cassette for triple chainset

[Thegreatthor]

hi, I have a Shimano Tiagra triple, 50, 39, 30 on the front with an 11-28 cassette on the back.

Is there any reason why I couldn’t have a 30 or 32 tooth on the rear? It might seem a big gear but it is heavy bike for long distance rides and I like to spin fairly briskly.

 

[CXRAndy]

hi, I have a Shimano Tiagra triple, 50, 39, 30 on the front with an 11-28 cassette on the back.

Is there any reason why I couldn’t have a 30 or 32 tooth on the rear? It might seem a big gear but it is heavy bike for long distance rides and I like to spin fairly briskly.

No reason at all

I have a triple 48/36/26. I usually run 11-32, but swap wheels and have 11-40 cassette for mountain cycling.

Just check chain length

I use Di2 shifting and program combination of gearing to restrict cross chaining

 

[C R]

hi, I have a Shimano Tiagra triple, 50, 39, 30 on the front with an 11-28 cassette on the back.

Is there any reason why I couldn’t have a 30 or 32 tooth on the rear? It might seem a big gear but it is heavy bike for long distance rides and I like to spin fairly briskly.

You will need to check the derailleur capacity to see if it can wrap the chain.

 

[Thegreatthor]

No reason at all

I have a triple 48/36/26. I usually run 11-32, but swap wheels and have 11-40 cassette for mountain cycling.

Just check chain length

I use Di2 shifting and program combination of gearing to restrict cross chaining View attachment 472582

CXR - that looks a really nice bike!!

 

[CXRAndy]

CXR - that looks a really nice bike!!

Thank you. I built it up a couple of years ago to be a do it all bike- the bike can, sometimes the rider cant

 

[Thegreatthor]

Thank you. I built it up a couple of years ago to be a do it all bike- the bike can, sometimes the rider cant

Emm, I’ve been looking at a few titanium frames for a do it all, but fairly Road focused bikes. Can’t decide whether Ti is worth the expense. A bit of a dilemma if you’ve never tried one!

 

[Cycleops]

Shimano derailleur max capacities can usually be run up by few teeth but if it can't handle the bigger gear you can get an extension for a few quid which moves the mech a bit further from the cog.
You'll need a longer chain.

 

[raleighnut]

Drop the front inner to a 28, it'll give you nearly as low a gear but not have such 'jumps' on the back when climbing.

 

[Thegreatthor]

I think I like the idea of dropping the front, 46, 36, 26, I assume I’d need a mountain bike Chainset. Are all the Shimano ones compatible?

 

[Cycleops]

All Shimano chainsets are compatible, I'm assuming you have a Hollowtech BB.

 

[Thegreatthor]

I think so Tiagra 4703 in steel frame.

 

[Cycleops]

Yes it has the Hollowtech BB so any compatible crankset road or MTB will fit.

 

[the snail]

Chainline is different on a MTB setup, so your front derailleur may not work with MTB crankset. 4703 has the funny 4-arm design, so I think your choice of chainrings is limited I think?

 

[Cycleops]

I see @CXRAndy has a Deore XT MTB chainset on his road bike above.

 

[CXRAndy]

I see @CXRAndy has a Deore XT MTB chainset on his road bike above.

I do. I use XTR Di2 front derailleur.


I had to use two spacers on the drive side and a single on the non drive. After a few tests to check shifting, thinned down one of the two drive side spacers by 0.5-1mm to perfectly position the crankset. This fine adjustment eliminated any chain rub at both end of gearing. I only use the 26t ring for 10% gradient s, but it does allow me to stay seated if I want and spin 85rpm+