[zac2944]

I'm unsuccessfully using the Sunrace 9 Speed 11-40T CSM990 cassette (with Rear derailleur Hanger Extender Link from JGbike on Amazon). I've tried it on two bikes and can't make it work well; poor shifting.

One attempt is on a 2001 Schwinn HG hardtail. This bike is set up 1x with a 32T front cog in the middle of an older 3x Shimano crank. Shifted very well with old 11-34 cassette, but I wanted more range so I replaced it with the Sunrace 11-40. First tried it using an older RD-M510 rear derailleur. Had to use the hanger extender link in order to make this RD clear the 40T. This worked but shifting was poor despite many attempts to tune it. It would often fail to shift in the middle of the range. In an attempt to address the poor shifting I replaced the cables and housing, aligned the derailleur hanger, and replaced the RD-M510 with a new RD-M4000. The new M4000 derailleur was easily able to clear the 40T without the the hanger extender link, but after all this I still have poor shifting. The only piece that is not new is the shifter, so maybe that's the culprit, but I'm fairly disappointed with this attempt to make the CSM990 cassette work.

On another attempt I tried a CSM990 cassette (a 2nd one, not the exact same cassette) on my wife's bike (2005 Jamis Dakar) with similar results; inconsistent and poor shifts. The wife is super picky about clean shifting so this had to be fixed. I put the old 11-34 back on this bike and shifting is great again.

I really wanted this wide range 9-speed to work, but I'm striking out. Was hoping for a simple/cheap solution to wider range 1x, but I'm fairly convince at this point that I need to upgrade the entire drivetrain.

 

[syl3]

you need to use a modern derailer made for wide ranges. sunrace make one. shimano 10 speed works ok too.

 

[richj8990]

you need to use a modern derailer made for wide ranges. sunrace make one. shimano 10 speed works ok too.

I didn't know Sunrace made rear derailleurs. Looked at their website, most modern ones are two 9-speeds, both 11-34t, pretty much a Shimano clone.

The SGS 9-speed Alivio one I have is rated 11-36t and as mentioned earlier in the thread with a tight cable pull with pliers it can get to 40t w/o an extender. If it's within 4 rated teeth it can do it (like you mentioned with 10-speed derailleurs, or the 9-speed Alivio), but within 6 teeth (34t max) probably not, I've tried with an 8-speed Altus and it won't stay in the 40t gear for more than a few seconds.

 

[syl3]

sorry i meant the current 10/11/12 speed sunrace generation, like this one:

https://www.aliexpress.com/item/Sun...ear-Derailleur-Bike-Accessories-Compatible-with-12-11-10-Speed/32952252357.html

It has shimano 10 speed cable pull ratio, so it will work on 9 speed when paired with sram 9 speed shifters.

it is rated for 11-50t on 1x setup, while shimano 10 speed are rated for 36t but will work ok up to 40t with stock btension screw, and sometimes 42t with longer screw.

you can also use shimano slx/xt 11 speed rd with sram 9 speed shifter.

 

[JACKL]

If you are just running one ring up front, a Sram 11-speed derailleur with a Sram 9-speed shifter will work perfectly. I am currently running that, and the indexing is dead-on for 9-speed spacing.

I am currently running a Bolany 9-speed 11-50 cassette (with the 50t and 42t removed). The SRAM 11-speed der can handle 42t no problem. Eagle derailleur and 9-speed shifter should work for 50t, but I have not tried it.

The Bolany Cassette 11-50 9-speed cassette is the first wide-ratio cassette I've ever found with decent gear spacing right out of the box, so I bought it.

 

[zac2944]

I think I figured out how to make the Sunrace 9 Speed 11-40T CSM990 work with my M4000 derailleur. I feel a little foolish, but it turns out I didn't attach the cable correctly to the derailleur. The image below shows the cable correctly attached below the locking screw, I had it incorrectly above the screw where the red line is drawn. This changed the pull angle ever so slightly and was leading to poor shifting. It is not perfect now, but definitely better. Before making this cable change I couldn't shift through all gears no matter how I adjusted the indexing. You'll notice in the video there is still some skipping and hesitation when shifting. (sorry about he reverse image in the video, I was using "selfie-mode" for the wider angle.)

 

[richj8990]

I think I figured out how to make the Sunrace 9 Speed 11-40T CSM990 work with my M4000 derailleur. I feel a little foolish, but it turns out I didn't attach the cable correctly to the derailleur. The image below shows the cable correctly attached below the locking screw, I had it incorrectly above the screw where the red line is drawn. This changed the pull angle ever so slightly and was leading to poor shifting. It is not perfect now, but definitely better. Before making this cable change I couldn't shift through all gears no matter how I adjusted the indexing. You'll notice in the video there is still some skipping and hesitation when shifting. (sorry about he reverse image in the video, I was using "selfie-mode" for the wider angle.)

View attachment 1226732

Don't feel bad, I could not even put the M4000 on at first! The opposite position of the cable inlet totally threw me off. 7/8 speeds have the cable wrap around the back in the housing and come in from the rear of the bike into the derailleur. 9 speeds have it come from the front in the housing directly to the derailleur without circling around. About 6 inches less cable total than 7/8 speed.

 

[richj8990]

sorry i meant the current 10/11/12 speed sunrace generation, like this one:

https://www.aliexpress.com/item/Sun...ear-Derailleur-Bike-Accessories-Compatible-with-12-11-10-Speed/32952252357.html

It has shimano 10 speed cable pull ratio, so it will work on 9 speed when paired with sram 9 speed shifters.

it is rated for 11-50t on 1x setup, while shimano 10 speed are rated for 36t but will work ok up to 40t with stock btension screw, and sometimes 42t with longer screw.

you can also use shimano slx/xt 11 speed rd with sram 9 speed shifter.

Cool!

https://singletrackworld.com/2018/04/exclusive-new-1x12-drivetrain-from-sunrace/

But that rear derailleur is 189 British Pounds = around $250 USD

So the 12-speed rear derailleur on Ali Express for $66 USD is likely either used or a fake.

 

[tyrebyter]

Have run 10-speed Shimano Shadow+ deraileurs over 9-speed cassettes with Sram 9-speed shifters successfully, but an even better combo would be Shimano 11-speed deraileur with Sram 9-speed shifter as the shift ratio is an exact match, and the deraileur is already designed for up to 46-tooth cogs, so no goat-link needed. And with SLX M7000 deraileurs going for under $50US, it's the best 9-speed performance at minimal cost.

 

[JMac47]

Have run 10-speed Shimano Shadow+ deraileurs over 9-speed cassettes with Sram 9-speed shifters successfully, but an even better combo would be Shimano 11-speed deraileur with Sram 9-speed shifter as the shift ratio is an exact match, and the deraileur is already designed for up to 46-tooth cogs, so no goat-link needed. And with SLX M7000 deraileurs going for under $50US, it's the best 9-speed performance at minimal cost.

Good to know. I have an XO 9 spd gripshifter bike looking for a newer clutch style rr derailleur that can handle a bigger casssette cog.👍😎

 

[syl3]

But that rear derailleur is 189 British Pounds = around $250 USD

So the 12-speed rear derailleur on Ali Express for $66 USD is likely either used or a fake.

umm nope

https://www.bike-discount.de/en/buy/sunrace-mx60-12-speed-rear-derailleur-806765

 

[richj8990]

Just some trivial information:

I had an 8-speed Shimano Altus rear derailleur lying around and decided to try it on a custom 6-speed 11-40t cassette I made. I need it 6-speed so the chainline doesn't rub the 2.4 tire in back (it's still really tight tho). Some info. 7-9 speed owners may find interesting:

The off-brand extender didn't fit (for the 2nd time, two different extenders on two 7-9 speed bikes). I've tried JG bike 22mm and ZTTO 22mm and they both cannot fit by a few mm, too short. My tentative conclusion is that 10-11-12 speed derailleur hangers are different than 7-9 speed ones, they are shorter than the 7-9 speed ones and can take the extender. I will probably take out the extender on my other bike that the LBS drilled it on to. Have not tried WolfTooth but I assume it's going to have the exact same problem on a 7-9 speed hanger.

Altus doesn't have a sparkling reputation for 'real' mountain biking, but I swear to you guys that this lowly $18 rear derailleur is the little engine that could. It does way more than it ever should. I like it a lot more than Acera. Barrel adjuster has a nice long screw housing that you can see going back and forth through its own housing, easy to adjust, B-screw is 'long enough'. And it, an 8-speed medium-cage 11-34t derailleur, fit the chain on to the 40t gear just fine, and it holds!!! Yes, there are some weird drivetrain noises in the 1st chainring, and there is some gear skipping but so far every gear holds that it goes into. So I now have a 24/40 granny, or 0.60 ratio. If it breaks, I'll move over the 9-speed Alivio M4000 SGS long cage RD from my other bike and put it on. Hard to believe it fits the 40t; I did use vise grips but did not pull the shift cable hard.

 

[hodak]

Just as a point of reference, my current Shimano Altus 8-speed long-cage RD, max cog of 34 can ALMOST but not quite hold the 40t granny gear of the Sunrace cassette. It can but I can see it's really straining.

I know this is an old thread but it is already open and i wish to ask : did you try the Altus w/o roadlink just with an extra long B-screw to see if it clears the 40T cog? Am attempting a 1x8 drivetrain with the 11-40T sunrace rear and 36T single front

 

[hodak]

Ok thought i'd share since the community here has been helpful to me for so long even as a lurker

I decided to gamble on the BTWin 7-9 speed RD and 8 speed BTWin grip shifter and am so glad i did!

With the included roadlink with the Sunrace 8 speed 11-40T, i did not need to use the extra long B-Screw with the BTwin RD! Shifting from 11T to 40T is buttery smooth and tbh this is my very 1st bike that i've picked out parts myself and though the initial plan was to assemble everything by myself i decided to leave the last part (RD, shifter, indexing) to my LBS and well glad i did cos i can't possibly do as good a job as the pros :thumbsup:

11T

40T

My front is a 36T NW single and even w/o a clutch type RD i only dropped the chain in front once and i guess that was the 1st few minutes as the chain and sprockets have not "bedded" in i suppose? Just now i decided to test long distance and choose a route with lots of climbs/descents and a) not once did chain drop off b) i actually like the grip shifting (my 1st) c) Thicc, fat & strong 8 speed chains FTW :thumbsup:

Hope my feedback is useful and open up a new "cheapo" avenue to those under 10 speed cyclists looking to go wide range Lastly if i had to guess the "class" that the BTwin RD falls in the Shimano hierarchy charts i would guess prolly between Altus and Acera perhaps? Oh also Decathlon has an excellent returns/warranty dept where i'm at and that was also why i choose to buy brand new and covered with 2 years warranty instead of dipping in the used market

 

[PDKL45]

Anyone seen this:

https://www.chainreactioncycles.com/kr/en/box-two-e-mtb-9-speed-cassette/rp-prod178807

An 11-50 9 speed cassette from Box Two for eMTBs. I read that it was a Sunrace OEM product, so I checked Aliexpress and there are quite a few of them, from the usual suspects (ZTTO and various other basically nameless brands in China).

The ZTTO ones were down around $40 or so. I understand the jumps between gears etc, and I still think they look really cool. Sadly enough, I just went to a 3x9 set up with NOS Deore componentry, but it's a neat option for the future.

An 11-50 9 speed cassette with a 30t chainring would basically have me covered. Still, what about a derailleur? It would just need a 39 total capacity capable derailleur, but with what? A goatlink? A roadlink? What do you think you would be able to use to get the top jockey wheel down below the 50t cog?

 

[Daniel O.]

I'm not completely advising this route yet... but...

I've been using a sram 1:1 9 speed shifter (x.9 iirc) with a shimano 11 speed (m7000) rear mech. The pull ratios are either the same or close enough that it works. I've tried it on two cassettes (11-34t and 11-42t 9 speed) with ~50 miles total. No promises it works 100% with every combo. 11-50 goes beyond it's rated capacity of the mech and there are mixed reviews on using the same rear mech with the ztto 11-50 11 speed cassette. I believe it's the closest you'll get to finding an off the shelf 9-11 speed mech to handling a 50t without using some sort of hanger extension. Seems like 46t is the happy limit and 50t is iffy for the m7000.

Personally, if you are getting a mech, shifter, and cassette... I'd be more inclined to go full 11 speed at this point... SLX shifter and mech are ~$80 total at the moment. I would think there is a less expensive cassette option as well - but I don't know much about the e-bike cassette market.

 

[PDKL45]

Personally, if you are getting a mech, shifter, and cassette... I'd be more inclined to go full 11 speed at this point... SLX shifter and mech are ~$80 total at the moment. I would think there is a less expensive cassette option as well - but I don't know much about the e-bike cassette market.

It's a good point. I have a bunch of 9 speed stuff I bought in preparation for the apocalypse, though, and 9 speed stuff is nice and hard wearing, being slightly chunkier. Still, I have a brand new 3x9 drivetrain, so a change isn't on the cards for a good long while.

 

[Daniel O.]

That's initially why I had stuck with 9 speed as well... but in hindsight I'm not sure I would go 1x9 with an 11-42t again. I was able to reuse the chain and shifter - so I spent ~$100 on a chainring, cassette (11-42) and derailleur. The alternative would have been to spend ~$200 and I'd have ended up with 100g lighter combination of parts and wider ratio (which would be welcomed on a few hero climbs around here). It's debatable whether the $100 extra spend is worth the 100g and ratio.

I'm quite happy with the jumps on 11-42t across 9 speeds but it really does feel like the largest range I'd like to go while only having 9 gears to select. If I had an 11-50t 9 speed kicking around I'd try it on my set-up for shits and grins. I wouldn't have the highest hopes but it's fun to try things a bit outside the box!

 

[richj8990]

Just a little trivial update: the 34t max 8-speed Altus rear derailleur is still working with a 40t granny gear without an extender...however...due to the immense stress on the system for going 6 teeth more than max, it bent the derailleur hangar forwards a bit (not to the side), so shifting is not affected but it's harder to put in the qr axle now into the frame. I have to carefully put in the axle end inside the frame and then inside the bottom of the dropout, not directly into the dropout from above, it won't fit now directly because there is 2-3mm of hanger blocking it. That's a ***** to do because the disk brake is on the other side so not a lot of room to fit it in this way. Just goes to show that if you tweak something off spec, it can have very unpredictable consequences to other adjacent components! Still works, all cheap stuff, if it breaks oh well.

 

[niconj]

Huge up. Is there a weight difference between the black and the silver Sunrace CSM990? I seem to only find the black one and while I don‘t care about the color, the cassette is for my son‘s bike so if the silver is lighter, I may order somewhere outside of the country (Germany).