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Discussion Starter · #1 ·
The alternator dropouts on my 2014 fargo slip backward under hard-er rear braking. They make a creaking noise when this happens. When I go to pedal, my pedaling forces pull the dropout back forward (and they make another creak). I'm sure this is exactly what is happening; I can make it slip from braking forces, get off the bike, and check that the chain has tightened up and that the set screw is no longer tight against the frame.

The set screw on the dropout only prevents the dropout plate from slipping forward. I would need another screw on the back side to totally lock the dropout in place.

After years of owning and working on other peoples bikes with sliders/EBBS/not-vertical-dropouts, I had convinced myself to never again buy a bike with them. But then I did. And naturally, they don't work correctly.

Anyone else have this problem?
 

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I had that happen. My dog caught an interesting scent or something and stopped in front of me. I clamped the brakes on hard and skidded the rear tire a bit. When I started pedaling again, something felt and sounded bad. Turned out the left dropout had moved slightly. Bolts were tight. I've been wondering if it's a problem for others. That exact dropout has been around for a few years now, and I had not heard of it happening. I'm using a full drive train on that bike at the moment, so I'm thinking of making some sort of insert to fill the back of the slot. Meanwhile, the bolts are *very* tight. There is a lot of torque on that part during hard braking. Maybe I should just move the dropouts to the all-the-way-back position and be done with it.
 

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Discussion Starter · #3 ·
I have a new 2014 Fargo with brand new dropouts. Rohloff dropout on the NDS too. This slipping/noise happens about 60% of the time I use my rear brake. My dropout bolts are *very* tight too.

Your idea to run the sliders all the way back is smart. I would have to run a tensioner on my rohloff, but a tensioner is better then slipping/creaking dropouts.

I would like to know if anyone else is noticing this. I haven't really taken my bike mountainbiking yet; if its bad riding around on the road and braking occasionally, I can only imagine it being worse riding trails.
 

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Bicycle part Line Teal Iron Metal


This problem should be easy to address, since the cause is the same as hub locknut slippage in track ends (such as on my Moonlander): paint on friction surfaces.

Get rid of the paint on the frame where the lower bolt (which rides in the curving slot) pinches the frame between the dropout and bolt acorn nut.

Also make sure the bolt thread is lubricated to get proper clamping force.

Removing paint from friction surfaces is how I stopped my rear wheel from slipping in the track ends during braking (left side back) or accelerating (right side forward) on my fat bike.
 

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Discussion Starter · #7 ·
This problem should be easy to address, since the cause is the same as hub locknut slippage in track ends (such as on my Moonlander): paint on friction surfaces.

Get rid of the paint on the frame where the lower bolt (which rides in the curving slot) pinches the frame between the dropout and bolt acorn nut.

Also make sure the bolt thread is lubricated to get proper clamping force.

Removing paint from friction surfaces is how I stopped my rear wheel from slipping in the track ends during braking (left side back) or accelerating (right side forward) on my fat bike.
I actually just stripped the paint on the entire lower casting, so that I could braze some eyelets on the dropout. I'll rebuild it w/o paint and see how it goes.

That being said, dual (front side and back side) set-screws would be a more elegant way to stop this from happening.
 

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Seems odd this would crop up all of a sudden for no reason. I've made a good living as a mechanic in the past, had lots of bikes, knew those bolts in particular needed to be tight, checked them before that very ride, in fact. I'm surprised at the finish on the plates. Expected them to be less shiny. Has something changed? As I said in my post above, I had not heard of any problems at all with this design.

One could try an old body shop trick for car door hinges that won't stay put. Fold over a bit of sandpaper (waterproof 220 works well) with the rough side out, and slip it in near the bolt. Kind of a kludge, but it beats having stuff slide around. Works on painted metal, unpainted metal, whatever.
 

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Discussion Starter · #9 ·
Dropouts haven't slipped since removing all the paint. I did cover the exposed metal in weigle framesaver though. I'm still getting some creaking that i've yet to narrow down; it could be the dropouts, but I'm not 100% sure yet.
 

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Discussion Starter · #10 ·
So I replaced a creaking old crank, which took care of that noise.

After 30+ miles in the rain yesterday, my dropouts began slipping and creaking on today's commute. I just tried the sandpaper method that austin popper recommended. We'll see how it goes.
 

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Interesting! I've never had my alternators slide back on my El Mariachi, despite running it single speed for years. The only issue I've had is having the lower bolt fall off due to old loctite. Even then they didn't slide backwards.

I wonder if this has something to do with the new frames being painted rather than powder coated?

Have you tried putting more loctite on the bolts? I could imagine bad things happening if the lower bolts come lose...although this didn't happen in my case.
 
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