Best IGH for BBSHD powered recumbent trike?

[Superb_Raccoon]

I've had the Enviolo HD (89Nm) for about 6 months now. It has the Automatiq shifter on it. Nice, because you set a cadence, it shifts up or down to accommodate that cadence. Using a chain because I don't have a belt drive option for the CYC yet. Because of the dropouts, I could conceivably convert to belt in the future.

It is a ~400% gear range, so with a 40:20 gearing on the bike, that means lowest is 1:1, highest is 4:1 40:40 and 40:10.

That gives me grunting up a hill at 60 cadence 5mph, and a top speed of about 35 if I am spinning out at 110 cadence.

It does shift under some load, I think utilizing the flat spots in your stroke to shift. I have had to take a half-beat pause climbing to get it to downshift on occasion.

The shift response is a little slow, but I understand you can get a more responsive shifting profile from Enviolo, I just have to remember to ask...

I use the BlueTooth shifter, which is not really made for drop bars, but I was able to wedge it so I can control the cadence with my right hand while in the drops.

Not as expensive as some of the options here, but it is not as highly rated for torque tolerance either. Sealed hub, no user maintenance.

It is a very odd experience at first, as the bike does not "shift" perceptibly. You are pedaling at 80 cadence... and if it is set to say, 75, you just get faster and faster and pedal pressure slowly goes up... until you are cruising at 18mph and 75 cadence.

I have it powered by a CYC Photon, and the gearing actually works. Increase the available power, you will go faster without "changing gears", just keep pedaling and it starts to go up the gearing ratio

 

[likes2bike]

How about a picture of the torque plate setup you have?

 

[Stealth_Chopper]

OK This is all great guys but there's nothing new under the sun and I collected the best SACHS IGHs already
BEEN THERE - DONE THAT and do you KNOW what ? There are NO frames and most disappointingly
NO full suspension frames for the best IGHs ever made and perhaps I'll get a ROUND TUIT AND WELD ONE UP !.
BRONX CHEER

 

[C.G.]

Mongo, thanks so much for your info on using Shimano eight speed IGH with a BBS02. I have a HP Velotechnik Scorpion with a Nexus 8 SG-C6001 that’s out of Europe and rated for e-bikes. But best I could find online, they’re limited to 50 nm. I recently put a BBS02 on it, but programmed it for a lower start current, decreased the slow start mode, and set stop decay to zero. I also limited the current to 18amp. Right now, I have a chainring/sprocket ratio of 38/23. So I also cheated a little bit on that. But I deal with some wicked hills and hot weather. I’m on the big island of Hawaii. I’m considering trying a 34 or even a 32 chainring which would be even further out of their recommendations. In your experience, would that be going too far? Thanks for all the info! I’ve been doing a lot of searches, and this has been the most helpful info.

 

[Paul Fithian]

I'm setting up a Long John bakfiet with a Bafang M620 mid-drive & Nexus 7 IGH. Here's a recent video showing how the Varstrom shift sensor cuts motor power when shifting under throttle control:

So far I have ~ 50 miles on this setup, works perfectly. But if it fails, next option is a Nexus 5 speed hub like this: https://bike.shimano.com/products/components/pdp.P-SG-C7000-5D.html

Any other suggestions?

 

[C.G.]

I'm setting up a Long John bakfiet with a Bafang M620 mid-drive a Nexus 7 IGH. Here's a recent video showing how the Varstrom shift sensor cuts motor power when shifting under throttle control:

So far I have ~ 50 miles on this setup, works perfectly. But if it fails, next option is a Nexus 5 speed hub like this: https://bike.shimano.com/products/components/pdp.P-SG-C7000-5D.html

Any other suggestions?

This is an older article, but it had some good information about an IGH on an Ebike. They think the 5 & 7 speed hubs are weaker than the 3 & 8 speed: Mid Drive Kits, Dump the Derailleur and get an IGH?

 

[Paul Fithian]

This is an older article, but it had some good information about an IGH on an Ebike. They think the 5 & 7 speed hubs are weaker than the 3 & 8 speed: Mid Drive Kits, Dump the Derailleur and get an IGH?

Yes, I saw that, but it's almost 10 years old now. Any more recent article like that one?

 

[C.G.]

Yes, I saw that, but it's almost 10 years old now. Any more recent article like that one?

I can’t think of any article in particular. I’ve done a lot of research to see how safe it is coupling a mid drive (mine is BBS02) with a Nexus 8. I also violated the gear ratio by putting a 34T crank chainring with a Nexus 23T cog. My Nexus 8 is rated for E-bikes (SG-C6001-8D). But my understanding is that it’s only available in Europe. And of course Europe limits power to 250 watts. I have a 750, although I do curb the power through my programming. I’ve read that a lot of mountain bikers have violated the gear ratio. The general consensus is that Shimano is conservative in their recommendations, but that you can violate it generally without problems.

 

[RiverR4t]

I have a Bafang Ultimate M620 with 2300 watts, Innotrace controller, Gates belt drive, and a 3x3 Nine IGH. I started with a Kindernay hub that failed at 350 miles. Tried a Revolute Hub I, and it didn’t shift properly. I the went to a derailleur and was extremely cautious about applying power. Now I have a 3x3 Nine and love it. It is rated for 250 nm, sealed with grease (no maintenance), and supports a Gates belt (no chain breaks or mess.) I can shift to any gear immediately, skipping any amount of gears I wish (after stopping the peddling.) Gears 1 and 2 are very low, useful for hill climbs, cargo bikes, and walking speed. Gears 8 and 9 for speeds greater than 25 mph. IMO, the 3x3 Nine is the only option at this time for high powered Bafang mid dive motors.

How is your 3x3 Nine holding up and performing?

 

[Paul Fithian]

I thought the hub failed, but turns out is was a broken sprocket at ~ 150 miles on this setup:



Replaced this with a solid cog, all good.

 

[amberwolf]

FWIW, that sort of damage occurs from repetitive lateral stress cycling, if the sprocket is not completely flat in the plane of the chaineline, or the chainline itself isn't completely straight and the side plates pull laterally on the "top" teeth during every rotation.

 

[Paul Fithian]

Agreed, but the chainline on this setup is aligned on both crank and rear sprocket. This cargo bike totes a heavy load and has to go up some steep hills here.

I've put ~ 20 miles on the setup with the new solid gear, no issues.

 

[amberwolf]

Not that it really matters, but***:

Even with a perfect chainline, if hte sprocket itself isn't perfectly lined up with that, so that it "wobbles" during rotation (not the right word but hopefully gets the image across) so that at the point the damage occured the teeth are being pulled laterally at the tips relative to the core of teh sprocket, bending them on eveyr rotation cycle, even a tiny bit, the repeated stress could eventually cause the damage you see. (I suspect lateral stress partly because of the wear marks from the sprocket/hub interface being only on one side, that may indicate the sprocket is being pulled laterally against the hub at those points, and the extra wear on the sides of teeth on just one side).


Could also be a tension failure from the cyclic loading on the teeth, but that's not a failure I've seen yet in sprockets (even the most spidery ones) in any of my cargo stuff (even pre-electric or when I used over-torquey middrives).

In either case, the initial failure is almost certainly at the outer portion between teeth where the crack is opened farther than anywhere else, and once that failed the stress was great enough in the segment cracked further inward to break it, which then put enough stress on the next one, and then the last one. There are probably other cracks that haven't separated, that might be findable with a dye or an extreme-closeup visual. I can see at least three obvious ones at the point where the sprocket is stamped to one side at the innermost circumference, that look like bending (lateral) types of failures, but those probably aren't the initiators of the failure, more likely a result of the initial problem. They have started on the same side as the greater tooth-wear and the sprocket-hub-interface marks.


If you can get a good close up view of the actual broken surfaces of the cracked areas, you can tell which kind of failure it was. Lateral stress would be a different surface pattern than a tension failure, for instance.

This is a clickable thumbnail of a crank arm that failed, the dark area is the older slowly-failing area, the bright part is the sudden final break. Cranks get loaded mostly in the tension type, but there is some lateral loading that's dependent on the Qfactor and the rider, etc.

There's a number of analyzed images here Fatigue Physics - Metal Fatigue Life Prediction (and plenty of other places) you can use as a reference, if you're interested.


***failure analysis is one of my most "fun" hobbies; my brain naturally just wants to find out why something failed, so it can be fixed / prevented / improved...

 

[C.G.]

Yes, I saw that, but it's almost 10 years old now. Any more recent article like that one?

Paul, I recently came across this article

Yes, I saw that, but it's almost 10 years old now. Any more recent article like that one?

I recently came across this more updated article. Doesn’t mention the Nexus 5, but it looks like he’s had good experience putting some powerful motors on Shimano IGHs.
Best Internal Gear Hubs for Electric Bikes | eBike Choices

 

[Paul Fithian]

Thanks for that new link! I have to look at the hub again, the last few times I used it skipped a few times. If I replace it, I may go with the Nexus 8, it would enable use of the same Chainglider I have now.

 

[C.G.]

Thanks for that new link! I have to look at the hub again, the last few times I used it skipped a few times. If I replace it, I may go with the Nexus 8, it would enable use of the same Chainglider I have now.

Glad you found the article useful. It certainly might set my mind at ease. I’m loving the Nexus 8. As I noted before, I have the model made for E bikes, which is the Nexus 8 SG-C6001. I now have over 1000 miles on it with no problems. And that’s with a smaller chainring that exceeds what they recommend, and a lot of hill climbing. I did tune down my BBS02 using the EggRider X2 to limit current, start current, and slow start mode, so I rarely exceed 500 watts on hills. I would imagine I could push it even harder, but I like to get a little exercise, too. Best of luck with your set up!

 

[Paul Fithian]

I installed an SG-C6001-8D on my ride, so far have put ~ 50 miles on it. All good, we'll see how it holds up over the summer.

I can attest that the gear range is much better with 42 front/18 rear gears.

I had to cut a relief on the center of the gear it came with to enable the snap ring to hold it in place.

 

[Thomsontouring]

Real world experience - I have 5000 miles on a Shimano Nexus 3 running on a BBSHD Ludicrous that puts out 3400 watts max. As long as I shift deliberately so it doesn't pop into gear it runs smooth and quiet. I also have 3 bikes I built for others which are running the Nexus 8 speed with the stock BBSHD. All have been running for 6-plus years. I would never trade my mid drive for a hub motor. Twice the acceleration in low gear, but I can still pedal along in high gear. No more maintenance than a single speed pedal bike and much easier to change a tire.

 

[Paul Fithian]

Recent rides reveal the Nexus 8 is starting to fail, skipping gears when under heavy load. Often with 2 or 3 kids on board.

I'll install an Alfine 8, hopefully it will be more reliable than what I've seen with the Nexus 8.