Electronic shifting

[Dozer]

The internet was abuzz all weekend with Shimano's XTR Di2 electronic shifting system for mountain biking becoming more of a reality. It has some bloody great features:
-Imagine running a cable through the entire frame, the bars, the stem and not have to worry about it being at an angle to hinder the shifting.
-It can be set so the guys running one or two chainrings can have the front drop to the lower ring / rings depending on what gear you grab on your cassette. Of course this can be customised and can be set to run manually. My understanding is it can also control the front and rear deraileurs on one shifter!
-The system battery can be stored on the bottle cage bolts, slipped inside a seatpost or just cable tied to anywhere where it integrates with the cabling of the system. Here's hoping it can go in a steerer and have a charging port made for easy access.
-The HUD can be placed on the bars, the stem or wherever you want it to be, that should reduce some clutter on your bars.
-It will likely have integration with Fox technology so you can change the fork and shock settings (ie CTD) and it will show on the HUD. That's tops!
-Word on the street is it may even have potential to be a GPS and could run maps etc on a big enough display.

I love the idea. Yeah, it'll be dear but it's more suited to the needs of mountain biking rather than road cycling. If frame manufacturers go with frames specifically designed to run Di2 then it may create some pretty fancy chances to change some traditional suspension travel lines. It may also make the design of a mountain bike frame entirely different to what we know.
My thoughts? I reckon other companies will be rushing prototypes to get in the market as this thing will and should take off. Two things bother me though; what the flipping hell would the system do if the battery expired and the cable tension was non existent? You'd be in the gear it went flat in? Surely a manual system will be implemented, thus making the entire system nothing more than a run of the mill current day shifting system? Why would we go for an electronic system when we still have rear deraileurs getting torn off and bent and making the whole show go arse up? Why not make gearbox technology before this system?

 

[Ivan]

I don't buy that their will be frame changes due to a lack of cables. Frame designers don't give a fig about cables now. The front dérailleur is the biggest hindrance to frame design.

My carefactor dial barely moved at the announcement of XTR DI2. It'll move when there's a lightweight, high efficiency gearbox.

SRAM have had a wireless proto in the works for a while.

 

[cleeshoy]

Yes it was certainly some big news this weekend, and with Absalon winning in Germany it got a good start!

I like the idea of shifting automatically between the small and big ring at the front. Of course if you only have a single front chainring it's not a huge deal. The front derailleur just shits me.

The quietness of the electronic shifting (well it is on the road) is cool.

Of course if the battery runs out, you are stuck in the one gear until the battery is replaced/recharged.

I still prefer the XX1 concept over electronic shifting.

 

[Zam]

Havent looked into it as my carefactor is pretty low about the elec shifting, but what is the weight of the system compared to a normal cable setup?

 

[Puddleduck]

I was interested from the point of view that it was some new-ish tech/gear. It does all sound rather cool. It will be intersting to see if frame manufacturers do embrace the Di2 system and as well as the broader MTB community. However, I too am looking forward to the day that we loose that dangly bit of metal from the back wheel and gearboxes become a standard. Gearboxes going mainstream will be the major and most significant game changer from my POV.

 

[Nautonier]

I still prefer the XX1 concept over electronic shifting.

+1, it's been the biggest game changer so far. The idea of the auto shifting between front rings is very cool, but having multiple front rings (complete with the loud rattle and chain drops) is not. The next real game changer could be an internal gearbox that offered a wider range of gears than XX1.

 

[cramhobart]

I've always had the impression that there is an efficiency issue(due to friction?) with gearboxes that stops them competeing with traditional drive trains. I've always wondered how efficient an electronic drivetrain would be- generator at cranks driving a motor at the rear hub- which opens the possibility for 2 wheel drive. I remember an episode of top gear with a diesel/electic hybrid which had a electronic driveline that was more efficient than any mechanical driveline available- surely this is the future? I was suprised hammerschmidt didn't gain much greater acceptance given that it solves a lot of the front deraileur "problems" without the range compromise. Given the lack of market penetration by rolhoff I'm not suprised the big players have continued with chains.

 

[thecat]

Only comes in Xpensive To Replace.

would rather an internal gear box over something that is hanging down just waiting for a rock or stick to rip another hole in my wallet

 

[SlowManiac]

I think its awesome, love the auto shifting on the front.

When it comes in XT I'll be rocking it! Wallet permitting.

 

[Art Vanderlay]

How can we buy it if we don't know how much it is?

 

[Dozer]

I wonder if it could have system put on it that charges the battery as you ride, similar to the kinetic energy recovery on some cars. The friction created between the contact of the brake pads on the rotor is stored as energy and then provides power.

 

[valium]

I like it, and in about 4 years when it's a decent price it'll be on my bike.

Things I like:
1. Wireless.
2. Smaller shifter pod that will probably be merged with the dropper remote (also wireless)
3. Smaller and lighter - there will be a shifter that is sans display, and give me a weekend warrior battery - the draw on this thing must be minuscule a single CR2032 for the shifter and mech should cover it.

Why do I want wireless? primarily for vanity, but also so I have use my smartphone to hack my buddies ride while he's heading downhill for funsies


Also, I'm all for gear boxes, but cannot see them ending up at a reasonable cost.

 

[madstace]

I don't buy that their will be frame changes due to a lack of cables.

+1 on this. I think the front derailleur and chain growth play a bigger part in FS frame design. And while the auto front shift feature seems pretty cool, I can't help but think they've left their run to save the front derailleur a bit late, given the popularity of 1 by drivetrains.

I still think the next revolution (this isn't) will be internal gearboxes, even though bikes like the Zerode and the Nicholai using the Pinion already exist. This is what will open up frame design, as I'd already consider the Zerode to be revolutionary. Bring on the 650b AM version, or do we want the Enduro version first? :dance:

 

[Nautonier]

I wonder if it could have system put on it that charges the battery as you ride, similar to the kinetic energy recovery on some cars. The friction created between the contact of the brake pads on the rotor is stored as energy and then provides power.

The hipsters will be chucking on an old school dynamo to charge them up. When you bike in tight black jeans, you don't care about friction.

 

[Jeffgre_6163]

How can we buy it if we don't know how much it is?

If you have to ask how much it costs you cant afford it!

Multiple thousands [my guess $2.5k] for the full 3 ring set up with all the whistles and bells?

 

[Nautonier]

If you have to ask how much it costs you cant afford it!

Multiple thousands [my guess $2.5k] for the full 3 ring set up with all the whistles and bells?

If it was 1.5k for the single ring setup that's only a fraction more than XX1, thus very doable for a lot of people. 2.5k would take it to another level.

I would happily pay less to not have the stupid little display thingy...

 

[ozdavo]

Quote i saw on cost was something along the lines of... similar difference in cost to mechanical XTR as Dura ace Di2 is to mechaincal... which was reported as around 40%, so expect around 40% more expensive than XTR mechanical.

 

[mitchy_]

How can we buy it if we don't know how much it is?

If it was 1.5k for the single ring setup that's only a fraction more than XX1, thus very doable for a lot of people. 2.5k would take it to another level.

I would happily pay less to not have the stupid little display thingy...

If you have to ask how much it costs you cant afford it!

Multiple thousands [my guess $2.5k] for the full 3 ring set up with all the whistles and bells?

reports are the rear derailleur is 450 pounds, and shifters are 150 pounds a pop. almost $1k for a derailleur is scary, enjoy breaking that one.

 

[crank1979]

Di2 is awesome on the road. That said, I can't see me ever putting it on an mtb. Ripping derailleurs off is why I bought a Nicolai and it is by far my favourite mtb to ride.

I find it interesting that so many people want an internal gearbox bike. They are definitely the way forward for mtb gear systems. A lighter, electronically operated Pinion style gearbox would be the ultimate gearing system I think.

 

[g-fish]

My thoughts? I reckon other companies will be rushing prototypes to get in the market as this thing will and should take off. Two things bother me though; what the flipping hell would the system do if the battery expired and the cable tension was non existent? You'd be in the gear it went flat in? Surely a manual system will be implemented, thus making the entire system nothing more than a run of the mill current day shifting system? Why would we go for an electronic system when we still have rear deraileurs getting torn off and bent and making the whole show go arse up? Why not make gearbox technology before this system?

There is no return spring in the derailleurs. So "cable tension" doesn't have an impact on holding the derailleur in place, instead the electric motor runs the derailleur in both directions. On Dura-Ace and Ultegra Di2 when the battery gets very low (5%?) the system will lock out the front derailleur (which eats more battery life than the rear) and only allows you to shift the rear. When the battery dies you can set a single speed limp home gear in the computer diagnostic system that the derailleur shifts into just before it dies. You can still change manually using limit screws.. but if you're the type you can't manage to charge your battery once every three months Di2 probably isn't for you..

I wonder if it could have system put on it that charges the battery as you ride, similar to the kinetic energy recovery on some cars. The friction created between the contact of the brake pads on the rotor is stored as energy and then provides power.

There's a hack floating around using a Son28 dynamo hub trickle charging an Alfine Di2 system. Dynamo hubs are getting pretty fucking good (son28, Exposure, even the Shimano XT hub) but naysayers will always complain about the drag they have.. It'll get there eventually. Magura and Tektro both have regenerative braking systems for electric bikes. Check it out on this bike. But I don't think the extra weight of these systems give a big enough benefit considering how infrequently it needs charging.

+1, it's been the biggest game changer so far. The idea of the auto shifting between front rings is very cool, but having multiple front rings (complete with the loud rattle and chain drops) is not. The next real game changer could be an internal gearbox that offered a wider range of gears than XX1.

One of the best parts of the road set up is an auto trimming front derailleur that hugs the chain without rubbing. That combined with the new chainring design and Shadow+ derailleur, I doubt there will be any chain drops. The chain pick up on the front derailleur is almost instant.

If you have to ask how much it costs you cant afford it!

Multiple thousands [my guess $2.5k] for the full 3 ring set up with all the whistles and bells?

If the road stuff is anything to go by.. I reckon $800-1000 for a rear derailleur. Cabling, junction box, charger and battery will ad $400-500 alone. It'll push over $3000..

I'm a massive fan of Di2. I came very close to building a modified Ultegra di2 setup for my mtb earlier in the year. But no clutch derailleur ended up putting me off. I haven't broken a derailleur mtbing in four years.. but I'm still not prepared to fork out the money and take that risk. Anyone who has ridden it on the road will know how awesome it is. The ability to get bullet accurate shifts no matter how muddy it is or how much power you're putting down is huge plus for mtbing... And not something that roadies could benefit from as much. Next step is for integration throughout the bike.. Magura and Fox are both doing electronic suspension. KS and Fox both have electronic seatposts in the works. I'm keen to see what other electric goodies come out.

Agree on a pinion-style electric gearbox with a gates drive being the way forwards though.. The only issue being gearboxes might hinder some frame designs. Though centralised weight is a big plus.