mschwett 

pretty sure i've gathered everything i need to replace my rear cassette and chain ring. currently 11-42 in the back and 46t up front. going to 10-42 in the back and 42t up front should give me 10% lower gearing at the low end and the same top end. those with the same wheelset say i need the SRAM XD driver (not XDr), the cassette itself (SRAM XG-1195), and the Specialized/Formula's XD driver for the rear wheel, all shown here.

chain ring should be easy, have the ring (wolf tooth 42t) and the bolt set (the stock praxis chain ring is threaded, BCD 110 x 5)

jury is out on whether i need to remove two links from the chain, but i have the chain tool and some new quick links. others are using the same derailleur with the same range cassette, even though the total capacity is listed as 31t, exactly corresponding to the 11-42 on the bike originally.

in addition to chain whip, cassette socket, chain tool, not shown are the basics, torque wrench, sockets, hex keys, grease, loctite, all that. i've built and unbuilt lots of mechanical and electronic things in my years, but have nearly zero bike wrenching experience. i've watched a bunch of youtube videos, and it doesn't look hard at all. any tips or pitfalls, other than "don't do it you idjut!"

shelbyfv

You can do this.

Rolla

I think you'll be pleasantly surprised by how easy all of it is. Not sure what you'll need the Loctite for -- I generally only use the stuff if something habitually comes loose, but rarely for an initial installation. You've anticipated the two most likely problem areas -- chain length and derailleur capacity -- but the chain is super easy to fit, and you'll find out quickly if the derailleur will work or not. Enjoy!

mschwett 

thank you Rolla and shelbyfv ! now I’m bummed I didn’t try it tonight 🙃

mikeymichaels

Every time I work on my car or bike, I tell myself, "I hope I don't mess something up."

You got this!

SoSmellyAir

Bikes are pretty resilient. Cars, not so much.

Good luck, mschwett.

Iride01 

You can always put the old stuff back on if it doesn't work.

himespau 

What chain whip is that?

Phil_gretz

"You can do it!"

mschwett 

its a venzo. i liked the look of the plier style better - and it was cheaper than the park options.

zebede

People who plan and research (such as you have done) have a higher rate of mission success.

mschwett 

well, i appreciate everyone’s confidence!

as i expected, there’s always something that doesn’t work/go as planned.

any tips on how to remove the endcap from the stock freehub? fh-521. through axle. there’s no lock screw, no tooling on the inside - totally smooth. i can grip the other end of the axle with padded pliers and turn the endcap in the direction marked “loosen” and it does turn with a bit of friction. but it just turns forever. doesn’t loosen. tried grabbing it with pliers and pulling it off. no go, at least not without damaging it more.

looking more closely - the end caps turn relative to each other, but the axle does not turn relative to the drive side end cap. seems like i need some way to hold the axle firm from the inside.

mschwett 

gave up and took the wheel to the shop. bummed.

hoped they could do it while i waited, but apparently it requires a bit more work than what the online references say, which is “twist it off with your fingers.” shop mech (who seemed knowledgeable) says the rotor and speed sensor and other endcap have to be removed to then be able to fix the through axle in place and then wrestle off the endcap. i had been hoping there was a tool that went inside the through axle and fixed it while the drive side end cap was twisted off.

jccaclimber

I would just get a locknut tool that clears the axle end.
It isn’t clear to me why else you would need to remove that to change the cassette.
Are you trying to change the body as well?

mschwett 

yeah, the 10-42 cassette requires the XD driver. i don't think the stock driver mates with any cassette that has a 10t.

it turns out to not be that hard - remove rotors, which allows you to pry/vise off the non-drive side endcap, which then reveals a hole through the freehub that you can stick a screwdriver/hex key in to stop the axle from turning while you loosen the drive side endcap. i should have tried taking the rotor and sensor off, but it didn't seem obvious to me that the non-drive side cap would come off at that point. lesson learned.

everything is back together now, about to go for a test ride. bonus savings of 253g of rotating mass

mschwett 

had a really nice ride. the gearing is great. it does feel livelier, probably my imagination since 250g of rotating mass probably is trivial compared to my weight. brakes still perfect, didn't kill myself.

the only buzz kill is some pretty annoying creaking/ticking sounds, only when pedaling under load. perfectly silent (other than the freehub) when coasting, and in some gears some of the time. especially loud out of the saddle. it also seems a tiny bit reluctant to upshift at time, or double shifts upward. hopefully just need to adjust the RD, but not sure why that would be load dependent. frame flex?

didn't hear it on the stand at all.

https://vimeo.com/613132741/69ddc0d746

it's sometimes less regular than this, sometimes a staccato pattern. sometimes louder.

Rolla

The sound *seems* to occur at a regular point of the wheel's revolution. Check all the dumb stuff, like the valve nut and the derailleur hanger alignment, if you haven't.

mschwett 

since it was also reluctant to downshift, i gave the rear barrel a half turn clockwise. also had the chain routed wrong through the cage (embarrassing!) and the sound is much reduced, but still present under heavy load in certain gears. will continue tweaking. hopefully it’s not a spoke. they all sound/feel the same though.