Tripe vs double chainrings

[Cyckelgalen]

Shimano sells different chainrings for double and tipple cranksets, same number of speeds . Are they really that different? Can you interchange them and work fine?

 

[BikeGremlin]

Shimano sells different chainrings for double and tipple cranksets, same number of speeds . Are they really that different? Can you interchange them and work fine?

That's a good question.

I wrote about chainring sizes (what to look out for when swapping) here:
https://bike.bikegremlin.com/8326/chainring-standards/

To answer the question more directly:

For as long as you match the number of holes and the BCD (so that the chainring can be mounted), it can work.

Will it be ideal? It depends on the particular combination and your criteria.

For example: middle chainring of a triple has ramps on both the inner and the outer side to aid shifting. A double chainring, on the other hand, has ramps only on one side (because there is no middle chainging on a double, of course).

Likewise, there are minor spacing differences between chainrings for fewer speeds compared to chainrings for more speeds.

Still, I would say that it works when the BCD (and the number of mounting holes, of course) is aligned.

Relja

 

[Cyckelgalen]

Thanks Relja,
Yes I thought of the ramps and the machining of the chainrings. But that would apply only to the middle ring of a triple, and I believe they sell all chainrings as 2X or 3X specific.
Then again, a lot of combinations that Shimano doesn't recommend work in real life.
The maximum capacity id rear derailleurs is a good example.

 

[ngocnhungplaza]

Good question. While the number of speeds might match, triple and double chainrings are designed with different spacing, ramps, and pin positions to optimize shifting performance for their specific setups. In many cases, you can mix and match, but it might lead to slower or less reliable front shifting. If you're experimenting, just be ready for some trial and error with front derailleur adjustments.