Here is the drive side screw on my 2012 Kona Unit: drive side tension adjust screw

The problem is the screw is very difficult to move and adjust tension.

It's so bad that I stripped the hex head used to adjust the tension, although it may be hard to tell in the photo. stripped hex head

Fortunately, I figured out a workaround to get the screw moving again: snug screws

I can snug these nuts together with a couple wrenches, and then wrench one of them to move the desired direction.

It appears that something is going on with the threading. After the screw moves through the frame, the threading on the screw looks different, it is sort of 'flatter'. I could not capture a good photo of this.

My question is, what to do next to fix the problem of the hard-to-adjust screw? I would like to replace the screw itself, at the very least because the hex head is stripped, but also because the threading on the screw could be the problem, or maybe the screw is bent? I just hope it is not the threading on the frame that is causing trouble. Basically, I just need one of the adjuster screws from this: https://www.probikeshop.com/en/gb/kona-cmphcc-derailleur-hanger/84435.html But not the entire hanger assembly. Any ideas where to go to find something? Should I try the hardware store?

  • Try your local hardware store.
    – Batman
    Jun 10 '17 at 17:38
  • 2
    You need to remove the bolt that's there (and toss it) and then "chase" the threads of the frame with a tap (hoping that they're not seriously hosed). And it may be wisest to break the chain and remove the wheel, then thread the bolt out the other way, if the damage to the bolt is on the far side. Jun 10 '17 at 17:59
  • 1
    Do you find yourself adjusting it that often? I think your workaround is perfectly acceptable for the foreseeable future. You could just get a cap-head bolt fr the hardware store to make it easier to tighten.
    – RoboKaren
    Jun 10 '17 at 19:35
  • 1
    If you want any chance of saving the frame, immediately stop what you a doing, put your tools away and get the bike to an engineering shop or a capable LBS. From what you describe you have been doing, your efforts are just making things worse. This kind of repair often needs to finely balance finesse and brute force - knowing how much when is only gained by experience.
    – mattnz
    Jun 10 '17 at 23:10
  • Interesting that the responses have so much range in terms of appropriate next steps. I will take it to my LBS and report back. Jun 11 '17 at 21:05

I ended up taking the frame into the LBS, and they removed the old bolt from the frame using my work-around. I purchased some replacement bolts from the hardware store, and with some lubricant, they slide into the frame nicely. It seems like the old bolt was damaged, and the frame is fine.

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