New Shimano mechs are poor.

[Milzy]

I've always had trouble with barrel adjusters on the new Ultegra mechs. I've now de-threaded one. What size screw thread is it so I can re-tap it out. Strange thing it actually works better now just sat in the first threads. Eventually it will need doing however.
Maybe someone else has done this?
Thanks.

 

[si_c]

Not had any problem with them myself. Seem to be much the same as the previous generation ones.

 

[Milzy]

Not had any problem with them myself. Seem to be much the same as the previous generation ones.

The plastic just spins. Terrible cheaper flimsy new design.

 

[raleighnut]

The plastic just spins. Terrible cheaper flimsy new design.

Are you sure you've not just unscrewed the threaded bit.

 

[Milzy]

Are you sure you've not just unscrewed the threaded bit.

It's de threaded inside. I've got a tapping set coming. M5 should do it.

 

[gbb]

M5 sounds right, I did my downtime adjuster bosses on a Bianchi some years ago, that was difficult because it's so close to the tube. On a mech, shouldnt be an issue....as long as the stripped out part has enough material left to accept the tap. I put copperslip on the new adjuster., mine was corrosion that caused the breakage, wasn't going to have that problem again .

 

[I like Skol]

I think the trick with these adjusters is, and always has been, to have them wound almost fully in. You should aim to have the cable tension about right from the start so it only needs 1/2 to 1 1/2 turns to dial in the indexing. If you are having to give it 4, 5 or 6 turns of the adjuster to get the cable tension right then you should wind the adjuster all the way back in and clamp the cable a bit shorter then try again.
It is only a small thread into aluminium so if you are working with just a couple of turns remaining you are asking for trouble.

 

[Ridgeway]

I've always had trouble with barrel adjusters on the new Ultegra mechs. I've now de-threaded one. What size screw thread is it so I can re-tap it out. Strange thing it actually works better now just sat in the first threads. Eventually it will need doing however.
Maybe someone else has done this?
Thanks.

Fully agree. I went through 2 on my bike, gave up on them in the end and bought a Dura Ace equivalent (cost about a fiver on Ebay) and it's alloy rather than plastic, never had an issue since then.

The factory one is pants.

 

[Ridgeway]

PS: not sure you need to re-tap the thread as it's an assembly. if you buy a replacement you get 3 parts, barrel adjuster, spring and male thread that fits from underneath ie there's nothing that needs re-tapping (going from memory but it was 2yrs back when i changed mine)

 

[Tom B]

I blame all the gram botherers.

Shimano do some great stuff especially for the price of some of it. They however have made some bad stuff over the years.

 

[Ridgeway]

This explains it well:


View: https://www.youtube.com/watch?v=_39lFgsF1eg

 

[Milzy]

PS: not sure you need to re-tap the thread as it's an assembly. if you buy a replacement you get 3 parts, barrel adjuster, spring and male thread that fits from underneath ie there's nothing that needs re-tapping (going from memory but it was 2yrs back when i changed mine)

The actual cast of mech is the bit getting tapped.

 

[screenman]

Seems odd that plastic will strip the casting, you would imagine if any damage was done it would be the other way around, best of luck with the tap.

 

[raleighnut]

Seems odd that plastic will strip the casting, you would imagine if any damage was done it would be the other way around, best of luck with the tap.

Yep similar thoughts here, how do you strip a thread in Aluminium with your fingers, it's not like you're turning it with a 'big bertha' bar and a socket like a ham fisted apprentice, maybe he'd had his Spinach that morning.

 

[gbb]

I suspect the plastic part Milzy is talking about is the thumb wheel part of the adjuster, the threads will be metal...I assume.