Steve B.

Whats a bottom bracket cover ?, never heard of that.

Are you saying the rear derailer was not connected to the e-tube cable ?, or that the cable seemed too short ?. If you are lucky they put the B Junction in the seat tube and you might have access to add a longer cable ?. This is really an issue the shop should fix.

SoSmellyAir

Sorry, that was not a good description. Both my other CF bikes have an opening near or under the bottom bracket shell that is accessible to help run cables and hoses through the frame, so does this new Synapse. But unlike the other two bikes, it does not have a cover to cover this opening!

The RD is connected to a Di2 wire but that wire is not long enough to plug into the Di2 battery. 12-speed Di2 bikes do not generally come from the factory with a junction. So I just need to replace that the RD Di2 wire with a longer one. It is the shop's issue, but I ordered this bike online from across the country.

Steve B.

Understand. My Specialized Chisel and my Cannondale Topstone both have openings under the b-bracket as you have described with no covers and as far as I can tell have never needed them. I also avoid riding in wet so it’s not been a problem.

I would be screaming at the dealer to be sending you free a new R derailer, 400mm or whatever cable.

Iride01 

Probably just need to pull the RD wire out of the frame more. However make certain it's not kinked or looped around something inside the frame first.

You had this sent straight to you in the box to put together? Or did the LBS build it out.

Steve B.

As follow up, with a battery, a front derailer and a rear derailer, how does the single cable off the battery connect to both derailers if it doesn’t use a B Junction box ?. I have 11 spd. so use the B Junction. How did they do it differently on 12 spd. Asking as I’m about to buy a bike with Di2 12.

SoSmellyAir

No need to scream. I spoke to the dealer this morning and he told me to go buy the appropriate length Di2 wire, and he will reimburse me.

With the bike inverted, I gently pulled the free end of the Di2 wire out of the bottom bracket, leaving its other end inserted into the RD. The thus exposed length of the Di2 wire is at least 3 inches shorter than the seat tube of the bike. I guess the bike was assembled by (1) inserting the Di2 wire into the battery, (2) inserting the battery into the seat post, (3) inserting the seat post into the seat tube, (4) routing the Di2 wire through the right chain stay, and (5) inserting the Di2 wire into the RD. Thus, when the seat post was removed to partially disassemble the bike for shipment to me, the Di2 wire got pulled out of the battery.

Just a partial disassembly by removing the front wheel and the seat post, and the handlebar from the stem.

The 12-speed Di2 battery (BT-DN300) has 3 ports, so I think it acts as a junction, to which both derailleurs connect. But this is my first Di2 bike so you best learn from: Independent Shimano Di2 help, tips, guides and tutorials - BetterShifting

PeteHski

I know it’s not the end of the world, but Shimano really should go fully wireless to avoid all these niggles. Getting rid of cables and internal routing should be one of the big advantages of electronic shifting.

SoSmellyAir

But then one would need two batteries, one per derailleur, for a 2x drivetrain.

PeteHski

That’s what SRAM do and it also provides redundancy in the unlikely event of a failure.

Iride01 

I also like the idea of one battery to charge instead of multiple batteries to charge. Though by the time I decide to get a new bike, I might not have that choice if I want the latest and greatest of that time. So I won't bemoan it that much and just get what's available then. Whether it's 1, 2, 3 or 50 batteries!

Two batteries and there is twice the chance that I'll ride with one of them not able to do what ever it's supposed to to.

Or am I understanding you to say, PeteHski , that SRAM can work all the components from one battery when one of the batteries is dead? I didn't think they were connected.

SoSmellyAir

That's true. But two externally mounted batteries are more susceptible to an issue with at least one of them compared to a single internally installed battery.

Exactly.

On my last group ride one woman had forgotten to charge her Di2 so she only had enough juice to shift the RD and was stuck on the small ring for the last half of the tide.

No, I think SRAM AXS is completely wireless, so there is not a wired connection between drivetrain components such that one battery can power the other derailleur.

Steve B.

We had a saying way back in the entertainment business that a $1000 mike with a wire was better than a $50,000 wireless mike. In essence, wired component are generally more reliable and I think Shimano understands this,

SoSmellyAir

Unless whoever was using the mic trips over the wire.

PeteHski

Each mech has its own small battery, but you can swap them quickly. So say the rear mech battery fails you can swap over the front mech battery so that you can at least keep the rear mech working. Or you can carry a spare battery as they are pretty small.

PeteHski

I don’t think that’s really comparable. I just don’t like the Shimano wired setup. At least it’s now semi-wireless but still not ideal. A fully wireless solution just eliminates any faffing with wires and makes battery replacement a 5 second task.

Sierra_rider

So far I'm actually liking the semi-wireless of my Ultegra di2 over the AXS on my XC bike. The Sram works fine, but I've found battery life to be slightly annoying on the XC bike...enough that I ride/race with a spare, especially on long rides. It might just be that I'm shifting that much more on the MTB, so maybe not an issue on your Etap? I haven't had the di2 long, but the battery life seems insanely long.

It's not exactly the same analogy with Shimano IMO. I prefer the Shimano set up, but the shifters are still wireless, the wires are essentially to allow for a large capacity battery for the derailleurs. I've had extensive use on my wireless Sram XC bike this season, it's been very reliable across some very inclimate conditions.

PeteHski

No I haven’t had any issues with AXS battery life on my road bike. I always fully charge before a big ride, but otherwise they usually last for a few weeks between charges. My mountain bike still has mechanical shift so no experience there.

Shadco 

It is much harder for someone to swap their depleted battery for your fully charged one at an event when you are using the loo.

.

SoSmellyAir

I suppose one can easily remove both batteries and stuff them in one's jersey pockets when using the facilities?

Iride01 

No one want's your batteries. Most won't know how to get them much less that they are even there.

SoSmellyAir

Happy to report that the SmartSense battery cradle was quite simple to remove with reference to page 24 of the SmartSense manual: 022_rev2-_smartsense-oms_138691__en.ashx (cannondale.com)

Except that the bolts holding the battery cradle are not M4 as specified in the manual. On mine they are M2.5.

My bike was shipped to me without the front light installed and I am not using the included seat post or seat, so no need to deal with lights or radar for now.