P.S.: Bill is absolutely right—comparing arm weights doesn't make much sense. After all, we ride complete cranks! As mentioned, RH arms are very light, but a little bit of that weight comes back with heavier rings. However, three bolts instead of five saves some weight—what matters is the end result.
Jan Heine Rene Herse Cycles Seattle, WA, USA On Friday, February 7, 2025 at 1:46:20 PM UTC-8 Bill Lindsay wrote: > Jan brings up an excellent point and it sent me back to my "notes" to > re-create what I was doing when I was taking those notes. > > What I was doing was deciding, on the basis of weight which excellent > crank set to use on a new build: a Rivendell Silver 3 or a Rene Herse. My > notes, assigning an effective weight of 418g was a SWAG at trying to offset > the extra weight penalty of using Rene Herse Chainrings. The Rene Herse > drive side crank arm has almost no spider, and as a result is very light. > Each Rene Herse chainring has most of a three arm spider, and that's a lot > of material that weighs more. For comparison, I just now weighed a > brand-new Rene Herse 46T ring and a generic cheap-o 110mm BCD 46T > chainring. The Rene Herse weighs 106g and the cheap-o weighs 84g. Rene > Herse rings are a lot nicer than cheap-ones rings, last a lot longer, shift > better, are more beautiful, etc etc etc. > > I was trying to do a light build, and I knew the lightest choice among > cranks I love would be the Rene Herse. In the calculations, I figured I'd > save about 50g with a Rene Herse 1x crank set in my setup. That 50g would > cost me $500, or $10 per gram, because the Silver 3 was already on hand and > therefore FREE. If I did not have the Silver 3 on hand, then it would have > been about a $200 price difference, so around $4 per gram. It's hard to > say what I would have chosen, if that had been the situation. > > So, again, my 418g estimate was a guess at an apples to apples effective > weight to account for Rene Herse rings being heavier than 110mm BCD rings. > For the OP, I think that was a reasonably relevant number, but I did not > make clear that it was my own guess. > > Bill Lindsay > El Cerrito, CA > > On Friday, February 7, 2025 at 12:28:30 PM UTC-8 Jan Heine wrote: > >> I don't have info on the Silver cranks, but Bill's Rene Herse crank >> weight seems high. >> >> The last RH 171 mm arms I weighed came out at 378 g. Since these are >> net-shape forged, the weight is very consistent. Polishing removes a few >> grams, but anything more than 3 g off the target weight would surprise >> me—and too much polishing will make them lighter, not heavier. As an >> additional datapoint, complete RH cranks weigh between 498 g (165 mm, 42/26 >> rings) and 528 g (171 mm, 46/30 rings). Larger rings will obviously weigh a >> bit more. >> >> Put into context, that's about 25% to 30% lighter than most cranks out >> there—without giving up strength. That's the result of the net-shape >> forging and the design, with just three arms. That's also what accounts for >> the price difference—not just the extra forging dies and more expensive >> materials (not all 7075, 2014, etc. aluminum is the same, even if the >> chemical composition is supposed to be similar), but also a different >> production process to ensure quality with a 3-arm spider that leaves very >> little room for error. >> >> Does it matter? Realistically, you won't feel the extra weight of heavier >> cranks by themselves. However, on the complete bike, it all adds up. If >> every part of your bike on average weighs 25% more, your 24 lb. bike >> becomes a 30 lb. bike. >> >> Years ago, Mark and I weighed every single part of our bikes, as well as >> some surprisingly light mid-century bikes. There was a late 1940s Alex >> Singer rando bike that weighed 10.2 or 10.3 kg (22.7 lb)—fully equipped >> with lights, fenders, racks (front and rear), 38 mm tires, etc. (It's in >> the Golden Age book.) We realized light weight in a bike doesn't come from >> one or even a few parts, but from every part being optimized. It's rare to >> save more than 50 g on a single part—except cranks, which can be quite >> heavy—but even for the other parts, 50 g x 20 is 1 kg. >> >> Jan Heine >> Rene Herse Cycles >> Seattle, WA, USA >> >> On Sunday, February 2, 2025 at 10:28:29 AM UTC-8 Bill Lindsay wrote: >> >>> I have weighed Silver 1 cranks in 173. I have weighed Silver 3 cranks >>> in 173. I have not weighed Silver 2 cranks >>> >>> My Silver 1 left crank arm in 173mm weighed 267g >>> My Silver 3 left crank arm in 173mm weighed 201g >>> My Silver 1 right crank arm in 173mm with my own idiosyncratic 40/37/34 >>> rings installed weighed 484g >>> My Silver 3 right crank arm in 173mm with a chain guard, 38 ring and 26 >>> ring installed weighed 438g >>> My Silver 3 crank arms 173mm with no rings and no chainring bolts and no >>> crank bolts weighed 460g >>> >>> According to my notes, Rene Herse 171mm arms weigh 418g with no rings or >>> bolts. >>> >>> Bill Lindsay >>> El Cerrito, CA >>> On Tuesday, July 18, 2023 at 2:26:00 PM UTC-7 Igor wrote: >>> >>>> Has anyone here weighed the 170 variety and can tell me the weight? >>>> Curious how they stack up against other cranks >>>> >>>> Thanks >>>> >>> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. 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