shorter chainstays) will produce much more dramatic changes in the rear triangle stiffness.
|Have you checked out Cervelo?||KillerQuads|
Aug 2, 2002 3:00 PM
|I too like the classic look of a narrowed tube steel or titanium bike. I have two lugged steel Paramounts. Steel has a great ride quality when putting the hammer down. But a steel fork will have some vibration. A carbon fork damps vibration and makes a road bike more comfortable.
My new bike is a Cervelo Soloist with and aluminum frame and carbon fiber fork. It is stiff for climbing, but comfy over ripples and bumps. It is the best of both worlds and a super sweet ride. The reason is the unique design of the frame tubes which are tear drop shaped for aerodynamics with more material on the sides for stiffness. The carbon fiber fork blades damp out vibration and are also tear drop shaped.
Does the aero design make a difference? Well I rode a personal best average time over my usual course. Also, when riding slow the bike is eerily quiet as it cuts through the air.
The bike is fairly light at 18.4 lbs (54 cm, no pedals)
|re: Frameset Questions - materials & design||sprockets2|
Aug 3, 2002 8:51 PM
|I have a stable of older and newer steel bikes, and a ti Litespeed Classic. All of the bikes have a similar design-more of a "classic" geometry with a longish wheelbase by today's standards, moderate-to-long top tube, and quick but not criterium-quick steering. Each bike is very different from the other because of the individual tubing type and tube specifics, and small differences in geometry.
About ti I can say that it is all that I thought-and heard-it would be, except that unless you are able to specify some custom tubes, a big, powerful rider will not find the frame to be unyieldingly stiff. For most riders, like me, that is not a problem. The other virtues, including weight, ride, handling, and more, outweigh the fact that on steep climbs where I am out of the saddle on the 63 cm frame, and hammering my 220 lbs. hard on the pedals, I can get some BB flex. I really appreciate the skill and design that went into the Litespeed. Manuipulated tubes, good geometry-very nice. Not all ti is the same. Some builders use straight tubes. Some butt the tubes without other manipulation.
About steel, I have found that it depends. The best steels do indeed seem to rival the other materials. Steel won't be lighter, but it is close enough to look seriously at in many cases. At the extremes of design-serious racing stuff, steel won't be the lightest, but most of us don't need to be at that extreme.
Having said that, many steel frames are built today with steel that is not close to the best steel in performance to weight considerations. For my money, tubes made from 853, OX Platinum, and the best Deda boron steel are going to satisfy those making aluminum/ti/steel comparisons.
My older, beautiful lugged frames have classic appeal, and use what was at the time state of the art steel, and they are heavy by today's standards. Even if they could have butted and manipulated the tubes better, the steel just wasn't as good as today's best steel, so the bikes wouldn't have been better performing by much. My new Gunnar frame (this is the welded bike from Waterford) otoh is quite a different matter. They use large diameter 853 and True Temper Platinum on the stays. My 62 cm frame is the lightest steel frame I have handled, except for a smaller Bianchi boron steel frame (so no comparison is possible). Here is how light by Gunnar is: my wife has a small Reynolds 531 racing frame that is heavier than my Gunnar frame with a seatpost and saddle on it. On the road the Gunnar might be the best bike I have ridden. Not as smooth as the Litespeed, but really close. Note, though, I like the feel of steel.