Digital shifting modes

19/05/24 21:08 Filed in: Gear

When your shifting is mechanical and actuated by Bowden cables, no matter how good it is it can only take the rider's movement of a lever at the bars and turns that into a movement of the chain at the drivetrain. One click equals one shift. And downshifting usually permits multiple clicks for multiple shifts although upshifting is usually one at a time.
Once you make the derailleur digital the relationship between the lever on the bars and the behaviour at the drivetrain can be modified in many ways. The first one I was familiar with was the multi-shift in AXS because that is applicable regardless of having a front derailleur or not. I tried briefly the multi-mode and returned to one click for one gear because the multi-mode is time dependent and if you leave your finger on the button for a fraction too long, you get an extra unwanted shift. Plus I like the one to one ratio of clicks to shifts.
The second one is sequential shift. Which only makes sense if you have a front derailleur. In this mode, shifting is accomplished as if you only had a 1x system - shifting at the rear derailleur only. But the computer decides when to shift the front derailleur. This is neither random nor computed. It is set by SRAM for each cassette type. On my 10-28T if you begin in highest gear (50/10) and ride along shifting into ever lower gears, when it reaches the 50T/24T ratio (the second largest/lowest sprocket) it changes pattern. Instead of going to 50T/28T (big:big) it drops the chain onto the smaller chainring (37T) and double upshifts at the rear (19T). In three more shifts, the lowest gear is reached (37T/28T). On the way back it doesn't reverse course but instead plots a slightly different pathway. Remaining in the small chainring (37T) until the eighth ratio is reached (14T), and only on the next shift does it move up to the big ring (50T) and double downshifts at the rear (16T). There are five more higher gears remaining until the highest gear ratio (where we started) is reached.
I think if it changed to and from the big ring with the 24T and 19T sprockets used then I'd be happy with it (if the small ring returned to the big ring at 19T on the upshifts and from the big ring at the 24T. I try to remain on the big chainring as much as possible. If there is a big ring option that's the same as the small ring option, then I choose the big ring option. Every time.
The final option I tried is what SRAM calls compensating mode. It compensates for the front derailleur shift by also shifting the rear derailleur. SRAM gives the rider the choice of 1 or 2 sprockets compensation. I chose 1 sprocket and I think it's great. Shift up onto the big ring and the rear derailleur also shifts one down onto the next biggest sprocket. Shift down onto the small ring and the rear derailleur also shifts one up to the next smaller sprocket. It means that the change is not so big. Rarely the big change is welcome, but that only works if you take the bike too far up/down the next gradient change. Shift early and it is too hard or too easy for a minute. Compensating by one sprocket diminishes the size of the change to the better.

I'm not 100% sure I'd use this racing as I do worry about losing the chain in a race (happened so many times with mechanical shifting - I'm paranoid). Since it is my commuting bike, racing is not an issue.

Shimano got to digital shifting first and they have a similar, but even larger, suite of features to delve into in Di2. As I haven't much ride time at all on a Di2 bike, I won't bother to comment as it would be wrong. I seem to recall that Campagnolo EPS also offers some digital features. I mean, why wouldn't you?

Michael Hanslip Coaching

If you want to go faster, you have to pedal harder

Digital shifting modes