twowheelies

I am looking for a new used road bike, and I want to find something with a lower gear ratio for the steeper climbs where I ride here in the Bronx and upper Manhattan.

I have an older Bianchi, with DA 7800 groupset. Cassette is 12/27 and chainring is 39/53.

My aging joints need something a little gentler to allow me to spin a little more up those hills. What groupsets should I be looking for to best accomplish this?

thanks all

WhyFi

Do you want to buy a new bike or would changing out some of the drivetrain be sufficient? You might be able to find a compatible long cage 10-speed derailleur, new cassette and compact crankset if you want to stick with the Bianchi.

If you want to buy a new bike, rear derailleurs with larger capacity are getting to be pretty common, as are compact cranksets. If you really want some capacity, some of the gravel oriented groups (GRX in Shimano) can handle pie plate cassettes.

twowheelies

Thanks. I would probably keep the Bianchi set up as it is, I love it and it’s great for flatter rides, like the ones I do on Long Island. It actually climbs beautifully as well, it’s just the joints need a break at this point. So I’m probably looking to add to it with something newer, 5 ish years old, something like that.

So should I be looking for something in a 105? Ultegra? Anyone have a good setup they love for getting a little more spin on a steep hill?

WhyFi

Either. Shouldn't be too hard to find something with a 50/34 crankset and a 32-tooth or so cassette. If you can't find that stock, replace the derailleur (with a long cage version) and/or cassette.

HTupolev

Do you have the RD-R7800-GS or RD-7800-SS on the bike?

If you have the RD-R7800-GS, then you should be able to just change out your chainrings and/or cassette for something wider-range/lower.

If you have the RD-7800-SS, you may need to swap it for something more tolerant to wider and lower gearing. Any Shimano 8-speed or 9-speed rear derailleur will be compatible with your shifters, so something like a Sora RD-R3000-GS should work fine.

rm -rf

A low gear of 34F - 32R would be 26% easier. That's a lot, maybe three more shifts easier.
I put on a 11-32 for some vacation mountain riding, and kept it on for the smaller local hills. I can stay seated on a 10% grade, and even on a 12% grade. Much better than having to stand up. And it's very nice to be able to keep a high cadence on easier hills.

I've put the 32 cassette on a bike that had 28 as the low gear. It's outside the recommended range, but it shifts fine. So if you find a bike with a 28, you could try it with a 32. Just make sure it shifts okay on a bike stand, and that the chain is long enough for the cross-chained big chainring-biggest cog. On the stand, shift to a middle cog. Shift to the big chainring. Now, cranking by hand, shift into the biggest cog. Is there a at least a small gap between the top pulley and the cog? The derailleur arm can't be extended so far that the chain has no angles at the pulleys--if so, a longer chain will likely fix it.

I'm guessing that 5 year old bikes are in short supply again this year.

Gear ratios:
39/27 = 1.444
34/32 = 1.0625

Then divide the two to compare: 1.0625/1.444 = 0.736 so it's about 74% easier.

twowheelies

Yeah, thanks... but I don't want to change anything on the Bianchi, I want to add a bike. Wondering what groupsets lend themselves to lower gear ratios, on say a 5-8 year old bike.

twowheelies

Yes! that's the idea. Spot on.

So my question is, what groupsets should I be looking for in a 5-8 year old used bike, that lend themselves to that kind of ratio?

WhyFi

This has been answered already - both Ultegra and 105 have derailleurs and cassettes that cover these ranges. If the installed derailleur/cassette doesn't cover the desired range, you can swap them out relatively inexpensively.

twowheelies

Well I was hoping for a little more specific info than just "ultegra or 105," anyone can kind of figure that out on their own. I was thinking maybe someone with a similar objective was using a specific model they liked, that i could look out for. but thanks man, much appreciated.

WhyFi

Specific model of what? Bike? Or are you looking for derailleur part numbers? 5-6 years ago was about the time of the transition to the current groupsets. Both the RD5800-GS and RD6800-GS will handle a 32t. Both the RD-R7000-GS and RD-R8000-GS will handle a 34t max.

twowheelies

See now was that so hard?

WhyFi

Like pulling teeth, because the person asking the question was too ignorant to know how to ask the question.

Koyote

better yet, the person asking the question could simply count the teeth - on the cassette and the chain rings.

see now, is that so hard?

colnago62

No good deed goes unpunished.

znomit

26% easier!

rm -rf

Quote:
Originally Posted by rm -rf View Post
Then divide the two to compare: 1.0625/1.444 = 0.736 so it's about 74% easier.

yes. oops. 74% of the original, 26% easier.

If you need 74% easier, that's a 34 front, 91 rear (or a "custom" 12 front, 32 rear, if you want to keep the cassette)
At 100 rpm, that's 2.89 mph. Gotta keep spinning.