SRAM eTAP Tuning?

Discuss light weight issues concerning road bikes & parts.
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ProfessorChaos
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by ProfessorChaos

I ordered eTAP it will arrive early next week. I did a search to see if any WW have been tuning the stuff yet, and to my dismay I found nothing. I'm installing it on a S-Works Venge ViAS in hopes it will be lighter than SRAM Red22 Mech with the absence of shift cables, and housing. I estimate it will be really close. So have any of you done any tuning to your eTAP?

I have an idea of running a cable between the two derailleurs tapping the power from one, and delivering it to the other. It would save a bit of weight, and shorten battery life.

Then the normal dremel work should do some good. I'm done using lighter pulleys after too many bad experiences. As a matter of fact, I'll probably purchase another CeramicSpeed OSPW setup as I've been very pleased with it on my mechanical Red despite the weight penalty.

So if you have eTAP, and you have tuned it. Please share your modifications here, and let's start a conversation about this.

NiFTY
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by NiFTY

Your idea to save weight is to add wires to your wireless groupset? If that is on the cards, add derailleur cables, mechanical shifters and mechs and you will definately save weight. It is well known that etap is heavier than mechanical red.
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by Weenie


Dez33
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by Dez33

ProfessorChaos wrote:I'm installing it on a S-Works Venge ViAS in hopes it will be lighter than SRAM Red22 Mech with the absence of shift cables, and housing. I estimate it will be really close.


What do you say is close? 200 grams?

glam2deaf
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by glam2deaf

The one battery option would be interesting, I have zero electrical knowledge, so no idea if it's possible. But the drop in battery life would be a pain personally.

Looking at the system it is pretty simple, there isn't too many places to shave much. Replace the shifter clamps with carbon or Ti, sand the brake levers. There isn't too much on the derailleur cage to take off, but yeah maybe the dremel on the derailleur you could take some off. The front derailleur is mostly battery, so running wire option would be an improvement.

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ProfessorChaos
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by ProfessorChaos

Below are the advertised weights which we all know can be erroneous. I know for a fact my FD was heavier than that, and my RD is actually lighter as it is a 10sp unit that has had a good bit of dremel work, Fiberlyte cage, and aluminum hardware.

SRAM Red
Shifters 280g
RD 145g
FD 69g
Total 494g

eTAP
Shifters 260g
RD 239g
FD 187g
Total 686g

So we are looking at a difference of almost 200g, that isn't factoring in the shift cable and housing difference. I just weighed .5m of shift cable housing and it was 17g by itself. There is probably 4-5m of shift housing in that bike. Probably another 30-40g in the two shift cables. So it might be very close indeed. If it is close, I'll be happy. I work on my bikes myself, and the ViAS is not a particularly easy bike to work on. So eliminating two cables ran through the bars/stem/frame will be a much appreciated win for me.

NiFTY
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by NiFTY

If the vias does run full length outers then it might be. Otherwise shimano shift inner and outer and ferrules for a standard bike weighs 55g (for both derailleurs) alligator mini i link weighs 35g.
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kkibbler
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by kkibbler

There's not much to shave off the base eTap group. You might save some grams going blips and blipbox only, and using some WW brake levers. Just an idea.

metabo
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by metabo

delete me
Last edited by metabo on Sun Jan 01, 2017 10:16 am, edited 1 time in total.

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oldnslow2
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by oldnslow2

If I were to do what you suggest, it'd want to do it without and permanent modification to the derailleurs.

I would make a "plate" that fits between the RD and the battery which passes power to the RD and then to a cable that runs to a second "plate" that fits the FD and snaps in where the battery would go.

Unless you have access to a 3D printer you would need to take parts from a 2 batteries and a FD which would cost more than it's worth.

I've heard rumors of "race day" batteries which are smaller/lighter and only good for 6-8 hours use.

Another option is to go with a 1x and eliminate the FD, small chainring and cannibalize the left shifter and make it a "brake" only unit.

DJT21
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by DJT21

ProfessorChaos wrote: There is probably 4-5m of shift housing in that bike.


Is it a tandem?

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Juanmoretime
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by Juanmoretime

Considering there are no mechanical shifting components in the shifters they should be lighter than 260 grams. Both derailleurs are pretty heavy too compared to mechanical Red. I use Mini I-Links for shift cable so my much weight savings there going without. Another grip is that where I live an 11-21 cassette would be very usable for me most of the time and so would an 11-23 11 speed cassette, I currently kick it old school 10 speed 11-23 with a 134 gram Red 1090 cassette. I know I can do Dura Ace but the weight would probably steer me to a Recon 11 speed titanium for the weight savings once I go 11 speed.
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ProfessorChaos
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by ProfessorChaos

Well to my delight the ViAS was 40g lighter after switching to eTAP. I had 99g of shift cable housing alone removed. I'm using an 11-25 Ultegra cassette on my daily CLX64's. I use a Red 11-25 cassette on my 808 Tubulars. This was with the CeramicSpeed OSPW on the before weight. I need to order an eTAP OSPW next. I'm glad the weight was so close. It also simplified that bike immensely. My other lighter Venge will remain mechanical Red22 with Jagwire segmented housing. No weight to save there. I might have to eTAP my Shiv though.

by Weenie


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steff
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Location: FRANCE

by steff

Hello
What about this tuning ?
Is someone save weight on:
Shifters : clamp ? Other ?
Dérailleurs : pulleys ? Screws ? Plates ? Others ?
Pictures are welcomes 😉

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