Chain Issue

[AZguy]

Very good points

Fortunately indexed shifters are relatively inexpensive, even good ones...

[73Eldo]

Other than the rim size what you are looking for is the inside width at the axle. 135mm was the original standard when mountain bikes got popular which was also about the time cassettes got popular. In the last 10-15 years there have got to me a lot more wider options but I think in the world of hub motors 135 is/was still a standard but since hub motors had threaded axles they could just use spacers to fit slightly wider frames.

So once you know what width you need you are looking for something that says HG spline. HG stands for hyperglide which was the first popular style of cassette from Shimano. There are other flavors like micro spline but HG came out in the 80's so its what everyone else copied. There were 7 speed HG cassettes in the 80's but I don't think they have been made for years. Once you get to 8 its the same with up to 10 as long as its the original HG standard. There were/ are others where things don't interchange and I think some 11's that work but if you are in the 8-10 and HG things should be fine. They full words HyperGlide is still a Shimano trademark so that is why you often see HG.

Derailleur may work with more speeds but you will need a new shifter unless you are going with a friction sifter as opposed to a index/click shifter. If the goal is more range you may have to change the derailleur anyway for the range.

[ncmired]

Dunno how useful it'll be to others, but I've been tinkering with the Sheldon Brown JavaScript calculator, extending the "Gear Units" dropdown to deal with higher full-throttle cadences and adding some tire sizes. To use it, I'd rename the file extension from ".txt" to ".html" and put it on your desktop. If when double-clicking on it, you get asked what program to associate it with, pick your web browser. The file is fully self-contained HTML/JavaScript and makes no external calls.

If you want some size value added to the dropdowns, post a comment on this post and I'll update the file.

[AZguy]

My 11speed bike and 7speed bikes are different frames but they are similar... the 11sp is much lighter.. I don't think the 11sp will take more room, if it does it's not much, the chains are much more narrow as is the cog spacing on the cassette... but it does require a freehub

[Retrorockit]

I like the idea of Box making strong E bike sets. But they are BMX/DH oriented. So maybe not in touch with what a street Ebike actually needs.
Box is drinking the the "One gear at a time" shifting coolaid, and offering only trigger shifters. They took the easy way out.
1-I'm running a Low Normal derailer (Shimano Rapid Rise) with a gripshift. This allows multiple shifts up or down even when stopped.
2- I'm running the rear freewheel (freehub) locked out with a zip tie. Up or down shift any gear any time the bike is moving using the BBSHD freewheel.
if Box does everything you need it to do go for it. But you will be locked out of a lot of other options when you do.

[Retrorockit]

I've had a click from one bent tooth on a rear cog plucking the chain as it goes by in the next gear.Usually the derailer cage will kick a little as it goes by.

[Retrorockit]

7-8-9 spd. are interchangeable on the hubs. maybe 10 also. 11-12 I think are different. Sunrace makes some affordable wide range 8-9 speed stuff, and derailers to match. M900 is a clutch type with a heavy spring. I'm with AZ on tossing the chain and casssette together on a BBSHD. The wide 8 Spd. Sunrace cassette is about $25. IMO 8 speeds are enough for a BBSHD.
Sheldon Brown lets you see what different gear sets can do for you. I solve for MPH a 90rpm in gear units. BBSHD can do 150 throttling.

https://www.sheldonbrown.com/gear-calc.html

[Retrorockit]

There are 8-9speed freewheels. But they have a reputation for tricky shifting because of play in the freewheel bearings, and the tighter tolerance between gears on the higher gear count systems. The problem with freewheels is the RH bearing is not at the end of the axle, but way inside like it was on single speed freewheels. A mid drive will really pull some play into that in the higher grears. I have an 8 speed frreewheel, and I may try to make a support bushing for the outer end to deal with the wobble, but I have other projects going on so no idea whne that will happen. They also bend axles due to the bearing layout. The only reason I'm even thinking of a freewheel experiment is because of a Mag wheel bike I want to build. With laced wheels I'd swap the freewheel out sooner rather than later.

[jaaklucas]

I can see now with a single front sprocket the rear cassette is the key element in the gear ratios. Did you use the same bike frame with the 11 speed and the 7 speed freewheel? I think I could fit a 9 in the rear with a new wheel and hub. Otherwise it is new frame time. Future winter project. Lots of riding to do in the meantime!

[AZguy]

I have a rear hub with 7sp freewheel and realized within months of getting it mid was going to be my world -~2kmi on it

I'm presently running BBSHD into 11-51t 11sp and super happy, >8kmi - did good fun ride last nite - would have done more tonite but more rain on the way =]

[jaaklucas]

Yea 7 speed freewheel. I think 7 is the max for a freewheel. 11 to 34t. I like to pedal . My last battery log showed 18,000K over 4 1/2 years. That was on an Ezee 1000W hub motor. I put another 2,000 on that motor with a new battery thinking I would kill that thing .No way, still working good this winter with zero maintenence. The nylon gears didnt make any noise but I could see the wheel bearings were getting worn. So I took the opportunity to switch over to the mid drive. Ive got a 29er and a 42 tooth front sprocket on the way for the BBSHD. Even with the stock 46t Im amazed at the hills Ive been doing with the mid drive. I can see the future will be a big cassette .

[73Eldo]

Wow you must put some KMs on and pedaling at least as hard as any other biker if you are wearing out a freewheel every year with a hub drive bike. It will be interesting to see what happens with your mid drive. Is your mid drive still a 7 speed freewheel?

[AZguy]

Guessing 7 speed? Those chains aren't as sturdy as the 10+sp gear chains but they are very inexpensive...

I've got an 11sp and I just use "normal" (shimano hyperglide, not remotely electric specific) chains and last one was ~$30 but that was a couple years ago so they're likely high-$30's these days... but still not much and I ride really hard, hills, dirt, fast on smooth, etc. and like mentioned last one was barely worn at >3000mi (about 1.5mm overall stretch) and just changed it since I was putting on a larger cassette

I'd just run a "normal" chain and keep taking a look at the stretch and replace before there's much showing as really cheap insurance and for less cogset wear - they wear much more quickly when the chain shows stretch...

[jaaklucas]

chains are cheap

My Ebike is still freewheel. For the last 5 years the 11-34t only lasts a year anyways so I change the chain at the same time. That was with a 1000W hub drive so Ill be interested to see how it goes with the mid drive. So far the hill climbing with the BBSHD is amazing. Must be pushing the limit of a regular bike chain going up my local mountain MTB stuff. I see they make Ebike specific chains and I read some of the comments about it on this site. Im loathe to spend money on chains unless I start breaking them from uphill stress which I intend to do alot of.

[AZguy]

Discussing chain maintenance seems to border on discussing religion and politics

FWIW you can use pretty much anything on an o-ring moto chain (nearly everyone uses o-ring these days) since the pin lubrication is sealed up in the o-rings... bike chains don't have that luxury - they need frequent lubrication for the pins... pretty much conventional wisdom for bike chains is that wd-40 is better than nothing (I actually did a torture test experiment running a chain without ever doing any maintenance , including lubing, but that's another story) but not much, mostly just preventing rust... really need something to lubricate those pins and it's simply not made for that and has relatively poor lubrication qualities - just based on "feel" even after the light stuff evaporates it just feels super thin and is likely a very low viscosity IMO (and plenty of others... but back to that religious discussion paradigm) not terribly well suited to the relatively high forces on a bicycle chain pin/bushing...

There are folks that religiously keep two chain, soak them in solvent, use fancy park tool chain scrubbers and put them in melted paraffin... mm'kay.... way too much effort for me with a $30 chain

There are plenty of tests that show "performance" of different lubes but for those tests it's typically about lowest friction and what's more important to me is chain longevity and ease of use (otherwise I won't so it often enough).. so for me I just use any decent lube I have around the shop and do it frequently... I've used transmission fluid (not bad for the task or motor oil in dripper bottles.. typically use more general purpose paraffin based penetrating lubes and have done fine with those - they go on in a minute or so and my last chain got well over 3000mi of very hard use so plenty good enough, at least for me... I've tried more bicycle specific lubes but haven't found them to justify the cost for me - they may offer lower resistance but carrying a big box of 'trons I just don't care about that

I guess bottom line is to do what works best for you and my belief is that as long as you do it often enough it doesn't really matter since chains are cheap


Clearly, as always, YMMV