It could be anything but what I think we know now is the chain is busted and chain and cassette are both probably pretty old. Based on my supposition - pulled out of thin air - that your chain never mated well with that cassette I would replace both now and see what happens.
Joe Bernard On Monday, May 30, 2022 at 12:23:13 PM UTC-7 George Schick wrote: > Bill - thanks for the quick response. Bill asks... > > *(have you been) riding the same SRAM 971 chain for 18 years, and you > actually ride the bike a decent amount, (if so) your entire drivetrain is > likely toast. Is that what's going on? Or, do you replace your chain > frequently, and the noise never changes?* > > I can't recall whether I've had that same chain in use on that bike for 18 > years. I regularly clean and lube it and check the chain wear with a Park > chain gauge. > > *Have you tried riding your bike with different pedals?* > > Yes, and it has still occurred over the years. > > *Have you tried riding your bike with a different rear wheel?* > > No, this bike has always had that same rear wheel, a Shimano Dura Ace hub, > a Velocity OC rim, and Wheelsmith spokes. I've removed, cleaned, and > re-lubed the rear axle several times over the years and I've never noticed > any uneven wear on the bearing races. > > *Is the noise the same regardless of which front chainring you are in?* > > The crank has a Velo Orange Cru with 48/34 chainrings. It originally had > a TA Syrius crankset with similar chainring sizes and it did the same thing > then. Because of the relatively flat terrain in NE Illinois I ride in the > larger 48 tooth chainring 95% of the time. The small chainring is only > used for longer steep climbs such as ones up from river bottoms to ridges > at the top. > > *Have you pulled the crank arms of and checked the BB bearings?* > > The BB on this bike now is a Phil Wood and it has never given any > indication of a problem. I have pulled the crank arms of, as you say, on > occasion when I noticed a different kind of clunking noise (though quieter) > and found that the fixing rings were loose. I took care of that problem > with LocTite and it has not occurred since. The original BB was an Axxis > and the clunking noise was present even then. > > *Sometimes, a headset problem can feel like drive train noise.* > > The headset on this bike had indeed indexed a number of years ago, but I > swapped it for an IRC roller drive and it's been fine ever since. > > *If you don't want to dive into iterative and time-consuming diagnostics, > have a mechanic you trust look into it,* > > Don't know of one in the area. Mostly just guess-work types who try to > swap this out for that, sometimes with success and other times not.. > > Nevertheless, thanks for your diagnostic suggestions, Bill. Are you in SE > Michigan these days or back in NoCal? > > > On Monday, May 30, 2022 at 1:51:10 PM UTC-5 Bill Lindsay wrote: > >> George indicates that he's had a loud clunking or crunching sound coming >> from his bike for 18 years under hard pedaling. He asks "what the heck >> gives?" >> >> Have you tried to address it in any way? What have you tried? >> >> Generally these "my bike makes sounds I don't like under hard pedaling" >> involve changing one thing at a time and using the changes in the sound to >> narrow down the source. If you've been riding the same SRAM 971 chain for >> 18 years, and you actually ride the bike a decent amount, then your entire >> drivetrain is likely toast. Is that what's going on? Or, do you replace >> your chain frequently, and the noise never changes? If that's the case, >> then you've likely ruled out the chain itself as the source. >> >> Have you tried riding your bike with different pedals? If the noise is >> the same with different pedals, then it's probably not the pedals. >> Have you tried riding your bike with a different rear wheel? If the >> noise is the same with a different rear wheel, then the rear wheel is >> probably not the source. >> >> Is the noise the same regardless of which front chainring you are in? If >> so, then one chainring is probably not the source. >> >> Have you pulled the crank arms of and checked the BB bearings? >> >> Sometimes, a headset problem can feel like drive train noise. >> >> If you don't want to dive into iterative and time-consuming diagnostics, >> have a mechanic you trust look into it, >> >> Bill Lindsay >> El Cerrito, CA >> >> >> >> On Monday, May 30, 2022 at 11:23:20 AM UTC-7 George Schick wrote: >> >>> Ever since I've owned my Ram I've had a unique, loud clunking or >>> crunching sound coming from the drive train, especially when I started from >>> a standing stop or occasionally when hammering up an incline. I used to >>> associate it with the "ghost shifting" phenomenon as posters here referred >>> to certain chain and cassette indexed shift combinations. But this loud >>> "clunking" sound never resulted in an unwanted change in gears; it just >>> sounded like something that shouldn't be happening. >>> >>> Well, this has gone on intermittently since about 2004. Yesterday, >>> however, the chain broke. Broke completely in half, both sides after >>> starting from a standing stop again. Fortunately, I was carrying a spare >>> SRAM Powerlink and the event took place while crossing an intersection near >>> a strip mall that had a bike shop. I borrowed their chain tool to drive >>> out the pins of the broken link and installed the Powerlink and took it >>> easy on the way home, worried that it might happen again. >>> >>> My question is: What the heck gives?? The chain is a SRAM 971 which is >>> designated as the proper chain by the manufacturer for 9-speed cassettes. >>> The cassette is a 9-speed Shimano hyperglide, and the crank/chainrings are >>> Velo Orange Cru. >>> >>> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/129c1425-a8f1-4918-89a7-5b972c4e35f4n%40googlegroups.com.
