Let me preface this question by saying that I’m not even sure I have the technical proficiency to ask this question correctly. With that being said … I know there are a lot of mechanically inclined MTBers on this board, so hoping someone here is able to give me a concise answer …
I have a 2019 BMC Agonist Two 02 which I purchased with the complete OEM spec. All I have changed on it is the addition of a dropper post.
It came with a SRAM NX drivetrain (not to be confused with NX Eagle) which is 11-speed with an 11-42 cassette.
I would like to upgrade the drivetrain to SRAM X01 Eagle, 12-speed with a 10-50 cassette.
I would also like to upgrade the wheels, but keep the OEM rims as well for winter riding. The OEM rims have shimano Deore hubs.
Questions:
My understanding is that any SRAM Eagle groupset requires and XD driver on the hub, and my current NX groupset (non Eagle) would not have this hub, correct?
Thus, if I wanted to upgrade to any Eagle groupset I would have to upgrade my wheels as well, correct?
It is my understanding that Shimano hubs (like the one on my current bike) are not able to be adapted to fit an XD driver … which means, I think, that if I did upgrade to X01 Eagle with new wheels with an XD driver hub, my old/stock wheels would essentially be useless as a back up wheel set with my new drivetrain because of the incompatibility with an XD driver, correct?
Like I said … I’m not even sure I got these questions worded correctly. But If there is anyone who deeply understands this topic, I would appreciate any thoughts, feedback.
You’d need new wheels, but IMHO the Alex rims that came with the bike aren’t that great. Alex rims are OEM wheels. They are very sturdy in my experience (my current mountain bike has a pair), but they are heavy. Price, weight, performance — pick two. With Alex rims IMHO you are paying in weight.
If your budget gets tight, go for GX Eagle instead and get a nice pair of wheels instead. That’ll be a much more meaningful upgrade.
I think the correct answers are already here in the first response.
As options, you can continue to run an 11 speed with the HG freehub with a couple cassette options. Not as good as 12 speed, but far cheaper upgrade. 11-46 is pretty close to the 11-50 option.
Or a 12 speed cassette that uses an HG body (SX and NX), though I’m sure there is an aftermarket option from someone like Garbaruk. Maybe also E13?
Someone also mentioned DT hubs (like DT350) where you can swap the driver out. This is a good option long term. Though I am sure there are other hub brands you can do this with. I’m using Hope hubs and I believe you can do that as well, though I only use XD when possible (not a fan of Shimano MTB stuff).
I am a fan of GX overall. That’s my first choice if I don’t need light weight and am on a budget. If I have more money then I add in X01 options. Slowly upgrading my long travel bike as stuff fails or wears…which only the cassette had worn out so far.
To run anything with a 10t sprocket, you need an XD driver. However you can have 12 speed without one, but you need a cassette that starts with 11t, not 10t.
Some hubs can be upgraded to an XD driver, but I wouldn’t think yours can, so you would need new wheels.
You should be able to have two 12-speed wheelsets, one starting with 10t, and one with 11t, and just swap between them.
However, the real question is if this is all worth it - do you really need that extra 12th gear? Maybe just getting new wheels instead is a better investment - though get some where you can upgrade the hub, so you have that option open for later.
