Death of the 5 arm 130 bcd triple?

[peetee]

The middle ring needs to be slightly larger than the halfway size, it seems to be due to the angle between the rings - the bottom-middle shift being less critical but getting the cage close to the ring for the difficult mid-top shift is important.

It’s mainly to do with the design of the front mech. From 9 speed (or thereabouts) the mechs have shift-assisting bulges on the inner plate that are exactly shaped to match the height of a specific tooth-count middle ring. Use a different ring and the bulge ain’t in the right place so you have to double click the shifter or suffer the chain jamming into the base of the bulge on the mech plate.
Back in the halcyon days of Deore (etc) 3x7 the front shifter wasn’t indexed and the mech plates were much simpler and you could chop and change your ring combos as much as you liked. Shifting was always perfect - and perfect for years and years because the more tactile shift allowed you to change gear carefully and reduce the wear on chainrings and mech.
The move away from this system was one of the biggest blunders Shimano ever made, not least because it came along with separation of drop bar and straight bar shifting compatibility.

 

[bikeworkshop]

More speeds on the back meant thinner chains, less tolerant of poor chainline, and front ring spacing remained about the same to avoid the chain catching on the neighbouring ring - it couldn't get closer) - this would have the effect of raising the risk of skating or jamming between rings if it weren't for pickup pins and plates.
You can see why rear indexing became more and more prevalent as cassettes moved from 7 to 8 and beyond - the knock on effect was to increase the need for front indexing, so riders lacking experience and finesse could have a trouble- free shift.
A consequence of all this is incomprehensible amounts of incompatibility. If the "correct" chainring is no longer available, you are really on your own.
You can use plain rings with some skill, but a lot of people, op included, find it feels crude.
In the olden days, front shifting was only now and again

 

[hamster]

Use a different ring and the bulge ain’t in the right place so you have to double click the shifter or suffer the chain jamming into the base of the bulge on the mech plate.

Or (like me) never have indexed shifting on the front, using either Campag Ergos with the micro-indexing, bar-end or downtube shifters.

As both previous posts demonstrate, front indexing was a fundamentally bad idea introduced in the name of convenience. It created more problems than it solved.

 

[Splatter Paint]

Front indexing has effectively been ‘solved’ by Di2 as it auto trims depending on the position of the rear mech on the cassette.

I have a nearly new Shimano 39t middle and I think I have 50t as well. I’m willing to sell these on if anyone wants them?

 

[bikeworkshop]

Front indexing works extremely well for a lot of our commuting customers, particularly those who see their bike as a purely functional form of transport and don't want to think about it at all.
They didn't particularly want 9 on the back let alone 11 - but a lot of modernisation is driven by racing and performance, and of course the big business need to keep stoking consumerism.
Shimano have had a few goes at a quality touring or commuting groupset, but it's often expensive and ill matched with almost anything else. Popular in Germany, where they spend good money on functional stuff.

 

[peetee]

For what it’s worth, if you want your cake and eat it, in other words have your 9 or 10 speed Shimano shifters (but not including Tiagra 4700) and have unconventional chainring sizes, just substitute the front mech for a Campag 9 speed triple.

 

[pigman]

For what it’s worth, if you want your cake and eat it, in other words have your 9 or 10 speed Shimano shifters (but not including Tiagra 4700) and have unconventional chainring sizes, just substitute the front mech for a Campag 9 speed triple.

Does the campag mech work with the Shimano indexing?

 

[Guinessisgoodforyou]

Does the campag mech work with the Shimano indexing?

@non-fixie is the chap to ask with mix n match.

 

[peetee]

Does the campag mech work with the Shimano indexing?

I’ve used it with Tiagra 4600 ten speed with no issues. That iteration of Tiagra was compatible with all the other 10 speed road systems of the time (105/Ultegra/Dura-Ace) as long as you used an double or triple mech as the shifters dictated.
As it happens, at the rear you could swap in 7,8 or 9 speed road mechs if that’s all you could lay your hands on.
To make it clear, Current Tiagra (4700) uses different indexing front and rear and you can see that the pull arm of the front mech is much longer.
Again, another step-change by Shimano. Users argue over which is the better system but no one can argue that the two ten-speed systems (3 if you add in the MTB line-up) is a right pain to navigate and especially annoying if you want drop bars and super-low gearing.

 

[non-fixie]

I am not familiar with @peetee 's setup, so I can't answer that particular question, I'm afraid.

Campagnolo doesn't use indexing for the front, but rather a ratcheting system. So the left Ergo levers work with pretty much any front changer. Which is why I like them, besides the good looks of the early Ergo levers of course.

The guide book I use for mixing and matching in the rear is here: Chris Juden's guide to rear shifting