Rail (625Wh) Rail Gen 2 motor reliability

[Sinkrate]

Hi all,

Thinking about picking up a 2022 Rail 9 for the other half.

It’s got the Bosch CX 250 watt motor 85nm

I know zero about Bosch motors, if anyone has one and can post a brief what’s good / bad then that would be great. Cheers

 

[Stihldog]

My Rail has the Bosch CX Gen 4 motor (2020 model). I’ve been trying to bust it for almost 4 years now. Wish me luck .
I think it has 12K+ km on it…maybe 18K. I recently installed a crank seal kit but I didn’t really have to. (Preventive measures). A few cooling fins have chipped off but I just softened the edges with a dremel tool. I broke one skid plate also.

 

[Peaky Rider]

Bosch Gen 2 motor failures are worryingly high in the group I ride with. This year three have just died and one more sounds as though it is on the way out.
So far they have all been replaced under warranty, even one that was technically out of warranty, but I doubt any had done more than 3000 miles.
Eight Bosch riders in the group so thats a pretty high percentage.
Three Shimano motors in same group and two of those failed.
It's all a bit pathetic.

 

[Mteam]

Bosch Gen 2 motor failures are worryingly high in the group I ride with. This year three have just died and one more sounds as though it is on the way out.
So far they have all been replaced under warranty, even one that was technically out of warranty, but I doubt any had done more than 3000 miles.
Eight Bosch riders in the group so thats a pretty high percentage.
Three Shimano motors in same group and two of those failed.
It's all a bit pathetic.

I think the op is asking about the Bosch gen 4 motor that is used in the second generation of trek rail bikes.

Think the Bosch gen 4 motor is largely considered the most reliable of all the various ebike motors, but that doesn't mean total reliability unfortunately.

 

[Zimmerframe]

It will be the Bosch Gen4 in the rail. (though the rail might be a Gen2 just to confuse things). I think on the whole they're pretty reliable - the main issue would be water ingress. If it's been jetwashed then there's a good chance it will fail much sooner. Whilst you can get that reparied, the main circuit board sits in the lower part of the motor, so if water has got in, that corrodes and then you're screwed.

Personally, I'd go for some of these. Banish any pre-conceptions you have :

https://www.chainreactioncycles.com/p/vitus-e-mythique-lt-297-vr-mountain-bike

I've had one for a few weeks/400km's and it's been surprising ! The motor's on a par with the Bosch or Brose.

The Fork on that model is crap (they all seem to be faulty for some reason), but you can get a Fox36 from Merlin Cycles for not much money.

The Tektro brakes lack power. The disks are 2.3 which is great and the calipers are fine, you just need to swap the levers out for Shimano's or TRP's (you can buy a full TRP brake set from bike discount for about €90 or Merlin for about €100 - just swapped mine over, though just the lever on the rear as I was in a hurry).

You can get motor parts or replacement motors easily enough. Parts are cheap (€11) for cranks from chain reaction for example.

Presently have a 180 Lyric on mine and it's amazing. I actually prefer riding it to my Kenevo or my Jam2 6.9 at the moment.

 

[Sinkrate]

thanks for the replies, v helpful info on the motor. Yeah I don't wash my e bike much at all apart from the chain etc etc, and will be doing the same with this one

 

[Peaky Rider]

I think the op is asking about the Bosch gen 4 motor that is used in the second generation of trek rail bikes.

Think the Bosch gen 4 motor is largely considered the most reliable of all the various ebike motors, but that doesn't mean total reliability unfortunately.

I've given up trying to work out what Gen they are, bikes affected were MY 21/22 Rails and Whites, none one of them 'Smart'. Shimano ones are Rises.

 

[Zimmerframe]

I've given up trying to work out what Gen they are, bikes affected were MY 21/22 Rails and Whites, none one of them 'Smart'. Shimano ones are Rises.

Gen2 had the tiny chainring which span at a different speed to the cranks. Incredibly solidly built motor but really needed bearing man's extra seals to stop moisture ingress.

Gen4 was the normal sized chainring. (gen3 was a commuter type motor). Worth doing the grease change behind the seals to help with limiting moisture ingress.

"Smart" is the same motor but with a different control board and connections just to pee everyone off

As @Mteam says, they're generally reliable and one of the most reliable .. but doesn't mean they're infallible.

 

[Peaky Rider]

Thanks Zimmer, all is crystal clear now and it appears they are all gen 4.
Going to write your identifying description on the garage wall now.

 

[Stihldog]

The 2020 Rail 9.7 that I received in 2019 may have had the first model of the Gen4 CX Bosch motor. Before I ordered this bike I had researched the other manufacturers. The motor longevity and reliability was the most important factor for me and for my eventual decision to get a bike with a Bosch motor.

Getting the first model of anything can be risky. Maybe the assembly worker was paying more attention to their task at 10:30am on a Wednesday with a quality control supervisor peering over their shoulder.

In my immediate circle we have 10 bikes with Bosch gen4 CX motors and one was replaced because the bracket bolts sheared off(operator abuse or incorrect torque …don’t know). My motor has seen many kms and all types of conditions and is still as quiet and reliable when I first received it. But eventually it’s gonna fail.

I recently installed the bearing seal kit which provided some waterproofing grease. The crank bearings seemed good at this time so I didn’t/couldn’t repack grease into those. I hope I can ride a few more thousand miles before this motor fails, but when it does I’ll go to plan “B”.

I probably could’ve installed a bearing seal kit earlier. It’s not too difficult if you have the right tools and I don’t think it would be too expensive if the LBS did the job. (1/2 hour to 1 hour labour, plus parts).

I’d really like to see our LBS keep a spare motor in stock or at least have a fast method of replacement under warranty or to purchase. A few basic parts would be nice too.

 

[Peaky Rider]

I have a bearing seal protection kit to fit as soon as the warranty on my motor runs out next month.

It is both rocky and can be very wet where my mates and myself ride in the Peak District/Derbyshire Dales and I guess that may account for the high motor mortality rate (almost fifty percent of us) in the last few months.

On a brighter note, Bosch did replace one of the motors which was nearly three years old, free of charge.,

 

[Stihldog]

Good idea for a bearing seal protection kit. I’ll probably get another kit to hang on the wall.

I would say our trails are mostly technical-rooty with some rocky sections.

However there are some long rock climbs for a challenge.

 

[deertrackdoctor]

Reliability is not an issue if you buy from a local shop Bosch warranty has been awesome in the 5 years I've had ebikes .
Latest CX is at 4k miles no issues.
I've previously had new battery and a new motor on a trek rail .All dealt with and back on the trails in 6 day from my LBS

 

[Highwayman]

On a side note.... Any ideas on whether a CXR motor replacement is an option. I have a gen 4 9.8 and the plan I have is when the CX motor dies to upgrade to the CXR from the higher end Rails. Just not sure if it'll lockout the system when connected.