pennpaul

I'm swapping in a bigger 9-speed rear cassette on my road bike going from 11-28 to 11-36. I have a 53/39 in the front. I currently have a short cage Ultegra RD and also bought a longer cage Sora RD and new chain.

However, the new cassette came with a cheapo road link which I decided to give a try. It seems to work without having to change the RD or lengthen the chain. Now I'm thinking is it even necessary to swap RDs or am I risking disaster? The Ultegra RD should not work according to its specs, but it does.

I'm not going to try big-big, but big and half-way on the cassette is still OK.

dsbrantjr

You are courting disaster. You had better ensure that the chain is long enough to shift comfortably into big-big or you will have a very unpleasant surprise when (not if) you forget and shift into that combination. You will be fortunate if you only tear up (or off) the derailleur and do not damage your frame.

VicBC_Biker

I am currently doing the same sort of change with my road bike.

Even with the hanger extender - which will let the RD shift up on to the 36T cog - the short cage derailleur arm is too short to tension a longer chain in the small-small combo.
So I think you should do everything you can to make even 'accidental' combinations like the big-big work.
Try the Sora.

Litespud

all the road link (I’m assuming an extended hanger) does is give you clearance for the larger sprockets - it does not address the chain wrap issue, and your short cage RD isn’t up to the task. You need a longer cage RD.

Iride01 

Some rear DR's are less expensive new than the wolf tooth extender some buy to try and make the old DR work.

Hangar extenders only allow you to get clearance from the cassette. Not increase the capacity so you can have huge differences from the small/small to the big/big combos.

What you need to look for is how close does that jockey wheel get to any of the cogs as you go from the smalls to the bigs. In the other direction, you don't want any slack in the chain as you go to the smalls.

VicBC_Biker

True.
But the knockoff extenders are under $5 with shipping, so OK for experiments, for me.

VicBC_Biker

Here a a couple of pics of my bike setup.
Triple chainrings 52-42-30 and 12-36 cassette.
I had to swap out the Ultegra RD for a Deore XT with a hanger extender.

Big-big 52-36


Small-small 30-12 Almost touching, but isn't. Not a disaster, but I'd never deliberately shift to that combo anyway, as with the Big-big - it would only be for a few seconds until I realized I'd made a mistake.

cxwrench

Exactly what everyone above posted. And why on earth do you post upside down photos? Just take them right-side up.

oldbobcat

You want your chain long enough to go big-big. Because someday you're going to forget what gear you're in and you're going to slam it into big-big. Small-small is a no-go for most of us, but at least if you find yourself there it will only be annoyingly noisy.

Iride01 

VicBC_Biker gave some good pics that sort of show what I was trying to say. See how the DR is stretched out in the big's, but has clearance to the jockey wheel. My 105 5800 GS (mid cage) DR looks stretched out like that too when in the 52F/32R. While a lot of literature might make you think that is too stretched out, as long as you have the clearance to the jockey wheel and the DR isn't at it's limit to stretch out more, then you probably are okay.

And clearly when in the smalls the chain isn't hanging slack with a big curve in it.

As for your bike, you ought to have it right side up when you adjust shifting and DR's. Gravity does have some effect on the components that will be different when you turn it over. You can just hang your top tube over the corner of a table or clamp some 2x4's through a ladder to hang the top tube on. Sometimes I just hang the nose of the saddle on something.

pennpaul

Well, I had nothing else going on this afternoon so I tried the Sora and I did need the new chain. Big-big just barely and small-small has enough tension. Now I've got to tweak the shifting. But man, that Sora derailleur is ugly.

Thanks for setting me on the right path,
Paul

VicBC_Biker

The photos are rightside up; the bike is upside down.
Without a bike work stand or a way to hang up the bike, it's easier to do derailleur adjustments with the bike upside down...but I haven't done that since the 1970s that because of all the 'stuff' that's attached to the handlebars on my bikes.

VicBC_Biker

Good points and good ideas.

VicBC_Biker

And you didn't need the hanger extender, so that's a plus.

VicBC_Biker

You won't mind so much when you are climbing walls and trees with your new low gears.

pennpaul

Yep, sadly no bike stand so this will have to do. Everything is easier to reach when the bike is upside down, but as someone else mentioned, gravity does play into it, too.

zandoval 

Got a new cassette... Why not a new long cage derailuer and a new chain. It would appear this good looking bike deserves it...

VicBC_Biker

That's what he did...
New Sora
New chain
New cassette + hanger extender.

But, I feel the OP's pain...I hated to take that purty Ultegra RD off the bike.