I’m riding an ambitiously hilly event in a couple of weeks (Grand Old Dukes, Aberfoyle, Scotland). It’s 111 miles with a mere 10000 feet off climbing. Training has focused on endurance and climbing. If I’m last man back I’ll be happy, so long as I finish.
My gravel bike (Sonder Camino 2x 10 speed) has a standard road compact chainset (50/34) and an 11-32 cassette. Drivetrain is Shimano 4700 Tiagra. Rear mech is the long cage version.
Front ring is getting on a bit so I’m swapping in a 48 tooth Tiagra ring. For the cassette…standard wisdom is 11-34 is fine, 11-36 is unclear. I’ve read it’s unworkable/fine/will run well/you could go 11-40.
Would swapping out the Tiagra road rear mech for a GRX 400 version be the surest plan and roll with a 11-36? Or can I save some cash and just go 11-36 with what I have?
Bike pic just because…😎
by Content_Barracuda294
2 Comments
GRX-400 rear mech can handle up to an 11-42 casette with some b-screw adjustment. Assuming your Tiagra shifters are compatible (the 4700 ones are I think?)
It all depends on your power, I can give you my example.
Amateur cyclist, switched from MTB to gravel last year, 4 W/kg FTP at the moment. I ride in the Swiss Alps, and I love climbing.
My Canyon Grail had 42t chainring and 10-44t cassette. I swapped chainring to 38t and I love it.
I use the lowest gear regularly on 12%+ gradients, it also lets me ride Z2 on smaller hills.