SRAM EX-1 EMTB Drivetrain, reviews?

[Coastsider]

Having just destroyed my Sunrace 11 speed cassette, chain and front chainring on my Moustache Race 8 in just 300 miles I'm looking at this SRAM E bike specific drive train to replace my standard issue components. I have adapted my riding style to allow for the high torque stress applied to the drivetrain by ebikes but still managed to trash my set up as supplied by Moustache. I'm kinda pissed that on such a high end bike Moustache use lesser drivetrain components (for some reason they use the EX-1 derailleur only, but nothing else), the Moustache website describes the drive train as EX-1 but quotes 11 speed (EX-1 is 8 speed). So, I have read good things about the complete EX-1 system but would love to hear if anyone has real world experience of this system and specifically how it's wearing. Cheers.

 

[Knobby]

I was just about to post about the SRAM EX1 setup (Derailleur & Cassette)... Wanted to hear peoples thoughts..

My experience so far has been eventful. First 150 miles i was getting creaking noises from the EX1 cassette, seems this was a result of the 40nm torque not being enough to keep the lock nut held tight.

150-250 miles noisy but could adjust it out.. Chain gap appeared to be the fix for this and got it running well. Seems to like running wet lube and being clean.

350 miles. Couldn’t adjust it myself. Its been into my local bike shop twice and still having problems. It won’t stay in the top two cogs, keeps jumping out. Checked the chain, and it appears to have plenty of life left in it.

Can’t decided whether to go back to LBS or have a play myself.. Still think the chain gap is a big factor or i have some damage somewhere.

 

[EddieJ]

Couldn’t adjust it myself. Its been into my local bike shop twice and still having problems. It won’t stay in the top two cogs, keeps jumping out.

The EX1 derailleur and often the hanger, are quite fussy in respect of correct and proper alignment. More so than any other system that I have used, but others might say differently and don't have an issue.

This though is one tool that I wouldn't now be without. park tool dag-2.2 derailleur hanger alignment gauge - EMTB Forums

If you happen to live in Sussex, I'd happily take a look for you.

Set up properly EX1 is super smooth, precise and very durable. Personally I find the jump between gear ratios too great, and don't like SRAM as a whole. For my use, their cassette and jockey wheels cause me nothing but hassle by clogging in the terrain that I ride. I've yet to find the same using a Shimano/Sunrace set up, and will be switching back when replacement time comes.

 

[Coastsider]

Just curious Knobby, do you have the full drive train including the special EX1 SRAM chain, front chain ring, shifter etc? Or just the Derailleur & Cassette?

 

[Knobby]

Just curious Knobby, do you have the full drive train including the special EX1 SRAM chain, front chain ring, shifter etc? Or just the Derailleur & Cassette?

SRAM EX1 chain
SRAM EX1 shifters
SRAM EX1 derailleur
SRAM EX1 cassette

Don’t know if the chain ring is SRAM. Would need to have a look. It’s on a CUBE AT, maybe someone else knows.

 

[knut7]

The Moustache website doesn't say, but you've got either the CSMX8 or the CSMX80 Sunrace cassette. Depending on which cassette it is, the one or two biggest sprockets are aluminium and will wear out quite fast. Also there is a 14t chainring, that will wear fast and need replacing every, or every other time you swap the chain. Once one of these parts get worn, they will accelerate the wear on all other parts of the drive train. 300miles isn't a lot, but it isn't unheard of.

I would get as much steel components in the drive train as possible, and a larger chainring. A 15t up front along with the Sunrace CSMS8 11-46t, and the Sram PCX1 chain should be more durable. But you're sacrificing the lowest gear. There isn't an all steel 11 speed 11-50t cassette as far as I know. But if you need the 50 tooth, I'd get the Sunrace CSMX8 (not CSMX80). Check with the dealer that there's nothing limiting you from increasing the chainring size, like that lower chain guard.

 

[Kernow]

As Eddie j says it’s all about set up , especially the tension , which needs to be set while sitting on the bike at normal sag , not with the bike unloaded .
My ex1 has done about 1200 off road only miles so far , first chain wore to .75 in under 500 miles in harsh winter use , the second chain is still doing well after the dry summer .
I think there was a faulty batch of shifters , mine was never good at changing to the large cog and the shifter was at fault , new shifter and it’s been no trouble since , I literally haven’t had to touch adjustment since . I’ve heard of a few shifter related problems .

Do I like it , ? the cassette is robust for sure , but expensive . For me 8 gears leaves too many gaps in the low gears when climbing and riding with other normal bikes . The durailure is huge , I have lots of scrapes on mine but it’s not got damaged yet . I could imagine it being poor in deep mud .
Will I buy it again , unlikely at that cost . But I’ve never been a SRAM gears fan , shimano is just so much smoother cheaper and easy to set up and still keeps going even when very worn.
I was actually looking at sunrace cassette and Xt durailure as a replacement when I need it , partly because sunrace do the 11-50 or 11-48 range which Xt dont . Iam waiting first to see the new Xt range , but it looks like it will be a while before I wear the ex1 out . Iam tempted to sell my ex1 partly because all my other bikes are shimano and I keep spares .

 

[Coastsider]

This is all interesting stuff! Still a lot of discovery happening with the new challenges faced by components with the huge stress and torque E motors put on EMTB drivetrains, suspension etc. I was hoping after reading the initial reviews that the EX1 system was going to be the nirvana of drivetrains, oh well. Steel cassettes are obviously the way to go along with heavy chains, good set up, regular maintenance and watch the chain stretch.

 

[Knobby]

So to some of the EX1 Setup experts...

If it’s been setup by a shop and they say it runs perfectly but not setup to my sag.

Then I adjust the chain gap to my sag. Does chain gap adjustment effect cable tension?

 

[Knobby]

My dirty EX1... (300+ miles)

 

[Coastsider]

My dirty EX1... (300+ miles)

View attachment 4820 View attachment 4821 View attachment 4822 View attachment 4823

While I can see some wear on the teeth, the cassette looks to be in pretty good shape after 300 miles, and one would hope so right? Here in the States the EX1 set up is around $800 for the whole thing!

 

[Japuserid]

So to some of the EX1 Setup experts...

If it’s been setup by a shop and they say it runs perfectly but not setup to my sag.

Then I adjust the chain gap to my sag. Does chain gap adjustment effect cable tension?

Hi @Knobby, It is possible for them to have set the gap using the Sram tool and B tension screw if they deflate the shock so that it sits at the 30% sag mark during the setting process. I use this method and I find it certainly helps get you in the ball park, but unfortunately not the whole way. I find a little less gap works best for me and get the best results after fine tuning out on the trail.

TBH, and as much as I really like EX1, it certainly is not easy to get it setup and running100%.

Everything really does need to be pretty much spot on for it to work really well and things like chain length, hanger alignment, hi and low stop screws, B screw and cable tension setting parameters seem to be far more sensitive than other systems I have used.

But once you get it right I really love it and much prefer it to my old 11 speed XT setup, not that there was anything wrong with XT, ran like a dream, just too many gears, fewer cogs with wider spacing, to me personally, makes far more sense on an E-MTB.

As to setting it up, my best advice is simply start at the beginning and really take your time to get each bit correct

Is your chain the right length?

Is your hanger properly aligned?

Are the Hi and Lo stop screws set properly? A little too tight and it will really struggle selecting bottom and top, a little to loose and it will fly off either end.

Make sure you set the B Tension screw at your Sag % whatever that % actually is and fine tune B tension and cable tension out on the trail.

Cable tension one click at a time and test it as you go and when finally you do find the sweet spot, leave it alone.

One thing that I personally found to be very frustrating early on was that getting it perfect whilst in the workstand is a complete waste of time as it only worked well whilst it was in the bloody workstand and invariably ran lousy out on the trail.

So in summary, I think it's fair to say that EX1 is not for the faint hearted or anyone that relies on workshops for basic maintenance, it could cost you a fortune. But if you are prepared to spend the time to find out what works and what doesn't, I personally think it's currently the best and sadly only E-bike specific drive train available at the moment.

Hope this helps

 

[Japuserid]

Worth a look if you are having setup issues with EX1, disregard the title it's actually EX1 specific.

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