All, Thanks for your replies. Brief update: On saturday I was able to get the bike in the stand and inspected both chainrings to make sure all teeth were in alignment with one another. I took the crank arm off, and filed any burrs off of the teeth. I then moved the smaller chainring by 1/5 turn as suggested by Bill L above. Put everything back together and took it for a test ride myself. Chain sucked right up on about the 3rd time I shifted from the larger chainring to the small. This was on not shifted under load, so I think that rules out operator error as the problem.
I was at the local bike co-op and the head mechanic there (and friend), who has been helping me a bit with the diagnostics, suggested replacing the 38t chainring with a 40t they had lying around as it was pretty new. This minimizes the gap between the frame and the chainring itself, so less room for the chain to suck up from, even though there is now a bigger gap between the two rings. I rode the bike around a bit after that change, and the problem hasn't resurfaced again - but time will tell if it actually solved the issue. Interesting comments about the front derailleur as well. I brought the bike over to my LBS last week and had the mechnic there throw it in the stand, and he had the same thought. He said everything looked good, but did mention that the 105 derailleur was a bit higher than he would like, but it can't actually go any lower because the bottom of the derailleur is right at frame height. This is because as you all mentioned, it is meant for larger chainrings. I haven't had time to track down a new front derailleur yet, but I will replace that as well. On Monday, March 10, 2025 at 2:52:30 AM UTC-4 Joe Bernard wrote: > You are correct, Bill. That 105 is meant for bigger chainrings, and it's > going to be narrow for a 10- or 11-speed chain. This bike probably has a > 9-speed chain. > > On Sunday, March 9, 2025 at 9:47:32 PM UTC-7 Bill Gibson wrote: > >> Is that Shimano 105 ok for these chainrings? The profile of the guides >> should closely match the chainrings, outer for outer, inner for inner. 105 >> was for a certain range large to small. Not for triples. I think. >> >> Bill Gibson >> Tempe, Arizona, USA >> My Photographs <https://billbgibson.myportfolio.com/> : >> https://billbgibson.myportfolio.com/ and on Behance: >> https://www.behance.net/BillGibson <https://billbgibson.myportfolio.com/> >> If you like my photographs, buy me a coffee! >> <https://www.buymeacoffee.com/04141955> >> >> >> On Sun, Mar 9, 2025 at 5:55 PM Nicolas H <[email protected]> wrote: >> >>> In that first pic it looks like your front derailleur is way too high. >>> It should be max 3mm above the large chain ring but it looks like it's been >>> spaced relative to the trouser guard. >>> >>> Thanks, >>> Nic >>> >>> >>> On Mon, Mar 3, 2025 at 7:27 AM Bill Lindsay <[email protected]> wrote: >>> >>>> I have three thoughts on the matter. Maybe four...maybe 5. Some, or >>>> all, maybe don't apply to your situation. >>>> >>>> 1. The first photo has the chain sucked all the way around to the top >>>> of the cranks, and my brain goes to "why did they keep pedaling that >>>> long?". It's like when you are driving on a mountain road, overshoot the >>>> corner and are now in the gravel, and you keep your foot on the >>>> accelerator >>>> for one second...two seconds, and keep driving off the cliff. Try to hear >>>> and feel it happening and stop. Don't drive through the gravel and off >>>> the >>>> cliff >>>> >>>> 2. Chain suck is always much worse when you shift the front under load >>>> at low RPMs. When I taught new riders how to shift the front, I told them >>>> the front shift should be dictated by the terrain, and should therefore be >>>> obvious and easy to see and easy to anticipate. The rear is for "feel". >>>> On a 24/38 in front, the 24 is for pedaling up steep inclines. The 38 is >>>> for everything else. The classic mistake that inexperienced riders make >>>> is >>>> they are cruising along at a good clip, get into a really high gear >>>> because >>>> they are cruising along fast, then they stop at a red light. Then the >>>> light turns green and they are grunting with all their weight on the >>>> pedals >>>> going "darn, this gear is way too high!" and slam the front shifter while >>>> still pedaling with all their might. The solution to that is shift to a >>>> good start-up gear before you come to a stop so there is no shifting under >>>> load. The axiomatic truth of front shifting is that the lighter your >>>> pedaling force the better the front-shift will be. >>>> >>>> 3. What happens during chain-suck is that the chain moves over from >>>> the OLD ring to the NEW ring. For a fraction of a second the chain is >>>> engaged with both. Pedaling force kind of rams the chain into position on >>>> the NEW ring. If the teeth are lined up just right that can make a >>>> pulling >>>> force on the part of the chain that is still on the OLD ring. That can >>>> make the chain "stick" to the teeth of the OLD ring, and so instead of >>>> rolling off the ring, it stays stuck to the old ring and gets pulled up. >>>> Hooked or otherwise damaged teeth can make a ring "stickier". A chain >>>> that's a hair too narrow can make a chain more likely to stick to the ring >>>> and get pulled up. The way the two rings are clocked to each other can >>>> influence the way the teeth line up. I'd recommend you make a black mark >>>> on the 24, and on the crank arm. Then remove the 25 and clock it by 1/5th >>>> a turn. Many 24T rings have an arrow on them and that arrow is intended >>>> to >>>> line up with a similar feature on the 38. Look for those features, see if >>>> they are lined up, and experiment with different orientations. >>>> >>>> 4. Big picture, it seems that a good mechanic who you trust should >>>> look at the bike, and a good rider who you trust should review front >>>> shifting techniques with your wife. One way to think about it is that you >>>> should always shift the front before you need to. The rear is for >>>> shifting >>>> right now because you are in the wrong gear right now. >>>> >>>> 5. These issues are one contributor to why so many bikes today are >>>> 1x. Rear shifting and front shifting are entirely different actions, and >>>> rear shifting is close to fool proof. The only truly fool proof front >>>> shifting is no shifting. >>>> >>>> Finally, never cross chain small-small, EVER, even as an intermediate >>>> step to get to another gear. Small-small is hot lava. Stay away from the >>>> hot lava. Only use the 24 when using the bigger half of the cassette. >>>> >>>> Best of luck getting it sorted. >>>> Bill Lindsay >>>> El Cerrito, CA >>>> On Monday, March 3, 2025 at 6:42:25 AM UTC-8 Bill S wrote: >>>> >>>>> Hi all, >>>>> >>>>> We recently purchased a used Clem H for my wife, and the previous >>>>> owner said she had only ridden the bike about 100 miles. She was the >>>>> second >>>>> owner, and said that the first owner also did not ride the bike much, >>>>> which >>>>> I believe because there really wasn't a scratch on the bike. >>>>> >>>>> On the first ride, when my wife shifted the front derailleur the chain >>>>> sucked up and got stuck in between the chainring and the frame. I was >>>>> able >>>>> to pull it out and we kept riding, but the same thing keeps happening. It >>>>> doesn't happen every time she shifts in the front, but it has happened >>>>> about 5 different times, and has happened every time she's ridden the >>>>> bike. >>>>> >>>>> The front is a double with a small 24 tooth chainring and a large 38 >>>>> tooth with microshift thumb shifters. I can't recreate the issue when the >>>>> bike is in the stand, but I did try putting a new chain on to see if that >>>>> would make a difference. I also put in slightly smaller spacers between >>>>> the >>>>> chainrings and made sure that all the teeth were aligned on each >>>>> chainring, >>>>> but so far nothing has made any difference. This issue has happened when >>>>> shifting from the small ring to the big ring and also from the big ring >>>>> to >>>>> the small ring. >>>>> >>>>> I think the next step is to replace the chainrings, but I am wondering >>>>> if anyone else has had this issue? Should I swap the 38 tooth with a 36 >>>>> or >>>>> a 34 to reduce the difference in size (although I know 38-24 is how it >>>>> comes from Riv)? Maybe I can try putting some zip ties where the chain is >>>>> sucking up into the frame? Is it possible that the wide (26x2.35) tires >>>>> that came with it are causing an issue, since the chain is pretty close >>>>> to >>>>> it? Any insight is appreciated. I've included some photos below. >>>>> >>>>> thanks! >>>>> Bill >>>>> >>>>> [image: IMG_9152.jpg][image: IMG_7098.jpg][image: IMG_7068.jpg] >>>>> [image: IMG_7117.jpg] >>>>> >>>> -- >>>> 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/35ac60a1-6cbd-4d39-b739-8d39777d4dc3n%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/rbw-owners-bunch/35ac60a1-6cbd-4d39-b739-8d39777d4dc3n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >>> 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/CAC_QeUKi9rWkVN2eFL%3DmPqNZuBL1nwyDkoJoFjQme7niHG3b_g%40mail.gmail.com >>> >>> <https://groups.google.com/d/msgid/rbw-owners-bunch/CAC_QeUKi9rWkVN2eFL%3DmPqNZuBL1nwyDkoJoFjQme7niHG3b_g%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. 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