Warning signs that a rapid fire shifter is about to die
 

[Planning in anticipation of longish tours in not so developed regions.]

My question is - are these (XT rapid fire) shifters subject to catastrophic failure (i.e. one minute all is good and the next nothing works) or do they give plenty of warning signs before they go?

Unless something actually fractures/breaks the failure is usually a slow gumming up of the many pieces movements. Of course this reality is seen through a perception that's not linear.


So, yes a catastrophic failure can and does happen. Impacts increase this possibility. But the vast majority are maintenance related, a lack of lubing the shifter pod or dealing with cables. Andy.

Didn't realize these needed lubing. Googling suggests generous spraying of WD40 if/when they gum up. This is what you had in mind?

I've done the wd thing to free up shifters but I know the stuff will eventually turn "gummy." On one set I removed a cover and very sparingly applied a bit of synthetic grease (so it wouldn't attack the plastic parts) to the pivot points and cogs. They worked fine but I sold the bike soon after so couldn't say if this was a good long range solution.

Would also like to know what others have done.

gauvins, Generally the Shimano shifters will fail following a long period of non use or in cold weather. I wouldn't worry about a shifting failure during a tour. While WD40 will restore shifting, it needs to be followed with a lubricant like Tri Flow or LPS3.

Brad

Some of the most hardcore insane tourers I know carry an extra bike with them on tours just in case this kind of thing happens. If you are scared of this problem I recommend buying another bike and towing it along during your tour.

Have found Rapidfire+ shifter to be one of the most reliable parts on a bike, I have well over 10,000km on set of R770 (Ultegra level) and have had no issues with them, never managed to break/had any failures with any of the SLX, XT or XTR I have had over the years either.

For emphasis, this. Just about any light-weight lubricant will work fine in a shifter. A drop on each pawl (pulling/releasing) will keep them moving smoothly after degreasing. Cleaning, as prescribed by Shimano, involves soaking the internals in degreaser--brake cleaner works very quickly, as does any solvent heavy lubricant (bonus, not having to apply lubricant after). The goal is to remove gummed up grease from factory assembly.

Slightly off topic, but if you work in a bike shop, it won't take long for a "tune-up" to come in, involving a '90's mtb w/ original equipment Shimano trigger shifters of some type that don't work. It's an amazingly regular occurence. A guy in our shop is so experienced (and good) at assessing these by feel when they arrive, he can basically tell the customer on the spot whether the shifter(s) can be made to work again, and he's almost always spot on with his predictions. If he can't bring them back to life, I'd bet it can't be done. Percentage-wise, even when the situation seems almost hopeless, he can usually bring them back to complete functionality. I rarely mess with them anymore, I just hand them over to him.

The worst thing you can do to trigger shifters is to go long periods without using them. They're extremely reliable and will last a long, long time, as long as you keep them moving regularly.

Yeah, I had to open up some deore shifters and sprayed a bit of tri flow and now the shifters are working quite well.

Why do they stop working with non use?

Factory grease hardens and the pawls stop springing back. The typical symptom is that you push a shift lever and it doesn't "catch".

+1

Ah. Well, I had that problem but I opened 'er up and gave the innards a good dose of tri flow. I'm assuming that since lube can't harden so I won't have a repeat of this problem.

Is this a potential issue with STI brifters also? I hope not.

I opened the pods and sprayed tri flow. Clicking action has returned to something akin to full force. To be honest, I don't even recall what shifting action was like day one, but its certainly a major improvement over the sluggish stuck in the mud clicks I was getting before.

Yes it is. Same repair steps.

Brad

Since you asked about XT, they do have some improvements over the cheaper ones, too. They tend to have more aluminum and some ball bearings. So, less likely to rust and should wear slower. The grease will still cake up, though. (Similar differences between components across the groups.)

thanks for pointing this out. was indeed prime motivation for going to that group.

I wonder if my XTR M952 shifter has this gumming up problem. Between 3rd and 4th gears, it doesn't seat all the way to 3 when shifting down. So that eventually it snaps into place. This used to be a bigger problem but I opened up the shifter and greased it up. Since then, it never snaps into place, but rather just doesn't fully seat correctly. So it just rubs on the cassette a bit, which I hear while pedaling, so I just push a bit more on the shift never which seats it into correct position. I will take it apart again, looking for this caked up old grease. I just assumed that the gear mechanism inside was just a bit too worn due to lack of grease.

For its price, XTR has no business showing up on this thread. How old is it?

friction shifters and up to 8 sprockets at the back. all else is less reliable.

XTR is packed with grease like every other trigger shifter, yes? If so, it can dry and harden and lead to shifter failure like any lower tier group. There is a simple solution however, as long as you have access to a mini screwdriver and some lube.

For the price and price premium over XT, I'd expect it XTR to use the space-tech lube used on the Mars rover.

I have been running a set of Altus 7 speed rapid fire shifters that were freed up with WD-40 when the bike was purchased off Craigslist about 10 years ago. At the time of purchase both the left and right shifters were not catching.

They have worked wonderfully for over 10 years. I would imagine the higher end units should fair even better.

+1. I have some first-series XTR shifters (ST-M900, 8-speed) that didn't work after sitting for several years. (They were waiting for the right bike project.) I removed the plastic cover, hosed out the inside with WD-40, and they worked perfectly after that.

Nowadays I would used petroleum-based lube since WD-40 tends to congeal and gum things up. I'll find out one of these days- the shifters were put back in storage when I upgraded that bike to 9-speed. I have another project going together now- and I have M900 XTR hubs built into wheels already.

In doubt?, replace it before leaving for your tour.