Custom steel emtb motor choice

[GeeWin]

Background:

• 52y old with 2 kids, have been riding/racing bikes since 1990, stopped tacing EWS and DH in 2023 after injuries. Only racing friends now as I promised the family will not ever race again
• Emtb’s owned:
  • 2019 Ghost with Shimano 8000 motor 504Wh ext battery. Liked it range was like 1800 vertical in 4 hours, but was much fitter. Sold it in 2020
  • Specialized Kenevo SL with 55nm liked the fact that with 20kg was close to my race enduro. Could do 1400m elevation. Bought in 2024 sold in 2025 as wanted a bike where I could do 1400 in less time
  • Current bike Mondraker Crafty Bosch Gen 5 since last year. Like the geo, kinematics, but pissed that 1 year in and they dropped the Zendit and some of my friends switched to Avinox bikes

Currently have a Zendit on order, but was thinking that i do not want to play this power game and I do not want ti change bike if I want to try a new motor

Solution:
Last year I ordered an analogue frame from vesselbikeproject tailored to my specs ( geo, kinematics) and he started to do a frame with different motor mounts. So if I would go down this route, I could keep the frame (which would be almost identical to my analoge bike) and i could always upgrade the motor/electronics when I want. I’m not after the latest tech/power so a “weaker” 85-90 nm motor would be great with a 600-800 Wh battery. Looking around I have counted the following options (I’m sure there are thousand others, happy for suggestions)

• Bafang. He has mounts for this. Initially I was thinking about the M820 but can not find a larger battery, and heard mixed feedback on the motor performance so the 510 would be my next candidate(560 is a bit overkill), not sure about total system cost
• Bosch: again he already has mounts for this, I could take it out from my Mondraker but then I would be left with a frame probably more difficult to sell. I could also get CX 5 motor new taken out from a new bike for like 600 EUR (bo warranty) and add a Bosch Power Pack 725 (BBP3570) for EUR 429
• New Shimano EP6 for EUR 200 with steps bt-en606 external 630 wh battery for EUR300. I know its old but at this price on bike discount it is worth checking out
• Maxon Air S: I would be happy with this motor along a 600 Wh battery. I have sent them an email, not sure they will reply

Battery is preferred to be external as it will have bms and easier to fix to the frame. I know that I will still need to buy additional parts for the electronics, but i would not think these would make a large difference between the options.

I would appreciate any ideas/feedback on my options there, even if you tell me I should just wait for the Zendit

 

[CarolinaCrawler]

Love the Vessel! I WILL own a Vessel Downhill bike one day (probably when my Commencal frame cracks).

That said, I have 2 Bafang bikes and really like them. I love the ability to repair everything myself and the parts are so cheap I keep a spare controller, display, and remote at all times. Also seeing how Jack's personal bike is Bafang powered he's super familiar with the setup too. As far as price goes, I know it seems to be around 1KUSD for the complete kit (motor, cranks, display, remote, battery and wiring) from any of the usual venders.

 

[kaaskopf]

motorkits are around 550 usd if you know the right people tho

used my bafang m510 for over 4 years and it is very reliable.
love the emtb vessel project!

 

[GeeWin]

@CarolinaCrawler thx for the heads up which motors do you have? Looking for opinions on the m820 or 510?

@kaaskopf thx did you have any chance to compare m510 to any other motors?

 

[Fresh]

i have been looking in to such a project,

cotic is the only company ive come across doing a steel ebike frame besides vessel modular frame

Cotic Rocket eBike : British made Steel Full Suspension eBike

The Cotic Rocket Steel Full Suspension Mountain eBike - Made in Britain - PERFORMANCE STEEL ELECTRIFIED

www.cotic.co.uk

i currently have a norco range vlt with the shimano ep8 motor.

you can buy the ep8 cheaper than most even the bafang, the power of the ep8 is enough, only problem i have shimano probably have or will stop making them.

and i recently made my first front triangle using a pivot firebird rear chainstay. love the feel of it.

And with that i've been thinking making a ebike frame next with the ep8 or bafang.

 

[GeeWin]

Hi @Fresh great looking bike! Any suggestion for sourcing the ep8? I’m more worried with Shimano about motor dying then anything else. EP6 was EUR 200, so at that price even this would be less of a concern for me

 

[Fresh]

Aliexpress, i've read on Facebook groups using them with no issues.

They are generally getting them as a replacement but all the small parts are on aliexpress to help make it work.

SHIMANO STEPS EP8 EP801 EP800 Mid-Ship-Antriebseinheit US-Gerät Klasse 3 unterstützt CAN ACC-Anschlüsse E-Bike-Teile DU-EP801-CRG Lastenrad - AliExpress 18

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Hi @Fresh great looking bike! Any suggestion for sourcing the ep8? I’m more worried with Shimano about motor dying then anything else. EP6 was EUR 200, so at that price even this would be less of a concern for me

 

[GeeWin]

Thanks i need to make up my mind as EP6 is currently 200 EUR at bike discount https://www.bike-discount.de/en/shimano-steps-ep6-du-ep600-motor-250w-85nm-drive-unit

 

[G-Sport]

Interesting thread. It's a shame that the motor companies are so reluctant to supply parts to enthusiasts (or even small builders). My first choice would be the Bosch SX (assuming you want to keep the weight down), any of the Bosch batteries should be compatible so that gives you a lot of options, take a 400 on small lightweight days and have a bigger one for big days. But I think getting a Bosch motor, loom, chageport, display etc will be hard and expensive.
Bafang M820 would be my next choice. I am fairly sure that they are battery agnostic so in theory you could make yourself a pack (or two) from high density semi-solid-state cells which would be potentially great.
Whatever you go for, watch the weight of the motor cradle/mount, in steel these could well end up being a huge part of the weight of the bike, so might well be worth making a custom one or spending some time cutting out excess material.

 

[bram.biesiekierski]

Another option you could consider would be something like a CYC Photon (or even X1). Or any number of other "conversion" type of mid-drive motors. These use a traditional bottom bracket style mounting system. It would be relatively easy for your frame builder to build around one of those, but incorporate custom tabs to suspend the specific motor system you choose.

I would highly recommend you use something from Bafang, (or CYC.) Purely from the PoV of a DIY enthusiast. Future servicing, and repairs are somewhat easier with these brands. Parts and information are available, and they dont have such a hard-on for anti-right to repair measures as the likes of Shimano and Bosch. They are far less locked down, and have a significant DIY culture that will mean less headaches for something like you are describing.

 

[GeeWin]

Thanks leaning towards the m820, if anybody has any experience with that motor please share it with me

 

[kaaskopf]

its gears are smaller than m510 and thus making more sound

i also read about overheating and lower efficiency over 300watts

i think the most stable diy motor is the m510. i use it in all my bikes and i can give it a tune, aggressively or more eco

also all parts are on aliexpress which i can recieve in 5-9 working days for all spare parts which keeps all my bikes running with minimal down time. i think most people forget this point. they say get a bosch ect, but if it breaks your without bike for weeks or months and with hefty repair bill after waiting for a long time

the newer 3.0 and 4.0 engines dont rattle as much down hill when coasting and generally feel tighter.

i have 2 motors that are over 4 years old and they work perfectly still.

for maintenance i clean the inside and relube it every year and i also put new paper seal and loctite on all screws. i think they will last for a long time. just replace a bearing once in a while

 

[GeeWin]

@kaaskopf great advice thanks. Is there any place I coud get info on all the conponents I will need. I guess motor, battery (i will need to take an external one as it will be easier to fix to the frame) and hmi like the dp c245.can? I guess the motor and hmi would come with all cables needed to connect together. How about speed sensor is it seperate?