This is the first time I've heard about flipping the rings over. I would never have thought about that and, honestly, it doesn't exactly register why only one side of the ring would have worn BUT you invoked Sheldon Brown, which is a trump card even better than, dare I say Grant, so you'll get no argument from me. I'll check the countersunk holes and see if that will work. I can buy replacement RH rings too if need be.
I think you buried the lede though. The real news, which IMO, deserves its own thread, is that you can sometimes post from your phone! One other question, because while training for PBP in 2015 I found out I had worn chainrings on my Hilsen when I got out of the saddle to push hard and the chain slipped from the chainring, I awkwardly fell forward, caught myself and tore my rotator cuff. How can you know your rings are worn before it's too late and causes problems? The shoulder injuring chainring was very obviously shark toothed, so visual inspections would have tipped me off but the current chainring doesn't seem extreme like the other one. When looking at the current chainring I'm not really all that sure I would say it was worn out with a visual inspection but with the old chain so stretched I can't see how it couldn't be worn out. Peace, Tim On Tuesday, May 26, 2026 at 9:56:01 PM UTC-5 Philip Williamson wrote: > Flip the rings over and start with the fresh faces. I don’t know if the RH > rings are countersunk to an extent that it wouldn’t work, but Sheldon Brown > told me to do that when my rings were worn. It seems doubly smart with > rings like yours that aren’t commodity items. > > Philip in SANTA Rosa and SF (and Grass Valley sometimes) who is proud just > to be able post from his phone on occasion > On Tuesday, May 26, 2026 at 3:24:12 PM UTC-7 Tim wrote: > >> I think you just nailed it Garth. I realize now that the chain that came >> off was noticeably "stretched" when laid side by side with the new one. I >> just checked them again and the old one gains 1.5 links. I noticed it at >> the time but didn't make the connection of how badly the chain rings >> might/must be correspondingly worn. >> >> Tim >> >> On Tuesday, May 26, 2026 at 4:23:05 PM UTC-5 Garth wrote: >> >>> Are the rings worn and while the CX70 allowed you to get by "normally", >>> the 105 does not ? Different cage dimensions and all that. >>> >>> On Tuesday, May 26, 2026 at 4:04:08 PM UTC-4 Tim wrote: >>> >>>> I changed the FD on my 650b rando bike (my only non-Riv). It's set up >>>> with Ultegra brifters with a Rene Herse double crank. The old CX-70 FD >>>> wasn't working well anymore so I swapped to a shimano 105 FD. The derailer >>>> shifts much better but now when I shift from big ring to small ring the >>>> chain now falls between the chainrings. It did this immediately upon my >>>> first ride so I took it to my LBS thinking I had installed the derailer >>>> wrong, although I kinda mostly know what I'm doing. When I went back they >>>> told me that my crank was bent. The mechanic said he even asked his boss >>>> and he agreed. He went on to explain to me that the Herse crank only had 3 >>>> bolts connecting to the crank where most cranks had 5 and he insinuated >>>> that the RH was weaker because of this, and that it was one of the bolt >>>> "tabs" that had bent. . >>>> >>>> I was very skeptical as the problem had never happened in the 10 years >>>> I've had this bike (It's a custom and came to me mostly assembled) and I >>>> have never crashed the bike. I brought the bike home to remove the crank >>>> and disassemble to check it out as much as i could. I removed the arms >>>> from >>>> the bike, removed the chainrings, cleaned the crank and reassembled. Th >>>> chainrings seemed flat when I laid them on a flat surface. I reinstalled >>>> the crank and on the first downshift on the bike stand the chain fell >>>> between the chainrings. >>>> >>>> I emailed Rene Herse and their answer was that you can't bend a crank >>>> by pedaling it and that the FD is the introduced variable that has caused >>>> the problem. I must say that I completely agree that the only change made >>>> is the one that caused this problem but I don't at all understand how or >>>> why the derailer would immediately cause this problem. So therefore I >>>> don't >>>> know what to do to fix it. >>>> >>>> Any thoughts? >>>> >>>> Peace, >>>> Tim >>>> >>> -- 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 [email protected]. To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/55a64bf6-5741-4959-a85b-6a30c5e1cfd4n%40googlegroups.com.
