So I’m piecing together a budget (ish) hardtail for my nephew as we couldn’t get hold of a Vitus Nucleus / Voodoo Bizango / Calibre equivalent.
Cheapest 11 speed rear mech was the new deore 5100, I found an Slx 11 speed shifter for a decent price and I’ve hooked it up to a Sunrace 11-46 cassette and a Sram non boost narrow wide chainring.
Got it all sort of working, but the shifting isn’t quite as I’d like it. I’m going to borrow a mech hanger checker to make sure that’s straight to rule it out as an issue - if there’s nothing wrong with that I’m a bit stumped.
The mech should cover up to a 51 tooth cassette and I’ve sized it according to shimanos guide for new style mechs on a hardtail.
Bike has a 73mm bb and I’ve fitted a dub crank just with 1 x 4.5mm spacer on the drive side per the instructions. 6mm offset steel chainring for non boost.
Rear of the bike is 135mm qr (frame is a Brand X HT-01) with a standard hg shimano freehub body.
The shifting is great in the highest 4-5 gears but after that it’s a bit patchy - although it easily gets up onto the largest cog. I’ve tried various cable tensions and b screw positions (I can’t seem to get it per the instruction where the biggest teeth in the biggest cog line up with the line on the mech cage - although I think that’s for a 51t - and you’re meant to be something like 46mm gap instead for a 10-45 cassette).
I’m wondering to improve they chainline if I could get a smaller spacer than 4.5mmfor the drive side and take a few mm slack over to the non drive side using the bearing preload collar thing.
Any thoughts?
Decent cable outers, good cable routing, cable clamped correctly at mech?
Yes, yes and yes.
I’m running a Deore M5120 mech with a 10-speed 11-46 SunRace cassette and an XT shifter. I also had problems getting quality shifting at the beginning, and it did turn out to be the mech hanger. One thing to watch out for is that, if your mech is like mine, the cage will appear to bend slightly outward when viewed from behind - this seems to be a feature of newer Shimano mechs designed to work with wide-range cassettes.
What’s the difference in the m5100 and m5120?
I haven’t checked the hanger or the mech is straight yet. It’s not awful, I just don’t want to hand over a bike to my novice nephew with slightly out shifting. Will borrow a mech hanger tool and rule that out next!
I got a 5100 rear derailleur to run on a 10 speed mash up of parts & it just wouldn't shift perfectly in all the gears.
Ended up biting the bullet & buying the shifter & 11-51 & setting up as the rather excellent instructions.
Now it's all good.
I think you should still use the alignment mark for b tension with a 1x11 11-46
I always reduce the chainline as much as possible, so that shifting on the big sprockets is improved. So if it was me I'd try a 2.5mm spacer instead, and see how that does.
As above try moving the crankset closer to the BB shell by using thinner/less spacers. Also check if the cassette/freehub combo requires a spacer or not behind the cassette on the freebub.
Cassette is a standard mtb one for an HG freehub and it’s a Shimano mtb hub - XT QR 6 bolt thing. So I don’t think it needs any spacers.
Defo still need to check the hanger and if that’s all good then it’s got to be either b screw or just not brilliant chainline. I think if I reduce the size of the spacer on the drive side I need to take that up on the non drive side - so maybe 2.5 drive side / 2 on the non drive side. Then use the preload collar to take up the slack m / preload the bearings. That’ll give me a much better chainline to the biggest few gears on the cassette.