# Sram 1x8 EX1 drivetrain, how is it working for you?



## highroad 2 (Jan 24, 2017)

After a Shimano derailleur and chain failure in the first 10 miles on my 2017 Haibike, I purchased the Sram EX1 drive train for the Bosch CX motor with a 14t front chain ring to get a decent low gear.
I am sure the faillure was due to the clutch not being engaged and not knowing to let off when shifting under a load.
This was my first mountain bike and did not set it up or know what a clutch was at the time or how to shift.

After 650 miles of moto trails I am not 100% impressed and wanted to get the impressions/solutions of those that also use the EX1.

I have not had any failures but am not pleased with how it shifts and the noise in comparison to the Sram 1x12 Eagle that is on my Hightower.

Sram said my derailleur hanger could be bent so I bought the tool to check and straighten the hanger as needed. 

The selling point of the 1x8 is that the additional torque requires less gears.
That may be the case in higher assist modes, but not in Eco.
I have ridden Levos and wish for more gears and am considering going back to the Shimano 1x11 (46-11) cassette the bike came with, and using the Sram 14t narrow/wide chainring instead of the 18t it came with.

1. How have your 1x11 drivetrains been holding up on your assited bikes?
2. Have you been pleased with the 1x8?
3. Have you been able to get the 1x8 to shift well and not be so noisy?

Thanks
Highroad 2


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## Gutch (Dec 17, 2010)

I had EX1 on one of my Levo’s and loved it. It was smooth and quiet. I like the insurance of not worrying about snapping chains under load.


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## Troy Carter (Dec 7, 2016)

I have only used a 1x11 on my Yamaha motor ebike. I like the idea of the EX1 but I ride 80% of the time without the assist or I have the assist in Eco so I enjoy the extra gears. I also dropped my chainring from the friendly 38t to a 32t to get a bit more gear without the assist on. 

With Shimano XT rear mech and 11-46 cassette I've only had issues when the chain got damaged from a chain drop. The slightly bent links didn't like to stay put but that isn't an ebike issue. Before and after it was sorted it's shifted well, not skipped, or had any other real issues. However, I'm pretty easy on shifts, particularly when the assist is on and think the EX1 would allow a little room for error. I do still worry about it more than on other bikes for sure but I'm not sure I'm willing to give up the gearing of the 1x11.


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## RickBullottaPA (Mar 4, 2015)

Mixed results. For whatever reason it seems super vulnerable to getting trail crud (grass, leaves, small twigs) between the cassette cogs and mis-shifting. Perhaps because of the 8 speed spacing? 

It isn't always that smooth shifting because of the bigger jumps and is super sensitive to derailleur adjustment (doesn't seem like the upper pulley is a floating pulley, which is odd). 

And took some getting used to the one-shift-at-a-time shifter.

When it fails I'll probably just go back to XT shadow.


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## High Rock Ruti (Dec 4, 2017)

*Ex 1 derailleur disaster there's more*

After breaking the same chain twice in 3 weeks I had the bike converted to the EX 1 drive train. Installed in March of 2017 I have just broken my fifth derailleur, I just bought two new ones from Niagara Cycle $112 each. The same failure every time, the upper roller in the chain cage that consists of one machine screw that sandwiches, two washers and a bearing that sits inside the plastic chain wheel. The screw pulls a small threaded extrusion completely off one side of the chain cage. The cage at this attachment point is very thin hence the need to extrude a small threaded 1/8 inch piece of aluminum. The lower end of the chain cage by contrast is over and 1/8 of inch thick and can tolerate the forces generated. Sorry Hard to describe easy to see below

I recently replaced the cassette and chain because of gear hunting, jumping between two cogs on the cassette. I now have about $1500 into EX 1, lesson? I should have replaced $28 chains every so often and keeper the more evenly spaced gear of the 1 X 11 Sram XO drive.

This drive chain is on my 2015 Turbo Levo Expert, I love this bike and will never go back to unassisted riding. With over 2000 miles and the bike is nearing the end of its two year warranty and I am on the hunt for a new E-MTB, Rocky Mountain Altitude and the Pivot Shuttle top the list right now. E bike's have come so incredibly far in the last two years that the Turbo Levo once the cream of the crop is now just average.

Specialized has been really stand up about the warranty (save the derailleurs), having replaced two charges and two batteries and recently the motor, which I think the drive belt broke however, no one but the manufacturer Brose is authorized to service the motor, Specialized told me that motor failures are vary rare. I was tortured for three weeks having to ride UN assisted during the repair.

SRAM by contrast have not been stand up about what is clearly a design defect that could be easily corrected for very short money. The jump between third and forth gear is huge and faster eighth gear would be nice however the governor kicks in to stop assist at 20 mph so asking for a taller top gear is a small quibble.

I could not recommend this drive train, it is noisy, the derailleur is JUNK and it does not jump two cogs at a time, it will not stay in gear

(am I in third no your in fourth no your back in third
again)

want to save your chains, get 1 x 11 single shift shifter and shift one gear at a time and the chains will last a little longer or better yet buy a spare chain and replace it when it breaks.

High Rock Ruti

NUMBER 7 TODAY


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## highroad 2 (Jan 24, 2017)

High Rock
Good to hear Specialized was good to you.
Was 2015 the first year of the Levo's?
I have had much better experience with the EX1 than you but as I started this thread it has not been perfect.
It has yet to let me down but I still wish for closer gear spacing like a 1x11 or 1x12.
Shifting only 1 shift at a time and letting off on the pressure would go a long ways towards longevity.
The Rocky Mountain Altitude also has the EX1.
It also has a unique drive in that only 1/3 of the chain is engaged to the front chain ring.
I am also looking at what will be my next e-MTB


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## motocatfish (Mar 12, 2016)

highroad 2 said:


> ...
> 1. How have your 1x11 drivetrains been holding up on your assited bikes?
> 2. Have you been pleased with the 1x8?
> 3. Have you been able to get the 1x8 to shift well and not be so noisy?
> ...


1. Shimano XT 1x11 on my Powerfly has been flawless, except gear range. Came with 11-42 and changed to Sunrace 11-46. Shifting is always perfect. Bosch claims to sense shift-cable movement & reduce power momentarily during shift. Its certainly feels like that on the Powerfly.

2. My buddy with 2015 LaPierre eMTB (came with Shimano 1x10) put the SRAM 1x8 EX1 system on it. He absolutely loved it for 2 months, until today. It was noisy today both times he passed me. Assumed chain needed lube. Last climb of 2-hour ride, he is standing on pedals & BOINK. Didn't break chain, broke the derailleur mount arm;









He hopes SRAM warranties the part & it doesn't happen again.

He went chainless out of the hills. Then he held onto my Camelbak & rode one-armed back to my place. We turboed down the street at 18mph! 

Catfish ...


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## highroad 2 (Jan 24, 2017)

That derailleur failure looks like what happened to the Shimano derailleur on my Haibike in the first 10 miles.
I have heard that in that case you can shorten the chain, bypass the derailleur and ride out in one gear.
Does that really work?
I feel I prematurely rushed into buying the EX1, thinking it was the last word in electric assist drive train.
I have had zero failures in hundreds of miles, had to adjust the shift cable many times, I thought it was noisy but that could be the gears in the CX motor and the SES wheel that the Haibike suspension design requires.
Knowing what I know now, I would have stayed with the Shimano 1x11, gone with a 14t chainring for the Bosch CX like you did, and learned to shift it properly.
There must be something to the EX1 otherwise the manufacturers would not be using it on their higher end builds.
On the other hand, it seems like the 1X11's are holding up well on the many other assisted bikes out there unless no one is talking about the failures.
As has been said before, the EX1 feature of only 1 cog per shift probably helps take the load off the drive train.
I called SRAM to see if they offered the same style of shifter for there 1x11's and they do not.
Does any one know if Shimano offers a 1x11 shifter that only shifts one cog per shift?
I could have purchased 5 Shimano derailleurs and chains for the cost of the EX1.


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## hobbit (Apr 23, 2007)

Got about 400 miles on my 2018 Levo and the 1x11 is holding up well. Also the shifter only does 1 at a time but don't know if Sram offer this after market but you could go to a Specialized dealer for one.


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## highroad 2 (Jan 24, 2017)

hobbit
Thanks for sharing that your 2018 Levo has 1 at a time shifting.
I went to Specialized website and they have on the $4500 to $7000 Kenovo what they call one-click shifting.
I assume that means 1 at a time shifting.
I am curious if that shifter would be compatible with the Shimano 1x11 cassette 11-46.
I called Sram last week to see if they had one-click shifting and they said no.
It is interesting that Specialized $7500 and $9500 levos do not have one-click shifting.
They do have the higher end XX1 and X1 derailleurs.
I am curious if the 1x8 EX1 is going to be obsolete.
Thanks for the info sharing


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## honkinunit (Aug 6, 2004)

I don't know about SRAM EX1 8-speed, but I have SRAM NX 11-speed (11-42) on my ebike and it works great. I have had several times where I screwed up and really forced a downshift under load and it performs without complaint. I am very impressed, especially considering the price point. You can get the entire group set: cassette, derailleur, chain, shifter and cables, for $200 on eBay. $200. That's crazy. For another $90 you can get the crank/BB.


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## highroad 2 (Jan 24, 2017)

The Sram NX 1x11 is a great bargain if the 11-42 offers enough range.
My reason for going with the EX1 1x8 is the cassette range of 11-48.
I really like the cassette range on the Hightower I recently started riding which has the Sram Eagle 1x12 with a 10-50 cassette


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## Harryman (Jun 14, 2011)

highroad 2 said:


> I have heard that in that case you can shorten the chain, bypass the derailleur and ride out in one gear.
> Does that really work?


Yes. Carry extra quicklinks with you.


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## Giant Warp (Jun 11, 2009)

High Rock Ruti said:


> I recently replaced the cassette and chain because of gear hunting, jumping between two cogs on the cassette.
> 
> View attachment 1170765


Gear hunting on the Levo is basically because the rear derailleur is not true with the cassette. I have to straighten mine about every month. If it is not true then no amount of cable adjustments or new chains or cassettes are going to help. My 17' Levo is at around 2000 miles. I did a test drive on the 18" with the updated one click shifting and I prefer the original setup that can skip gears if needed. The 17' came with a KMC chain that is bullet proof. At 1500 miles I had no detectable stretch when using my park tool chain gauge. I would say that the you still have to be careful (depending on your weight) when shifting. I was trying to beat some guys KOM and stood up on the pedals (instead of downshifting) while cranking up a short step up and blew my chain in two places at the same time. It literally exploded. LOL. Word to wise with the KMC riveted chains, extra quick links are nice to have but when the chain breaks you need a pliers to get the pin all the way out of a link in order to use the quick link. I've been using spray on chain wax from Maxima designed for motorcycle chains with O-rings. It lasts a good month when riding on moon dusted trails and doesn't wash off.


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## highroad 2 (Jan 24, 2017)

The first tool I purchased ($80) after getting into mountain biking earlier this year was the derailleur bracket alignment/ straightening tool.
Like Warp said no amount of adjusting the derailleur will fix the shifting if it is out of alignment with the cassette.
Why would the Levo need monthly adjustment unless the derailleur is getting bent on the trail or it is too fragile for the e-bike torgue.

I called Sram and was told that the one click shifting was proprietary to specislized.
I assume the intention was to reduce failures, probably for those not familiar with how to manage assisted shifting, which I did not know in the beginning.
The 2 highest cost Levo's do not have one click shifting.
If you spend $7500/$9500 for a bike you will apparently know how to shift.

My conclusion after starting this thread and reading your responses is that the 1x8 EX1 does not stand out as being the last word in assisted mountain biking drive train.
For the terrain I ride with a Bosch/Haibike the lower gearing of the 48t cog on the cassette is needed.
I do miss the closer gear spacing of a 1x11.
The 1 click shifting is open for debate


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## Harryman (Jun 14, 2011)

highroad 2 said:


> The first tool I purchased ($80) after getting into mountain biking earlier this year was the derailleur bracket alignment/ straightening tool.
> Like Warp said no amount of adjusting the derailleur will fix the shifting if it is out of alignment with the cassette.
> Why would the Levo need monthly adjustment unless the derailleur is getting bent on the trail or it is too fragile for the e-bike torgue.
> 
> ...


IME, with the closer spacing of 1x11, any weaknesses in the der hanger and it's frame interface quickly become evident. I have one bike that comes out of alignment at the slightest gust of wind, and another that is rock solid unless you smash it into a boulder. I bought a hanger tool like you have and I'll use that if bike #1 gets all wonky, but I've done it enough now that if it's slightly off, I can just tweak it with my hand on the trail.

It was interesting with the hanger tool, how many bikes I've built up or checkd and every one is off to some degree.

Anyway, you'd think 1x8 would be have lower tolerance and be better, but I don't know for sure. I also would think that all the motor's torque would be captured between the chainring and cassette except for any side loads while shifting multiple gears, so I wouldn't think it would be that hard on derailleurs. Cassettes, chains and chainrings for sure though.


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## Gutch (Dec 17, 2010)

What’s the tool? From park?


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## highroad 2 (Jan 24, 2017)

I have not measured the spacing between the cogs on the 1x8 and compared with the spacing on a 1x11, but it sure looks the same.
When I first got the EX1 I expected a beefier looking chain and looks like a 1x11.

I have the Park tool that retails at the LBS for $80.


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## Harryman (Jun 14, 2011)

Gutch said:


> What's the tool? From park?


Yeah, or a clone.

X-Tools Pro Gear Hanger Alignment Tool | Chain Reaction Cycles


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## PierreR (May 17, 2012)

I have had no issues with the stock Guide SRAM 11X42 setup and Shimano chain. I thought about going to the SRAM EX1 but I ride with low assist and most of the time the assist is not providing much assist. I have shifted it many times under load, even full load but I do have a gear shift sensor that cuts the power momentarily. There is enough delay to change two gears. If I need to drop more than two I momentarily pull the brake lever to cut the power and pedal hard until the change is done. I have about 5000 miles on this setup. 5% snow biking, 15% single track and 80% bike path/roads. 

I am considering a 11x50 rear cassette for better gearing as my front chain ring is 42t and sometimes I have to stand on the pedals to climb without much assist.


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## highroad 2 (Jan 24, 2017)

Seems like it would way easier and cheaper to change out the front chainring unless you need the 42t chainring for speed.
Most mountain bikes come with 30-36 front chainrings so you must be really fast


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## PierreR (May 17, 2012)

A 42 tooth chain ring is the minimum in order to get a good chainline. I have it set to top out at 20 mph. Most of my riding is at 8 to 15 mph at about 5 to 8 watt hrs per mile.


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## dkw (Jan 14, 2018)

My 2016 haibike had a standard 11-speed Shimano. Shifting was excellent but cassettes only lasted four to five hundred miles. My 2017 haibike has the EX1 and the cassette shows no wear at 1200 miles but shifting isn't as smooth.


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## justin70 (Sep 17, 2007)

Other updates on sram ex-1 durability and function?


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## highroad 2 (Jan 24, 2017)

I started this thread since I had a Shimano derailleur/chain failure within the 1st 10 miles of buying a Haibike.
I attributed the early failure to the derailleur clutch not being engaged and not knowing how to properly shift an assisted mountain bike.
So I purchased the Sram EX1 drive and as others have voiced the EX1 has not been a win/win.
This week while on a ride I had a chain link pin failure. 
No problem, I always carry a new spare with me and figured I would be back on the trail in 10 minutes.
This chain has ~900 miles of dirt and mud single track so it was due for a new chain.

The new chain wondered between chain rings on the cassette, made lots of noise, acted like it was skipping teeth and was not rideable.
On the stand it shifted great but under a load it was not rideable.
I put the old chain back on with a repair link and it was very ride able but noisy as usual.

So replaced the EX1 1X8 (cassette is 11-48) drive with Shimano 1X11 (cassette is 11-46) the bike came with.
There are climbs that I miss the 48t on the cassette.
Its amazing how smooth the Shimano shifts and how quiet it is and it is not finicky to get adjusted.
I like the closer gear spacing of the 1x11 at times and miss the wider 1x8 spacing at times.
I like the 1x8 shifters ergonomics in relation to my thumb way better plus the 1x8 requires significantly less thumb pressure.
I will try a new shift cable and housing to see if the Shimano shifter will shift with less pressure.

I called Sram and the tech guy said you have the chain on backwards plus that the EX1 quick link is directional which made no sense at all looking at the chain and link.
I called another tech guy and he said the chain is not directional but the quick link is.
Both pieces of the quick link look identical under a magnifying glass so who knows.
Obviously Sram does not have consistent tech info.

Bottom line; They said the cassette and chain wear together and need to be replaced together.
At ~$400 for the cassette I think my EX1 experiment is over.

With the 1x8 I never felt electric would be desirable since it shifts relatively easy.
I would sure like to try electric shift with the 1x11 since I find I am shifting much more often to keep a good cadence.

Is the jury out on mountain bike electric shifting on a 11-46 cassette?
I am ready to try one if the option exists as a retrofit.
Thanks
Highroad


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## Bigwheel (Jan 12, 2004)

"I called Sram and the tech guy said you have the chain on backwards plus that the EX1 quick link is directional."

Now that's one I haven't heard before! RFLMAO


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## Giant Warp (Jun 11, 2009)

A noisy gear train might be wear from junk chain lube. If your derailleur hanger is straight then you might have worn cables. Have you ever used a chain wear gauge to check the chain. Every manufacturer recommends new cassette and chain ring with new chain but if you use the chain wear gauge then you can change out the chain before it causes to much wear to the cassette. 

A 1X8 or 1X11 isn't going to make any difference in the smoothness of shifting or longevity. Any problems would be in the setup and maintenance of each system. IMHO. There is also the possibility that your chain is too long. My Levo came with a 1X11 SRAM cassette and a KMC chain. I've been very happy with it. At first I thought the 1X8 would be the way to go but I really like the 1X11. My model also allows skip shifting but the new model is one click only. I prefer the skip shifting ability. 

So I reallize everyone may have a differnt experience and I have had plenty of years with both Shimano and SRAM gear trains. My experience has been that the Shimano is the smoothest but cables always have to be in tip top shape to prevent ghost shifting. The SRAM requires more effort, does not not have the dellicate/crisp shift but it is bomb proof, does not ghost shift, and can be completlely worn out and still shift OK. This is just one guys experience. 

Cheers


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## shaquille_o'wheel (Sep 27, 2015)

If anyone is looking to sell their ex1 cassette I would be interested in taking it off your hands. I have an analog bike project that I'd like to experiment with this cassette and friction thumbies....

Thanks!


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## brilleaux (May 13, 2016)

EX1 8 speed Cassette is Narrower than a 10- or 11-speed cassette. Has anyone measured how much this help to fit wider tyres if chain clearance is tight using 11speed cassette?
How much biggest cog is outer than 11sp cassettes cog?


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## cyclopath1000 (Feb 22, 2009)

I just got a commensal meta 650 b Shimano e8000 with 34 tooth Shimano chainring and the sran e8000 1x8 cassette and rear derailleur shifter but a sram 1051 chain ( 10 speed design) holy mother of cluster f dom. The chain can't be correct for the sram stuff. The cassette gears are 0.5 mm wider than a 10 or 11 speed cog and the shifting under load is very bad. I ordered a ex1 chain but I don't know how it will work on the Shimano chainring Which of course is 11 speed. Anybody else think along these lines and work on a solution ?


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## brado (May 13, 2010)

cyclopath1000 said:


> I just got a commensal meta 650 b Shimano e8000 with 34 tooth Shimano chainring and the sran e8000 1x8 cassette and rear derailleur shifter but a sram 1051 chain ( 10 speed design) holy mother of cluster f dom. The chain can't be correct for the sram stuff. The cassette gears are 0.5 mm wider than a 10 or 11 speed cog and the shifting under load is very bad. I ordered a ex1 chain but I don't know how it will work on the Shimano chainring Which of course is 11 speed. Anybody else think along these lines and work on a solution ?


I think the shimano chainring might work. Commencal is getting you the right chain aren't they?


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## cyclopath1000 (Feb 22, 2009)

So I've taken the ex1 8 speed chain for two rides. Again the commensal came with a 10 speed chain but the ex 1 ,
8 speed groupo. Maybe it shifts a bit better. It isn't as good as my m8000 2 by on my tall boy. I'm just in it to try and not destroy the rear derailleur when shifting under extreme load such as super steep hills. The sram just isn't as good. I'll check the hanger for sure. I already bought a spare hanger . If I eat a deraillier I think maybe it's m8000 time. Cheaper and probably better.


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## BCsaltchucker (Jan 16, 2014)

have completed 3 mtb rides now on my Powerplay 70. so far the shifting has been good, if a bit noisy. I was worried about the gear spacing but honestly it is not an issue, I am mainly in gears 1-3 most of the rides and the Rocky's power is immense enough to make the jumps irrelevant even in eco mode.

I just wish SRAM made a Gripshift unit for it. I am skeptical that some older or cheap 8sp grip shift will have the right pull ratio. I miss having the ability to jump multiple gears and the triggers dig into my hands! If something breaks I might put on SRAM 11sp


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## cyclopath1000 (Feb 22, 2009)

I'm talking about going g up super steeps and trying to optimize a big rear cog such as going g from two or three down to the 48 toother. That's where the shifts suck. It seems that the design is to shift one cog at a time so if u are wanting to go up four cogs u need four separate shifts.


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