New Shimano 11-40t 8 speed cassette and derailer in vintage Shimano format.

[Retrorockit]

Shimano has a new cassette in traditional HG 8 speed format. No weird chains or shifter/ derailer sets like Box, SRAM and Microshift sell..
CS-H400-8 Cassette Cogs11-13-15-18-22-27-33-40t This produces a very evenly spaced set of gears when I entered it at Sheldon Brown. Very similar to the 11-40t Sunrace, but not exactly the same, and much better than many others I've looked at. The 2 lowest cogs are riveted together.

HG CASSETTE 8s | SHIMANO BIKE-US

With a welcoming balance of gear range and simplicity, this 8-speed cassette delivers reliable shifting performance with a premium plated design.

bike.shimano.com

They also have an ACERA long cage derailer to match with 45t total capacity 11-40t rear cog size.

SHIMANO ACERA Rear Derailleur 8-speed | SHIMANO BIKE-EU

The SHIMANO ACERA M3020-8 rear derailleur with Double Servo technology helps you ride challenging terrain with fewer interruptions.

bike.shimano.com

I don't have my hands on these yet, But I've been pretty happy with the similar Sunrace 11-13-15-18-22-28-34-40 cassette with a 50t ring on a 26" BBSHD.

I'm not a Shimano fanboy. In fact I think they seem to have abandoned the formats they created to other players. Too focused on OEM customers. But this looks good to me.

 

[richj8990]

This cassette has been around for years. I started using it in 2018. Just stopped and completely went to 11 speed around the beginning of this year. Yes for 8-speed it's great. But most people I've talked to say that 10-12 speed is fine for a mid-drive, most have never broken a chain yet. They make e-bike specific chains now too. I even use them for normal bikes. They only weigh like 30 grams more than a normal chain. But it's up to you if you'd like to stick with 8-speed or not. There is no reason to besides the $$$ needed for a drivetrain conversion. You can get 10-12 speed cassettes for $60 now, chain $45, rear derailleur under $100, sometimes around $60. So really it's about what you are comfortable with. I wanted to standardize 11-speed for all 4 of my bikes, and I'm glad it did, but 8-speed did fine for many years.

I think for Acera, and really all 8-speed rear derailleurs the max tooth size is 34. I had an Acera too and I swear that was the best shifting of all four 7-8 speed RD's I had. Smashed it in a car door and that was the end of that. If you want to use this 11-40T cassette, you'll need a derailleur extender. They can be had for around $20. The shifting will take a little longer in back but otherwise it will work fine. One thing I do want to warn you about for the extender is that they often don't fit older QR frames, so you may need to shave the hanger down to make it fit. If it's not fitting by just a couple mm you can file the metal and make it work, just remember the hanger isn't going to be the same again!

 

[Retrorockit]

The post was about a new Acera derailer that has the capacity for an 11-40t cog without an extension.. Shimano has been ignoring wide range 8-9 speed parts. If the 11-40 cassette existed I never came a cross it. I've been running the Sunrace 11-40 for a few years.
On my 1500W BBSHD extra gears just mean wasted time skipping cogs I don't need. Wasting time in urban South FL traffic is not something you want to do. God help anyone who believes E bikes can only shift one gear at a time (Box) and has a 12 speed.. But I find that older 8-9 speed equipped MTBs with disc brakes make great donor bikes for street mid drives. I replace chains and cassettes as a pair.
Sunrace M900, Microshift Acolyte, and now Shimano Acera have native support for wide range 11-40t 8-9 speed cassettes. The Acolyte requires a proprietary shifter. The Sunrace is a heavily sprung headbanger part. I haven't broken a chain, but I've stopped using Connex links because i've broken a few of those.

 

[Warren]

I made my own 14-40, 8 speed cassette, for my mid-drive Linear, and ran a NOS, 8 speed Deore XT derailleur. The only change necessary was to run the hanger screw further in, so the jockey pulley would clear the 40 tooth. I ran 200-350 watts most of the time, rarely hitting 500 watts max. Even that much power would eat 11-12 tooth sprockets, and then chains, which is why I went from an 11-34 to my own 14-40 cassette. The manufacturers really love selling replacement parts, hence these stupid e-bike drivetrains.

 

[richj8990]

I see the new Acera now. I don't understand why they can't just take a longer-caged 10-12 speed RD and simply change the pull ratio to fit 7-8 speed. That's great that they finally made an 8-speed RD that can take 40t, but the upper part of it looks the same old 20th century design. Hopefully the spring is stronger than before. Anyway, you'll probably be fine with it.

 

[Retrorockit]

The width of the idler changed between 7/8 and 9 speed. The 9 works OK with 7/8. The chains keep getting thinner but the new ones actually last longer. The other reason I'm staying with 8speed is I have some Rapid Rise (Low Normal) Revoshifters and RR derailers and I can dump a bunch of gears stopped if I get jammed up in traffic. Shimano made 9 speed RR derailers, but no reverse pattern shifters for them, so 8 it is for me. I already own the clutch type Sunrace
M900 with the heavy spring. The Shimano stuff is on the way.
But I've been busy with something else.

Mid drive front freewheel mod.

This mod is so simple, cheap and easy to try, I would like to ask you to try it before posting here. There have been threads about using the front freewheel that most mid drives have instead of the rear one that bicycles already have. So this would apply mostly to converted bikes with mid...

endless-sphere.com

I made my own 14-40, 8 speed cassette, for my mid-drive Linear, and ran a NOS, 8 speed Deore XT derailleur. The only change necessary was to run the hanger screw further in, so the jockey pulley would clear the 40 tooth. I ran 200-350 watts most of the time, rarely hitting 500 watts max. Even that much power would eat 11-12 tooth sprockets, and then chains, which is why I went from an 11-34 to my own 14-40 cassette. The manufacturers really love selling replacement parts, hence these stupid e-bike drivetrains.

I made my own 11-36 out of the Sunrace 11-40. I dropped the 2 low gears for a single 36t, and added a 12t at the top. So I have 11/12/13 to spread the wear around. But the $20 Sunrace just gets replaced when the chain wears so it's always fresh. 20mph into a 20mph headwind I'll be pushing 1000W. I Squirt wax the chain every other ride, But I always have a spare set on hand. I cut 2, 2/3 long ends of a stock derailer hanger and welded up a longer one.
I'm running a 50t chainring so most of the time i'm in the 13t cog. The 11t is just a run for your life overdive.

 

[Bengy22]

But most people I've talked to say that 10-12 speed is fine for a mid-drive, most have never broken a chain yet. They make e-bike specific chains now too. I even use them for normal bikes. They only weigh like 30 grams more than a normal chain. But it's up to you if you'd like to stick with 8-speed or not. There is no reason to besides the $$$ needed for a drivetrain conversion. You can get 10-12 speed cassettes for $60 now, chain $45, rear derailleur under $100, sometimes around $60. So really it's about what you are comfortable with. I wanted to standardize 11-speed for all 4 of my bikes, and I'm glad it did, but 8-speed did fine for many years.

I disagree slightly with this, I'm a big believer that most people at most need 10 gears on a emtb, the electric assist makes up for the slightly bigger jumps in gears. Parts are getting cheaper which is good but they still are a fair bit more, and even though they make e-rated chains I've still heard a far amount of stories of a snapped chain usually the result of a bad shift under power though. You can't really get around the need to run a thinner chain. Of course if you want to run more you, just think its not needed.

And that's for the 250w eu bikes, I run a bbshd and stock my 8 speed 12-46t was great never left me wanting more gears. Large 46t in the front (could easily drop to 42t if needed), and I hardly ever touched 1st gear. I now run a modified bbshd with the same 8 speed and if I could find a 5 speed cassette I would run it. I never touch my 1st gear, even second is enough to get up the largest climb near me and that was struggling to keep the front wheel down while also keeping enough weight on the rear to not have it spin. Third gear ends up being a lot easier top control but a little slower. But that power does come at the cost of accelerated wear (and I don't even want to think about how much faster it would be with a 10+ setup) new chain every 1250ish miles at $8, cassette every double that at 2500 miles for $30 ($10 if I lived in the EU). Can't beat those prices!

 

[richj8990]

I disagree slightly with this, I'm a big believer that most people at most need 10 gears on a emtb, the electric assist makes up for the slightly bigger jumps in gears. Parts are getting cheaper which is good but they still are a fair bit more, and even though they make e-rated chains I've still heard a far amount of stories of a snapped chain usually the result of a bad shift under power though. You can't really get around the need to run a thinner chain. Of course if you want to run more you, just think its not needed.

And that's for the 250w eu bikes, I run a bbshd and stock my 8 speed 12-46t was great never left me wanting more gears. Large 46t in the front (could easily drop to 42t if needed), and I hardly ever touched 1st gear. I now run a modified bbshd with the same 8 speed and if I could find a 5 speed cassette I would run it. I never touch my 1st gear, even second is enough to get up the largest climb near me and that was struggling to keep the front wheel down while also keeping enough weight on the rear to not have it spin. Third gear ends up being a lot easier top control but a little slower. But that power does come at the cost of accelerated wear (and I don't even want to think about how much faster it would be with a 10+ setup) new chain every 1250ish miles at $8, cassette every double that at 2500 miles for $30 ($10 if I lived in the EU). Can't beat those prices!

Yes most dudes run 8-speed if they have a BSSxx I've noticed. Probably a good idea. Here, a new complete e-bike is almost always 250W and 11 or 12 speed. What they basically do here is take a normal bike and make an e-variant out of it. They simply modify the frame to fully integrate the battery on the downtube, change the bottom bracket area to fit the mid-drive that the manufacturer chooses, and that's pretty much it. The rest of the bike is more or less 100% stock normal acoustic bike, even the brakes, tires, suspension. They'll say that so and so part is reinforced, blah blah blah, but it's just a variant of what they already were selling.

About 8-9 speed: if someone is not dropping the chain and they don't need any more range than that, then it's fine. But I swear on a normal bike I've broken way more 7-8 speed chains than 11 speed. I've only broken one 11-speed chain (non e-bike), at the beginning of a super steep hill where I literally stood on one of the pedals in too high of a gear. Never had a problem with any other 11-speed chain. Now we'll see with the new mid-drive build how long I will be able to say that! If someone IS dropping chains, the 10-12 speed clutches and the much, much stiffer cage springs are really good at stopping that. On my XC bike I normally don't even turn on the derailleur clutch because the cage spring is so stiff. That to me is the main advantage of 10-12 speed besides the range: the derailleur springs are way stiffer. So it's really about range if needed and dropping the chain or not.

 

[Retrorockit]

The 11 speed chains are known to be strong and durable. A 350W EU bike is an assisted bicycle and would probably benefit from all the newer bike tech. A BBSHD is different. With 130Nm torque and 140rpm cadence under throttle it doesn't need a lot of gears. A cheap $20 Sunrace 11-40 cassette has the right cogs, and can be replaced with the worn chain in a set. Some guys run $14 KMC chains. Brake pads, chains and cassettes don't last long on these bikes. With too many gears you spend too much time cutting power to shift and actually go slower. It also confuses drivers following you. fast/slow/fast/slow etc.
Even with 8 gears when you throttle up to 140rpm you need to shift up 2 gears so you can pedal again. Why make it 3 or 4?
Sunrace M900 9 speed derailer has a very stiff spring and clutch with a capacity of up to 50t cassette in 1x.

CSM993 9AZ

M9 9-speed wide-ratio cassette

sunrace.com

SunRace M993 Cassette - 9 Speed, 11-50t, ED Black, Alloy Spider and Lockring

Wonder why the SunRace M993 9-Speed Cassette is a mountain biker favorite in the Cassettes collection? Part #CSM993.9A50.ES0. The SunRace M993 9-speed cassette offers a wide ratio for MTB and features a light weight design and ED black finish for added durability. Light weight design uses a 7075...

www.worldwidecyclery.com

RDM900 MD

Rear derailleur 9- speed

sunrace.com

 

[Retrorockit]

You're actually more likely to break a chain standing on the cranks pulling up on the bars than with a motor. The motor spreads it's power all the way around 360* rotation. Broken Ebike chains usually happen when shifting while leaned over in a turn when you can't pedal.
There is a cure for this.

Mid drive front freewheel mod.

This mod is so simple, cheap and easy to try, I would like to ask you to try it before posting here. There have been threads about using the front freewheel that most mid drives have instead of the rear one that bicycles already have. So this would apply mostly to converted bikes with mid...

endless-sphere.com

 

[Retrorockit]

I put this on the Ebike. and got it working with a Mid Cage XTR Rapid Rise derailer. No extended derailer hanger. It would shift into low gear with the B screw all the way in, but the idler and cog were almost touching. A longer B screw and a few more turns and everything is working fine. I didn't need the Acera for this. I had used this derailer with a Sunrace 11-40 cassette before on an extended hanger. I decided to check out some rumors at MTBR about this working. I'm running the corredt 8 speed Rapid Rise Revoshifter with this. The benefits of Rapid Rise get lost when run with trigger shifters.

 

[Retrorockit]

One user at another forum reports running a Shimano 11-42 8 speed cassette with the Acera derailer. I don't have a part# yet, and haven't seen one for sale so far. But it looks like Shimano is getting serious about supporting their older formats.