How to rework rear sprockets for mid drive systems...

[Onemorejoltwarden]

A fine complement to mirrors is the Varia.
Pricey, but once you try it , there is no turning back.
Looks back to 160yards, back where you can't hear esp the 'lectric cars

[paxtana]

You want it to just clear when a chain is attached. Otherwise you get missed shifts.

I don't know about your specific derailer but on mine there is a screw on the back you can adjust so you can find the sweet spot between the derailer being too close vs too far from the cassette.

[aurover]

Because the derailleur moves down as it moves left, (and up as it moves right) doesn't this cause an issue with clearance when moving the larger sprocket outwards? Is it necessary to get a hanger extender?

I reworked mine and it clashes when there is no chain, but seems to just clear when a chain is attached. However I am concerned it is causing shifting issues. Anyone else have similar experience?

[paxtana]

If you limit it out of a low gear (or in this case, multiple gears) it literally does not let you shift into that gear. Pushing the shifter once you are at the limit does not do anything, you can't even push the shifter. You don't need to shift twice or anything like that. The spacing between each gears should be the same. Shifting should be basically as smooth and normal as you stock. You probably will need to tune the derailer after doing this though. A local bike shop can do that if needed.

[aurover]

I have a 9 speed derailleur and cassette and would like to re-order the cassette to about 4 gears for better chain alignment. However I am curious how gear changing works given that my shifter supports 9 gears. Adjusting the low and high limit screws doesn't adjust the number of gears, just the positions.

Does the gear change with each single shift, or do you need to shift twice? What happens when shifting into 5th, 6th, 7th etc? Do you then need to shift down several times before it changes?

Would I be better off buying a 8 speed cassette and using it with my 9 speed derailleur? Is that even possible? Anyone know?

[dev]

People wanting to rework the rear cassette as suggested here might find out that it is almost impossible to find a cassette where individual sprockets are standalone and can be rearranged as the original post shows.

Ideally, a person buying a cassette for this purpose would want all sprockets and spacers to have the same design, allowing arbitrary order.
However, most cassettes on the market today (including Sunrace) seem to have the first few and last few sprockets built in a special way where order cannot be changed.

For example, on SRAM cassettes, the first (smallest) two or three sprockets have non-standard spacing and the needed space is cast/molded into the sprockets, rather than using separate/standalone spacers like they do for other, larger sprockets. Similarly, the last (largest) two or three sprockets are held together by a spider as a monoblock, and they can't be separated nor moved to a different position because they keep special distance from the wheel to the largest sprocket.
(See first two pictures just for general illustration of the problem.)

Long story short, after a lot of searching, I have found that italian manufacturers Marchisio and Miche produce cassettes which have all sprockets separated with spacers, without using spiders or rivets.
(See last three pictures for an example of a Miche cassette.)
And see this PDF with more info: https://www.miche.it/pub/media/produ...eeds_laser.pdf
Miche and Marchisio are supposedly compatible with each other, and Miche seems to have a better distribution and can be found in stock in various online stores.
For some reason Miche website does not show a 10-speed version (only 11 and 12), while in online shops a 10-speed can also be found.

They also sell individual sprockets and spacers; the retail cost is roughly 8 EUR for the first (leftmost and rightmost) sprocket, 5.5 EUR for sprockets in between, and 1.5 EUR for spacers.
However, I was only able to find individual sprocket options in bike shops and not online. Also, supposedly they only sell individual sprockets during summer season after they meet their other production goals.

Hope it helps.

[wagonrd]

Thanks for the info ykick.Using your knowledge, I modified my 8 speed 11-40 sunrace so that te 40 tooth cog is in the 5th position ( counting from the outside in). Three cogs with lesser teeth are mounted to the outside, with the 11 tooth cog as the final cog. I set the derailler limits so that I only shift cogs 2, 3, 4, 5. This setup allows me to install the luna cycle mighty mini 30 tooth sprocket on my BBSHD motor and thereby keep the chain line functioning within its limits. Now , when I run out of battery juice on some hilly dirt road I can pedal the bike home using the 30/40 ratio instead of pushing it

[ApexBM]

I thought I would want more gears also... mine is built with 4 and at the time I was building it, I thought I would want 5... but 99% of the time I only use 3 gears.

42t up front driving 32, 24, 18 on the cassette with an occasional 15 for short bursts only. Powered by a stock BBSHD this gets me to 35-38mph on the 15t which can only be used in very select situations even with a massive 203mm disc brake up front.

[Kocho]

I lost track if this is already mentioned, sorry if a dup.

I am converting my 7 speed freewheel to a 7 speed casette to add a disk brake in the rear and a more capable wheel (wider rim and tire). I am planning to use a hub for an 8 speed casette with a 4.5mm spacer and a 7 speed 11-34T casette. So I will with some luck not need to swap out the derailleur and shifters.

While at it, I will probably try a 4 or 5 speed rearranging to see hiw it feels. I think 3 speeds is too few for me as I like to use my legs more, but I find I mostly use the top 2 and bottom 2 gears. The middle gears I do go through on occasion when I want to get the most out of the motor, accelerating in traffic...

[ApexBM]

Just wanted to chime in and say that this has remained one of my favorite modifications, so much nicer to not have to shift a million times and with the gearing gaps I can "feel" based on intuitive speed what gear I'm in rather than having to look down at my cassette all the time.

Thanks again for making this thread otherwise the thought wouldn't have crossed my mind.

I did about 350 miles pre-"reworked sprocket." And am now ~750 miles post reworked sprocket.... which reminds me I was planning on doing a first 1000 mile lessons learned thread...

[ApexBM]

I'd be iffy on this, worried that lateral play would develop over time. I'd be more apt to purchase a spacer that that I could torque down similar to what's on the end of most cassettes... but that would require making custom sized spacers, so probably not viable for mass production.

[ykick]

Could see it useful for some cluster re-arrangements? Gotta use spacer with 15T or smaller. About $25-$30 shipped/pair. Good find....

[commuter ebikes]

Well there's something new under the sun. That sure would make it easy to set up a straight chainline. I see that it fits on both Shimano and SRAM freehubs.

[paxtana]

Would like to hear some input from you guys on whether this would work for folks that want to maintain a clean look by using this to hold the cogs in place.
So hypothetically you would only have the cogs you want on the cassette.
Or would it be better to just recommend a bunch of cassette spacers behind whatever's left of the modified cassette?

[ykick]

When I rode hub motors I “always” rode in the tallest gear. But since shifting over to mid-drive I normally use medium gearing for majority of riding.

My tallest gearing is really only best for flat level with neutral or tail wind and of course downhills. Any sort of incline or head wind on level road I find myself in one of the lower “medium” ranges.

3 wide speeds being sorta extreme and although it "works" I’ve found preferring 4-5 wide spaced gears with a 2-3 focused in the middle ranges.

Greyhound for some situations and a Granny for steep situations but the majority of riding I’m happiest with a couple medium-high ratio choices.