Shimano Rear Mech for 10 Speed Sunrace 11-46 Cassette?

I have a Shimano XT M8000 Shadow+ 11 Speed Rear Mech and a Sunrace MX3 11-46 10 speed cassette in a 1×10 setup.

I took these along with a new frame to the local bike shop to get it all fitted….   however when I went to collect they said they cannot get the mech to shift properly to the largest cog.  Both items were fitted on my old frame and the shifting worked, but only just and never very well.  Can someone shed some light on whether a different derailleur is required to make the Sunrace work properly?

Thanks.

Is it not just a matter of a longer b-tension screw being required. Or a Goatlink or similar.

Could try something like this

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F323202769538

Other sellers / versions available

Thanks.

After some further research I have also found the OneUp Components RADr Shimano Rear Derailleur Cage which most say seems to help.

Can anybody else offer guidance on which method to go for – there must be hundreds on here who have faced the same issue….

I’ve not had this issue, but…

the rad cages were designed for 10 speed mechs. The Shark cage works with 11 speed. Wolf Tooth do a cheaper version.

Possibly daft question, is it a question of chain length? Technically the 8000 series mech should work with a 46 though a longer b-tension screw would be a good place to start.

In the old days the screws from electrical sockets used the same thread as derailleurs. If this is still the case it could be an easy way to confirm the theory.

Just buy the Deore mech that’s designed to work with this range… cheaper and better working than any of the other options. Have put one on my daughters bike (with the cheap wide range Deore cassette).

Kelvin how is the Deore Mech different to the Shimano XT M8000 Shadow+ mech please?

I’d say its a set up issue, B screw adjustment or chain length due to chain stay change. Have the shop explained why it wont work? Whats the new and old frames?

I was in a bit of rush picking up the bike from the shop so we didn’t discuss the issue it at any length.

If I recall though, it was actually someone on here who recommended the Shimano XT M8000 Shadow+ 11 speed to work with the Sunrace.  I have gone from a Vassago Jabberwocky to a Solaris Max new version.  I think you might be right about chain length, I will take it into a different shop and enquire.

Kelvin how is the Deore Mech different to the Shimano XT M8000 Shadow+ mech please?

It’s designed to be used with a big cog in the 10spd position, not the 11spd position.

I’ve just fitted an SR 11-50 to my 11 speed XT medium mech. Just took a couple of twiddles on the b tension screw to work. Didn’t even have to wind it all the way in. Standard mech and no goat link, etc.

Does your new frame take a direct mount derailleur? If so you may need to remove the B link from the mech to get the Sunrace to work.

I had the same problem when I initially tried to fit an 11-50 Sunrace and an XT mech. It wouldn’t shift to the big ring at all. Took ages to realise what was wrong as I didn’t release my derailleur hanger was direct mount. Removed the B link and then as above, it worked a charm. Loads of B screw left to play with and and no need for any extra components.

I’d be surprised if LBS didn’t suss this themselves but you never know.

Behold the arrangement……

What does it do on the big sprocket?

Hmmm should work. I’ve run that mech and 11 speed M7000 SLX on my 10 speed bikes with 11-46 Sunrace cassettes.

I’ve found (it is probably just coincidence) the XT mech attracts rocks like a magnet. I’ve bent the cage four times now and it plays havoc with shifting. Your mech looks brand new compared to the battered one I’ve got though!

Check the cage is not twisted/bent, sometimes it’s hard to see! The top and bottom jockey wheels are different! It’s not unusual for people to mix them up and/or put them back the wrong way round!!

medium cage xt (GS) with 11-46 xt cassette and sunrace 11-50 with no issues

I have in the past used a 10 speed deore mech with the one up radcage with that cassette. It shifts pretty well no problems at all. that setup still resides on my spare bike.

I was under the impression the read cage was designed to mimic the the guide wheel setup that’s on the M8000 mech.

It’s designed to be used with a big cog in the 10spd position, not the 11spd position.

Might be worth working out the cog pitch difference between 10 and 11 speed and whether having the big cog 2mm further inboard makes any difference. Its never caused me a problem 😁