Re: [CR] Wheel weight


Example: Framebuilders:Brian Baylis

From: Tom Dalton <tom_s_dalton@yahoo.com>
Subject: Re: [CR] Wheel weight
To: classicrendezvous@bikelist.org
In-Reply-To: <188.dbcc589.2aafb4ae@cs.com>
Date: Thu, 12 Sep 2002 09:40:38 -0700 (PDT)

Tom Wrote: Remember, even in their day Ergals had a well-deserved reputation for brittle failures on the inner face, around the ferrules. They were not well suited for sub-36 hole use or for dish beyond 120mm 5-speed.

Greg wrote:

Well..... That doesn't mirror my experience with Ergals.

I have been riding on 24- and 28-spoke Ergals on the road for decades, 126mm-spaced. I weigh 155-165 pounds, and ride 175mm cranks. From what I've personally experienced and have been told by others, Ergals generally fail by having a ferrule pull out after many thousands of miles. Additionally, because they are made from 7000 series (Ergal) alloy, they don't go out of true or flat spot like GEL280s do - the GELs (which are more like 300-310 grams, whereas the Ergals are 280-290) are made from the much more common (for rims) 6000 series alloy. Like crank arms, there are usually warning signs before Ergal rims fail (cracks around the ferrule).

Tom Wrote:

Exactly the failure I was thinking of. I may have described it more generally as cracking on the inner face, but taken to the endpoint, that's what happened. As I recall it was not always after many thousands of miles. By the time I started riding, Ergals were semi-rare and hard anodized rims were getting popular. Given how few Ergals were around I saw a surprising number of these failures, and not always on well used rims. In point of fact, it may have been no more than three failures that I personally saw, but I don't recall seeing any other model tubular rim failing this way, including the models that were far more common. Was this because Ergals were fundamentally flawed? No, I don't think so. They were very, very light. As you pointed out, they were even lighter than GELs. I think the Record Du Monde was the only similarly light mainstream rim. Your point about the 7000 series material is well taken. Perhaps the reason Rec du Mondes didn't seems to have the brittle failure propble is because 1) they were not as brittle 2) being softer, they flat spotted well before they were fatigued to failure.

In any case, I still think of Ergals as failure-prone. They may be the most durable sub-300 gram rim ever, but I consider sub 300-grams to be extremely light. Perhaps a fine choice for lighter riders who are either very smooth or not particularly strong, and certainly best in the hands of someone who keeps a close eye on his equipment. For most riders, they were "racing only" rims. So, I'll ammend what I said to:

"In the time and place that I was first racing, many of my fellow cyclists thought of Ergals as failure-prone. This reputation was based on observed failures that were likely a function of the rims extreme light weight. It is well within the realm of possibilities that they were very robust rims for their weight, but people generally preferred heavier rims because of better durability."

It's funny to think that a lot of riders probably though that GP-4s and Montreals were stronger than Ergals and even Champion du Mondes because of the new "heat treatment, " rather than because they were so much heavier.

Greg wrote:

Just weighed a set of 28-spoke Ergal road wheels, Campy (N)Record hubs with OEM skewers, DT 15-gauge spokes. 1750 grams for the set. About $300 NOS, ready to go. Versus those $8000, 1200-gram wheels, I'd call that a bit of a bargain!

I'd call that cherry-picking your facts. For one thing, the ADAs are currently a mere $2950 per pair ;-). For another, I doubt that one can just order up a set of NOS wheels as described. $300 sounds like what you'd pay once you tracked down the parts at a fair price and then built them yourself.

The point I was making regarding the earlier post is that yesterday's feathery wheel was not well suited to daily use (though you may disagree). It's cool that he showed a new rider that SL gear is nothing new. But then, as now, lightweight gear is subject to compromises. I'll add that by making some fundamental changes to materials choice, distribution of material and specifically to spoke configuration wheels like the Ksyrium SSC SL can weigh less than 1600 grams/pair (according to Mavic) while supporting the added efficiency of several extra cogs and the convenience of clinchers, if desired. I could go on to say that they are more aero, more rigid and more durable than the referrenced Ergals, but while I believe they may well be, I'd be buying into the hype without actually using a pair.

Tom Dalton

Bethlehem, PA