Hypno Toad

I've got a 2021 Bianchi Infinito with SRAM AXS Force group set, and I'm looking to minimize my gear ratio for an all day climb.

The stock gearing is a min combo is 33x33 (1); it looks like I can replace the chainrings and cassette to get 30x36 (.83)... but I'd like to get to something more extreme, like .76 or lower.

Anybody converted an AXS Force to a smaller than .83 ratio?

Kontact

Seems like your limit is really lowering the FD any more.

Time for a bigger cassette and MTB RD.

DaveSSS 

I use a Shimano GRX 46/30 crank with 10-36 cassette. You can get a longer RD cage from cycles Chinook for $200 and allegedly use a 10-44. They seem to recommend a wolf tooth road link, but I'd try it without first, or maybe use a longer B screw. My 33T capacity Force RD can actually wrap 42T and works with a 10-36 but you need close to 50. There's no need to wrap anything smaller than a 13 with the little ring, but to be safe, you should have enough chain length to wrap the big/big. 8 teeth more than a 10-36 requires 2 more inches of chain. If sequential mode is used, it shouldn't allow either of the two largest sprockets to be used with the big ring. I really dislike sequential and never use it myself.

https://cycleschinook.com/product/ro...8IAwLsQNNNkH90

DaveSSS 

[QUOTE=wayold;22842308]No. I use a Force AXS FD. I also use 2mm spacing washers to move the chain rings in by 2mm to road bike chain line. The GRX cranks shift great with AXS.

wayold

[QUOTE=DaveSSS;22842317]That's really interesting. I didn't know the SRAM FDs would play with the GRX chain rings. Do you know what their limits are?

DaveSSS 

I've used 48/31 and 46/30 GRX models and campy chorus 48/32. No problems.

Camilo

[QUOTE=wayold;22842327]Maybe I'm thick and missing something, But the Shimano, Campy, etc cranks being mentioned won't do anything a 46-30 Force AXS crank won't do. If they work better than Sram, fine, but they don't provide any more range, do they?

I think he's going to try to figure out a AXS RD that will work with a larger cassette that has a larger sprocket than the 36t.AND wrap the double crank and larger cassette, maybe the aftermarket RD cage mentioned above?

I don't have any experiences with combining non-modified AXS MTB RDs with a double crank. They certainly have the "big sprocket" capacity, but I don't know about the wrap that's needed with a 46-30 double crank - regardless of what's used in back, it would need 16t more wrap than with the 1X group they're normally designed for, usually just the largest cassette they're designed for, with no wrap needed for the difference between two chain rings.

DaveSSS 

Sram doesn't make a 46/30 crank. They make a 43/30. They'll never offer cranks with a 16T difference. The RD cage is NOT for an MTB 1x RD. It's for a 2x RD. The idea is to get more low gear without losing so much top gear. A longer cage increases wrap capacity. SRAM under rates the wrap capacity of their current 2x RDs. They will work with a 42T of wrap. (16+26).

SRAM FDs are constantly criticized for poor shifting, but they work great with Shimano and Campy cranks, so the blame seems to belong with poor shifting ramps.

Camilo

[QUOTE=wayold;22842327]ah, so I am thick! I knew I must be missing something, but didn't catch it. Thanks for the kind correction. I must have been thinking of a bike I just bought for my wife that does have a 46-30.

But if the OP is looking for lower gearing, the 46-30 doesn't help with that at all. That was at the core of my confusion I think. No need to change the crank to 46-30 to address his issue unless he's dissatisfied with his high gearing which wasn't mentioned.

The aftermarket cage is intended to increase wrap on a road RD, how does that address the limit of large sprocket @36t or 33t (depending on which RD model) if it's not intended for a MTB RD which would have that larger sprocket capacity? My guess is that the Wolf Tooth extender mentioned in post #3 is necessary in addition to the extender. Without it, I doubt if the Force RD would be able to accommodate a little bit larger sprocket than a couple of teeth more than the 33 or 36t even with a longer B screw. My guess is that it would still not work with the larger sprocket he needs, thus the Wolf Tooth.

A big FWIW and not germane to the topic, for me the 43-30 X 10-36 on our AXS bikes gives functionally the same high gear (43X10) as the fairly common 50X11 that we have on our road bikes. I'm sure there's riders for whom the little better high end would be welcome, especially if their cassette has 11t instead of 10t. But, for me, at least, the 46t chain ring with a 10t rear sprocket would be superfluous, but a solution that allows an AXS RD to work with a larger cassette (wolf tooth) and the chain wrap for a 2X crank (longer cage) would be very valuable, should I need lower gearing.

As for the supposed Sram poor front shifting, I'm not arguing because I've seen the same criticism of Sram front shifting over the years. It's just that I've just never experienced it with my two mechanical 10 speed bikes (Force and Red) as well as our two AXS Force 12 speed. bikes. The front shifting has always been great. And I do have two Shimano bikes to compare to (an older Ultegra 9 speed and newer 105/Ultegra 10 speed). To each his/her own I guess. But I do take care in adjusting no matter what the brand. Maybe Sram just needs more care in adjustment? Or my standards are not as fine as others? I move the shifter, it shifts quickly and accurately is all I care about.