Replacement drive train - opinions please!

[DrChris]

After 6 months, I'm almost ready to replace the SRAM Eagle NX 12 speed drivetrain that came stock on my '19 Commencal Metapower. During this time I've snagged the derailleur on a branch (also destroying my rear wheel) and seem to catch a lot of trail debris in the long cage derailleur quite regularly. I also don't seem to use the 50t cog much.

So my plan was to switch to a 10 speed set up with a SRAM GX medium cage derailleur (and 10sp shifter), SUNRACE CSMS2 cassette (all steel cogs and spiders), and a KMC e10 ebike chain.

So a couple of questions:
1) Those of you who have switched out your drive train, what combination has worked for you ie. number of cogs, mixing SUNRACE with SRAM derailleur and KMC chains, and did you miss your 50t cog?

2) Has anyone kept their 12 speed shifter and gone back to an 11 speed or 10 speed cassette? Did it still work OK?

Any comments appreciated!

Dr Chris

 

[33red]

Well depending on our fitness, our weight, our trails the proper gearing is personal. What is your rear tire size? Do you plan to use that size? How many T in front? You can use the fallowing gear calculator. Sheldon Brown's Bicycle Gear Calculator My original cassette was 10 speeds 11-36, on day 1 i switched for 11-42, that is pretty much the minimum range that is decent if you are not on flat areas. Remember a small gearing allows us to go up slower saving our battery. What is your battery capacity, 500Wh? For sure a 10 speeds is less expansive and could cover you, they offer 11-46 cassette.

 

[Gary]

with an 11-46 and 36t chainring I rarely ever use my 37t sprocket nevermind the 46T.
Infact I only really use the 46t when i ride the bike uphill with the motor OFF (I do this when riding with less fit/newer riders and kids) or very short steep technical sections where a lower assist level and lower speed gains more grip. I do ride very hilly terrain but I'd manage get away with running a 10 speed 11-36 cassette if I wasn't ever going to ride the bike uphill when switched off again.
I couldn't comment really as to whether this range would cover your needs for where you ride.

Personally I wouldn't ever touch a sunrace cassette at all. Especially for Emtb use.
The durability is poor and they're often finicky shifting

If choosing a 10 speed drivetrain I'd also choose Shimano shadow+ clutch mechs and shifters over SRAM. Partly from personal preference but I've also found Shimano 10 speed SLX and Zee mechs and shifters to simply be higher quality and more durable than the 10 speed SRAM offerings available now that their higher end groups are 11 and 12 speed.

If you're clumsy and catch your mech cage often. I'd def go with a Zee shadow+ FR mech (shorter cage and slightly more durable mech design) but the Zee mech is only meant to shift up to a 36T sprocket. (as are older Deore, SLX and XT 10 speed shadow+ mechs*)
shifter wise SLX has a gear display window wheras Zee doesn't but there's not a lot in it.
XT is slightly better quality and has a multi shift function on both levers.

Shimano also do 10 speed cassettes in 11-42 now if you need the extra range designed to work with the Deore GS (mid cage) M6000 rear mech.

*Sometimes an older 10 speed mech will actually work with a 42t sprocket but it's dependent on the frame design and chain length as much as anything and it's just a case of being lucky as to whether it will or not.

 

[33red]

There is an example, he likes 36-36, i like 32-42.
You need to build a family, 10 chain/cassette/derailleur and shifter

 

[DrChris]

Thanks for the replies so far. To clarify:

1) I plan on changing from a 34t front chainring to 32t, while going for a 42t largest rear cog, so should give me a slightly easier lower gear than 34t/42t which I predominantly use now as my lowest gear (I don't usually need to use the 50t cog). This will be sufficient for the short punchy technical climbs I ride locally in the northern beaches of Sydney, Australia.
2) I've had no particular issues with SRAM derailleurs and shifters over the past 20 years, and know the GX medium cage rear derailleur will work OK with a 42t rear cog.
3) I was hoping by going with a steel cog cassette (Sunrace CSMS2) it will be a bit more hard wearing than alloy cogs on the SRAM NX cassette? I've had no experience with Sunrace though, so am interested to hear about bad experiences. The very low prices are obviously attractive though!
4) The plan to go for a shorter cage (medium) derailleur is because I tend to have a lot of fallen branches and debris on my local trails which kick up into my derailleur on rides.
5) I'm running a 2.6" Maxxis DHF on a 30mm Chromag rim with Cushcore installed which is definitely an improvement in stability on the original 2.6" Hans Dampf on 35mm Spank rim, which was a bit too squirmy on cornering.

Thanks!
DrChris

 

[33red]

That is a safe plan. 10 speeds are no problem SRAM or Shimano i have both. People sell their set to upgrade. 2 of my 3 bikes are on 11-42, my other is 10-42. We just need to use the proper front.

 

[khorn]

Thanks for the replies so far. To clarify:

1) I plan on changing from a 34t front chainring to 32t, while going for a 42t largest rear cog, so should give me a slightly easier lower gear than 34t/42t which I predominantly use now as my lowest gear (I don't usually need to use the 50t cog). This will be sufficient for the short punchy technical climbs I ride locally in the northern beaches of Sydney, Australia.
2) I've had no particular issues with SRAM derailleurs and shifters over the past 20 years, and know the GX medium cage rear derailleur will work OK with a 42t rear cog.
3) I was hoping by going with a steel cog cassette (Sunrace CSMS2) it will be a bit more hard wearing than alloy cogs on the SRAM NX cassette? I've had no experience with Sunrace though, so am interested to hear about bad experiences. The very low prices are obviously attractive though!
4) The plan to go for a shorter cage (medium) derailleur is because I tend to have a lot of fallen branches and debris on my local trails which kick up into my derailleur on rides.
5) I'm running a 2.6" Maxxis DHF on a 30mm Chromag rim with Cushcore installed which is definitely an improvement in stability on the original 2.6" Hans Dampf on 35mm Spank rim, which was a bit too squirmy on cornering.

Thanks!
DrChris

I'm running a Sunrace 11-46t cassette right now and it does its job but not perfect. I run it together with a 11 speed XTR setup and it does not shift as good as a Shimano. Also, the shifts are quite a bit noisier but as it cost 1/4 of a XTR cassette I can live with it.

Karsten

 

[iXi]

Watching this with interest. Have the same drive train and was thinking of moving to a 10sp 11-36 as I never use the 42 or 50. Just tossing up if I go the full shimano route, derailleur, shifter etc.

 

[Zimmerframe]

Obviously it's only a small part of the cost if you change, but I just bought a new CS-HG50-10 to have a spare for mine (as that's what's already on the bike). They're about €25 which didn't seem too bad and a KMX x-10 chain as they seem well rated and it was cheap....

 

[Gary]

I'm running a Sunrace 11-46t cassette right now and it does its job but not perfect. I run it together with a 11 speed XTR setup and it does not shift as good as a Shimano. Also, the shifts are quite a bit noisier but as it cost 1/4 of a XTR cassette I can live with it.

Karsten

This doesn't make any sense to me.
Why not just fit SLX 11-46 cassettes?
They work properly (performance wise exactly the same as XTR) AND last
BUT cost 1/4 of XTR

 

[khorn]

I'm a bit Scottish so I will wear out the Sunrace BEFORE I shift back to Shimano

Karsten

 

[Gary]

3) I was hoping by going with a steel cog cassette (Sunrace CSMS2) it will be a bit more hard wearing than alloy cogs on the SRAM NX cassette? I've had no experience with Sunrace though, so am interested to hear about bad experiences. The very low prices are obviously attractive though!

it's not the larger Alu sprockets that wear out fastest. it's the smaller (less chain wrap) sprockets where you'll experience chain slip from wear. Even more so on an Emtb.

I was testing sunrace 11-50 cassettes and wore out the STEEL 15T sprocket on two cassettes in less than 200 miles for each cassette. It's junk.
SLX lasts me 10 times that length of time.

SRAM HG Cassettes are decent but design wise not quite as durable as shimano.

5) I'm running a 2.6" Maxxis DHF on a 30mm Chromag rim with Cushcore installed which is definitely an improvement in stability on the original 2.6" Hans Dampf on 35mm Spank rim, which was a bit too squirmy on cornering.

Squirm in corners simply means you are not running high enough pressure to support the sidewall/carcus/tread edge. Cushcore adds support allowing you to run lower pressures with the increased support in the same tyres.

 

[Niklas]

I had the new XTR, twisted the chain after a week, sold it and got me EX1 and love the big hops between the gears so happy with that.

 

[DrChris]

An update:

I've ordered an 11sp SLX cassette 11-42t, 11 speed XT shifter and XT medium cage rear derailleur and a KMC e11 chain. Got great pricing from Merlin Cycles with free shipping to Australia.

I've got a new Chromag 104BCD 32t alloy narrow/wide chainring hanging around to put on, but was also considering a stainless steel Wolftooth chainring. The main issue for me is that they cost AUD$150. But I hear that they last 5-10x longer than alloy rings.

Anyone running a stainless steel front chainring?

Thanks
DrChris

I had the new XTR, twisted the chain after a week, sold it and got me EX1 and love the big hops between the gears so happy with that.

 

[jsalas2]

I swapped back to 11sp from an EX8 very expensive to replace. I am using sram gx shifter and deraillier withe Sunrace all steel 11-46 cassette Csms8. Works great and very inexpensive to replace when necessary. Cassette in the US only around $60. Have also used sram nx shifter and deraillier with no problems. I am using on a Commencal MetaPower.

 

[ccrdave]

I run an 11-46 sunrace cassette with an NX 11sp rear mech and in my opinion, it shifts better than the cheap sram PG 1130 cassette

 

[Gary]

it doesn't

hope that helps