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Hello fellow cyclists,

Could someone please explain to me why XPLR rear derailer is 1x only? I want to install it on my gravel bike with 43/30 double chainring upfront. What can go wrong?

Thanks!

----- EDIT -----

Let me give more context. I already have 2x Force AXS 10-33 casette and quite like the setup. I also have 2 pair of wheels: one for road, another for gravel.

30-33 is not enough for me to ride steep uphils, I don't think 30-36 will change the situation drastically.

XPLR seems to use the same chain and should be able to handle both 10-33 on a road wheelset as well as 10-44 on a gravel wheelset.

Looks like a perfect match to me.

It sould be able to have enough room for chain especially with with AXS sequential shifting.

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  • Why not go with 2x Force instead? Are you looking for a gravel-specific groupset or just want a wider range? Feb 14, 2022 at 16:30
  • @Klaster_1 That is exactly what i have right now Feb 14, 2022 at 18:06
  • what chain did you end up using and how many links did you need?
    – Toast1927
    Sep 9, 2022 at 21:23
  • I used the longer Force chain with 120 links, i removed a few links Sep 12, 2022 at 11:29

3 Answers 3

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Couple of possible problems that might occur with such a setup.

The first is that with a chain sized with the extra links for a wide range Xplr cassette. Then the rear derailleur mechanism might be unable to take up enough chain to maintain tension when it's run on the smaller of the 2x chainrings and smaller cogs on the rear cassette i.e. max cross chain.

Secondly, when Shimano brought out GRX they made a big(ish) deal of it being the first 2x with a clutch system. SRAM Xplr has a rear clutch mechanism that's not been designed for 2x, so it seems quite likely that its extra tension might muck up front 2x shifting.

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I bought XPLR rear derailleur and 10-44T cassette anyway and tried that out.

It runs without issues when sequential shifting is active. No problem with B screw in both rings.

It has indeed too much chain when coupled with 43/30 front rings in cross chain positions. Luckily, this is solved by sequential shifting, so one never crosschains.

B screw adjustment is needed for better shifting experience when switching to a smaller 10-33 cassette, but everything else works great.

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  • I'm building up a bike with XPLR and was considering trying the same thing if I can find a used front derailleur - are you using the wide version or standard?
    – Lee
    Jun 27, 2022 at 8:18
  • I use a wide version Jun 29, 2022 at 21:18
  • How do you find the ride on the 43/40 with the 10-44? I'm mainly looking for better on-road performance over the 1x setup while keeping the 44T in the back for off-road.
    – Lee
    Jul 8, 2022 at 16:40
  • I have 10-44 cassette mounted on gravel wheels and mostly ride them off-road. On road it feels ok thanks to spacing distribution of XG-1251, however I prefer the spacing of 10-33 for high speed constant cadence rides. Jul 10, 2022 at 7:35
  • I was using speed at cadence calculator when was choosing ratios: bikecalc.com/speed_at_cadence Jul 10, 2022 at 7:49
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Well, I can't say I entirely understand the answer, but SRAM have answered this question on their support page.

It is due to the upper pulley being offset.

https://support.sram.com/hc/en-us/articles/4404886728987-Why-does-the-XPLR-derailleur-only-work-as-a-1x-

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  • I believe the premise is that it uses an amount of offset (and presumably an unsprung upper pivot) such that with a double, once you have the B-gap set right on the lowest gear (small ring, large cog), the chain wrap may not be enough in some gears once you're in the large ring. If it had a sprung upper pivot, the B-gap adjustment would have been made in a position where the derailleur body is being pulled back by the upper pivot spring, so when you go into the large ring the pulley offset is still doing the same thing, but it's compensated for by the derailleur body being pulled forward. Feb 16, 2022 at 16:38

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