Broken Barrel adjuster
 

Taking apart my Miyata One Ten and the barrel adjuster on the rear derailleur just snapped in two. How universal are these? Can I replace with this?
https://cimg2.ibsrv.net/gimg/bikefor...0844ed779c.jpg

Yup. There are cheaper ones out there, like at a bike shop.

Typical solution for a shop is to dig into their old take off parts and find a replacement. Andy

Any adjuster with the correct size and threading will work. These older ones just use friction or a plastic insert to keep it from loosening.

The piece you linked would probably fit, but won't provide any benefit over cheaper ones. Your RD probably doesn't have the serrations to interface with the plastic piece (see the little nubs on the end) that gives it an 'indexed' feel.

what derailleur? there are a couple thread sizes in japanese/metric that are fairly common, but anything french or italian is a best-guess situation.

got a measuring caliper handy?

is there a well-stocked hardware store, or a Co-op bike shop, nearby?
the hardware store can help pin down the thread size/pitch...

i have TWO small parts drawers filled with them... and dig into the parts-only ders box sometimes too...

It ought to work as long as the thread matches. Brake barrel adjusters are typically 6mm x 1mm; derailleur/shift barrel adjusters 5mm x 0.8mm

Your local shop probably has something or an old derailleur in a parts bin they can scavenge from. Not every shop will do it but many shops have parts bins with all sorts of stuff or access to a wide range of bike parts.

Thread pitch on a Campagnolo derailleur is different than the others.

There’s no substitute for just trying a bunch of old ones.

They are pretty universal.

Send a self-stamped/self addressed envelope to.... Gosh I'm dating myself; I remember when this was a thing. Just kidding. Send me a PM with your address and I'll put one in the mail for you.

i have at least FOUR thread rates/sizes in my adjusters drawer... and several lengths/configurations.;)

Ahh, thanks mate! But I just went on down to the bike shop and they hooked me up.

Only four? I can fill half a cup with just the plain ones like the one that he needs. Easy enough to screw what he had in a known thread size nut to confirm what he needed.

For the vintage of his bike both Shimano and Suntour were using the same thread standard.

my sortings are fairly granular... the shifter adjusters separated from other types, etc. and the number quoted relates to only the derailleur adjusters for majority suntour and shimanos... many of the other brand adjusters land in the parts der. bin, still in place on the ders.

shifter and brake adjusters have their own drawers in the small parts stacks, and those are also sub-categorized as called for.

i have a LOT of parts.. organization of them is a necessity. :D
twelve years ago, my parts collection fitted into a small fishing tackle box... it would now neatly stack into a PODS Container, and the frames/wheels/tires/bikes would fill three more.... mind you, i'm a retired rock and roll big hair/metal roadie/sound eng., and really good at fitting things into containers/trailers/trucks

i've got a lot of parts.

and the vintage of a bike can be fairly meaningless regarding what derailleur is on it now.

I had the caliper ("Boley gauge"), then found a metric thread gauge on sale... I'm set for life!

https://cimg1.ibsrv.net/gimg/bikefor...9723627ad5.jpg
The thread gauge has 28 different pitches! I'm expecting to use maybe 3 or 4!

any chance I can take you up on that too? I snapped my barrel adjuster for a 1st gen campy chorus, and so far struck out at a few local shops having a suitable replacement.

maddog34 ditto for you too.

https://cimg2.ibsrv.net/gimg/bikefor...5ea732070.jpeg
Labeled “6”
https://cimg3.ibsrv.net/gimg/bikefor...e77b136c3.jpeg
Part number 7350227
https://cimg4.ibsrv.net/gimg/bikefor...1fd880489.jpeg
Photo from eBay (mine was left at the shop after I snapped it…hope they didn’t chuck it out, will see later today).

The two most standard sizes of barrel adjusters are the larger M5 (same as for mounting your water bottle cages and rack/fender mount points) and M4. Try a water bottle cage mount bolt and if that's too big, there is a 99% chance it is M4. Let me know, I have both sizes.