Cassette/rear der/shifter compatability

I am due to change the cassette on my touring bike …currently running 105 cassette/rear der from a dura ace 10 speed bar end shifter.
I need more range at the granny end and am wondering if I can change the rear to SLX cassette and der, and still have indexed dura ace bar end at the front…or are their different pull lengths…
If not, are there other options that only need changes at the rear to give me a 34+ option?

Rear mech will need to be 9 speed as they changed pull ratios for MTB 10 speed. So get a long cage 9sp mech and 10sp MTB cassette.

Nope.

Get yourself a 9sp MTB mech. Cheapest great option for this is the RD-M4000 Alivio shadow 9sp mech (it has a barrel adjuster!! my XT shadow doesn’t) and takes up to a 36T. Or the RD-M592 Deore 9 shadow is ~ the same price and a little nicer

If you only want a medium cage (coz no triple up front), spend ~$10 more and get the RD-M772-GS XT 9 shadow, it’ll take a 34T on the rear (officially).

The Deore & XT will need a jagwire rocket or Ritchey barrel adjuster that you jam into the cable stop, or use an inline barrel.

Then pick your 10sp cassette (SLX, whatever) and get a new, longer chain.

10sp MTB Dynasys mechs and 11sp MTB mechs won’t play nice.

Alt, the last 10sp road mechs (like a 6700A) will go to a 30T officially and maybe further.

Or, the Altus megapulley RD-M310 costs nearly nothing and will work with a 34T.

@Jono: Long cage only needed if there’s a triple up front. Cage length doesn’t affect max sprocket, body geo does

Thanks chaps…forgot to mention I am running a Sugino triple up front, but it looks like you have given me options

I dinnae know tha’. Noted.

So if touring frame and has downtube braze-ons why do you need barrel adjuster on the mech if adjusters on frame?

My fave rear mech is still XT M771 - not shadow.

You don’t ATMO. It’s just handy if for some reason you can’t fit a barrel adjuster otherwise.

If you’re running a triple you’ll need a long cage mtb derailleur. I run an old pre-shadow (can’t remember the #) XT derailleur which has a barrel adjuster on my touring bike.

Make sure you buy an mtb chain (hg-x) as the road chains are hg. 10spd road and mtb cassettes have different ramps.

If you’re running bar end shifters (sounds like you are). Microshift make a shimano 10spd compatible bar end shifter (they also make thumbies) which means you can run a clutch derailleur on your touring bike (hooray).

I’ve stretched a long cage 10spd 10t derailleur to do a 32t cassette without it being terrible.

i wouldn’t recommend this to anyone, shimano may say it’s sweet, alternatively it may be a design issue with the tarmac, but I have seen many 7900 mechs maxxed out with a 28T cassette…

6700A =/= 6700 or 7900.

Related, want to upgrade my cassette to something 30t (or higher). Running Rival rear deraillleur with a max 28t (I think?) at the moment. Need 10spd, what should I be looking at? Have 34/50 on the front. Everything else is also Rival. Have spotted a Tiagra 10spd 4600 cassette for ~$30 in Tokyo, or should I save my $$ / ¥¥ and get something better?

If the rival can only handle a 28t big cog you’ll need a SRAM medium cage MTB mech to start.

Yeah, looks like the short cage can only handle 28t, medium is 32t. I’ll keep my eyes open for SRAM stuff here, but I have mainky seen Shimano and Campy.

Do NOT buy a tiagra cassette. 105 is the best value proposition, ultegra if you need a specific tooth count.

Unlike shimano where you can usually safely exceed rated max sprocket and capacity a little, short cage SRAM might work with a 30T with some B-Screw finangling, but it’s not guaranteed. If your hanger is slightly longer than average you’re more likely to succeed. Capacity might also be an issue, 50-34+30-11=35 and your mech is rated for 33T I think, so big-big could explode the mech.

Going to a med cage wifili will definitely solve your issues though.

Tiagra = no alloy cassette spider therefore heavy

This is a touring bike. Do you really think that saving 100g is important?

It’s more the crappy loose steel sprockets than the weight. But that’s a nice bonus.

Means 100g extra SPD sandles??

Or some A530 pedals.

mmm ok I’m with you now