Sincitycycler

(Yeah, I know. No Ron Jeremy jokes, please...)

Seriously, I went from a 50/36 to a cyclocross 48/36t
.
Does the chain need to be shortened?

What are some problems associated with incorrect chain length?

crypticlineage

Follow Sheldon's Method to make sure your chain length is fine. It worked great for me.

If your chain is short, it may fall off or even slip when you get out of saddle. Not sure about slipping though.

HillRider

If your chain is too short it can bind and do a lot of damage if you shift into a chainring/cog combination it can't fit. Otherwise there is no problem. It won't fall off or skip just because it's too short.

A too long chain can go completely slack if shifted into a chainring/cog combination the rear derailleur can't "wrap up". In this case the chain could spill and will be very slack on the bottom run. Usually this does no damage but shouldn't be used anyway.

JanMM

If you went from a 50/36 to a 48/36, it's not worth worrying about, unless your chain was too long to begin with.

operator

Probably not. Unless the chain length was too long on your original 50/36.

bluehair

You don't seem to be able to get a straight answer. Your asking because you want the correct chain length not the length you can get away with, right? Put your bike on a workstand and shift to the smallest chainring and the smallest rear cog. The rear derailleur needs to be able to take up all the slack in the chain; so check the distance or clearance of the chain between the bottom pulley and the guide pulley. The chain shouldn't touch itself as it wraps. My mountain bike has about a 1/4" clearance; my road bikes have about a 1/2" clearance. Of course your chain also needs to get around the largest cog and largest chianring too, but that should not be a problem for you unless you take out too many links. I hope this helps.

operator

So in a nutshell: do the chain length check then ride.

miamijim

Correct. The key to your conversion/switch is the 36 tooth front chainring. If your rear derailleur was adequetly taking up chain slack with the 50/36 it will still take it up as it was previously.

Going from a 50 to a 48 will not create more slack. It will remain the same. Maximum slack occurs in the small/small gear combo. You didnt change this so your slack situation remains the same.

Your situation may have actualy improved going to 48. While in the 50 if shifting into larger diameter rear gears caused high tension switching to a 48 would help ease the tension.

bottom line......you dont need to change anything if it was OK before the switch.

Jim

cyccommute 

I folded a 53 tooth chainwheel in half on a tandem when I shifted a too tight chain to the 34 tooth cog on a freewheel once. It tough to see what gear you're in on a tandem

Otherwise, not problems.

miamijim

Dam...the only time I folded a front chainring was moments after an impact with big 'ole log.

JanMM

It's tough for a guy to do, but whenever it seems like a shift didn't go right, I ask my wife/stoker: "What gear are we in, dear?"

wroomwroomoops

"That's noting! I fold chainrings for breakfast, thrice, and get a one-inch thick chunk!"

The topper

Retro Grouch 

Can you say: "Flight Deck"?

cyccommute 

Not on a 1986 Burley you can't

cyccommute 

Little tougher to do when your stoker is only 4 years old.
"What gear are we in sweety?"

"I donnow. 1..2..4..3..6..8..eleventy"