Rear Derailleur

[bleedToWin]

10 minutes ago, DieselnDust said:

Where did I say larger small ring reduces decap? I said it would start to limit the big sprocket size. What I didn't clarify was "for the same chain length".

Okay, obviously DeCap is constant, but you said that if you increase your SR you should decrease your largest sprocket, then posted math to justify it, but the math posted stated the inverse of what was said. Again you are now doubling down on it limiting the big sprocket, but your math (and in fact reality) is that larger small ring (all else equal) allows for a larger big sprocket.


 

Edited September 26 by bleedToWin

[DieselnDust]

11 minutes ago, bleedToWin said:

Okay, obviously DeCap is constant, but you said that if you increase your SR you should decrease your largest sprocket, then posted math to justify it, but the math posted stated the inverse of what was said. Again you are now doubling down on it limiting the big sprocket, but your math (and in fact reality) is that larger small ring (all else equal) allows for a larger big sprocket.


 

I posted numbers by way of example not math. That wasn't even arithmetic 😂

and those numbers were based on constant chain length to illustrate that if you reduce the SR you can enlarge the bs within the derailleur capacity which served to answer the OP's question on how its possible for the 32T sprocket to work with a derailleur of limited a capacity. The answer is its not that far away from its capacity (Which is often understated anyway as a safe limit) since the SR was reduced in size to accommodate the larger rear sprocket (and the chain length might have been increased but I don't know that for a fact.

sorry I can't furnish you with your need for an argument today.

[bleedToWin]

10 minutes ago, DieselnDust said:

sorry I can't furnish you with your need for an argument today.

Lucky for me you both posted the incorrect argument and the math to prove yourself wrong. 🤷‍♂️

[bleedToWin]

1 hour ago, DieselnDust said:

DeCap= (BR-SR) + (bs - ss)

DeCap - BR + ss = bs - SR

You say all the left is constant, which implies if SR goes up then bs can go up. But you advised OP of the inverse relation, which simply isn't true, and you supplied the math to show it. 

And nothing you said in answer to OP's question was relevant to OP who posted a video where both rings were changed so that chainring contribution to derailleur capacity was unchanged. It's all about guide pulley clearance.

Edited September 26 by bleedToWin

[DieselnDust]

24 minutes ago, bleedToWin said:

DeCap - BR + ss = bs - SR

You say all the left is constant, which implies if SR goes up then bs can go up. But you advised OP of the inverse relation, which simply isn't true, and you supplied the math to show it. 

And nothing you said in answer to OP's question was relevant to OP who posted a video where both rings were changed so that chainring contribution to derailleur capacity was unchanged. It's all about guide pulley clearance.

again you make up your own narrative. Where did I say the left is constant.. I said I consider the ss constant since most cassettes for road bikes have an 11.

Till you learn to read we're done.

[bleedToWin]

Reducing the SR has no effect on largest possible sprocket if you change BR (as recommended).  
Reducing the SR takes up more derailleur capacity if you keep BR the same size, so less capacity is left for cassette range.

Why is this a hill you chose to die on?

[bleedToWin]

7 minutes ago, DieselnDust said:

I said I consider the ss constant since most cassettes for road bikes have an 11.

I simply went with your suggestion on constant ss and BR to use your math to illustrate the direct relationship between bs and SR. The extreme of this is 1x where all the derailleur capacity is available for the cassette (BR == SR).

[NotSoBigBen]

4 hours ago, droo said:

Snip snip snip

A hanger extender is a recipe for terrible shifting.

Besides all the background noise and 'ego tripping' I have to agree on the hanger extender. I have tried many different options over a few years with one of those and I can maybe recall one time it worked 'ok' ... Yes it will clear the big gear on the cassette but as you say at a cost of shifting performance. 

For me it's normally a last resort and then I just accept the crappy gear selection for what it is.

[Akon]

3 hours ago, DieselnDust said:

... with your need for an argument ...

 

2 hours ago, NotSoBigBen said:

... background noise and 'ego tripping'...

[DieselnDust]

7 hours ago, NotSoBigBen said:

Besides all the background noise and 'ego tripping' I have to agree on the hanger extender. I have tried many different options over a few years with one of those and I can maybe recall one time it worked 'ok' ... Yes it will clear the big gear on the cassette but as you say at a cost of shifting performance. 

For me it's normally a last resort and then I just accept the crappy gear selection for what it is.

Hanger extenders simply bend to much. I’d avoid 

[Mongoose!]

17 hours ago, droo said:

A hanger extender is a recipe for terrible shifting.

guess I was just lucky then. On three of my bikes where I installed hanger extensions with perfect shifting.

Ultegra R8000 short gage - 32/11 cassette 11 speed (Supersix evo) 

Tiagra R4700 short gage - 32/11 cassette 10 speed (Cervelo S 5)

Sram XO (Red shifters) 46/11  (one by) 10 speed (Giant XTC monster cross)

[bleedToWin]

2 hours ago, Mongoose! said:

guess I was just lucky then. On three of my bikes where I installed hanger extensions with perfect shifting.

Ultegra R8000 short gage - 32/11 cassette 11 speed (Supersix evo) 

Your first example is possible (although out of spec) without the extender, so maybe it helps that you are not asking too much from the extender...

[Mongoose!]

5 hours ago, bleedToWin said:

Your first example is possible (although out of spec) without the extender, so maybe it helps that you are not asking too much from the extender...

yes, you are correct, Tried both (with and without extender)

Both worked, but slightly better with extender. (in my experience) 

it is also very important that your derailleur hanger on bike must be 110% straight when using a derailleur hanger extender...