On Dec 5, 2011, at 2:35 AM, Jim Thill - Hiawatha Cyclery wrote: > We had a string of rim failures this summer, maybe 5-6 in just a few weeks > (it seemed). All were cases of simple wear, except in Eric's case, where > there was an obvious groove likely caused by a foreign object in an otherwise > lightly worn rim. One guy had worn out and cracked both rims in a very short > time, but he is well known at the shop for his rapid pace of brake pad wear > (I suspect he brakes subconsciously at every intersection or any long-shot > potential for danger). > > Rims are definitely a wear item. I've read claims by old-timers like Jobst > Brandt that suggest rims should last tens of thousands of miles. IME, that is > generally not the case. Perhaps modern rim alloys are softer, or maybe brake > pads are different, or perhaps there are more bike commuters out in foul > weather nowadays?
With the MA2 (non-anodized, spoke nipple sockets) and 36 spokes on a 5 speed/120 OLN or 6 speed 126 OLN wheel that was possible. With 8/9/10 speed wheels on 130 mm it ain't gonna happen, especially with the minimal spoking patterns now considered normal. Modern road frame designs aren't going to accommodate the 145 mm OLN that would be needed to sufficiently reduce dish. Bike components are no longer durable goods in the eyes of the bike industry. They think it's just fine for you to spend $5000 every 2-4 years to replace your bike. What, a bike should last longer than that? Pah! My All-Rounder has 135 mm OLN with a 7 speed Phil hub and freewheel (Jim's shop knows this wheel well, they spent about 4 hours trying to get a freewheel off of it, finally resorting to disassembling the freewheel and cutting it off with an angle grinder. I didn't ask for the details. But I digress). The original build was in 1996 with a Sun CR-16 rim (polished, no eyelets). The dish is only about 2 mm. That rim lasted for 14 years/30,000 miles until it finally developed a crack by one of the spoke holes. I've never broken a spoke on that wheel; now I can't remember if I used new spokes when I rebuilt that wheel or taped the new rim (CR-18) to the old and transferred the spokes to the new rim since the ERD is within a mm between the two. I think the key points of rim longevity are (1) number of spokes, (2) less dish is much, much better and no dish is perfect, (3) minimizing braking wear. The last point is going to be dependent on a lot of factors- if you live in a mountainous rainy area you're going to wear through rims faster than a fair weather rider in Kansas who can go for a 50 mile ride without touching the brakes except at the very end of the ride. Many modern rims have some kind of wear indicator built into the braking surface. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
