Shimano 105 Di2: Delivers 12-Speed Shifting, Wireless Performance to More Riders | Hacker News Reader

Shimano 105 Di2: Delivers 12-Speed Shifting, Wireless Performance to More Riders

bike.shimano.com

32 pointstosh36 comments

The aggressively closed & closed-minded behavior of Shimano, their active legal pursuit of anyone else using the abundant data here, turndd me off incredible from the company. One example: forcing Hammerhead Karoo to remove support.

https://www.dcrainmaker.com/2022/05/shimano-forces-hammerhea... https://news.ycombinator.com/item?id=31604152 (257 points, 2mo ago, 333 comments)

Bikes are such a pure & free thing. Im also a computer lover, but computers are so easy to misuse for control & constraint, to obstruct involvement. It's so sad to see bicycles- a symbol of freedom & personal choice, one where standard(-ish) parts has long been a thing- fall sway to the darker corporatistic evils computing alas so often can encumber the planet with. Di2 is a defiler of spirit.

Hammerhead got bought by SRAM, which is the primary competitor of Shimano. It made sense for Shimano to remove support.

>It made sense for Shimano to remove support

But, they didn't remove support. They demanded a 3rd party who had reversed their protocol remove support. They actually put legal work in to put an end to someone else's technical work.

A reasonable response would be to say "use at your own risk" and refuse to put any resources to supporting the 3rd party.

Thanks! Good job calibrating. Yup!

As a customer of both, it really didn't.

I like innovation and this certainly is clever. But do I really need it? I agree that it can be hard to shift cleanly but after I wiggle the levers a bit it all works out.

You never need to recalibrate your rear mech. Ever. This to me is the best part of di2. You also never need to replace dirty/old cables.

Di2 is amazing. If you do > 500km riding a year it's a worthwhile upgrade IMO.

>If you do > 500km riding a year it's a worthwhile upgrade IMO.

Did you miss a zero? I do 500km a year, taking my kids to nursery on my beat-up old MTB.

Probably. I did more than 20Mm (20k km) so far on my mechanical 105 in 2 years and had to replace a single rear shifter cable in between. Mechanical transmissions are not exactly high maintainance either, and maintaince is fairly trivial. Probably would have spent more time charging batteries in 2 years with DI2 than with cable fixes and adjustments on mechanical. But I'm still somewhat intrigued to try it.

I love biking because it makes me independent. Adding electronic complexity and the need to charge is the antithesis of why I own bikes.

I might have to change the cable once in a while, but I don't ever have to upgrade the firmware.

Is there Di2 for MTBs? I'd like to get a new bike this year, but they all seem to be SRAM.

The battery need to be replaced at which interval?

road bike innovation is rarely needed, it's mostly a step of incremental small improvements that add up to a large quality of life difference.

it's much more pleasant to ride a new age ergo-centric composite bike than it is to ride a Gios from the 70s, for a variety of reasons.

source : family bike shop; I don't ride myself.

These are justified when looking at the truly elite level. You’re looking for fractional improvements that might add up to a watt or two. Aero frames, internal cables, spandex, are all about things that will make a marginal difference at an elite level.

Disc brakes have been a bit of an outlier with extra weight and safety issues brought up by riders. Though it’s easier to internally route cables, and you can stop quicker and more predictably. Maybe the aerodynamic issues of the cables are big enough to switch for the elite riders.

Disc brakes are a must-have for me on a bike now. They add a tiny bit of weight, but the performance difference much more than makes up for it. They stop faster, but they're also much easier to modulate, and their performance doesn't change when it's raining, so for real-world riding (I frequently get caught in the rain where I live, and I ride my normal bike for commuting and shopping) it's a huge safety improvement. There's no way I'm going back to rim brakes.

In the future, I expect to see some improvements with disc brake hose routing. They're hydraulic, so they don't actually need to be straight like mechanical cables, so this would enable a lot of changes that can't be done with old-style cables, much like electronic shifting allows changes because it uses electric wires or even wireless comms.

As an amateur cyclist, I can tell you that this is false. Make a climbing with a 15 years old bike and a modern bike and you will feel the difference, even if you are not a professional rider.

It's a matter of better fluency, less frictions and better power transmission.

If you have to ask, you don't need it.

If you ride 1k+ miles a year and care about performance, maintenance, etc. then it's _absolutely fantastic_

It feels really nice though. They are always exact and all you do is press a button, no lever action needed.

> £1,730 / $1,890 / €1,869

At that price point you can convert bike to electric assist and have same effect - easier peddling.

Adding electronics to a bicycle shifter seems like an incredibly bad idea. Just because you can doesn’t mean you should.

I have the wired Di2 2x11 GRX Gravel Groupset... and it is awesome. It _snaps_ into the next gear, every single time, reliably. If you want to jump someone, having a .5s faster shift time allows you to create a gap and hold it.

My girlfriend has the top of the like mechanical GRX equivalent, and while it's also a faster shifter, the Di2 is just a bit faster. Both are equally reliable, but hers will ultimately require more maintenance (cable tension, replacement parts) and is more sensitive to a bent hanger.

The Di2 nterface is dead simple: A single cable CAN bus for data. This also carries power for all the attached parts to the bus. The other benefit I love is sequential shifting. The onboard computer moves the front ring for me automatically and downshifts the back when I hit the threshold point. This ensures optimal power transfer by avoiding oblique angles with the chainline.

All in all, it was a great investment and I very much like it.

I wanted to know if with this system you are able to shift when you are transmitting power, or you also need to prepare your gears before the climb like a mechanical one?

CAN bus is 2 wires and seems an overkill, a LIN bus (single wire) with power seems more suitable.

Right now this is a function of cassettte/chain design rather than derailleurs; not sure electronic shifting could do anything to improve that situation.

Modern Shimano drivetrains with Hyperglide can be shifted under "quite a bit" of torque, but I wouldn't say a 1x12 can be shifted under "full gas". I've yet to break a chain on my 2x11 GRX even at full stupid. My 2x11 even survived Unbound Gravel this gear with the _absolutely_ mudfest of riding conditions in the second half of the 100mi race. I have broke a chain on my 1x12 under full gas though; is an XT Cassette, XT Chain, and XTR derailleur and a plain-ol mechanical shift cable system.

All that being said, you absolutely should prep your gears at the same time you're prepping your body position. GRX/XTR and to a lesser extent Di2 allow you to delay this to the last second.

Di2 uses a "barrel connector" so the thing appears like one wire to the consumer. This also allows DC power to be transmitted over the single wire. On a bike, you don't have a return path for current.... Never heard of a LIN bus, learn something new every day :)

Still don't want to shift under high power, though shifting while going uphill is actually doable, I quickly got used to going light on the pedals momentarily. Of course it requires already having a decent cadence to quickly ride out the dead spot.

Is this the first time you've heard of it? Because it was initially released in 2009 and is basically standard across the pro peloton.

The brakes aren't electronic, only the gears.

Yes, first time hearing of this.

I'm sorry to say this, but you really couldn't be more wrong here.

Electronic shifting has been a huge milestone in cycling. It's better than traditional cable shifting in almost every way.

It's a tradeoff. The most recent 11 speed mechanical from Shimano is really superb--if you keep it maintained. The electronic stuff stays true if you don't maintain it, but is a pain to set up. And if anything goes wrong, it is an expensive trip to the shop. If you fancy yourself a competent home mechanic, and enjoy working on bikes, it is a step backward. (Though, internal cable routing has taken all the joy out of working on bikes.)

For me, it is about lever feel. The up and down shifts are too close together. I've had this happen before, where I meant to shift down. Didn't work, so I press the button again, it is yet worse. Oh, I shifted the wrong direction, but now it is quite steep and I am quite misgeared. And shifting under load is bad for the system even if a motor drives the mech. Now i make that mistake less often, but I am still generally displeased about Di2. (Why am I on it then? My frame won't accept mechanical shift cables, and SRAM was out of stock. And I really wanted that bike.)

Also, nobody really needs 12 speeds. 1x13, you can almost cover the same range as 2x10 but keep the same ratio between shifts (there are a lot of redundancies in 2x10). And then no more front shifting. 1x14 and you are there. Wake me up when that happens. Yes, Campy Ekar, I know.

1x12 in Mountain Biking is one of the best innovations to happen in the last couple of years. The reason is sequential shifting.... Sequential shifting is a "nice to have" in gravel and road biking... but for MTB is a must.

You need an absurdly larger climbing gear on MTB (51-52 tooth) for climbing and wheelie-ing the front off the ground while on inclines. You need a relatively small gear for some speed on downhills and to load the suspension.

And because the terrain changes rapidly, you need to fly between the combinations quickly and any point on the cassette. Being able to dump a few gears and quickly pull them back in a few seconds later is a trick you can't pull off with a 2x setup. It's a party trick a 1x12 does in practice and still gives you reasonable jumps between gears.

A 1x12 is also a pound or two lighter than a 2x setup. It also is _far_ more reliable... Dropping a chain with a big-little chainring is unheard of and this can be done without a chain guide or bash guard. Losing these two components is another weight savings... You also can't do big-litle chainrings with a 2x setup, because it's nearly impossible to derail the chain.

Finally, and maybe most importantly, a 1x12 free up cockpit space for a dropper lever on the left side or a suspension lockout lever (if you're into that).

I still miss having a big ring for the times I want to ride to the trail. A 39 up front and a 11-12 out back just isn't fast enough for that kind of thing. There are a good many trails where having a big ring makes sense too. The current hot setup is too focused on the lower end of the range and totally gave up the high end.

I recently bought a 105 level road bike with wide tire clearances and stuck the largest gravel tire I could fit on there and use that in place of my MTB for riding the gravel paths around town. It's nice to be going fast again.

MTB manufacturers listen up - make frame clearances support larger than a 39 tooth ring up front. People like me will thank you.

Also - back in the 3 ring / 10 speed days I was riding full XT and chain drops were a similar non-issue then too.

39 up front??? How fast are you going man

Im a Texan and its relatively flat here. We have some undulations and rises but not too many real climbs here. A 39 is the max the average Santa Cruz supports - Im running a mere 36 on my Salsa Timberjack because one more tooth and I got a frame grinder. It's adequate but if you're out on a ride with an equally fit friend with a 39 you just get smoked.

Now knowing that 700c roadie wheels and 29" MTB wheels are the same circumference ... riding a roadie on gravel with a 48 up front and a 11 out back is comparatively fucking fast!!! Im not going to take any "real trails" on the thing but as the gravel path around the lake goes - fitness rides etc - it hauls ass like my old MTBs that had the similar gearing. I really miss it to be honest.

I’m sure it’s a better shifting experience, but I’d never tour with a Di2 shifter.

I was doing a group cycling tour with 3 friends, one of whom had a Di2 GRX shifter. He pinched the Di2 cable in the rear axle when reassembling his bike and shorted the whole system. Needed to replace everything. That ended the trip for him, had to go back into town and get it fixed.

The system might provide a better shifting experience, but from a durability and field-repair standpoint I think mechanical shifting still has the edge.

This is the crux of my uninformed opinion. It sounds like it makes sense for competition but touring and commuting requires reliability.

Have they done a good job at preventing hacking or disruption of the wireless parts of these systems?

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