Topic starter
My dad has a compact 2x9 set up on his road bike. 50/34 at the front and something like 11-30 at the back. He wants lower gearing and the most straightforward way seems to be a new chainset. I've found a 10 speed gravel double with 46/30. Will this work with his 9 speed chain and current shifter? I think everything else is Sora. Open to other suggestions too, I've got a bit out of the loop on this stuff!
Posted : 03/06/2024 7:14 pm
What is the chainset? The chain and rings will work for sure
Posted : 03/06/2024 7:23 pm
Why not an 11-34 or 11-36 cassette?
Posted : 03/06/2024 7:24 pm
Topic starter
Why not an 11-34 or 11-36 cassette
I was thinking that would require a new mech.
Posted : 03/06/2024 7:52 pm
Topic starter
What is the chainset?
Although I'm now wondering if there would be issues with using the existing front mech on a much smaller chainset.
Posted : 03/06/2024 7:54 pm
Older Shimano 9 speed MTB and road rear derailleurs have the same pull ratio, so you can replace the Sora one and get a bigger cassette. The front derailleur will probably work ok with smaller chainrings, but might not shift as smoothly.
I had the same Sora setup on my road bike, switched to a 42t single N/W chainring and 11-36t cassette. Lost a bit of top end speed but I'm not a super fast rider anyway!
Posted : 03/06/2024 9:30 pm
Topic starter
Older Shimano 9 speed MTB and road rear derailleurs have the same pull ratio, so you can replace the Sora one and get a bigger cassette
Cheers, I think I was coming round to this idea!
Posted : 03/06/2024 9:54 pm
I m lowering the gearing on a touring 3x9 setup, with a medium cage derailleur spa cycles reckon I can go to 24 34 44, based on that's the tooth difference on existing setup. If it doesn't change as smoothly as existing i m not that bothered as don't expect to be using the granny ring that much.
Posted : 03/06/2024 10:25 pm
Although I’m now wondering if there would be issues with using the existing front mech on a much smaller chainset.
That could be a real issue with a 46 or smaller chainring it depends on how low the front derailleur can drop on the frame. If its clamp on or a clamp on support you are most likely in the clear. If the support is fixed to the frame often it doesn't go low enough.
Posted : 04/06/2024 9:10 am
GRX sticks out 2.5mm further to clear wider hubs and fatter tyres. The road front mech might not be able to deal with that and engage the big chainring
Posted : 04/06/2024 9:50 am
nevermind
Posted : 04/06/2024 11:41 am
