Clutched Ultegra RD for the road ...

[MichaelB]

Hot on the heels of the new 105 level groupset (R7000), it seems that Shimano have pulled something pout of left field with the Ultegra RX, a clutched RD for the roadie/CX/gravel riders

From Cycling Tips



For some, this will be great, some will complain that yep it's good for chain slap, but it makes shifting crap (does it really ?), and some will suspect that a single ring groupset is around the corner.

Discuss.

[Jmuzz]

You can turn it off anyway which neutralizes any effect, so worth having for CX bikes. Worst case leave it off and it's a standard deraileur.

Basically just behaves like a stronger spring, though it is actually just more like stiff joints in one direction.

[Jawa]

Obviously this would be unveiled during the spring classic season but im not sure where the normal roadie consumer would benefit from this? Assuming you keep you drivetrain serviced where’s the risk of popping off the chain? Then again I don’t even bother carrying a chain tool or quick link.

The linked article mentions the benefit for 1x drivetrains, maybe Shimano have an all new group in the pipeline

[Jmuzz]

It's not for roadies.
It's for the cyclo-cross racing where they use road gear where it should really be MTB gear.
So this bridges a gap to add more MTB tech into the road groupset for those guys.

Would be nice if they would just fully synchronise the two styles so either can be used without spacer hacks and pull converters and stuff.
Crazy having two slightly different lines.

[Duck!]

So this bridges a gap to add more MTB tech into the road groupset for those guys.

Would be nice if they would just fully synchronise the two styles so either can be used without spacer hacks and pull converters and stuff.
Crazy having two slightly different lines.

They did.... It's called 9-sp.

[Jawa]

It's not for roadies.
It's for the cyclo-cross racing where they use road gear where it should really be MTB gear.
So this bridges a gap to add more MTB tech into the road groupset for those guys.

Makes sense, maybe a CX specific group in the pipeline then

[dmwill]

Makes sense given SRAM has had groupsets aimed at CX for a while now (Force 1, Rival 1, etc). They dominate the CX bike market.

Haven't read the full article, but if they can do a mechanical version it should be pretty good value against the Force 1 group.

[BugsBunny]

I know what a clutch is in a car, but what is a clutch in an RD and what is it supposed to do in this context?

My laymen understanding of a RD is it just moves left/right up and down the cassette. So where would a clutch come into this?

[Duck!]

My laymen understanding of a RD is it just moves left/right up and down the cassette. So where would a clutch come into this?

That's only half of the derailleur's job. Each gear ratio needs a certain length of chain; as you change to a bigger sprocket or chainring, you need more chain, Therefore when you have sufficient chain to wrap around the big ring and biggest sprocket, as you shift to smaller sprockets you end up with slack in the chain. The derailleur's second function is to absorb that slack and maintain tension with its cage and tensioning spring.
The clutch is a one-way friction mechanism on the derailleur's cage pivot. It improves chain stability by resisting forward movement of the cage; effectively a helping hand for the spring to maintain tension.

[BugsBunny]

Thanks Duck!

[MichaelB]

Thinking of getting one of these for the Slate - changing the chainrings from 52/36 to 50/34, and have sourced a 11-34 R7000 cassette.

I can either use a long cage 105 Rd (5800 series) at home or look at getting the RX800 (Pushys have it for $113 atm, and other places are $141) as I do a bit of bumpy single track riding.

Thoughts ?

Feedback from anyone that's actually got one ?

[Patt0]

I got the rx805. Looks sexy AF! yet to use it but. Its going on my new, yet to assemble, training/everyday bike. Going with a 50/34 and 11-32.

[MichaelB]

Cheers Patt0.

Looking fwd to seeing rest of build !!

[Duck!]

Thinking of getting one of these for the Slate - changing the chainrings from 52/36 to 50/34, and have sourced a 11-34 R7000 cassette.

I can either use a long cage 105 Rd (5800 series) at home or look at getting the RX800
Thoughts ?

5800 upper body geometry may take objection to the 34T sprocket unless your frame has a generous hanger length.

I'd just lash out & grab the RX; even without the clutch the Shadow derailleur design is vastly superior to traditional models, especially when it comes to dealing with cassettes at the big end of the range. The major factor is that the upper pivot is not sprung, rather the B-tension screw is a positive stopper against forward movement of the derailleur body, so once sprocket/pulley clearance is set, that's where it stays.

[MichaelB]

Cheers for the confirmation. Was planning on ordering today anyway

[mogwaiboi]

I've got one on my Giant TCX, running a 46/36 with an 11-40 cassette. Works like a charm so far (for the couple of rides I've done with it). It replaced an XT rear derailleur with a Tanpan converter and it shifts noticeably better than that set up did.

[MichaelB]

Cheers - have you played with the tension at all or have plans to ?

[joomz]

I just got an RD-RX805 clutched di2 derailleur. It works nicely with the clutch off. But, the motor struggles to shift to larger cogs with the clutch on. I've already backed off the clutch tension a bit. Is the motor a bit underpowered for the clutch? I'll keep experimenting with the tension, but it'd be pretty useless if it had to be backed off so far it's not much different to the clutch being off.

[simurs4]

Glad to see a thread like this pop up. I am thinking of going down the same road with my old faithful commuting/everything else SL3 S-Works.

The 10spd Sram red crank on it is totally shagged and I feel like its a good oppurtunity to move from my standard 53/39 to a compact 50/34 with 11-34t so I can tackle some more serious mountains local to me.

I don't want to splurge on Dura Ace, as my other bike has R9150 already so full R8000 with the clutched RD sounds like a good idea.

[MichaelB]

I used the RX800 on my Cannondale Slate, and it works great.

I honestly can't tell much of a difference with the clutch on or off (no adjustments made yet). If anything, the downshifts to the smaller cog is slightly slower, but that's about it