Middle ring Q

[Jiveman60]

Is the inner ring on a double chainset the same as a middle one on a triple chainset?

 

[grantoury]

Is the inner ring on a double chainset the same as a middle one on a triple chainset?

It depends on which chainsets you mean. Newer ones will have differing teeth profiles to aid shifting. And do they have the same bolt circle diameter? A picture could be helpful

 

[mdvineng]

Most common double is 52 42. Triples tend to be 52 42 36 but this is always a personal preference thing, depending upon the terrain and loads you're going to be encountering. Mtb triples are 48 38 28 with many other variables.

 

[Jiveman60]

It depends on which chainsets you mean. Newer ones will have differing teeth profiles to aid shifting. And do they have the same bolt circle diameter? A picture could be helpful

I've got an unused 130bcd 42t that was for a Shimano double chainset. I'm in the process of making up a triple with a Shimano 130bcd/74bcd Triple crank. I need to buy an outer and inner, just wondered if my unramped 42t would work as a middle?

 

[grantoury]

I've got an unused 130bcd 42t that was for a Shimano double chainset. I'm in the process of making up a triple with a Shimano 130bcd/74bcd Triple crank. I need to buy an outer and inner, just wondered if my unramped 42t would work as a middle?

It will work. Shifting may be slower. Front derailleur has to be compatible with those specific chainrings too, if it is a triple derailleur.

 

[pigman]

The outer 2 are the same bcd, the inner one is smaller bcd

 

[Jiveman60]

It will work. Shifting may be slower. Front derailleur has to be compatible with those specific chainrings too, if it is a triple derailleur.

Cheers, I hoped it might. I suppose once upon a time no rings were ramped and pinned.

 

[mdvineng]

I have used a few so called double front changers work on triples without isssue.

 

[grantoury]

I have used a few so called double front changers work on triples without isssue.

A double will always work, triple derailleurs are shaped for certain chainring combinations.

 

[mdvineng]

Some doubles struggle with reach and range though, when asked to triple I've found.