Please Help: Need Smaller Gears for R9200

[LedZeppelin007]

Hi,

I’m a large man (190cm, 90ish kilos at the moment). While I’m in decent condition (315 watt FTP), I’ve started doing longer rides and Fondo events with significant climbing.

Currently, I have R9200 on my bike with 52/36, 11-30t combo.

What I find is (especially if it’s hot) that I’ll be fine at first and can punch up climbs. After 60 miles, though, I’m fading hard and really paying for having to put in 400 watts to keep a comfortable cadence on that 12% 1/4 mile grade at mile 10.

Have a long, hilly event here in a couple of weeks. I would really prefer to have AT LEAST a 1:1 climbing gear so I’m not burning matches early on simply to climb steep rolling hills.

For the life of me, I don’t think it’s possible to get 50/34 chainrings for R9200 at the moment. I do have an 11-34t R8100 cassette, but I really (oddly?) couldn’t get acceptable shifting performance with it despite using an appropriately long chain and doing plenty of microadjusting.

What are the options? I’m willing to get funky, but would rather not shell out a ton of cash.


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[CyclingGiraffe]

Hmmm . . . the 11-34 8100 cassette should be fine, as the 9200 rear derailleur is officially rated to a max cog of 34t (which usually is slightly conservative). You say "appropriately long chain" -- is it a new 8100 or 9200 chain, and how did you calculate the length? Getting that cassette to work is probably your best bet.

[spdntrxi]

50/34 and the aboved mentioned 11-34 cassette..

[LedZeppelin007]

50/34 and the aboved mentioned 11-34 cassette..

I’ve looked and looked and looked. Can’t find 50/34 rings to save my life.


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[LedZeppelin007]

Hmmm . . . the 11-34 8100 cassette should be fine, as the 9200 rear derailleur is officially rated to a max cog of 34t (which usually is slightly conservative). You say "appropriately long chain" -- is it a new 8100 or 9200 chain, and how did you calculate the length? Getting that cassette to work is probably your best bet.

It was a new 8100 chain. I did the big/big sizing method with two links. I did end up shortening it a little to try and add some additional tension in the big-big combo as it was skipping some.


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[LedZeppelin007]

I’m guessing there are absolutely no options to run subcompact? I was even thinking about buying a used R9100 crank and using those subcompact Absolute Black rings in combo with the 11-34 cassette. Sounds like it could be a disaster.


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[Mocs123]

The 8100 cassette "should" work but perhaps it's not easy to set up? Would the easiest and cheapest thing be to see if a professional mechanic could get it shifing properly with the 11-34 cassette?

For some reason I seem to remember hearing that Dura Ace 9200 wouldn't offer 50/34 chainrings, which seems odd to me as I tend to think that's the best chainring sizes for us everyday joes that live in mountainous areas. Of course I guess with Ultegra and now 105 Di2, Dura Ace may go back to just being a "pro" level groupset.

A 9100 Crankset with 50/34 would certainly work, even a lot of pro teams are still using 9100 series cranks. There have been some reports of dropped chains, as I think the Q factor is a little different, but they must work pretty well if they are still using them.

[LanceLegstrong]

Rotor has 50/34 rings that would work. May not shift as well as stock Shimano but could work until Shimano inventory improves.

https://rotoramerica.com/collections/ro ... 1364294683

[spdntrxi]

Rotor has 50/34 rings that would work. May not shift as well as stock Shimano but could work until Shimano inventory improves.

https://rotoramerica.com/collections/ro ... 1364294683

I use rotors's on my AXS system... yes they will not be as good as Shimano, but they will work alright enough.

you can also try just getting a 34t inner.. I've seen them on ebay.

I run a 52/34 extralite rings(9100) and my riding buddy runs 52/34 on his 8100 ultegras.. it works.

[PoorCyclist]

Regulate yourself early in the course, don't push into the red early on and you will feel a lot fresher at mile 60.
Resist the temptation to follow the guys going 30 mph in the first 20 miles.

Also look into how much you are eating. It can make a big difference.
Then you wouldn't need a 1:1 and you will save $ and save weight.

[TobinHatesYou]

Then you wouldn't need a 1:1 and you will save $ and save weight.

1:1 at just 75rpm is 6mph/9.7kph. On a 12% grade with equipment, I'd be doing ~4.0w/kg. That's fine for me because my FT is around 5.0, but the OP's FTP is around 3.5.

Long-term it makes a lot of sense to go 11-34t in back.

[StiffWeenies]

What about the new 105 level non-series CS-HG710-12 11-36T cassette? The sprocket gaps will be bigger and shifting performance won't be as nice but it's a cheap way of getting that 1:1 gearing while keeping your existing 52/36 chainrings.

[DukeNiemand]

You can also try Wickwerks 53/34 chainrings. Shifting is better than Shimano. Last I heard they were testing compatibility with 12sp in spring.

[Karvalo]

50/34 and the aboved mentioned 11-34 cassette..

I’ve looked and looked and looked. Can’t find 50/34 rings to save my life.

Get some from Rotor or Absolute Black or anyone else who makes them for the Shimano 4bolt pattern. It might not look great but who cares as a stopgap?

[LedZeppelin007]

50/34 and the aboved mentioned 11-34 cassette..

I’ve looked and looked and looked. Can’t find 50/34 rings to save my life.

Get some from Rotor or Absolute Black or anyone else who makes them for the Shimano 4bolt pattern. It might not look great but who cares as a stopgap?

I don’t actually think either AB or Rotor chainrings will fit on the 9200 crank arm. Shimano has changed the interface subtly. The inner ring might fit, but I don’t think the outer ring will


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