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Highest total capacity of rear derailleurs

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Highest total capacity of rear derailleurs

Old 11-14-22, 03:46 PM
  #26  
70sSanO
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Originally Posted by Hondo6 View Post
Well, I guess I was wrong. Isn't the first time in my life, and certainly won't be the last - maybe not even today. Thanks for setting me straight.

OP: The man's advice is sound if you decide to go with the 9-speed cassette and respace it, provided you can get the spacers and order (and modify) the cog he suggests.

I guess it's now time to see how crow tastes with Tabasco or Cholula . . . .
Not time to eat crow. I just happened to have done what the OP is planning. Will my setup be better than using a 9 speed cassette? No way. A 9 speed 12-36 is better than what I did everytime.

For 99% of the people out there what I did would be considered stupid and a waste of time. I just happened to have a 126mm aluminum bike and wanted to use an 8 speed cassette without a force fit. I installed the wrong freehub body with shims and manipulated the OLD to get close to 127mm.

My 14-36 (14-16-18-20-23-26-30-36) with a 6500 (28t inner) triple works well for me. Basically it is a 14-30 with a 36t bailout. If I make a change it would to add a 13t (9 speed). I find the 30-36 6t jump fine and wouldn’t add to any of the other gaps to run 32-36. On a number of rides I don’t use the 28t granny ring or the 36t bailout.

John

Last edited by 70sSanO; 11-14-22 at 03:49 PM.
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Old 11-14-22, 04:20 PM
  #27  
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I think the visual give-away for several sprockets on a "carrier" (more on this below) is the brass-colored rivets around the circumference of one or more of the sprockets, per the image that Hondo6 posted earlier of that CS-HG400-8 cassette. In that case, the largest sprocket is riveted to the second-largest, with the requisite spacer of course. It looks like these two are the only ones riveted together in that way, meaning you couldn't really separate the largest and second-largest sprocket without potentially destroying either one. I agree that the 9-speeds don't appear to be this way...they simply have most of the stack riveted together with the conventional long rivets down near the splines.

I do have a recent Shimano 12-28 7-speed where the largest sprocket is riveted to the second-largest...and the second-largest is riveted to the third-largest...very much like a modern Shimano freewheel. I'm guessing the motivation here is a reduction in parts -- they can stamp one 21t sprocket, one 24t sprocket, and one 28t sprocket, and use them on both cassettes and freewheels. I originally liked this idea, as the pictures showed what appeared to be some sort of metal carrier internal to the cassette, where the torque loads on the larger sprockets would be spread over a larger area (reducing the tendency to notch an aluminum freehub body.

In fact, however, it's not like this at all, at least not with the 12-28 7-speed cassette I have. What appeared to be a metal carrier internal to the cassette was simply a plastic spacer ring. Rather than the torque loads of the larger sprockets being distributed over a larger area, they're all run through the third-largest sprocket. The torque on the largest sprocket is transferred to the second-largest (via the rivets), then to the third-largest (via the rivets), and then to the freehub body (via the splines).

Just a little nuance of these newer cassettes where some of the large sprockets aren't full sprockets...and just ride side-saddle with the next-smaller sprocket.
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Old 11-17-22, 04:27 AM
  #28  
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sunrace makes a derailleur that is 9 speed shimano compatible, sunrace rdm900. Not easy to find and economic in cosntruction, but for 1X it works.
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Old 11-17-22, 04:49 AM
  #29  
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Originally Posted by defraz View Post
sunrace makes a derailleur that is 9 speed shimano compatible, sunrace rdm900. Not easy to find and economic in cosntruction, but for 1X it works.
In case no one's said this before: welcome to Bike Forums.

Interesting product; thanks for mentioning it. But I'm not sure if it's something that will fit the OP's needs.

OP indicated above he's planning a 3x config (FC-M2000, 40-30-22) and already has the crankset. The OP is planning to run a 3x config, so that means the RD's total capacity is important as well as min/max sprocket size supported.

Unfortunately, Sunrace doesn't specify max total capacity for that RD (max front difference plus rear difference supported) on their web page for the item; they only specify min/max rear sprocket size supported. While I'd guess it is roughly comparable re: total capacity to the RD the OP plans to use (RD-M3020-8), without published data we don't know.

Finally, OP is in India. Don't know if Sunrace products are readily available there (Microshift products apparently aren't).

Last edited by Hondo6; 11-17-22 at 05:06 AM.
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Old 11-17-22, 08:38 AM
  #30  
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Originally Posted by defraz View Post
sunrace makes a derailleur that is 9 speed shimano compatible, sunrace rdm900. Not easy to find and economic in cosntruction, but for 1X it works.
Unfortunately, as mentioned in post #29 this model is a no-go for the OP. Here is a list of some of the specs and only offered in a med. cage with a 41t capacity and 1x crank only. Scroll to row #433 Bicycle Cassettes & Drivetrains - Google Sheets
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Old 11-19-22, 12:45 PM
  #31  
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Why do I need such low gears?

Injured my knee and want to start with low effort.
Live in an area where most roads either go up or down. So, I am either climbing or coasting. Cannot find a loop of even 1 mile where the roads are flat. Can of course use a 400m track but that gets too boring.
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Old 11-21-22, 07:52 PM
  #32  
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Gave up on customising cassette since I have to travel 180kms each way to reach closest bike shop that can handle modern bikes. Can't make multiple trips with my knee.

Proposed configuration

Existing crankset FC-M2000, 22x30x40
New 9-speed cassette CS-HG400, 12-36T
New 9-speed shifter SL-M3100
New 9-speed chain SRAM PC-951
Existing 6/7 speed RD-TY300-SGS
https://bike.shimano.com/en-US/produ...TY300-SGS.html

Total capacity of RD is 43

Low sprocket_Max is 34T
Low sprocket_Min is 11T
Max front difference is 20

Recall reading that the rear derailleur can handle a sprocket 2T larger than the Low sprocket_Max as long as the total capacity is not exceeded.

If this is not the case, will go for RD-M2000 or RD-M3100 that support 36T.

Thanks to all the members who helped me and kept the discussion on track.

Last edited by anga; 11-21-22 at 08:02 PM.
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Old 11-21-22, 09:40 PM
  #33  
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Smart to go to 9 speed. Generally you can push beyond max cog, and a longer B screw can help.

Max cog and capacity are not related. Capacity is really about the small-small as it is the amount of chain wrap the derailleur can wrap.

John
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Old 11-21-22, 10:53 PM
  #34  
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Originally Posted by 70sSanO View Post
Smart to go to 9 speed.
John
Tried to stick to 8-speed but availability of first position cog was the limiting factor, in addition to travel.
A bump from 8- to 9-speed seems to roughly double the price of every part of the drive train. Same for 9- to 10-speed.
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Old 11-22-22, 08:09 AM
  #35  
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Originally Posted by anga View Post
Gave up on customising cassette since I have to travel 180kms each way to reach closest bike shop that can handle modern bikes. Can't make multiple trips with my knee.

Proposed configuration

Existing crankset FC-M2000, 22x30x40
New 9-speed cassette CS-HG400, 12-36T
New 9-speed shifter SL-M3100
New 9-speed chain SRAM PC-951
Existing 6/7 speed RD-TY300-SGS
https://bike.shimano.com/en-US/produ...TY300-SGS.html

Total capacity of RD is 43

Low sprocket_Max is 34T
Low sprocket_Min is 11T
Max front difference is 20

Recall reading that the rear derailleur can handle a sprocket 2T larger than the Low sprocket_Max as long as the total capacity is not exceeded.

If this is not the case, will go for RD-M2000 or RD-M3100 that support 36T.

Thanks to all the members who helped me and kept the discussion on track.
I'd suggest using either a 32 middle ring or 42 large ring to eliminate gear duplication. But, before purchasing anything, I would play with a gear calculator.
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Old 11-22-22, 09:37 AM
  #36  
anga
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CS-HG400-9 12-36T is sold out!
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