mid-drive durable cassette for Micro-Spline cassette hub?

[stw]

considering a mid-drive BBHDS(?) conversion of a bike with a micro-spine cassette hub that has a 12sp cassette. After conversion I won't need 12 speeds of course, and won't need as much of that range either. But it would be really good to have a durable cassette to use with the mid-drive. Anyone aware of a strong durable moderately wide range cassette that works with micro-spine?

This is on a 170 fat bike rear hub wheel, which is why I'm reluctant to build a new wheel with a different cassette standard. At first I was planning on converting with a Bafang 750 fat bike rear hub and new rear wheel. But this bike will do some long steady climbing in the mountains, and mid-drives are good at that. Plus if converting it means I replace something and now have redundant parts, I'm thinking I'd rather have a redundant 1x crank than a redundant rear wheel. Fat bike wheels are expensive, especially rears, and harder for me to justify having one sit around un-used after I've gone to the trouble of getting exactly the rear wheel I like on this bike and it matches the front properly, etc.

 

[Boostin22]

The Shimano 12 speed Deore cassette is all steel ,mostly pinned cassette (up to the smallest 4-5 cogs I believe). It is the best option for an ebike on the 12 speed Shimano system.

That’s what I’m running on the Dengfu fatbike I’m building up this fall.

10-51 gearing, all steel construction (the important part) and a good price. The higher level Shimano cassettes all use aluminum on some of the cogs, and cost way more.

If you want extra durability, try to source out a steel microspline freehub body for your hub. The gears will eventually eat into the aluminum splines of the freehub body with a grippy fatbike tire and electric motor.

I bought a steel microspline freehub body for my DT Swiss 350 hub, but had to order it out of Europe, it’s not a commonly stocked part, but was developed for usage on ebikes.

 

[stw]

The Shimano 12 speed Deore cassette is all steel ,mostly pinned cassette (up to the smallest 4-5 cogs I believe). It is the best option for an ebike on the 12 speed Shimano system.

That’s what I’m running on the Dengfu fatbike I’m building up this fall.

10-51 gearing, all steel construction (the important part) and a good price. The higher level Shimano cassettes all use aluminum on some of the cogs, and cost way more.

If you want extra durability, try to source out a steel microspline freehub body for your hub. The gears will eventually eat into the aluminum splines of the freehub body with a grippy fatbike tire and electric motor.

I bought a steel microspline freehub body for my DT Swiss 350 hub, but had to order it out of Europe, it’s not a commonly stocked part, but was developed for usage on ebikes.

Thanks, good to know there is a source for steel microspine freehub bodies. I will look for one. It didn't occur to me when I ordered microspline (for the 10-51 range on a loaded push-bike) back in the spring I'd already be planning an e-bike conversion on it. If I'd thought ahead, I might have stayed with 8/9/10 cassette body and 11-50 range.

Now I have to decide whether to convert with a BBSHD or a geared hub motor for 170mm wide fatbike rear wheel/hub. The BBSHD is tempting because I like the wheels as they are and replacing a rear wheel on a fatbike is more expensive than hub conversions on non-fatbikes. Also because it will be climbing canyon roads. My only concern about the BBSHD is drivetrain durability.

 

[Boostin22]

I had to source mine from Europe. They are very hard to find in North America. I think they are made for OEM e-bikes and most shops don't carry them.

 

[JRA]

You might consider a front hub motor for you fat bike. Not a popular option amongst the masses but after thousands of miles using one, albeit on a more gravel type bike platform, I can say that they work just fine.

Allows you to forget about messing with your currrent gear system and putting additional power through it. Turns you bike into effectively two wheel drive, which if you plan on using it in loose dirt, slick or snow conditions is a great feature. If you don't need or want e assist for some riding situations just swap out for your stock front wheel and leave the battery at home.....

Probably a geared hub also and 1000w peak ability but planning on using 500w peak for the most part. You will get all the power you would use with a BBSHD without the drivetrain wear and tear and a better balanced rig that will pedal as a normal bike would with and without assist enabled.

 

[stw]

You might consider a front hub motor for you fat bike. Not a popular option amongst the masses but after thousands of miles using one, albeit on a more gravel type bike platform, I can say that they work just fine.

Allows you to forget about messing with your currrent gear system and putting additional power through it. Turns you bike into effectively two wheel drive, which if you plan on using it in loose dirt, slick or snow conditions is a great feature. If you don't need or want e assist for some riding situations just swap out for your stock front wheel and leave the battery at home.....

Probably a geared hub also and 1000w peak ability but planning on using 500w peak for the most part. You will get all the power you would use with a BBSHD without the drivetrain wear and tear and a better balanced rig that will pedal as a normal bike would with and without assist enabled.

Interesting suggestion which I've thought about since seeing Grin has a front hub motor I like.
But my reason for getting e-assist on this fatbike would be to make if more useful on the road. I like the non-assist push-bike set up fine for the offroad I do on it, but want e-assist to use it on the road efficiently. From what you wrote is sounds like the front hub benefit might be best for offroad?

 

[JRA]

Interesting suggestion which I've thought about since seeing Grin has a front hub motor I like.
But my reason for getting e-assist on this fatbike would be to make if more useful on the road. I like the non-assist push-bike set up fine for the offroad I do on it, but want e-assist to use it on the road efficiently. From what you wrote is sounds like the front hub benefit might be best for offroad?

Not at all as it is very effective for on road use which is where I have the most experience with it actually. However it does ok off road as well but I do admit that my eMtB has a mid drive unit on it as I prefer torque sensing PAS over the set watt output and forget method I use on my hub bikes that allows me to dictate my own cadence and pedal input as usual during the higher cadence I tend to use while road riding.

I use the Grin Any Axle motor btw as I find a DD hub to work well for my variable surface road riding that will climb just fine as long as I put in some effort and I like the added feature of regen braking. I have it set up for tool less take off also which is nice and it has a solid torque arm which is required for any hub motor application.

 

[Alaskan]

The cassette is won't be an issue but the 12 speed chain might give you fits. I have a trek Allant with the 11HT-51 tooth cassette and a Sram AXS derailleur. The mid drive motor on that bike is a Bosch Gen 4 Speed. The gear range on the microspline 12 is fantastic as I live in a hilly place and love riding at speed through the river valleys. It is a way fun bike to ride with a great drive train. However, the chain has broken three times during a ride requiring me to put in another quick link to get home. I now always carry a full spare chain in my tool bag.

In all cases the chain has broken in the middle, not at the quick link. It has occurred while upshifting after a steep climb or during high speed riding applying lots of power to the cranks.

A 12 speed chain has the thinnest chain plates, allowing it to fit between the thinner space between cogs on a 12 speed cassette. This gives the pins precious little material to hold on to on each side. My chain breaks have all occurred with a pin getting bent loose from a plate on one side. The Bosch motor has a shift sensor that pulls motor power temporarily during shifting, yet still this has happened three times in two years.

As I understand it the BBHDS has much greater wattage and torque than the Bosch. I would be warry of combining that powerful motor and a 12 speed set up due to the necessarily thin construction of a 12 speed chain. If you go for it, I highly recommend you carry along a spare chain as you may well need it.

 

[stw]

Thanks Alaskan, that's the main concern I have about 12sp on this conversion. I have a lot of experience running sub-12 high-cog-count chains, and overall have found 9sp and 10sp chains to be, if anything, more durable on non-assist push-bikes than 8sp chains. But as you say, that doesn't take into account the extra yank on the chain from a mid-drive motor. My only e-bike so far is a Bosch Gen 4 with an 8sp chain, and sometimes I do sense a chunky hard shift in those situations you describe, where I wonder if the Bosch shift sensor has not cut power for the shift, or if I shifted too fast to give it a chance.

Even though a mid-drive is a good choice for a bike that will climb canyons, (I live in the mountains), my concern has been sending the BBSHD torque through a 12 speed chain. Secondary concern is quickly wearing out an expensive 12sp cogset. Can't think of any other reason why such a thing would exist but sort of wishing there were an 8sp cassette designed for a Microspline hub so I could use a stronger chain. Especially since I've found on my Bosch 8sp bike I don't need the number nor the range of gears on an e-bike as I do for a push-bike on the same terrain. This is why I'm sort of wishing I'd ordered it with the 8/9/10 speed HG cassette body so I'd have more choices for conversion.

Of course, I wouldn't have the chain-torque issue with a hub drive so I'll have to consider JRA's and others experience with using hub drives for climbing fatbikes. The Grin All-axle motor was definitely on my list, or perhaps a Bafang geared hub motor or Mac10 motor if they make that in a 170mm wide fatbike axle.

I do like to put in effort for any/all climbing. The climbing for this fatbike would be mostly on-road canyon grades climbing or steady graded dirt road canyons--this wouldn't be for single track e-bike climbing.