[kidwoo]

Riding the same setup I've been on for 4 months (X01 gruppo bravo pesto), my bike started ghost shifting on me last night on the face of some jump lips. They're kind of tall but not terribly steep faces, enough to pop pretty well but certainly still in the realm of MTB jumps. Not exactly crazy compressions. Every time I'd hit one of the bigger ones my bike would shift on the face, and then I could hear the chain and derailleur move down while I was in the air.

I haven't ever in the history of ever had that happen with any bike I've owned, from zero to 8" of travel, scram or shimano setups. Cable routing is fine and the same as what I've had on this frame for years (turner dw 5-spot) and it runs on top of the down tube a right above the slightly elevated chainstay...........pretty much an ideal route.

It's not even just a cable tension and release thing. It straight up indexes the friggin shifter too. I literally would finish a line of 4 jumps in a different gear in every way: shifter was shifted out, chain was on mr 10 toothy, the whole 11 yards. The only thing I can think is that there's more tension on the derailleur from running a tensioner on a narrow-wide ring, and the stretch is literally yanking the indexer out on the shifter pod.

I just read up on some scram 11 speed stuff and came across this:

By taking vertical movement out of the equation, this design doesn't just make shifting faster— it reduces shift force and eliminates ghost shifting.

So for the first time in my life, I have with a system that eliminates ghost shifting, causing something really really similar to ghost shifting, in that it's the exact same thing, and even worse.

What new demon is this? Ghoul shifting? Jesus just thinks you're in the wrong gear shifting? Secret electronic with my drunk buddy in the bushes with the remote control shifting?

Anyone else ever had this happen? I can't duplicate it with the shock off in a stand.

 

[blindboxx2334]

are you pedaling off the lips of jumps?? odd.

 

[kidwoo]

are you pedaling off the lips of jumps??

Sprinting my balls off. Straight off the end. It's really the safest way to hit jumps.

 

[shirk007]

The ghost knows you're supposed to be going faster. He/she is trying to tell you something.

 

[Nick]

The only thing I can think is that there's more tension on the derailleur from running a tensioner on a narrow-wide ring, and the stretch is literally yanking the indexer out on the shifter pod.

I don't get this.

How could a use of a NW ring and tensioner create more tension than a normal ring?
- and-
If the gear was being yanked/forced, I'd think the index teeth inside the shifter would show signs of it and fail pretty quickly after that.

 

[jackalope]

I'm at a complete loss, but the only thing I can think of is the shifter trigger is somehow being activated by the unique compression of hitting hitting a ramp - even one that's not a straight up DJ. Any chance you can try a different shifter? I mean, who doesn't have a couple 11 speed shifters laying around?

But I think the only real solution is to get a rigid SS 29r and always stay in contact with Terra firma.

 

[kidwoo]

I don't get this.

I don't either

Have you ridden an 11sp setup? There's just way more spring tension from the derailleur pulling on a ring that just doesn't want to let the chain off. Just kind of stabbing in the dark since I've ridden 9 and 10sp setups on this bike with nothing like this ever happening.

But yeah I'm kind of worried for my shifter.

 

[Westy]

I am not really one for spending too much time off the ground but a little common sense tells me that the conditions you describe occur under vertical acceleration. I once had similar problems when the bike was seeing sustained vertical loads (more than a bump, less than being fat). In short order the frame broke.

Are you running a full housing?

If so, could the jump lips be causing a marginal frame to flex and the effective cable length to change?

If not, could a wheel or frame asymmetry be causing flexure between the wheel hub and derailleur mount?

Are you getting a weird boner that is getting caught on your shifter cable?

 

[Fool]

Clearly the answer is 12-spd. 13 would be even better.

 

[kidwoo]

Are you running a full housing?

Yes!

If so, could the jump lips be causing a marginal frame to flex and the effective cable length to change?

Not in a straight line up a lip, 5.5 inches of suspension sure, but not flex......... And who's bike you callin marginal!?

If not, could a wheel or frame asymmetry be causing flexure between the wheel hub and derailleur mount?

Hadn't thought about that one. I'll give'r a go. I actually was riding a different wheelset than I had been. The wheel had been in that frame for two years prior but not with an xx11 cassette.

Are you getting a weird boner that is getting caught on your shifter cable?

Boner maybe but containment is good when I wear this.

http://www.vitalmtb.com/product/guide/Riding-Shorts,64/Specialized/Mountain-Bib-Liner-with-SWAT,14516

 

[Samoto]

Clearly the answer is 12-spd. 13 would be even better.

nah

XTR Di2 is the answer!!

 

[Da Peach]

Bike is too old. Clearly. The drivetrain is rejecting the frame.

 

[Nick]

I actually was riding a different wheelset than I had been. The wheel had been in that frame for two years prior but not with an xx11 cassette.

26" wheels??

There is your problem.

 

[kidwoo]

Fvck You

Just because.


I just got back from riding a trail with some hard compression berms/banks. There was something weird going on with the derailleur but it wasn't shifting. Again, I can't duplicate it in a stand. It's gotta be something with the chain getting pulled down with my hella massive G-forces. But that's weird because the clutch should tame that. Maybe it's a combo of the tension plus the clutch dragging on the rebound......

I don't know. I still think it's funny that the system that completely eliminates ghost shifting gave me ghost shifting for the first time in my life.

 

[Da Peach]

Left turns and right turns have the same effect?

 

[slimshady]

I'm putting my money on some torque issues with the lower link combined with an odd chainline...

Do this: place the derrailleur in the gear you get more ghost shifts, put your front wheel against a wall, grab a fistful of front brake, step on the cranks and have somebody else look at the derrailleur cage from behind. I bet you'll find it to be bending like crazy.

EDIT: F*** my phone's stupid auto corrector, I had to edit the post six times...

 

[kidwoo]

Do this: place the derrailleur in the gear you get more ghost shifts, put your front wheel against a wall, grab a fistful of front brake, step on the cranks and have somebody else look at the derrailleur cage from behind. I bet you'll find it to be bending like crazy.

I was kidding about sprinting off lips.

There's no unusual twisting in the rear triangle. Certainly nothing pulling the derailleur funny under pedal loads. (I know because that's how I find frame creaks and do it pretty regularly anyway).

It's a coasting thing. I've got a little hub drag that might be helping things get freaky.

 

[Westy]

I find it hard to believe you wear any kind of pants, with or without containment. I suggest taping it back drag queen style and reporting back.

 

[marshalolson]

You might adjust the clutch. My bet is it's tightened a little thru riding (normal) and just needs to be reset.

 

[kidwoo]

dickshifting™

 

[kidwoo]

You might adjust the clutch. My bet is it's tightened a little thru riding (normal) and just needs to be reset.

I've messed with some shimano ones but you can do that with scrams?

 

[Nick]

even if the frame was flexing that much, the gear should shift back when the flexing stopped flexing.

Did your rear cable just slip?

 

[kidwoo]

It's definitely not the frame. I've been ridng this frame since 2011 and have ridden these trails forever. Indexing was/is still spot on. I put on some yoga pants, drank some ayahuasca and meditated with my balanced chi against my cassette.

I had a vision of hub drag, a flopping chain and a gnarly kickback on the rebound pulling my indexer out on the shifter. I'm just going to loosen up my hub. And if that doesn't fix it, I'm going to get some footage of it today because.....well..........it's just kind of funny.

 

[6thElement]

Left turns and right turns have the same effect?

This is 'Murica. Turning right while going fast is for communists.

 

[Dogboy]

If something was truly pulling hard enough to index the shifter it would shift up the cassette into a lower gear, wouldn't it? It's doing the opposite of that and releasing cable.

 

[kidwoo]

If something was truly pulling hard enough to index the shifter it would shift up the cassette into a lower gear, wouldn't it? It's doing the opposite of that and releasing cable.

If so it would only be 'temporary', because you'd need moAr cable tension to pull it up the cassette, but then it would relax without indexing. This really is like the cable's being yanked out of the shifter enough to make it slip into a smaller gear. I mean everyone knows the chain fall down the cassette thing but then as soon as you pedal it goes back into the gear you were in. This just isn't doing that.

I really do think something violent is happening with the hub. Same wheelset/axle/bolt I've been using for years but I did just put an XD driver on it. Something's binding it up pretty hard.

 

[Dogboy]

What hub?

 

[kidwoo]

Mavic ITS-4 thing (crossmax SX). I talked to a shop owning buddy of mine and I think I might have an axle/XD driver mismatch. The wheels are a few years old and apparently there's an 'update' in axle style. I'm going with that for now.

 

[Bikael Molton]

Belt drive

 

[marshalolson]

dickshifting™

Yup pull the little plastic dust cover and remove the pulley cage.

It's a giant 55torx under the dust cover, but an 8mm fits perfect. Loosen the 4mm behind the der cage and re tighten to "just tight".

This bolt tightens over time, so do this regardless of your hub/axle shenanigans.

 

[4130biker]

Maybe if you ride just a bit "harder", you'll reach the point where it will actually un-ghost shift, solving your problem.

 

[StabprimoMonkee]

Maybe if you ride just a bit "harder", you'll reach the point where it will actually un-ghost shift, solving your problem.

Yeah, he needs to unlock the ghostbusters mode.

 

[kidwoo]

I pulled out the throoobolt and it was bent.

It had to be the hub binding. I just got back from riding with my other wheelset and no weirdness at all.

Time for a full hub dissection with some new bits. I had completely forgotten I'd done some uh......customization to make the old axle work. Funny what happens when you don't touch a wheelset for a year.

 

[mykel]

I'd be checkin that belt - me thinks yer being a bit constricted.

 

[bizutch]

Try it meow?

 

[jonKranked]

I pulled out the throoobolt and it was bent.

It had to be the hub binding. I just got back from riding with my other wheelset and no weirdness at all.

Time for a full hub dissection with some new bits. I had completely forgotten I'd done some uh......customization to make the old axle work. Funny what happens when you don't touch a wheelset for a year.

take that hub douse it with kerosene and flame on. problem solved.

 

[kidwoo]

take that hub douse it with kerosene and flame on. problem solved.

Are you another one who formed their opinions on mavic hubs in 1998 and never looked at them again?