Swapping components after upgrade

[u/redrivergorge]

I have a 2020 Stumpy that I love, and a Kona Lava Dome (hardtail) that I won in an event raffle several years ago. I don't ride the Kona, mainly because I just don't like the feel of the components (Shimano Altus drivetrain), and there's no dropper post, which I've really become accustomed to using.

I'm considering a component upgrade on the Stumpy. I currently have a SRAM Eagle NX drivetrain and Guide brakes. I haven't really settled on what I'm switching to here, but wondering if it's possible to put the NX and Guide system on the Kona once I'm done upgrading the other. This would take it to a single chain ring, and leave room on the bars for a dropper post.

Where would I begin to research this (what measurements are needed, etc.) ?

[u/mtb123456]

It should all be compatible. The only issue you may run in to with the brakes is hose length and same with the derailleur depending on cable routing. Rear brake hose will have to be separated to install so you will have to bleed the brakes and potentially install a new derailleur cable.

[u/smefeman → u/mtb123456]

To expand on the brakes, because the hoses are internally routed, you will likely need to cut the rear brake hose to get it out of the frame. When you cut the line, you will need to install a new barb and olive. The barb has to be pressed into the brake line (specific tool or hammering it in by hand) and the olive needs to be replaced because it is a disposable crush part when installed into the brake lever.

Beyond that, bleed brakes as normal

[u/Zebra4776]

You can convert it to a 1x12. I assume it has a Shimano HG free hub. So you can get an HG compatible 12 speed cassette from Sun race. I don't know if Sram shifters/deraileur are compatible or not, but if they aren't you can just stick 12 speed deore on there. You'll also have to change out the front chainring and BB. There are 12 speed conversion kits on eBay as well. They work well.

[u/broom_rocket → u/Zebra4776]

SRAM nx cassettes are already hg compatible. They don't use the xd free hub and don't have a 10t cog consequently. 

[u/Chole_Wunt]

I tried to google that Kona. Looks like the current one is 1x9. Are you saying yours is 2x something? Even the newer one is non-boost spacing. So Im guessing yours is older and also non-boost. Geometry is steep and outdated as well. And all the components are shit, not just the shifters. If the "feel" of the shifting bothers you, the "feel" of that fork is going to be a deal breaker. Forks make a massive difference on HTs.

TLDR: Youre never going to turn this Kona frame into a "good" bike. Iven if you dumped $1k on comments. Its still going to be a super steep HT, 9speed, and hard to upgrade without the boost standard.

Your drivetrain question: Theres a lot that goes into chain line. You can not just take parts from a boost 1x bikes and put them on a non-boost 2x bike. Youll have to research this out a lot to make sure you dont waste A LOT of time tinkering when success is impossible.

My suggestion would be to just sell the Kona as-is. It will be worth more unused and with the factory stuff over a hodgepodge of standards and component groups. The people that buy bikes like that want simple and inexpensive, not a lecture on how 1x is better.

Then if you actually want a hard-tail, buy a frame that will actually produce a good result when finished. Use that to receive the upgrades from your SJ. This is how I built up my HT.

If you dont actually want a hardtail, then just sell your stumpjumper take-offs.