SRAM Red Etap Front Derailleur Adjustment

[Calnago]

Ha, I hate robots.

[PaulDunn]

eTap won't shift from the inner ring to the big ring under power uphill. It's a built-in protection thing.

As an electrical engineer with SRAM, I can tell you that what you describe is not happening. eTap does not communicate with any brand of power meter, nor does it detect/use inclination for anything.

That said, I can confirm this "action" from a user experience standpoint; missed FD shifts when going slow (uphill). I've experienced it. But the issue is that when you have a marginal adjustment, the road vibration (being on flat ground) helps the chain hit the pins and complete the shift. Uphill you're going to slow, there is reduced vibration, and the FD seems to not work. Then on gravel, everything is always great.

So if you experience this, you have a marginal adjustment. Note that eTap is very sensitive to adjustments; make sure you get all adjustments as specified (b-screw, limit screws, FD height, FD angle, etc.) Also make sure you don't have a loose BB; play in the BB will prevent good FD shifting.

[RichTheRoadie]

I stand corrected.

Odd that it shifts immediately when the terrain flattens out, though - and I know I'm. It the only one who has experienced this.

[Calnago]

eTap won't shift from the inner ring to the big ring under power uphill. It's a built-in protection thing.

As an electrical engineer with SRAM, I can tell you that what you describe is not happening. eTap does not communicate with any brand of power meter, nor does it detect/use inclination for anything.

That said, I can confirm this "action" from a user experience standpoint; missed FD shifts when going slow (uphill). I've experienced it. But the issue is that when you have a marginal adjustment, the road vibration (being on flat ground) helps the chain hit the pins and complete the shift. Uphill you're going to slow, there is reduced vibration, and the FD seems to not work. Then on gravel, everything is always great.

So if you experience this, you have a marginal adjustment. Note that eTap is very sensitive to adjustments; make sure you get all adjustments as specified (b-screw, limit screws, FD height, FD angle, etc.) Also make sure you don't have a loose BB; play in the BB will prevent good FD shifting.

Well there you have it. There's no inclinometer. No accelerometer. It's strictly a setup issue, albeit harder than it should be and more sensitive than it should be imo given the other brands don't seem to have this issue, or at least certainly not to that extent. And sounds like the smoother the roads, the more this issue would happen; it actually needs those vibrations from road roughness to help the chain catch the pins. Ouch. Great for gravel grinding, but smooth roads are fun to ride road bikes on. So that's a fail in my books.

[PaulDunn]

it actually needs those vibrations from road roughness to help the chain catch the pins. Ouch. Great for gravel grinding, but smooth roads are fun to ride road bikes on. So that's a fail in my books.

Just to be clear, when properly adjusted, the system does not "need" vibration. It is just that when the adjustment is just on the margin of working, the vibration "helps". This is true with any drivetrain, and I've certainly experienced it on competitors product.

[Calnago]

Ok, and yes, agreed... bad adjustment is bad adjustment, and in fairness it's impossible to tell how badly the users' above systems were adjusted "on the margin" over the internet, but it does seem to be a little more "sensitive" than maybe it should be. And according to the user @Sugarkane, who does some pretty high end builds... he claims similar issues...

its got an accelerometer.. so the guess is it can tell when your going up hill
I've had the same issue and with customers.. going up hill and shifting the big ring up just won't work.. as soon as you get on a pretty much flat road or down hill shifts up like normal.. thing is.. why would you do it.. my customer has a bad habit that we are trying to stamp out..

Albeit he also claimed it had an accelerometer...

[sugarkane]

The group has an accelerometer that wakes up the groupset... there is one present in the rear mech I think..

[PaulDunn]

The group has an accelerometer that wakes up the groupset... there is one present in the rear mech I think..

There is an accelerometer, but not inclinometer, nor does it use the accelerometer to detect inclination. It is just to know when to be awake; sleeping saves power.

[sugarkane]

I think ETap is sensitive to chain line and that can be hard to control with aftermarket BB and crank setups. All the bikes I've seen that struggle to shift up the front while going up hill all have non SRAM cranks

[sugarkane]

@PaulDunn good to know.

[Calnago]

I think ETap is sensitive to chain line and that can be hard to control with aftermarket BB and crank setups. All the bikes I've seen that struggle to shift up the front while going up hill all have non SRAM cranks

Well, you can't slam anything that isn't working quite right if it isn't using components that are all intended, designed and tested to work together. In my experience there's usually, but not always, compromises here and there when the mix and match "it'll work, trust me" crew starts stirring the pot. And all of the new groups are extremely sensitive to chainline these days. Case in point... Shimano moving their inner ring 0.04mm to the inside on 9100 in order to better accommodate the altered chainline of the wider spacing required for disc brakes.

[sugarkane]

I think ETap is sensitive to chain line and that can be hard to control with aftermarket BB and crank setups. All the bikes I've seen that struggle to shift up the front while going up hill all have non SRAM cranks

Well, you can't slam anything that isn't working quite right if it isn't using components that are all intended, designed and tested to work together. In my experience there's usually, but not always, compromises here and there when the mix and match "it'll work, trust me" crew starts stirring the pot. And all of the new groups are extremely sensitive to chainline these days. Case in point... Shimano moving their inner ring 0.04mm to the inside on 9100 in order to better accommodate the altered chainline of the wider spacing required for disc brakes.

im not SLAMing anything. i have it and love it.. all the cases of this I've seen are using non SRAM cranks and not all built by me.. the real problem is my one customers bad habits.. Tap doesn't brute force stuff a'la DI2, personally if i want to climb in the big ring i'll start the climb in it.. also if you need to put it in the big ring it does need to be 'clutched a bit more than Di2 or ESP. i'l running a SRAM red quarq on my eTap bike and its not an issue.. with rotors, THMs, Da SRMs etc uphill it can be an issue.

[Calnago]

Sorry, I wasn't saying you were slamming it at all. Quite the contrary. If anyone was, it was me. I only quoted your clarification that the systems you've seen where it was an issue were not 100% complete eTap systems to reinforce my point. I should have said... "one can't slam a system that isn't comprised of components all designed to work together". I was using "you" in the same sense as I'd use a generic "one". Not referring to anyone specific at all. Hope that makes better sense.

[pjo]

getting the front/rear guide marks on the cage exactly aligned is important, the height does not seem so critical, i mounted slightly higher than the guide mark and also set the high limit to put the cage slightly further out from the chainring

shifting on mine is fine, old srm/sram red cranks with praxis works rings and red 22 chain, not had any failed shifts

is the fd mount to the seatpost flexing? the clamp on mine is really chunky, i didn't need to use one of the supplied wedges, the motor in the fd probably applies much more force than manual fd, if the mount is flexing it will throw off the shifting

I'm trying also to fix issues with fd but everyone is saying "getting the front/rear guide marks on the cage exactly aligned is important" but there is zero info on how to do this. Also i fid it confusint the there is no info on which of the fd screws is high, and which is low. Though someone has stated that they operate topsy tuvey in comparisom to mechanical group but.

A: How do you align the fd so that chain ring is in line with guides (vide does tell this nor anyone has produced info re. that)
B: Which of the fd screws are high-limit the upper?

Thanks in advance

/Patrik

[RichTheRoadie]

Read the SRAM instructions online - they tell you *exactly* how to do it.