6800 to R8000 RD upgrade + Wheel removal advice needed

supermurph09

As per the subject really.

I have Ultegra 6800 on my Canyon Ultimate, I was looking at replacing the jockey wheels but wondered if the new style R8000 rear mech would straight swap on?

I noted this on the wiggle site:

"The groupset offers two specific rear derailleurs: one for cassettes 11-25 and 11-30 and one for cassettes 11-28 and 11-34, securing a smooth ride in even the highest and steepest mountain areas. Due to the integrated Shadow RD Technology with its race-proven, low profile design, the derailleur is more compact and fits closer to the frame, ensuring less damage in a crash"

Given I run either an 11-25, 12-25 or 11-28 cassette I thought I'd gather more info.

Thanks

mamil314

yes

supermurph09

Admire the confidence, thanks.

poptart242

Yup, I've swapped over with no fuss, you'll be fine. Make sure your new RD comes with the new cable outer though, it's super spongy and flexible compared to the 6800 one.

svetty

Yes, should be a straight swap. Chain length might need adjusting as Shadow design is slightly different and has more wrap around the cassette sprockets

supermurph09

many thanks.

supermurph09

Do I need medium or short cage?

I'll be running 11-25, 12-25 or 11-28.

svetty

Standard/short

supermurph09

Svetty wrote:

Standard/short

thank you

bobones

Svetty wrote:

Yes, should be a straight swap. Chain length might need adjusting as Shadow design is slightly different and has more wrap around the cassette sprockets

Shouldn't make any difference the required as chain length is usually measured without routing the chain through the derailleur (big-big or small-small).

svetty

bobones wrote:

Svetty wrote:

Yes, should be a straight swap. Chain length might need adjusting as Shadow design is slightly different and has more wrap around the cassette sprockets

Shouldn't make any difference the required as chain length is usually measured without routing the chain through the derailleur (big-big or small-small).

Assuming the Shimano recommended method for the Rx000 series is used: If it suggests adding 2 links it is fine, if it suggests adding either 1 or 3 generally 3 is the length to go for.....

davethebike

yes I've just replaced the same. one point:
and others have had this:
unlike the 6800
the 8000 body stays static in operation, that's the design, it's only the cage that moves.
but when removing the wheel, just as with the 6800, you have to manually rotate the body back to free the cassette cogs away from top pulley. You'll find that yes it Will rotate, but nowhere near as far as the 6800 does, and so, it's a pain getting the wheel out and back in. Unfortunately the 8000 is a faff

supermurph09

davethebike wrote:

yes I've just replaced the same. one point:
and others have had this:
unlike the 6800
the 8000 body stays static in operation, that's the design, it's only the cage that moves.
but when removing the wheel, just as with the 6800, you have to manually rotate the body back to free the cassette cogs away from top pulley. You'll find that yes it Will rotate, but nowhere near as far as the 6800 does, and so, it's a pain getting the wheel out and back in. Unfortunately the 8000 is a faff

Sound like fun. Fitting it tomorrow so will have a play around at home with it rather than on the road!

svetty

The extent to which it is awkward getting the wheel in and out is dependent on the hanger orientation, tyre size and chainstay length. I have no issue with my bike with R8000 - a Look 585 - but other bikes are more of an issue I believe.

supermurph09

Looks great, changes are super smooth but is there a knack for swapping wheels in and out? I didn't have much time last night to swap my road wheel for turbo wheel so managed to do it but not really sure how. I'm sure it's very simple!

lesfirth

I find it is easier to remove the wheel if the chain is on the smallest cog.

supermurph09

lesfirth wrote:

I find it is easier to remove the wheel if the chain is on the smallest cog.

Yeah always do that, it's the motion of how the wheel pops out and back in. I'm pretty sure there is more mech moving needed, just didn't instantly get the knack.

supermurph09

Others have the same issue it seems

https://www.reddit.com/r/bicycling/comm ... l_removal/

poptart242

Having previously stated no issues - now that I'm on DA Disc, flipping heck it's difficult. Will try the method in the video above in the Reddit post, because right now I feel like I'm about to snap the hangar every time I take the wheel out.

svetty

I just hold the bottom of the jockey cage between thumb and forefinger and extend it backwards and away from the dropout. The wheel can then clear the mech and slides out. I seldom have to touch the chain and get my fingers oily.

supermurph09

Back to the R8000.... cracked it now.

Essentially you need to hold the RD and twist it clockwise until it pops out the wheel. This is is done on small front and small rear.

To put the wheel back in you need to ensure the chain is lined up on smallest cog and twist the RD even further, almost feels like you’re going too far but it then pops in.

Nerves settled! I’ll try and do a video as I’m sure this would be useful for people.

davethebike

Yes you can replace with the R8000 but as many have already found:
Wheel removal/replacement is difficult due to the new design which lacks the greater range of movement found on the 6800 and where hence the r8000 upper jockey wheel tries to stop the cassette (even with chain on smallest cog and with top gear set) from getting past it on wheel removal/ replacement. Additionally difficult with disk brakes when as well as trying to get the axle between the dropouts, you're also trying to feed the rotor between the pads, without scratching the frame to buggery.
You Can do it but, you'd do well to:
a) Remove any qr skewers
b) loosen mech bolt at dropout, rotate mech fully back and re-tighten. This provides a small amount of extra room allowing the cassette to (just) clear the mech
When finished, rotate mech forward again to original position, and re-tighten bolt

Note, re sudden change in shifting accuracy:
If you also, unexpectedly, end up with the shifting out of kilter, then it's almost certainly because you're in a "new" mech rotational position compared to that of when the shifting was initially set.
Rotating mech back makes as if the cable is too tight ie in worst case can mean that one click is still left in shift lever when chain is on largest sprocket. So if ever this symptom presents, Before thinking about re-adjusting gears, check firstly, the mech rotational position, and that it's not rotated back compared to where it was as before. Keep it forward if possible. Similarly, if mech was initially adjusted in a rotated back position, then any forward mech rotation causes the opposite, ie slacker shifting. Shimano obviously never tested for any of this.
Dave

johngti

I actually find it easier if the chain is on the third or fourth cog rather than the smallest one. No idea why.

Matthewfalle

davethebike wrote:

Yes you can replace with the R8000 but as many have already found:
Wheel removal/replacement is difficult due to the new design which lacks the greater range of movement found on the 6800 and where hence the r8000 upper jockey wheel tries to stop the cassette (even with chain on smallest cog and with top gear set) from getting past it on wheel removal/ replacement. Additionally difficult with disk brakes when as well as trying to get the axle between the dropouts, you're also trying to feed the rotor between the pads, without scratching the frame to buggery.
You Can do it but, you'd do well to:
a) Remove any qr skewers
b) loosen mech bolt at dropout, rotate mech fully back and re-tighten. This provides a small amount of extra room allowing the cassette to (just) clear the mech
When finished, rotate mech forward again to original position, and re-tighten bolt

Note, re sudden change in shifting accuracy:
If you also, unexpectedly, end up with the shifting out of kilter, then it's almost certainly because you're in a "new" mech rotational position compared to that of when the shifting was initially set.
Rotating mech back makes as if the cable is too tight ie in worst case can mean that one click is still left in shift lever when chain is on largest sprocket. So if ever this symptom presents, Before thinking about re-adjusting gears, check firstly, the mech rotational position, and that it's not rotated back compared to where it was as before. Keep it forward if possible. Similarly, if mech was initially adjusted in a rotated back position, then any forward mech rotation causes the opposite, ie slacker shifting. Shimano obviously never tested for any of this.
Dave

seriously? undo the mech everytime you take wheel out.

sounds a right faff.

davethebike

You only slightly loosen it to make it easier to move the mech back. You can do it without loosening the bolt but the chances are, the bolt will then loosen by itself anyway, and need tightening
Yes it Is a faff but try removing or replacing the wheel without doing that.

It's no great pain but if I'd known about this I'd have got another 6800

Still can't see how Shimano made such a fundamental design error