Extending the cassette range on a Defy

[Jody]

My bike is cuurently running Tiagra 34/50 front and 12/30 rear but I am struggling with some of the really steep ascents round here. My knees are really feeling it after last night.

What is a larger cassette I can swap to without changing mechs. Think the current bike has a medium cage mech. Can I swap out for a MTB cassette, say 34 or 36? Or is it better to swap the chainset for something smaller without changing the front mech

Edit. Just looked and Tiagra doubles are 34 minimum so that is out of the question

 

[jowwy]

My bike is cuurently running Tiagra 34/50 front and 12/30 rear but I am struggling with some of the really steep ascents round here. My knees are really feeling it after last night.

What is a larger cassette I can swap to without changing mechs. Think the current bike has a medium cage mech. Can I swap out for a MTB cassette, say 34 or 36? Or is it better to swap the chainset for something smaller without changing the front mech

for £20 you can buy a wolftooth roadlink adaptor, which will allow you to run upto a 40t rear cassette without changing your rear mech............https://www.wolftoothcomponents.com/products/roadlink

 

[Rooster1]

Thats a shame. I run a 11-30 on the back which is a pretty big cog imo, however I have a triple up front which makes the nasty ascents easy.
Obviously converting to a triple is a whole heap of hassle and cost as you'll need a triple shifter, front mech and not to mention the front chainset. See how it goes with a bigger rear cog I guess.

 

[Jody]

With the triple on my MTB and a 36 rear I can ride up just about anything. I am wondering also if the length of the cranks have anything to do with it as they feel shorter than the MTB.

 

[jowwy]

With the triple on my MTB and a 36 rear I can ride up just about anything. I am wondering also if the length of the cranks have anything to do with it as they feel shorter than the MTB.

whats the crankset on your MTB

 

[Cycleops]

If you have the Tiagra RD 4700 GS Shimano say you can go up to a 34t on the cassette with a double.