What is the maximum tooth sprocket you could fit on the back using a Deore DX rear derailleur?

2/3+2/3 is not as long as a hanger with an extender added. But using an Xacto hobby saw you can cut opposite ends off of 2 hangers and make a longer one. The DIY idea looks good except a lot of hangers are thinner in some places, which is a little harder to DIY.
But yes 40t with just a longer B screw.
Here it is in action (my video skills suck)
50tx11-40t 8 speed cassette with Rapid Rise XTR mid cage, RR Revoshifter, and zip tied cassette to activate the front freewheel in the motor.
2004 Gary Fisher Solstice comfort bike with lots of MTB rated upgrades + the motor.
There are reports of Shimano Zee M640 short cage derailleurs doing this also. You need the Freeride version, not the DH model.
The shift ratio ended up the same as SRAM 1:1 so 8/9 speed with SRAM shifters is on the menu also. This means 9 speed twist shifters can be used. Clutch type deraillleur with no plastic bits if you want to update an older bike. SRAM 11 speed gipshifter work with these and the SLX mid cage also.
I have the mid cage SLX on my XC bike with SRAM 11s gripshifter. I own the Zee but might ship it off to my brother in NYC for stress testing. Keeping the derailleur out of the spokes is more of an issue for him.
The video didn't show anything regarding the 2/3+2/3 hanger. Still don't understand what that is tbh.
 
Just buying an extension is the sensible choice if you really want to try this :)
as others have pointed out it might compromise shifting, especially at the high end of the gear range (ie the smallest sprockets) as its essentially just pushing the derailleur further away from the sprockets

It potentially has a negative effect on capacity as well - most people trying this sort of thing tend to be on 1 x setups up front, not a triple with a very small granny ring!

that doesn't mean it definitely won't work, just things to be mindful of if you're determined to try.

they are not expensive and likely to be accurately made as opposed to a DIY bodge if you're not entirely sure what your up to (which I'm pretty sure applies)

https://www.sjscycles.co.uk/gear-spares/ztto-derailleur-hanger-extender/https://alpkit.com/products/sonder-...Vwr5L9UiULPjq59Zi6aJxifEYL7cnZGygzdrmldSd9Db3
 
It's a double ring I believe, so a bit easier on the chain and the mech through its cage swing.

Do they make a hanger that replaces the hanger on these shadow mech (M771 will be a shadow rear mech so has the floppy hanger thing.) scratch that theat wa the 770, 771 was normal (old) style!?
 
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Just buying an extension is the sensible choice if you really want to try this :)
as others have pointed out it might compromise shifting, especially at the high end of the gear range (ie the smallest sprockets) as its essentially just pushing the derailleur further away from the sprockets

It potentially has a negative effect on capacity as well - most people trying this sort of thing tend to be on 1 x setups up front, not a triple with a very small granny ring!

that doesn't mean it definitely won't work, just things to be mindful of if you're determined to try.

they are not expensive and likely to be accurately made as opposed to a DIY bodge if you're not entirely sure what your up to (which I'm pretty sure applies)

https://www.sjscycles.co.uk/gear-spares/ztto-derailleur-hanger-extender/https://alpkit.com/products/sonder-...Vwr5L9UiULPjq59Zi6aJxifEYL7cnZGygzdrmldSd9Db3
Yes I know they are cheap, seen on sjscycles for a few quid. Would buy one if I feel the cause to.

Funny thing is I have read that using hangers increases wear but also not using a hanger and having the jockey wheel too close the the cassette will cause wear to damned if you do damned if you don't. 🤪

Since it already works as is I question whether there is any point adding a hanger if that too could cause wear.

Wear happens one way of the other anyway doesn't it so perhaps just accept as par for the course and ride away and replace with new parts if they do wear out.
 
2/3+2/3 is not as long as a hanger with an extender added. But using an Xacto hobby saw you can cut opposite ends off of 2 hangers and make a longer one. The DIY idea looks good except a lot of hangers are thinner in some places, which is a little harder to DIY.
But yes 40t with just a longer B screw.
Here it is in action (my video skills suck)
50tx11-40t 8 speed cassette with Rapid Rise XTR mid cage, RR Revoshifter, and zip tied cassette to activate the front freewheel in the motor.
2004 Gary Fisher Solstice comfort bike with lots of MTB rated upgrades + the motor.
There are reports of Shimano Zee M640 short cage derailleurs doing this also. You need the Freeride version, not the DH model.
The shift ratio ended up the same as SRAM 1:1 so 8/9 speed with SRAM shifters is on the menu also. This means 9 speed twist shifters can be used. Clutch type deraillleur with no plastic bits if you want to update an older bike. SRAM 11 speed gipshifter work with these and the SLX mid cage also.
I have the mid cage SLX on my XC bike with SRAM 11s gripshifter. I own the Zee but might ship it off to my brother in NYC for stress testing. Keeping the derailleur out of the spokes is more of an issue for him.
From that video I can see why, from the comments I read, e-bikes go through drivetrains like toilet paper with all the extra work it does! :LOL:
 
Ok!

I got the new cable today and put it on.

Results...

Shifting is a lot cleaner and responsive but really only for the gears that would index before anyway with the trouble gears on either side still causing the same issues, just a bit less. It is closer but still will not index everything cleanly.

I can just about get everything to change but very very loosely. The highs and lows still complain. Granny gear lows are only just indexing with some jumping about and the high gears I have to overshift with click and push just to the edge before the next click to shift up a cog.

Now I have ruled that out I am thinking it is like the mechanic said earlier that the parts were just not made for each other. As such thumbies seem to be the way forward now! As @Imlach noted in an older thread "friction will solve all your problems".
 
Ok!

I got the new cable today and put it on.

Results...

Shifting is a lot cleaner and responsive but really only for the gears that would index before anyway with the trouble gears on either side still causing the same issues, just a bit less. It is closer but still will not index everything cleanly.

I can just about get everything to change but very very loosely. The highs and lows still complain. Granny gear lows are only just indexing with some jumping about and the high gears I have to overshift with click and push just to the edge before the next click to shift up a cog.

Now I have ruled that out I am thinking it is like the mechanic said earlier that the parts were just not made for each other. As such thumbies seem to be the way forward now! As @Imlach noted in an older thread "friction will solve all your problems".
Yeah every time I've run combos outside spec I've used friction. If sticking to indexing it usually won't work well, as Ben said, it's not designed to go together. Usually you can make stuff work but not without caveats, so it's a balancing act on your part to determine what is worth the hassle.
 
Yeah every time I've run combos outside spec I've used friction. If sticking to indexing it usually won't work well, as Ben said, it's not designed to go together. Usually you can make stuff work but not without caveats, so it's a balancing act on your part to determine what is worth the hassle.
As thumbies were my preference even before experiencing this indexing quagmire it just makes sense and now I have good justification to use them!

Also good to get confirmation this is a common issue with more experienced tinkerers.
 
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