Rear derailer rebuild-Loccktite?
 

Is it proper to use "Lock tite" or a product like that for the sprockets in the rear derailer? How do you keep the proper tension on those little bolts? :(

You mean the two little pulley wheels? If there isn't a torque spec for them just "fairly tight" is good enough. There's very little force acting on them.


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Loctite? NO WAY! Hell, I grease the threads so I can remove the pins to allow a good cleaning of the pulley bearings and cage about once a year. Just a firm pinch on the allen key with two fingers is all you need. Like DMF says there's not much force on them so a few inch-lbs does the trick. If in doubt use less than you think it needs and check them after each ride to see if it comes loose. If it does pinch them tight a little harder until they don't come loose. I've found that most folks guess at too tight than too loose. If you want to get techincal you're looking for about 4 to 5 inch-pounds of torque for these. That's 4 to 5 pounds of force with one finger on the center and one an inch away. It's not much but it's enough.

I'm pretty sure Shimano puts threadlock on these bolts at the factory. I've found a red threadlock like film on new shimano derailleur pulley bolts when doing the first maintenance. Regardless, I have used threadlock for years and never had a problem getting the bolts out. I started the practice of using threadlock after a fellow rider lost her derailleur pulley about 40 miles into an 85 mile loop and after searching for 30 min for the bolt, we flagged a car down to give her a ride. You're probably safe without it and I got by for years without it but it won't hurt anything to use it.

Just make sure that it doesn't set up hard.

Thanks all, I know it had something locking the pulleys in place. DMF, thanks for the link, much helpful info.

Are you guys sure the red stuff from factory isnt anti sieze?,cause red locktite would be way to strong to use on such small bolts.Blue maybe but i wouldnt use anything.

The pivot bolts are shoulder bolts so you can't thread them in too far. Just install them good and snug and they will be fine.

I disagree.

Once those pivot bolts have been removed, they MUST be reinstalled with loctite. There isn't a lot of thread engagement and there have been plenty of problems with people losing those bolts after a repair where grease/anti-seize was applied instead of threadlock.

This is one of those other places where I advocate loctite rather than the usual grease - the other notably being rack/fender mount hardware. I can't think of a reason why grease would be superior to loctite in this situation.

It's a mild threadlocking compound. If it was red loctite those bolts would not be removeable without application of heat.

FWIW, Park tools lists the torque spec at 27-34 inch pounds for Shimano rear derailleur pulley wheel
(idler wheel) bolt.

The pulley bolts are not pivot bolts. Which are we talking about here?

If you read the whole thread, the context makes it clear. It's the idler wheel bolt. ;) :D

The idler wheel bolt is what I am referring to.

This has gotten interesting. When I put what I would estimate to be 25 lbs of pressure on the pulley wheel bolt, it is stiff. 4-6 lbs seems to allow for a freer spin.

rogerstg is referring to inch pounds, not foot pounds. 27-34 inch pounds is around 2.5 foot pounds.

Yeah, if you put 25 ft-lbs on them, I fear for the life of the bolt.

Well, I've been doing it wrong for decades and never had a pulley bolt come loose after removing it and just threading it back in good and snug.

Either way, if you can give me one reason why grease is superior to loctite in this situation i'll stop using it.

I would use the Locktite. I lost the screw on the lower pulley in the middle of the night while bicycling in outback Australia. The RD bent, a spoke or 2 was broken and I had to hitch hike all the next day to get to LBS about 700 (yes that is no typo) km to get to a "L"BS to repair and replace... The 48 spoke wheel was in pretty good shape...

Yup, use the Locktite. You won't have an issue getting the bolt out. I noted "red" pigment on some RDs sold in my LBS, but don't know if it is original Shimano stuff, or some tweak by a bike techie at the LBS.

Locktite, you betcha. I use the red. Never had a problem removing a Locktited pulley bolt - as someone pointed out, the thread engagement is pretty minimal. I started doing that after spending a good hour searching the roadside for a buddy's derailleur parts. We found them, though. Daylight.

On my bikes, I throw the Shimano pulleys away and replace with sealed bearing pulleys.

There is a reason Shimano uses a bushing with lateral play on the upper pulley.

True, but if your shifters are adjusted properly, it doesn't matter. A little more bother with friction shifters, but again, no biggie. I like everything as frictionless as possible, just personal preference.

I don't grease them either. I remove the bolts to let me clean the pulleys and the insides of the cage plates, then lube and reassemble the pulleys and replace the bolts dry. Loctite isn't a bad idea, it's just that I've never had any of these bolts come loose so I've never been forced to use it.

For index shifting the floating upper pulley allows fast reliable shifts even if the cable adjustment or cassette cog spacing isn't perfect.

Also, Shimano isn't the only one with floating pulleys. Campy uses them too. I assume SRAM does also but I've never used their rear derailleurs so I'm not sure.

For friction shifting, the float is a non-issue but why do you think non-floating pulleys are more "frictionless" than the floating type?

Sealed ball bearings. Pretty hard to make a floating pulley with sealed bearings. Can be done - like in a self-aligning pillow block - but haven't seen anything like that available.

Actually, the float is more important with friction shifters, because it's a pain to dial it in precisely. I have a rain bike with friction and a nice bike with brifters, so I know. I'm saying I did this on my own bikes. I would never do it on a client's bike. I don't ride Campy, but I assume they're at least as accurate as Shimano, where at least the Ultegra group is plenty accurate enough to dispense with the float.