Shimano – Bonkers 🤪 A Crazy Move To Limit Di2


Shimano says “Dear Hammerhead Please Stop Using Our Di2

Yes, another day and another company does something crazy or, as some of us in the UK say, “Bonkers“. It’s more to do with running out of commonsense than running out of carbs.

A Very Quick Background Explainer

Hammerhead was a startup bike computer maker that produced two iterations of a bike computer based on Android and called Karoo. Both the Hammerhead and Karoo names remained in use after the former was bought by SRAM in December 2021.

SRAM, of course, have their own electronic groupsets with their eTap system.

Karoo Gen 1 gained Shimano Di2 support and Garmin Varia support way back in October 2019. I think SRAM eTap support was added at about the same time.

Di2 is the Shimano equivalent to ETap for Shimano’s own groupsets. In one sense the physical shifting within Di2 is an independent and closed system that requires all-Shimano parts. But Di2 also communicates with other bike tech in two broad ways, a) it transmits derailleur & battery status information like ‘Gear’ and b) it transmits simple commands from the buttons on the lever hoods to some bike computers that change pages or add laps. Importantly for this story, the Di2 communication is over a PRIVATE ANT+ channel rather than by using a public ANT+ profile.

What’s Just Happened

Shimano has issued a ‘pretty please’ notice. aka “Stop linking to Di2; ideally NOW“. With NOW being defined as June 2nd, 2022.

The update will remove on-screen battery status and shifter mode data, front and rear derailleur indications, and Karoo screen control via the Di2 hood buttons from Shimano Di2 drivetrains.


How Hammerhead Explain This

You won’t have to wear your rose-tinted spectacles for this as they are already built into the announcement which is:

“..all other Karoo 2 functionality will continue to work for Shimano riders, it is this small subset of Di2 features that Shimano has withdrawn permissions for until Hammerhead is able to forge a new agreement.”

And of course, it probably is a small subset of Di2 features. It’s also every single one that Hammerhead-SRAM uses on the Karoo!

As I said. Rose-tinted spectacles.

From Shimano’s Perspective

We want to really encourage riders who have many bikes to exercise choice and to get as many experiences as possible to ultimately discover that our groupsets are the best. We also want you to use our own bike computers rather than Hammerhead’s

I just made that up.

I’ve no idea what Shimano’s perspective is, other than the Di2 Supremo waking up after a little too much Sake and deciding to empty the pram of all the toys in it.

Ultimately Shimano is probably correct as Di2 is a ‘private’ ANT+ system.

From the Consumer Perspective

Let’s take a not too untypical example:

I’ve just spent £7,000 on a Cervelo S5 with Di2. I’m a bit flash and love my Hammerhead bike computer. A lot of that £7k is for Shimano’s groupset and now you’ve really, really, really, just hacked me off. Sure I can afford to buy a different bike computer but, patently I can also afford to move away from Shimano on my next bike in a couple of years’ time. Maybe my other bikes or my partners’ bikes don’t all have Shimano groupsets?

Note: I do have Cervelo bikes but haven’t just spent £7k on one

OK I Get It

I really do get that eTap and Di2 are competing systems.

I get that Shimano wants everyone to use their system (I do!!! I love Di2, Ultegra and Dura Ace)

I do get that SRAM/Hammerhead want to support eTap and Di2.

But this is just freakin’ stupid, right?

In one sense “I don’t care, as I tend to use my Wahoo Bolt“. On other occasions, I’ll just use whatever I use but sometimes that will involve a mild annoyance on my part if Di2 and Hammerhead are both involved.

I suspect a resolution will come and it might, just might, involve a bit of cash in a licencing deal. Surely that licencing treatment will need to be applied to every other bike computer maker? Even Garmin right? Er, no. I doubt it.

The EU Supremos love a bit of anti-competitive behaviour. Let’s see what they make of this one. They need the cash as well. Most of it tends to come from Apple and Google ATM.


Important note: all other Karoo 2 functionality will continue to work for Shimano riders, it is this small subset of Di2 features that Shimano has withdrawn permissions for until Hammerhead is able to forge a new agreement.

Also in the news this week from DCR on Shimano. Another own-goal. 0-2.





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4 thoughts on “Shimano – Bonkers 🤪 A Crazy Move To Limit Di2

  1. > But this is just freakin’ stupid, right?

    Yes. 🦇💩🤪

    It also shines a light that Campagnolo and SRAM are using an open standard and Shimano is using a proprietary one and they are willing to promote an integration and then yank it back. Maybe they think they are punishing SRAM but really they are punishing anyone that bought a Karoo and has Di2. Those are high-end consumers who are going to be pissed off.

    1. yes. maybe it’s about getting some revenue – tho not that much i wouldn’t have thought, maybe its about finding out how many karoo units have sold in case they have ambitions themselves?

  2. Shimano bought Panasonic or something, I think. Maybe they think they can force people to use a Shimano head unit but I don’t think so. Garmin is probably the beneficiary. It’s cheaper and easier to buy a Garmin Edge than change your group set to SRAM or Campagnolo.

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