Capable chain repair tool? Does one exist that can be carried on the bike?
 

If I had to repair a chain at home I'd use my hydraulic press. That isn't very portable.

I have a cheap screw type chain repair tool and tried to use it before - its pretty much worthless as the screw just bends and walks off.

Is there something out there that is good quality and durable enough to work well that I can carry on the bike?

Try another screw type, they work fine.

I would suggest a quality chain tool like a Park CT-5. Very common and likely the most common replacement pin if one should break. But I'll add a tip. Once the chain is positioned in the too, the pin is screwed onto the chain's rivet and it mbegins to move slightly. Then back off the tool's pin and restart the screwing in. What this does is let the tool's pin better center on the chain's rivet before plunging into the chain's holes. If the tool's pin hangs up on the edge of the hole two things can happen. One is that the chain plate's hole can be punched larger then wanted. The other is the tool's pin can bend. Once bent it is vastly harder to line up with the next rivet and bend further. Andy

I took a chain tool on a cross-country ride and never used it. What are you doing that you need to carry such a tool? “Durable” implies that you expect to use it a lot.

Not featherweight at 75g, but this is robust, compact & inexpensive.

https://www.amazon.com/Pedros-Six-Pa...ustomerReviews

I carry this:

https://www.parktool.com/product/min...hain-tool-ct-5

and have on multiple occasions helped someone who has a broken chain on our heavily used MUP/Greenway. It has always been a broken quick link that is now missing, so I usually break the chain for a pin and put it back together one link short. It gets them home. I also carry different speed quick links, but usually the person just wants the chain shortened and do not want to take my quick link as a fix.

Are you trying to reuse a pin because that is a huge PITA and not a good idea. Pick up some quick links and carry those then you only need the chain tool to break the chain. Even pretty crappy chain tool can break a chain.

Another vote for Park Tool CT-5.

I managed to mess one up pretty badly, but it took me a decade to do so, and I'm very good at breaking things.

I have this multitool (different but with the same chain repair) and tried in on a piece of chain I have. Bit harder on the thumb but this work to extract and reattach a new pin.

https://cimg3.ibsrv.net/gimg/bikefor...c47ec89b6a.jpg

https://www.prestacycle.com/product/...ain-accessory/

combined with the Presta ratchet and bits that I now carry instead of a combo multi tool, this really works great

I have owned many chain tools, never really had a problem with any of them. If the push pin is bent, get a new tool.

+1
You may have to do this 2-3 times before you get a good, straight push.
I'd use a Quicklink for repair. Too many chains that are not supposed to be rejoined with the pin.

Park I Beam and KMC Missing Link.
Never leave home without them.

:)​​​​​​​

I've found even the ones included in multi tools (as above) adequate for on the road repairs. Generally you are just pushing out one pin to remove the broken link. Quick link for the repair. Technique and patience are key.

Hydraulic press for a chain seems like a bit of overkill to me. At least what I consider a hydraulic press.
https://www.northerntool.com/shop/to...1793_200641793

Another vote for the CT-5.

This is overkill. There is no need to file or Dremel the pin before removal. A decent chain tool will easily remove a riveted pin from any chain if used properly (i.e. aligned over the pin). I have a Park CT-3 that has cut dozens and dozens of chains to length over 25+ years and has never needed a new pin. I carry a very small chain tool on my bike but have only used it once and that was to help another rider who's chain was improperly installed initially.

Carry a quick link for when you really need a road-side chain repair.

That was my thought as well. We assembled hundreds of chains daily at Trek, using chain pliers:

http://www.os2.dhs.org/~john/gianrobert.jpg

But pliers aren't very portable. I carry a "chain pup" with me on rides (I've had it for years and haven't had to use it yet):

https://farm9.staticflickr.com/8401/...258252d1_b.jpg

:)​​​​​​​

Modern bushing-less flush rivet head derailleur chains are never lengthened,
only shortened and joined with a quick link.

to effect repairs you bring a section of the same chain and more quick links...

So for pressing out the rivet pin, the chain tool can be simple , though it needs to be reliable..


gave a trusty, but not the lightest one, to a friend , he found a lighter, more aluminum one , brought it instead ..

and somewhere in the southern Argentine Andes foothills he had to find a nail and use a rock ,

when the lighter chain tool broke..








.....

Yeah, I have a couple of those and have them on my daily ride bikes. I used it one time to repair another rider's chain and it worked but it certainly isn't a "shop quality" tool. I haven't seen them for sale in years and wonder if they are still being made.

:)​​​​​​​

:beer:

The OP wanted a LIGHT WEIGHT TOOL to carry.
Not a heavy chain.