|   opinions on dt vs. wheelsmith | dirtdonk
Jan 17, 2004 11:07 AM | | anybody have an opinion on which is better when comparing 14 ga. spokes? in terms of overall quality. resistance to stretch. and general toughness. or are we splitting hairs here. thanks for the input. by the way it was a spectacular morning for a ride here on the front range in colorado. just had to make it out before the thaw. |
| sorry for the double post | dirtdonk
Jan 17, 2004 11:08 AM | | |
| Wheelsmith's single-butted DH13 is nicer. | Bianchi4Me
Jan 17, 2004 11:44 AM | | If you are comparing straight 14 gauge (2.0mm) spokes than there really isn't a difference between the two brands. They are both very high quality products and will perform reliably.
However, a better choice for applications where you want maximum strength, durability, and the stiffness of a 14 gauge spoke is Wheelsmith's DH13 model. This is a 13 gauge (2.3mm) spoke at the hub end and butts down to 2.0 out to nipple end. They only weigh 7g more than plain 14 gauge spokes for 32 spokes. They are particularly nice in hubs with larger 2.6mm spoke holes (Shimano) or when building on used hubs. |
| I've used both DT and Wheelsmith spokes in 14/15/14 DB.... | Bikeless Rider
Jan 17, 2004 4:44 PM | | ...and found the Wheelsmith to be slightly smaller actual gauge and more resilient, requiring more retensioning during breakin. I have not used the Sapim 14/15/14 spokes, but they are affordable, raved about for quality, and becoming more common in the states. The only LBS here in Seattle that specializes in DH bikes swears by them. The same traits can be expected from each of these in their staight gauge form as well. |
| Wheelsmith DBs designed narrower, but straight gauge isn't. | Bianchi4Me
Jan 17, 2004 7:20 PM | | The Wheelsmith DB14, which is commonly refered to as a "14-15-14" gauge spoke is designed to be lighter and is therefore narrower in the center section than it's DT or Sapim equivalent. The manufacturer's spec dimensions for the DB14 is 2.0-1.7-2.0mm versus 2.0-1.8-2.0mm for the DT and Sapim products. So the DB14 is really a "14-15&1/2-14" gauge spoke.
This dimensional difference is only true for the Wheelsmith DB14 and DB15 spoke models. Everybody's straight 14 gauge spokes are the same diameter, 2.0mm. Unless you have really sophisticated analytical equipment, you won't be able to tell any difference between wheels built with DT or WS 14 gauge spokes.
Also, not sure what you meant by "break-in", and whether that was taking place during or after the wheel build. Ideally, a hand-built wheel does not have a "break-in" period after building. Not saying there will never be a wheel that doesn't need a spoke tweaked after hard initial riding, but the wheel should not need to be "re-tensioned". You should fully seat the spokes as part of the original building process by pre-stressing them. If you do find yourself having to re-tension the wheel after riding, than you might benefit from doing more pre-stressing during the build phase. Not trying to tell you how to build, or saying you are doing it wrong, just wanted to suggest something to play around with on your next build. |
| In saying the straights probably share the same characteristics. | Bikeless Rider
Jan 19, 2004 2:38 AM | | ...I meant the tensile strength/resiliency within the same brand. In other words, Wheelsmith in my experience, is more resilient ie: stretch more) than the DT.
One thing I'm really old school on is wheel building. I've learned from a guy here in Seattle that uses hand stressing and feel for proper tension. I am well aware that there are many good builders out there that do not believe it's proper or necessary to retension when the spokes "stretch" during the first few hundred miles of riding. To me, it sounds alot like the shift/brake cable manufacturers that claim their cables are "prestretched", and don't require readjusting, just ain't gonna happen. I even talked to a guy that was a fellow rider in the local road bike club whom builds wheels for people that says he uses a mallot to pound on the spokes, rather than pushing them down with the thumbs. Many mechanical methods such as pneumatic presses are used, and I can't help but think, why not just let machines do all the work. IMO, the spokes are never going to reach their maximum stretch during build up unless you overstress the wheel (hub flanges, rim eyelets, nipples, etc.). This is not acceptable to me, and I see the teaching of the new school method to be favoring time over carefull monitoring of the wheels. There very well might be many wheel components that can handle this kind of prestressing, but in heavy aspects of the sport (FR/DH). Even still, I don't think it's logical to expect even the heavier wheelsets to not need retensioning, as they're put through more stress in riding.
BTW B4me, in responding to what you said about the hub engagement, I wanted your opinion on the use of steel hardware in an aluminum drive chamber (Am Classic/WTB), vs steel drive rings pressed into a hubshell like most do. The gal at White Ind and I seemed to agree that Am Classics design would never be as durable and reliable as those using the other method. I wanted to ask you though, as I know you're in the biz and see how the latest stuff is working. Any problems since Am Classic did their latest redesign, which was the new cams I think, or is it too soon to tell yet? |
| I'm sorry, but none of that is really accurate. | Bianchi4Me
Jan 22, 2004 6:49 PM | | I'm not trying to do the put-down, but I think you are the victim of a lot of bad info and some off-target speculation.
I did understand your earlier post. You compared your experience with a thinner 2.0-1.7-2.0mm butted spoke to a thicker 2.0-1.8-2.0mm spoke. The thinner spoke is more elastic, just as it should be. You thought this was because the two spokes are different brands, presumably because you did not realize the two brands "14/15" gauge spokes aren't really the same size. You therefore concluded, incorrectly, that Wheelsmith's material is somehow stretchier than DT spokes. It is not.
ALL types of steel alloys are almost identical in elasticity. A cheapo zinc-plated 2.0mm spoke on a Wal-Mart bike is going to be almost identical in elasticity to Wheelsmith or DT 2.0mm spokes. It will not have as high a tensile strength, or fatigue lifespan, but it will not be any more, or any less "stretchy". Where straight gauge 2.0mm spokes are concerned there is no functional elasticity difference between DT and WS spokes.
Your understanding of the prestressing process is based on the incorrect idea that you are "stretching" the spokes during riding. It is, in fact, very important that your spokes do NOT stretch and that you keep the tension below the elastic limit of the spoke. Once a spoke stretches past it's elastic limit (point at which it is able to spring back to length), it's diameter is reduced to some extent. Think about it, the ONLY way for a spoke to get longer is to get thinner, right?
Once the diameter has been reduced by non-elastic stretching (plastic elongation) it will NEVER be capable of holding the same tension load as the original spoke. So it's vitally important that you NOT cause your spokes to permanently stretch (plastically elongate) during building or during riding. Since your spokes do NOT stretch during riding (or should not), there should be no need to re-tension them. A consistent need for re-tensioning is a clear sign of improper building techniques.
The majority of what you think of as "stretching" is caused by the spoke settling into the hub flange. The hard steel spoke starts out sitting on a sharp 90-degree corner of softer aluminum on the hub flange. As it is loaded and unloaded during riding, it will gradually mush this aluminum corner down and create a little groove, or channel, for itself in the flange. As this channel is created, the contact area between the spoke and the flange increases, distributing the load over a larger area of the flange. Eventually, when the groove is large enough, the load will reach equilibrium with the amount of supporting surface area and the spoke will stop cutting down into the flange. By pre-stressing the spoke you accelerate this process so that it can be completed uniformly prior to riding. Your concern about pre-stressing damaging parts is not a reason to avoid prestressing, but it is a reason to do it properly. I really doubt DT Swiss would painstakingly train people to damage their DT Swiss hubs and rims as part of their wheel building course. Proper pre-stressing poses no threat to your components.
If you let this "break-in" happen during riding, it will take place at different rates and at different spots on each wheel. When you hit a hard bump that spot on the wheel looses tension suddenly and then suddenly has it re-applied, which will cause the spokes at that one spot to settle in faster. Imagine suddenly yanking down on a spoke with 220 pounds of force and the effect this has on the hub flange. That's exactly what happens when you hit a bump hard enough for the spoke to go nearly slack and then pop back to 100kg. The result of skipping pre-stressing is that your wheel will go out of true as well as loosing tension.
The bending of spokes against the hub flange is a different process, where you are bending the spoke to fit the path from the hub to rim. This keeps the spoke from resting in a natural "arc" shape that is only being kept straight by the spoke tension. If you do not eliminate this arc by correcting the spoke line (bending it so it sits pretty much flat without being under tension), the spoke will flex back and forth from the arc shape to straight when the tension load changes under riding. You do not want your spokes to be wiggling back and forth as this causes fatigue failure. The goal is to minimize movement of the parts of the wheel during the rotation cycle.
Note that brake CABLES are woven from tiny individual wires and their "break-in" is a completely different process. As they are loaded the woven wires are drawn closer together, causing the cable to elongate. The tighter weave in effect reduces the distance that the wire must travel from end to end. The tiny wires inside the cable are not actually stretching, they are getting packed more tightly together. As above, if the individual wires themselves actually stretched, they would get narrower in diamter, weaker and just keep on stretching.
Regarding the Am Classic hub...it's a completely different, patented freehub design that does not even HAVE a "drive chamber" in the hubshell. So you can't simply compare it with a generic spring-pawl design and arrive at conclusions based on the materials used. The Am Classic hub uses cam-activated pawls that completely disengage during coasting. Unlike a spring-pawl system, where the pawls are constantly forced up against the drive teeth during coasting, the Am Classic pawls don't even touch the teeth unless they are engaged. White Industries makes a reliable product, so I wouldn't bet against them, but it's not as simple as "aluminum verus steel". A lot of 50 year old aluminum airplanes are still flying, and only one of these hubs has a LIFETIME warrantee. It's not White Industries. |
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