# Di2 in the dirt



## PMK (Oct 12, 2004)

Grabbed this from BikeForums.net.

http://www.bikeforums.net/showthread.php/723019-Di2-amp-Compact-Crank-amp-11-36-Anyone-tried-it-yet

Seems the high end road group is seeing an aftermarket surge to make it off road worthy.

Not saying good or bad, but the more wealthy or brilliant road tandem crews seem to like the idea of electric shifting.

Too rich for my blood, either dirty or paved. For us in flatland Florida, this is in the $5 per shift range.

PK


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## clj2289 (Jan 2, 2010)

The fact that your bike would require a battery pack kinda seems to take the point out of riding a human powered vehicle in the first place...but maybe that's just me...


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## rkj__ (Feb 29, 2004)

I think Di2 makes a ton of sense on a tandem. I find trying to tune the shifting very difficult with the cable and housing lengths required on a tandem. 

Apparently, the batteries last a really long time, and the shifting is excellent.


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## Blaster1200 (Feb 20, 2004)

rkj__ said:


> I think Di2 makes a ton of sense on a tandem. I find trying to tune the shifting very difficult with the cable and housing lengths required on a tandem.
> 
> Apparently, the batteries last a really long time, and the shifting is excellent.


I'm not sure what cables and derailleurs you're using, but I just built up my tandem with 970 XTR shifters and derailleurs with Jagwire Slick Shift cables and Shimano SP-41 housing, and this bike shifts amazingly well. Shifts just as good as any of my "normal" bikes. I don't credit the XTR stuff to the performance but the cables and housing instead. BTW, I only used XTR stuff, since it was left over from an XC build that didn't happen.

But I've heard the same about the batteries lasting a really long time. Even still, I'd be tempted to charge it before every ride.


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## rkj__ (Feb 29, 2004)

Blaster1200 said:


> I'm not sure what cables and derailleurs you're using, but I just built up my tandem with 970 XTR shifters and derailleurs with Jagwire Slick Shift cables and Shimano SP-41 housing, and this bike shifts amazingly well. Shifts just as good as any of my "normal" bikes. I don't credit the XTR stuff to the performance but the cables and housing instead. BTW, I only used XTR stuff, since it was left over from an XC build that didn't happen.
> 
> But I've heard the same about the batteries lasting a really long time. Even still, I'd be tempted to charge it before every ride.


My limited experiences were with Tiagra and Alivio level stuff on stock builds from KHS and Norco.


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## Okayfine (Sep 7, 2010)

KHS in particular liked to mix MTB and road shifting components. Been there, done that. We started on a KHS Tandemania and that bike never shifted well.

Have since learned enough to do my own maintenance and have had great shifting on our Ventana with SRAM parts - even with cable splitters.

Di2 is/was also heavier than the comparable DA group, not to mention more expensive.


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## zibell (Apr 13, 2007)

I'm not sure yet about Di2 on a tandem. I think it may be a great idea for a xc racer (2 x 10) half bike, but we seem to have good luck with cable shifting. I'm not sure about the 10 speed shifting needed with the Di2 on a tandem. We are riding a compact crank 20t and (12-36) 9 speed cassette something that wouldn't be available with a 10 speed set-up. I'll wait and see what shakes out of this.


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## PMK (Oct 12, 2004)

zibell said:


> I'm not sure yet about Di2 on a tandem. I think it may be a great idea for a xc racer (2 x 10) half bike, but we seem to have good luck with cable shifting. I'm not sure about the 10 speed shifting needed with the Di2 on a tandem. We are riding a compact crank 20t and (12-36) 9 speed cassette something that wouldn't be available with a 10 speed set-up. I'll wait and see what shakes out of this.


The sounds from the road tandem camp are saying big gear cassettes and hybrid derailleurs to get the shift. The photos show a pretty simple upshift / downshift switch module.

PK


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## TandemNut (Mar 12, 2004)

I'm all for technological advances in components for bikes. Things like disc brakes and decent suspension have made our tandems so much easier and safer to ride. Improvements in cassette cog design and chainring design have improved gearing options and shifting immensely. 
However, I'm not sure I see the point in this electronic shifting thing, other than Shimano's continued attempts to make everything else obsolete, non-interchangeable, and therefore disposable. Maybe I'm a retrogrouch in my middle-ish age, but this sort of seems like a solution in search of a problem. We have set many a tandem up over the years, and shifting hasn't ever been much of an issue, that I know of. 
A true leap in bicycle technology would be an internally geared wide range hub that had no more resistance than a chain drive, and that didn't cost as much as some complete bikes. Add a switchable generator to that for night riding, and you may have something useful.


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