trenzterra
New Member
I have a 20" folding bike that is about a month old and came with a Tiagra drivetrain. It has a chainstay length of 400mm.
I subsequently switched it out to a 11 speed drivetrain (Shimano 105 R7000 with flatbar SL-RS700 shifter). The cassette is an Ultegra 11-30t and the chain is a KMC X11EL. 56T single chainring in front. All are brand new.
I was having indexing issues in that when I tuned the tension just right for the smaller cogs, the bigger cogs would have its indexing slightly off such that it will chatter. I would then have to turn the barrel adjuster clockwise, but when I went down to the smaller cogs, I would then experience a bit of chain chatter.
Having Googled extensively I thought the issue would be either the cable or the hanger. So I changed the shift cable and housing and made it slightly longer than needed to avoid shifting issues due to kinks etc. Then I bought the park tools DAG3 and aligned the hanger to about a 1mm-2mm tolerance (think it was off by about 4-5mm at the start).
The combination of these two steps seemed to help a little bit. However, I am still experiencing the symptoms, i.e. when shifting from the largest to second to third largest cogs, I get the same chatter noise and I need to turn the barrel adjuster about two clicks clockwise. But if I do so, I get a very slight chain chatter on the 2nd and 3rd smallest cogs. I tried changing shifter cables again to another Shimano but this did not help. The sound is very subtle but noticeable. I confirmed this by recording a slow motion video on my phone and the chain rubs against the smallest cog ever so slightly sometimes. Turning the barrel adjuster back anticlockwise works but then I end up with the same issue on the larger cogs.
While there are exactly one or two barrel adjuster positions that works reasonably well, you can tell it is a bit of a compromise as it is noisier than if it were perfectly indexed for that gear. Granted, this plays out mostly on the bike stand and on a noisier road, the slight noise is drowned out by the surroundings.
I have tried the following troubleshooting steps over the past week:
I subsequently switched it out to a 11 speed drivetrain (Shimano 105 R7000 with flatbar SL-RS700 shifter). The cassette is an Ultegra 11-30t and the chain is a KMC X11EL. 56T single chainring in front. All are brand new.
I was having indexing issues in that when I tuned the tension just right for the smaller cogs, the bigger cogs would have its indexing slightly off such that it will chatter. I would then have to turn the barrel adjuster clockwise, but when I went down to the smaller cogs, I would then experience a bit of chain chatter.
Having Googled extensively I thought the issue would be either the cable or the hanger. So I changed the shift cable and housing and made it slightly longer than needed to avoid shifting issues due to kinks etc. Then I bought the park tools DAG3 and aligned the hanger to about a 1mm-2mm tolerance (think it was off by about 4-5mm at the start).
The combination of these two steps seemed to help a little bit. However, I am still experiencing the symptoms, i.e. when shifting from the largest to second to third largest cogs, I get the same chatter noise and I need to turn the barrel adjuster about two clicks clockwise. But if I do so, I get a very slight chain chatter on the 2nd and 3rd smallest cogs. I tried changing shifter cables again to another Shimano but this did not help. The sound is very subtle but noticeable. I confirmed this by recording a slow motion video on my phone and the chain rubs against the smallest cog ever so slightly sometimes. Turning the barrel adjuster back anticlockwise works but then I end up with the same issue on the larger cogs.
While there are exactly one or two barrel adjuster positions that works reasonably well, you can tell it is a bit of a compromise as it is noisier than if it were perfectly indexed for that gear. Granted, this plays out mostly on the bike stand and on a noisier road, the slight noise is drowned out by the surroundings.
I have tried the following troubleshooting steps over the past week:
- Changed shifter cables and housings twice (now using Jagwire Pros), tried both oiled and unoiled. No difference.
- Tried my old RD (the Tiagra 4700 which has the same indexing ratio as the R7000), same issue
- Re-checked the hanger alignment three times and did it within a <1mm margin of error (basically I made sure at the 3, 6, 9 and 12 o'clock positions the metal rod of the tool barely rubs against the rim. And yes, I did measure at the same spot on the wheel (the valve area).
- Changed shifters in case the shifter was pulling the wrong amount of cable - no dice
- Changed to a Shimano Ultegra 11-speed chain
- Degreased the chain and re-lubed with Finish Line Ceramic Wax
- Tried a smaller chainring -- 52T instead of 56T.
- Adjusted B tension back and forth
You seem to have done everything and found cul-de-sacs at every turn.
