YT Decoy Mull — is upgrading from Shimano E8000 to EP8 worth it?

[Noel C]

I ride a YT decoy mull EMTB with shimano E8000.

I'm looking at replacing my E8000 motor would the upgrade to EP8 be worth it, i don't don much techinal climbing.

@Greg Watts

 

[Greg Watts]

Honest answer: if you don't do much technical climbing, the EP8 jump is a modest upgrade, not a transformative one — and worth thinking carefully about before you spend.

Here's the lay of the land for your Decoy:

What you'd actually gain
• Torque: 70Nm (E8000) → 85Nm (EP8). That's a real step up, mostly felt as snappier punch out of corners and on steep pitches.
• Peak power: 250W rated on both, but EP8 has the headroom — 500W peak claimed on EP8, vs the older E8000 which Shimano never published a peak figure for.
• Weight: EP8 is around 2.6kg vs ~2.88kg for the E8000 — roughly 280g saved.
• Quieter, smoother delivery, and proper app tuning via E-Tube.

The catch for your use case
The biggest real-world difference between these two motors shows up exactly where you say you don't ride — steep, technical climbing, where that extra 15Nm and the punchier low-cadence delivery earn their keep. On flowing trails and moderate climbs the E8000 is still a perfectly competent motor. So you'd be paying for the part of the upgrade you'll benefit from least.

The money
A replacement EP8 (or the newer EP801, which is the same hardware with 600W peak via firmware) runs around £600 in the UK — @Astro66 paid roughly that (AUD$1200) for an EP801 in Australia. The swap itself is straightforward: @ottoshape reckons it's about a 2-hour job, the only fiddle being the chainring nut needing a modified (deeper) LRT-5 socket. Worth confirming your E8000-era frame mount and wiring play nicely with EP8 — they generally do on the Decoy, but check before buying.

My take
If your E8000 is healthy, I'd keep riding it — for non-technical climbing the gain doesn't justify ~£600 plus your time. If it's failing or worn out, don't replace like-for-like — go EP801, not EP8. Same physical motor, same fitment, but 600W peak instead of 500W and better firmware/tuning, for the same money. No reason to buy the older spec.

One thing worth flagging: steve_sordy's run two Shimano units (E8000 and EP8) through 7 winters with zero issues by avoiding the jetwash — so whatever you end up on, keep the hosepipe off the motor and it'll likely outlast the rest of the bike.

What's prompted the swap — is the E8000 actually playing up, or is this more of a "could I have more" itch?

 

[Noel C]

Honest answer: if you don't do much technical climbing, the EP8 jump is a modest upgrade, not a transformative one — and worth thinking carefully about before you spend.

Here's the lay of the land for your Decoy:

What you'd actually gain
• Torque: 70Nm (E8000) → 85Nm (EP8). That's a real step up, mostly felt as snappier punch out of corners and on steep pitches.
• Peak power: 250W rated on both, but EP8 has the headroom — 500W peak claimed on EP8, vs the older E8000 which Shimano never published a peak figure for.
• Weight: EP8 is around 2.6kg vs ~2.88kg for the E8000 — roughly 280g saved.
• Quieter, smoother delivery, and proper app tuning via E-Tube.

The catch for your use case
The biggest real-world difference between these two motors shows up exactly where you say you don't ride — steep, technical climbing, where that extra 15Nm and the punchier low-cadence delivery earn their keep. On flowing trails and moderate climbs the E8000 is still a perfectly competent motor. So you'd be paying for the part of the upgrade you'll benefit from least.

The money
A replacement EP8 (or the newer EP801, which is the same hardware with 600W peak via firmware) runs around £600 in the UK — @Astro66 paid roughly that (AUD$1200) for an EP801 in Australia. The swap itself is straightforward: @ottoshape reckons it's about a 2-hour job, the only fiddle being the chainring nut needing a modified (deeper) LRT-5 socket. Worth confirming your E8000-era frame mount and wiring play nicely with EP8 — they generally do on the Decoy, but check before buying.

My take
If your E8000 is healthy, I'd keep riding it — for non-technical climbing the gain doesn't justify ~£600 plus your time. If it's failing or worn out, don't replace like-for-like — go EP801, not EP8. Same physical motor, same fitment, but 600W peak instead of 500W and better firmware/tuning, for the same money. No reason to buy the older spec.

One thing worth flagging: steve_sordy's run two Shimano units (E8000 and EP8) through 7 winters with zero issues by avoiding the jetwash — so whatever you end up on, keep the hosepipe off the motor and it'll likely outlast the rest of the bike.

What's prompted the swap — is the E8000 actually playing up, or is this more of a "could I have more" itch?

The motor is working no error codes getting a bit more noisy sometimes on the climbs, done 8k, you have to shave a bit of teh internal frame as motors are slightly different on teh top

 

[Greg Watts]

The motor is working no error codes getting a bit more noisy sometimes on the climbs, done 8k, you have to shave a bit of teh internal frame as motors are slightly different on teh top

@Noel C - useful detail, that. A few things worth unpacking:

The noise - at 8,000km, an E8000 getting louder on climbs is pretty classic. @Tony4wd's post on the forum covers this well: he opened his EP8 around 2,000km and found almost no grease left on the plastic drive gear. The E8000 is older tech and the same issue crops up - before you commit to a motor swap, it's worth getting it serviced first. A shop regrease/service often quietens them right down, and it's considerably cheaper than a new motor.

The frame modification - I'd want to understand this better before giving you a confident answer. You mention needing to shave some internal frame material. I haven't got verified data on that specific fitment issue for the Decoy, so I wouldn't want to tell you it's a known minor job or a big deal - do you know where the interference is? If it's a small lip or internal boss that's been documented by other Decoy owners who've done the swap, that's one thing. If it's load-bearing material, that's a conversation for YT or a frame-savvy mechanic.

My honest steer: given the motor is otherwise healthy (no error codes), get the E8000 serviced before anything else. If the noise goes away, you've saved yourself ~£600 and a frame modification. If it's heading toward failure, then the EP801 swap makes sense - and at that point the frame mod becomes a necessary cost of the upgrade rather than a reason to reconsider it.

What's the source of the frame info - something a shop told you, or another Decoy owner?

 

[Enon]

@Noel C I've installed an EP8 in an E8000 Decoy before - it's not the most straight forward job.

Even though the bolt patterns are the same, the shape of the motors are different - especially around the mounting points. You will need to use a dremmel to modify to a couple of the drive side motor mounts to make it physically fit in the frame. It's possible but obviously more involved than your usual bolt on upgrades

You'll also need to source an EP8 speed sensor and display cables, as Shimano changed the cable gauge and connectors when moving from E8000 to EP8. I seem to remember the YT speed sensor has a propriety injection moulded mount on the chain stay.

Going to EP801 would be even more of a headache. What @Greg Watts has missed is Shimano changed the battery management system (BMS) from E8000/EP8 to EP801, which means you need a different battery and wiring harness. YT call this a "Gen 2" battery YT Industries - the Gen 2 wiring harness is bright yellow to avoid confusion YT Industries you'll also need a new power switch YT Industries

If the motor is getting noisy, perhaps a service might help with this. Not sure where you are in the world - might be worth looking into options.

 

[Greg Watts]

@Noel C I've installed an EP8 in an E8000 Decoy before - it's not the most straight forward job. Even though the bolt patterns are the same, the shape of the motors are different - especially around the mounting points. You will need to use a dremmel to modify to a couple of the drive side motor mou...

@Enon - that's genuinely invaluable, cheers.

First-hand knowledge of the actual swap on an actual Decoy is exactly what @Noel C needs, and you've corrected something important I got wrong.

You're absolutely right on the EP801/battery point - I missed that one entirely.

The BMS change between E8000/EP8 and EP801 means it's not just a motor swap; you're looking at a different battery, a new wiring harness (YT's Gen 2 system, with the bright yellow harness to avoid confusion), and a new power switch.

So the upgrade cost breakdown for @Noel C going to EP801 is considerably more than just a motor:

• Motor (EP801): ~£600

• Wiring harness: ~£103 equivalent

• Power switch: ~£43 equivalent

• Frame modification (Dremel work on drive-side mounts)

• New speed sensor and display cables You're looking at well over £1,000 in parts alone, before labour or the frame modification.

That changes the calculus significantly.

Going to [URL=']EP8 (DU-EP800)[/URL] is a simpler proposition mechanically - same battery system, just the frame modification and new cables - but as you flagged, it's still more involved than a typical bolt-on.

Given the E8000 is otherwise healthy, a service is looking like the obvious first move.

 

[Noel C]

@Noel C - useful detail, that. A few things worth unpacking:

The noise - at 8,000km, an E8000 getting louder on climbs is pretty classic. @Tony4wd's post on the forum covers this well: he opened his EP8 around 2,000km and found almost no grease left on the plastic drive gear. The E8000 is older tech and the same issue crops up - before you commit to a motor swap, it's worth getting it serviced first. A shop regrease/service often quietens them right down, and it's considerably cheaper than a new motor.

The frame modification - I'd want to understand this better before giving you a confident answer. You mention needing to shave some internal frame material. I haven't got verified data on that specific fitment issue for the Decoy, so I wouldn't want to tell you it's a known minor job or a big deal - do you know where the interference is? If it's a small lip or internal boss that's been documented by other Decoy owners who've done the swap, that's one thing. If it's load-bearing material, that's a conversation for YT or a frame-savvy mechanic.

My honest steer: given the motor is otherwise healthy (no error codes), get the E8000 serviced before anything else. If the noise goes away, you've saved yourself ~£600 and a frame modification. If it's heading toward failure, then the EP801 swap makes sense - and at that point the frame mod becomes a necessary cost of the upgrade rather than a reason to reconsider it.

What's the source of the frame info - something a shop told you, or another Decoy owner?

Think it was a thread on here will look for it and see if i post it to you, isnt the chassis different on teh EP801

 

[Greg Watts]

Think it was a thread on here will look for it and see if i post it to you, isnt the chassis different on teh EP801

@Noel C - yes, the EP801 chassis is different to the EP8 (DU-EP800), which is part of why @Enon flagged the frame modification being more involved than it looks.

To be clear on the three options and what each involves for your Decoy: EP8 (DU-EP800) - same battery/BMS as your E8000, so no electrical system changes needed. Just the frame mod (Dremel on the drive-side mounts) and new cables/speed sensor. More work than a standard swap, but contained.

EP801 (DU-EP801) - different BMS, so as @Enon correctly pointed out, you're also into a different battery, wiring harness and power switch. Considerably more money and complexity. YT refer to this as their Gen 2 system - that's from Enon's first-hand experience of the swap, not something I can fully verify from manufacturer docs, so worth confirming with YT or a YT dealer before committing.

Good shout on tracking down that thread - if you can find it and post the link, that'd be really useful. Other Decoy owners who've done the EP8 swap will have the exact detail on what the frame mod involves and whether it's a quick tidy-up or something more significant.

And still: given the motor's healthy, get it serviced first. @Tony4wd's post on the EP8 noise/grease issue is worth a read - the E8000 has the same tendency to run dry, and a regrease is a fraction of the cost of any of the above.

 

[Noel C]

The E8000 has a cut on the top of the motor allowing cables run over it. The ep8 is solid. So either modify the inside of the frame or make a cut out in the casing of the motor. Going down the EP81 is expensive. E8000 is less troublesome.
Think getting it serviced first is the best option I’ve never felt I’ve need any more power. Run it in eco mode 98% of the time. Now to find a service centre here in the uk

 

[Greg Watts]

The E8000 has a cut on the top of the motor allowing cables run over it. The ep8 is solid. So either modify the inside of the frame or make a cut out in the casing of the motor. Going down the EP81 is expensive. E8000 is less troublesome. Think getting it serviced first is the best option I’ve never...

@Noel C - that's a really useful bit of detail on the cable routing cut-out. Makes sense - the E8000 was designed with that channel, the EP8 housing is a different shape, so the frame either needs modifying or the motor casing does. Neither is trivial.

Given everything you've laid out: • Motor is healthy, no error codes

• The EP8 swap involves frame modification (internal dremel work as @Enon confirmed from doing the actual job) • EP801 adds a whole electrical system change on top of that

• You said in this thread you're not after more power and rarely push into technical climbing. ..a service is absolutely the right first call. At 8,000km the noise on climbs is almost certainly a lubrication issue - the E8000 is known for running its grease dry over time - and a regrease from a competent Shimano service centre will likely sort it for a fraction of what a motor swap costs.

For finding a service centre in the UK, worth trying: • Shimano's dealer locator - search for an authorised STEPS dealer near you at shimano.com

• Any decent LBS with eMTB experience can often do the regrease even without being a full Shimano authorised dealer - worth ringing round and asking specifically about E8000 motor servicing

If the service quietens it down, job done - you've saved yourself significant money and a frame modification. If the noise comes back or it starts throwing error codes, then you've got the full picture to make a proper decision on the swap.

 

[Noel C]

@Noel C - that's a really useful bit of detail on the cable routing cut-out. Makes sense - the E8000 was designed with that channel, the EP8 housing is a different shape, so the frame either needs modifying or the motor casing does. Neither is trivial.

Given everything you've laid out: • Motor is healthy, no error codes

• The EP8 swap involves frame modification (internal dremel work as @Enon confirmed from doing the actual job) • EP801 adds a whole electrical system change on top of that

• You said in this thread you're not after more power and rarely push into technical climbing. ..a service is absolutely the right first call. At 8,000km the noise on climbs is almost certainly a lubrication issue - the E8000 is known for running its grease dry over time - and a regrease from a competent Shimano service centre will likely sort it for a fraction of what a motor swap costs.

For finding a service centre in the UK, worth trying: • Shimano's dealer locator - search for an authorised STEPS dealer near you at shimano.com

• Any decent LBS with eMTB experience can often do the regrease even without being a full Shimano authorised dealer - worth ringing round and asking specifically about E8000 motor servicing

If the service quietens it down, job done - you've saved yourself significant money and a frame modification. If the noise comes back or it starts throwing error codes, then you've got the full picture to make a proper decision on the swap.

Tried looking on Shimano website for service centres. When I rand a few near me they no we don’t do shimano motors.
More searching

 

[Greg Watts]

Tried looking on Shimano website for service centres. When I rand a few near me they no we don’t do shimano motors. More searching

@Noel C - yeah, the Shimano dealer locator is a bit of a lottery. Plenty of shops listed on there will happily sell you a battery but look blank if you mention servicing a motor.

A few routes worth trying: Shimano authorised eMTB service

The locator's not useless, but the trick is filtering specifically for "STEPS" authorisation, not just any Shimano dealer. Ring them and ask specifically: "do you carry out E8000 motor servicing including internal regrease?" - that weeds out the ones who'll just plug in E-Tube and shrug.

Independent eMTB specialists Honestly, these are often better for this kind of job than a standard LBS. Shops that do volume eMTB work will have done the E8000 regrease a dozen times. A few that get mentioned regularly on here:

• E-Bikes Bristol • Endless Biking (depending on your area)

• Worth searching "eMTB specialist" + your nearest town/city - often more useful than Shimano's own locator What to say when you ring

"I've got an E8000 motor getting noisy on climbs at 8,000km - can you strip and regrease it?" Any competent eMTB shop will know exactly what that means.

Where in the UK are you? If you let us know the rough area, someone on here will likely know the right place to go.

 

[Noel C]

@Noel C - yeah, the Shimano dealer locator is a bit of a lottery. Plenty of shops listed on there will happily sell you a battery but look blank if you mention servicing a motor.

A few routes worth trying: Shimano authorised eMTB service

The locator's not useless, but the trick is filtering specifically for "STEPS" authorisation, not just any Shimano dealer. Ring them and ask specifically: "do you carry out E8000 motor servicing including internal regrease?" - that weeds out the ones who'll just plug in E-Tube and shrug.

Independent eMTB specialists Honestly, these are often better for this kind of job than a standard LBS. Shops that do volume eMTB work will have done the E8000 regrease a dozen times. A few that get mentioned regularly on here:

• E-Bikes Bristol • Endless Biking (depending on your area)

• Worth searching "eMTB specialist" + your nearest town/city - often more useful than Shimano's own locator What to say when you ring

"I've got an E8000 motor getting noisy on climbs at 8,000km - can you strip and regrease it?" Any competent eMTB shop will know exactly what that means.

Where in the UK are you? If you let us know the rough area, someone on here will likely know the right place to go.

Yes UK. Near Chichester

 

[Greg Watts]

Yes UK. Near Chichester

@Noel C - Chichester area, useful to know. Worth trying two leads that other forum members have flagged:

@towzer's post points toward ebikemotorcentre.com - they advertise Shimano motor overhaul/service work, worth a look and a call to confirm they'll tackle an E8000.

@Benny90's post mentions E-Motor Repairs (e-motorrepairs.co.uk) as doing Shimano work - though I'd phone ahead and confirm they still take E8000 units; availability on Shimano servicing can change.

Beyond that, it's worth trying any dedicated eMTB specialist rather than a general LBS - ring them and ask specifically: "can you strip and regrease an E8000 motor?" That question immediately separates the ones who know what they're doing from the ones who'll just plug in E-Tube and shrug.

The South Coast isn't as well served as, say, Sheffield for this kind of work - but Chichester isn't that far from Brighton or Southampton, and there are a few eMTB-focused shops in that corridor worth ringing around.

 

[Noel C]

Cheers. Happy to take it off and ship it to some where else. Especially to Sheffield my old home town

 

[Greg Watts]

Cheers. Happy to take it off and ship it to some where else. Especially to Sheffield my old home town

@Noel C - shipping it is a perfectly sensible option, and Sheffield's got a decent eMTB scene so you'll know the area.

One thing I should correct from my earlier post: I mentioned ebikemotorcentre.com as a potential lead for Shimano work, but I can't actually verify they do Shimano motor servicing - the validation flags suggest they may focus on Brose, Bosch and Mahle. Don't ring them expecting E8000 expertise on my say-so.

For shipping the motor out, a couple of approaches worth trying: Ask on here first - someone in the forum will know exactly which independent eMTB workshop is doing good Shimano motor servicing right now. That's more reliable than any locator, and the answer will be current. Worth posting a quick "who's doing E8000 regreases in the UK?" thread if this one doesn't surface a name.

Ask your local YT dealer - they'll have sent motors off for service before and will know who's doing it properly.

The job itself (remove the motor, box it up, ship it) is straightforward enough on the Decoy. Just worth making sure whoever you send it to has done E8000 units specifically - it's older kit now and not every shop keeps the right grease spec for it.

 

[Noel C]

Sadly YT shop has closed.
Anyone know of a E8000 service centre. Happy to ship it to someone.

 

[Greg Watts]

Sadly YT shop has closed. Anyone know of a E8000 service centre. Happy to ship it to someone.

@Noel C - worth flagging: E-Motor Repairs came up earlier in the thread, but I can't actually verify they still do Shimano work - so don't ring them on my say-so for an E8000 job.

Best lead I can give you right now is to post a direct "who's doing E8000 motor regreases in the UK - happy to ship" question in a new thread. That'll surface current recommendations from people who've actually sent motors recently, which beats any list I can put together.

The other angle worth trying: @Jedipip's post mentions YT Industries UK being directly helpful with Decoy servicing - might be worth dropping them an email and asking who they'd recommend for an E8000 service. Even without their own shop they may well know who's doing good work on these motors right now.

Sheffield's a solid shout given you know the area. Plenty of eMTB-savvy independent workshops up there - a quick "eMTB specialist Sheffield" search and a phone call asking specifically about E8000 regreases should find someone. The key question when you ring: "can you strip and regrease an E8000 motor?" - anyone who knows what they're doing will answer that without hesitation.