Going past the RD max spec

[Veloo]

So what happens if you use a 32 cassette with a rear derailleur spec'ed to a max of only 28? In this case, a 1996 STX-RC.

Will the pulleys and teeth of the 32 cog crash into each other catastrophically?

[hollowgram5]

So what happens if you use a 32 cassette with a rear derailleur spec'ed to a max of only 28? In this case, a 1996 STX-RC.

Will the pulleys and teeth of the 32 cog crash into each other catastrophically?
Potentially. Just buy a Wolftooth Road link.. should save your der from an implosion..

[Ralph]

If they do rub.....and you can't adjust it out with B screw after getting chain length correct.....and don't want to use a different RD, there is a work a round. Take some chain links out...usually 2. This will shorten the chain and pull the upper pulley out of the way in the small front big rear combo so it doesn't rub. Now....there may not be enough chain to wrap the big to big....so don't shift to that combo....it may tear the RD off. The short cage may not take up slack fast enough to keep from throwing a chain sometimes with that cassette. But it will work if you don't use big to big. No one likes to set one up that way.....in case you forget and try to make that big to big shift (I know....you don't use that combo...except when you forget).

[ColonelJLloyd]

So what happens if you use a 32 cassette with a rear derailleur spec'ed to a max of only 28? In this case, a 1996 STX-RC.

Will the pulleys and teeth of the 32 cog crash into each other catastrophically?

My tandem runs the exact derailleur and a 13-32 6s freewheel with indexing shifters. You're good.

How many of these derailleurs could you buy for the price of a Road Link? :)

https://c5.staticflickr.com/8/7266/7819778708_de13b9b260_b.jpg (https://flic.kr/p/cV1pLQ)Untitled (https://flic.kr/p/cV1pLQ) by ColonelJLloyd (https://www.flickr.com/photos/51002114@N03/), on Flickr

[spartanKid]

You can often get a longer B screw (any screw with appropriate threads will work) if you're just a bit away from clearing.

[ripvanrando]

Two of my road road bikes can run 32 teeth using SRAM Red 22 derailleur owing to longer derailleur mount and the other two can't because they have a shorter mount and it is just too close for comfort. On one bike I did pony up for the mid size caged derailleur.

The risk is torching the derailleur and maybe some skin.

[oldpotatoe]

If they do rub.....and you can't adjust it out with B screw after getting chain length correct.....and don't want to use a different RD, there is a work a round. Take some chain links out...usually 2. This will shorten the chain and pull the upper pulley out of the way in the small front big rear combo so it doesn't rub. Now....there may not be enough chain to wrap the big to big....so don't shift to that combo....it may tear the RD off. The short cage may not take up slack fast enough to keep from throwing a chain sometimes with that cassette. But it will work if you don't use big to big. No one likes to set one up that way.....in case you forget and try to make that big to big shift (I know....you don't use that combo...except when you forget).

Yup..used to put big cogsets onto DA 8s stuff for Mt Evan's..all shorter chain does is rotate the top pulley away from the bigger cogs but try to go big-big..may kill a frame.

[AngryScientist]

How many of these derailleurs could you buy for the price of a Road Link? :)


well, the roadlink is only 20 bucks...

https://encrypted-tbn2.gstatic.com/shopping?q=tbn:ANd9GcQ4Vz6RasMbN6Ej_LRsWso7V_1r2P2 saxs1Axrb7BZNOevy85HwktBb2MsrvyAb9d7sMAodtfo&usqp=CAE

[ColonelJLloyd]

well, the roadlink is only 20 bucks...

Ah, I was thinking of a different Wolftooth product. So the answer is 2-2.5 then.
;) I haven't used a road link, but it makes me think that by using one shifting would be suboptimal, especially on the smallest cogs because you're moving the pulley further from the cog (not as intended). Is this ever an issue in practice?

Regardless, the OP's derailleur will shift a 32t cog as is.

[fa63]

http://uploads.tapatalk-cdn.com/20161101/64252e41097e926f1c6f5250e1d6f947.jpg

Mine shifts great with the Roadlink. That is a 11-40 cassette with a mid cage Ultegra RD and a compact crank.

[rkhatibi]

11-42T with the longer Goatlink and XT RD. Shifts surprisingly well with a 46/36 in front.

[mmelito]

11-42T with the longer Goatlink and XT RD. Shifts surprisingly well with a 46/36 in front.

+1

That is an awesome setup.

[dem]

I will see your 11-42 with 46/36 (23 gear inches to 113), and raise you 10-42 with 44/30 (19 inches to 119)

(Goatlink + XTR RD + Tanpan + Shimano 11 speed road shifters + DT240S hub with XD driver and SRAM 10-42 cassette)

http://www.haphazard.com/bikes/gears.jpg

[rkhatibi]

WOW! dem, I have questions. From Wolftooth,

"Double chainrings (2x) is supported and requires a long cage (SGS) rear derailleur with no more than a 12t difference in front chainrings (with an 11-46 cassette)."

With the 14t difference and 10-42t you're happy with performance? I do have a 34t for the front on order, but wanted to get comfortable with the current setup. Also had ideas about two cassettes, two chains, and a bag of missing links to swap 11-32 for cx and then back to the 11-42 for gravel.

Also is the chainstay wrap for aesthetics or do you see some chain slap even with the clutched XTR?

[fa63]

I have a 16 tooth difference in the front (50-34) and it still works great. I should note that I try my best to avoid going big-big, though I forget on occasion :)

[91Bear]

I have a mid-cage XTR on my MTB and a 31 large cog. If you accidentally get to the large cog and the largest sprocket (which you should never do, but I did once), I found out that it binds and pulls rear wheel out of the dropouts!

[dem]

I am personally not a believer in a suicidal big-big, if you don't have enough chain for big-big you will crash or break something eventually. Some things you can fudge a bit, but I don't think that's one. :)

Other than chain length (I use big-big + 2 links method), you have to worry about:

1) Does the RD top pulley clear the biggest cog. The Goat/roadlink + B-screw fiddling will get you there.
2) Chain wrap capacity of the RD, can you take up enough slack in small-small to handle that huge chain without it flopping all around (45T on the long cage XTR M9000, and I'm at 46T)
3) FD tooth capacity, biggest jump it can handle (16T in the case of the road shimano, and assuming you did, indeed, size it for enough chain!)

So the trick is to balance those three. In my case, there's not much tension on small-small, so I put in a bit more B screw, which probably degrades shift quality and cassette lifespan a bit.

If I enable the clutch, shifting doesn't behave consistently, so I leave it disabled. It may be the Tanpan introduces some cable friction, or my chain length is not spot on. Not having the clutch hasn't been an issue, so I haven't investigated further.

In my case, the front shifting is just fine. Other than the rear derailler capacity issue, I see no reason why the FD couldn't handle the 16T jump.

Given I ride this thing on all sorts of inappropriate terrain, and often descend washboard that rattles my eyeballs so hard I can't really see, I figured the chain stay wrap was a good idea. :)

I have 1000 miles or so on this combination and it is still working great.

Best of luck.

[rkhatibi]

Awesome, thanks for the extra data everyone. Good to hear other people have gone big with reasonable reliability. Sorry ( not sorry :banana: ) about the thread hijack.