DKMcK 

Yes, What Merlin said.

BNB

that makes sense ...

pdlpsher

Indeed. So to be able to use a 11-40 cassette it seems the WiFli cage is still too short to provided the needed chain wrap capacity for the 11/40 and 34/50 combo. Although cross-chaining is not desirable I'm more concerned about making a mistake in cross-chaining (I've done it before) and damaging the derailleur. It appears the House of Tandem modified derailleur has even a longer cage than the WiFli, which would make sense for a fool-proof solution.

merlinextraligh

IMHO, you can push the wrap capacity of a derailleur, if, and its a big if, you size the chain for the large/large combination.

This will make the chain too long for the small/small, and things sloppy on the small chainring and the smaller cogs.

But you can avoid getting in those combos, and nothing catastrophic happens if you inadvertently shift into the small/small.

Size too short, and inadvertently go large/large bad stuff can happen as you now.

BNB

Just do it! I gotta say this after 3 years of crappy shifting on the tandem (not to blame shimano!) and less than stellar on my single bikes. This is so easy to install (at least the second time around it will be).

We converted to an electric car years ago and now can hardly think about driving an ice vehicle. I feel the same about this shifting; now I want to convert all my bikes!

JiMaggie

Hi BNB, I found this thread today and would *love* to get more info from you on converting to etap. Our bike has never shifted well, and we looked into etap last summer but after much research came to the conclusion that there was no way to get a compact crank. This looks like the answer.

BNB

I will write up what I did and post it; at least as I remember it.

Also, we will be at the cape memorial weekend with our tandem and would be willing to meet up with you if you want to take a look.

JiMaggie

That would be great!! I can't send you a private message yet because I'm a "Newbie" but if you can send me one I will give you my contact info.

BNB

FYI:
Understand that I am not a professional bike mechanic; my terminology might not be fully correct and what I did with my bike might not work for yours. I started with Shimano 105 shifters/derailleurs and a FSA Gossamer triple crankset. I am writing a step-by-step process even when it seems obvious.

I started by watching the Sram installation video for their regular (short) cage Etap system. Make sure to watch the separate Wifli video as well. I recommend downloading the installation instruction manual from the Sram website (which should be easier to find than it is imo).

I charged the batteries and paired the Etap shifters and derailleurs as spelled out in the Sram instructions.

I ordered a 34-tooth, 74 bolt-circle-diameter (bcd) chainring and slightly shorter (modified) chainring bolts from House of Tandem in Texas. Peter White in New Hampshire also carries the chainring, I believe.

I converted the original triple chainring to a double. I removed the 3 chainrings and positioned the 52-tooth chainring to the inside of the spider where the middle ring used to be. I used the shortened bolts to fasten the 52 chainring. I installed the 34-tooth chainring where the smallest chainring used to be (in my case it was a 30-tooth ring). I found I had to move the crank spacers so that there was one spacer on each side of the bottom bracket. I originally had both spacers on one side.

I installed the new shifters and adjusted the reach for my smaller hands.

I had to buy a braze-on adaptor clamp to mount the front derailleur to the frame.

I mounted the rear derailleur and promptly freaked out when the derailleur, without the chain, hit my rear wheel spokes - even after micro-adjusting the derailleur fully outboard. That is why it is important to follow the instructions for Wifli which states that the chain must be ON the drive train when adjusting the rear derailleur.

I removed the original 10-speed cassette and spacer and installed a Shimano Ultegra 11-speed 11-28 cassette; I recently replaced that with a shimano 11-32 cassette which required an additional full link longer chain.

With the chain on I was able to follow the directions to adjust the derailleurs for the 11-28 cassette; the alignment was not perfect but worked well. When I installed the 11-32 I found I needed to get the exact alignment of the derailleur pulley under the largest cog. I could not, because my derailleur hanger was not correctly aligned. Aligning the derailleur hanger is one of the first steps in this installation but I did not have the tool so I didn't do it. It is definitely worth checking to avoid wasted time trying to make an impossible adjustment with a misaligned derailleur hanger.

The shifting works great. The derailleur is fully extended(?) when it is cross-chained (big chain ring with biggest cog) and I am not comfortable with that. A solution, if one is needed, TBD.

JiMaggie

Thank you so much for writing up your process - that is really a big help. I got your private message, but the system won't even let me reply to it until I've made ten posts. So, let's see, this is two .... In the meantime, I'm checking in with my local tandem group to see if there is somebody else already in this forum who can message you on my behalf!

BNB

I don't understand the reason for the forum policy and I remember having the same issue wanting to contact a member. We can be reached via wbethan1 with the typical yahoo email address.

Road Fan

I think it's based on trying to make this be a Forum (group discussion) rather than a place just to locate expertise.

Paul J

Not to take this off topic but... when I first started on the Forum I went to to general section and welcomed some of the new people joining and quickly got my posts up to the required number.

JiMaggie

Thanks, Paul - that did not occur to me!

Paul J

You bet, here is the section Introductions - Bike Forums

colotandem

Speaking as someone else with experience using the Sram etap on a tandem, I too had that "freak out" moment when my deraileur was hitting the spokes without the chain installed!

That was not fun.

We are not using the the new Wifli etap, but instead an last year's etap that came with a normal cage that we had modified to a long cage via House of Tandems. Also using the Wolftooth roadlink.

Our set up is 52/36 with 11/36 cassette. It shifts flawlessly. LOVE IT!!!

rlp

If the derailuer hits the the spokes without the chain installed does that mean that it will immediately hit the spokes at speed if you break the chain? I have only broken one chain in almost 10K miles but it could if catastrophic if that is the case.

BNB

That is a very good question and a concern of ours. I was also worried that simply dropping the chain off the chainring would be an issue - but I can attest that dropping the chain isn't a problem. Tested a few times.

A broken chain. Yikes. But I'm willing to take the chance for fantastic shifting. I've got it in my calendar to measure the chain every 3 months and replace when needed.

bobother

I just installed this Etap standard cage on a 2016 BMC SLR01. I have a 50-34 in the front and 11-30 in the rear. It seems to work well except for 1 issue. It doesn't shift from my smallest cog to the next cog. However, it will go to the third cog on the next shift. All other shifts are fine. I've tried micro adjusting but didn't have with good results. Coming down from large cogs to small cogs is no problem, just going up on that one cog. It drives me nuts, but fortunately it's a cog I rarely use. Anyone else with this problem? I have Dura Ace 9070 also on a Cannondale Synapse. I think the DA drive train is bit quieter.

Artmo 

We've just returned form the Georgia Tandem Rally in Valdosta, GA, where House of Tandems had an eTap WiFli demo set up on a stand. The cassette was 11-40 and chainrings 53-34 and it behaved flawlessly. They installed an extended rear derailleur cage and simple modifications to the triple chainset to be able to use a double without having to change the cranks. Seriously thinking of putting this on our Macchiato.

NYC_Cyclist

Hi,

Slightly off topic because I am not doing this for a tandem but rather a single person custom built steel frame road bike. The frame is in the process of being built with qr disc wheels and a bit longer than normal dropout.

I have read everything I can about using sram etap wifli with a 11-40 cassette and 50/34, along with a Roadlink.

Can anyone here confirm that it will work without issues? Or does this only work with the House of Tandem modifications to the rear derailleur cage?

How bad is the chain wrap and sag in the 50-40 or 11-34? Anything else to worry about?

I live in a hilly part of CA now and would really love to make this happen.

BNB

I just modified our tandem drivetrain with the roadlink and an 11-36 cassette (the 18%+ hills in the white mountains, NH were brutal with the 32 and our home street is 18% in parts). I originally modified our triple to a double 52-34. This configuration is out of spec with the roadlink as they spec no greater than 14 teeth difference in chainrings. You can read the spec on the wolftooth website for your configuration.

The chain I had with the 32 tooth cog was too long with drooping in the 34 chainring and the 11,12 cogs on the rear. I shortened the chain by one link and the chain works OK with the 34 / 11&12. BUT it is too short for cross-chained big chainring and 36 cog. NOT a good situation. Since we are not riding fast club rides here I think we will be OK since we rarely use the big chain ring anyway preferring to coast down the steep declines right into another big incline, typically. Still, I will look into a 48 tooth chainring ...

bogriver

Hello,

I am currently running this setup on our Tandem, Sram Etap Wifli Roadlink with 52/34 and 11-40 cassette, and it works/shifts great! I have the chain wrap set-up for the 52-40 combo as that's the combo to most likely be used and would do the most damage if chain wrap were not correct. With the 34-11 combo the last three smallest cogs are really not usable. But you really shouldn't be there anyway, but if it does occur, no major harm will be done. Your 50-34 combo should help even more.

As a side note, the Etap Wifli derailleur is significantly different from the standard Etap short cage derailleur. Not only is the cage longer, but the geometry is different, from the mounting point on the hanger to the location of the upper jockey wheel! Sram has recently published this info.

Also, newer Garmin Head units allow for ANT communication to the rear derailleur for gear position info, showing both front and rear gear positions making it easy to avoid cross chain situations. Works great!

BNB

That is what I found and "not usable" as in the chain droops badly which is far from ideal. I didn't want to find out what kind of trouble this might cause though it won't rip off the expensive wifli derailleur, I suppose, but not sure. A chain slapping onto the frame and all over the place can't be good either.

geoffs

Has anyone tried the SRAM eTap levers with TRP Spyre brakes? We're using Ultegra levers with the Spyre brakes and are really happy with how they are working. I managed to squeeze in a Hope V2 disc and would like to keep this setup. After seeing another riders hydraulic brakes spring a leak on a recent tour mechanical seems reliable.
We're touring in Germany at the moment and I'm thinking about buying the eTap kit for the tandem while we're here.