Di2 upshifts

tdougan

Hi All,

I got Di2 fitted to one of my bikes a little while back. The shop without me really realising till recently put a 11 speed 105 casset on rather than a 6800 casset.

It's fairly 'Clunky' when i up shift (to a harder gear). It shifts very quickly and gets the gear every time, but it's pretty loud and you feel it right though the bike. This is especially noticeable under load.

I've tried fiddling with the adjustments up and down a couple to see if it helps - it didn't.

What do you think? is it normal? is it a setup thing or is it the casset?

Cheers,

Tony

DKay

The 5800 cassette will work identically to the 6800 item, so any 'clunkiness' won't be down to that and the difference in weight is pifflingly small. To be honest, what you're describing sounds pretty normal when changing to a smaller sprocket under load, even for Di2. The type of wheel you're using can make a difference to how load the 'clunk' is too.

CiB

Clunky sounds like the spacer behind the cassette is missing. Check or get your LBS to have a look. You probably have to remove the cassette to see it, from memory.

964cup

CiB wrote:

Clunky sounds like the spacer behind the cassette is missing. Check or get your LBS to have a look. You probably have to remove the cassette to see it, from memory.

There is no spacer behind the cassette for Shim/SRAM 11-speed.

Brailsford Bad

Had the same problem with my Di2 rear mech last year. On one particular ride going uphill and putting power through it, the rear mech just sheered off and went straight into the wheel, completely torn in half.

Turns out the chain was too short for the largest cog and when shifting into the big cog it was pulling the jockey wheels far too forward, in the end the unit could take it and just sheered forward.

So check the chain length.
Then make sure the cassette is compatible with the rear mech ie: 11-28 max for a standard size Di2 unit (the new 11speed Di2 will go to 11-32 if you get the medium cage).

It shouldnt be jumping and grinding like you say it is, somethings not right. Since fixing mine i can barely hear it, especially when shifting.

Bar Shaker

Loud clonks on up shifts are more to do with using a decent stiff wheel than the cassette.

I'm using an 11sp Force cassette on both of my wheel sets. Some changes are loud, some aren't. Di2 works fine with any 11 speed cassette, even an 12-29 Campag Chorus.

DKay

Exactly. The OP hasn't complained of skipping or jumping and his shifting is fine. Clunks are perfectly normal.

964cup

External or internal battery? If internal, connect the charger to the bike and to your PC, download the software from etubeproject.shimano.com and see what your shift speed is set to. The shop may have decided to set it faster than normal, which will increase shift speed but decrease smoothness.

Bar Shaker

Shift speed has no effect on smoothness or clunking, it isn't like a car gear change. The chain goes clunk when the changed links reach the area of highest tension, at the top of the cassette.

Use the shift speed adjustment to match your typical cadence.

If you want smooth or quiet changes, just back the pressure off a bit until the changed links have passed out of the cassette. It is easy to make cable gears go clunk, if you are too aggressive with them. Di2 just allows you to be that aggressive all the time.