Derailleur Cage Length, Bent Hanger, SS Quick Fix

[Virtuoso]

Hey Guys,

 

Recently broke my rear derailleur in a race. Was wondering if it would've been possible to take some links out the chain and convert it to a SS somehow to finish off the race?

 

I also have a horribly bent hanger now and wanted to know if it needs replacing or just straightening?

 

Then finally would a XT with medium cage be fine for my 3X10 setup. I know that technically certain gears that I should not need would not be selectable. Would I damage my bike by changing into these gears? (The post i read said that it would just cause the derailleur to fold in on itself and possibly throw the chain off but no damage). I seldom make use of my 30T ring and doubt I have or will ever select one of the non-selectable gears. Would it be a good idea to go for the medium cage to avoid pick ups in future and for faster changes or should I play it safe and go for the long cage?

[Kranky]

Breaking my derailleur was the straw that broke the camel's back for me. My bike hasn't had one since

Edited May 5, 2014 by Nick.

[Guest Smimby]

Hey Guys,

 

Recently broke my rear derailleur in a race. Was wondering if it would've been possible to take some links out the chain and convert it to a SS somehow to finish off the race?

 

I also have a horribly bent hanger now and wanted to know if it needs replacing or just straightening?

 

Then finally would a XT with medium cage be fine for my 3X10 setup. I know that technically certain gears that I should not need would not be selectable. Would I damage my bike by changing into these gears? (The post i read said that it would just cause the derailleur to fold in on itself and possibly throw the chain off but no damage). I seldom make use of my 30T ring and doubt I have or will ever select one of the non-selectable gears. Would it be a good idea to go for the medium cage to avoid pick ups in future and for faster changes or should I play it safe and go for the long cage?

 

Medium cage will not be happy with a 3x10 setup. You could damage the RD but not the bike. Unless you remove the small ring and set the FD to only use Middle and Big......

[David Marshall]

Usually you can straighten the hangar. Best done with the right tool.

[fanievb]

Usually you can straighten the hangar. Best done with the right tool.

 

sorry for the high jack,

 

which one would you suggest? I only know of the PT DAG-2

[Sniffie]

Hey Guys,

 

Recently broke my rear derailleur in a race. Was wondering if it would've been possible to take some links out the chain and convert it to a SS somehow to finish off the race?

Yes with a chain breaker and quick link.

 

I also have a horribly bent hanger now and wanted to know if it needs replacing or just straightening?

LBS should have the tool, but if it is horribly bent it might break when they try to straighten it.

 

Then finally would a XT with medium cage be fine for my 3X10 setup. No. I know that technically certain gears that I should not need would not be selectable. Would I damage my bike by changing into these gears? (The post i read said that it would just cause the derailleur to fold in on itself and possibly throw the chain off but no damage). I seldom make use of my 30T ring and doubt I have or will ever select one of the non-selectable gears. Would it be a good idea to go for the medium cage to avoid pick ups in future and for faster changes or should I play it safe and go for the long cage?

[Sniffie]

sorry for the high jack,

 

which one would you suggest? I only know of the PT DAG-2

http://www.parktool.com/product/derailleur-hanger-alignment-gauge-dag-2

Simple looking tool but does the job brilliantly.

[Virtuoso]

Thanks for quick input guys. Guess I'm going with a medium cage and dropping a chainring or two. Have a friend that can bend old hanger straight or possibly even has a spare lying around.

 

Are there any complications on just shortening chain and going SS without running the chain through the derailleur? Would the chainring and selected gear on cassette need to be aligned or could you put the chain anywhere on the cassette and it wouldn't try bounce out? Will definitely be doing the makeshift SS trick next time in the race.

[Flowta]

Thanks for quick input guys. Guess I'm going with a medium cage and dropping a chainring or two. Have a friend that can bend old hanger straight or possibly even has a spare lying around.

 

Are there any complications on just shortening chain and going SS without running the chain through the derailleur? Would the chainring and selected gear on cassette need to be aligned or could you put the chain anywhere on the cassette and it wouldn't try bounce out? Will definitely be doing the makeshift SS trick next time in the race.

 

Technically the max. capacity of the long cage is 43t and the medium 35t.

 

The only time you'd need a full 43t capacity is if you are severely cross-chaining.

i.e. large front & large rear (42t+36t = 78) as well as small front & small rear (24t+11t = 35) (78-35 = 43)

 

If you say more used large chainring and 2 down from the largest sprocket (42t & 28t = 70) and smallest chainring and second smallest sprocket (24t & 13t = 38).

Even this is fairly extreme IMHO.

 

Then the capacity required is 33t, which medium will happily cater for.

 

In practice, I buy what I can afford/get hold of. Wanted a medium cage shimano clutch RD, could only get a large so that's what I have, works great.

[paarlmtb]

Replacing a hanger is cheap, having to buy a new wheel when it breaks and throws your RD into your spokes, not so!!!!

[Flowta]

Replacing a hanger is cheap, having to buy a new wheel when it breaks and throws your RD into your spokes, not so!!!!

 

Good point

 

Straighten the hanger, BUT install a new one.

 

Keep the "straightened" one in your camelback just in case

 

EDIT: Reminder to self, get a spare hanger

Edited May 5, 2014 by Flowta

[Pipsqueak]

I have 2 Shimano rear dérailleurs with bent or broken cages. I've been looking for replacement cages everywhere for months. No joy.

 

Anyone got a hot tip?

[Mojoman]

I have 2 Shimano rear dérailleurs with bent or broken cages. I've been looking for replacement cages everywhere for months. No joy.

 

Anyone got a hot tip?

Which derailers do you have? Coolheat may be able to assist. I have a M773 and I struggled to get some parts for that.

[Daniel J Méssem]

Technically the max. capacity of the long cage is 43t and the medium 35t.

 

The only time you'd need a full 43t capacity is if you are severely cross-chaining.

i.e. large front & large rear (42t+36t = 78) as well as small front & small rear (24t+11t = 35) (78-35 = 43)

 

If you say more used large chainring and 2 down from the largest sprocket (42t & 28t = 70) and smallest chainring and second smallest sprocket (24t & 13t = 38).

Even this is fairly extreme IMHO.

 

Then the capacity required is 33t, which medium will happily cater for.

 

In practice, I buy what I can afford/get hold of. Wanted a medium cage shimano clutch RD, could only get a large so that's what I have, works great.

 

Im running 3x10 with medium cage - did these calculations before buying it.

 

I took note of which combinations I use, I try to keep my chain straight. The calcs I did for myself said that I would be fine with a short cage derailer

 

Something to remember though, if you have rear suspension the derailers will also be taking care of chain length as the distance from BB to rear axle changes - the amount of change depends on the bike - mine moved 2 links from what I remember.

[JXV]

BTDT. If you have rear sus then going SS when ur hanger breaks can be a problem. Most suspensions cause small changes in BB to axle distance as they flex. Every time the chain goes slack on suspension movement it wants to change up at the back and eventually it rides up onto the biggest gear it can and locks out the suspension. May go so tight you cant turn the cranks.....at which point you might break something if you keep riding. Emergencies only IMO. I always carry a spare hanger 'cos I never want to do this again>_>

Edited August 8, 2014 by JXV

[Pipsqueak]

Which derailers do you have? Coolheat may be able to assist. I have a M773 and I struggled to get some parts for that.

The one I have here is M675, and I'll take either a med or long cage, whatever I can get.