Author Topic: Help - my shifter cable has frozen stuck  (Read 8995 times)

scottydog

  • Stubble
  • **
  • Posts: 132
  • Location: Montreal
Help - my shifter cable has frozen stuck
« on: November 12, 2013, 01:22:49 PM »
The shifter cable has stuck on my cargo bike.  It has a shimano nexus 8 internal gear hub, with a full cable housing from the shifter to the hub.  The cable housing says "shimano sealed", presumably to prevent problems like this.  The shifter is stuck in 4th gear - which is lucky, since if I had to pick a single gear that would be the one I'd pick, and I usually leave it in 3rd gear.

When I shift down to 1 or 2, I get lots (maybe 1/2") of slack at the shifter end and can easily inspect the cable housing end (neat - it's "sealed").  At the hub, I can detension the cable by pushing counterclockwise on the hub and can similarly get lots of slack.  Since the shifter and hub can both move, I'm deducing that the cable must be stuck somewhere inside the housing.

If it was regular housing, the typical advice seems to be to flush the housing with WD-40 to get the water out, and then lubricate with light oil.  What should I do with this "sealed" housing?  The weather is supposed to warm up in a couple of days, so I expect it to improve at least temporarily, but it's only a matter of time before the mercury drops below freezing and stays there until sometime in March.

In hindsight, this isn't such a surprise.  I leave the bike outside, covered by a tarp, and the tarp rests on the right handlebar and after a heavy rain the handlebars are quite wet.  Yesterday we had lots of rain that then turned to ice pellets and snow.  I don't have time to build a bike shed, so I'm planning to cover the handlebars with heavy plastic bags to try to prevent this from happening again.  If you have other suggestions, please share!

the fixer

  • Handlebar Stache
  • *****
  • Posts: 1037
  • Location: Seattle, WA
Re: Help - my shifter cable has frozen stuck
« Reply #1 on: November 12, 2013, 01:29:09 PM »
My suggestion is to just replace the cable and housing. You don't need special housing on any bike. Make sure you put a small amount of grease on the new cable before you run it through the housing, that should keep moisture out.

scottydog

  • Stubble
  • **
  • Posts: 132
  • Location: Montreal
Re: Help - my shifter cable has frozen stuck
« Reply #2 on: November 12, 2013, 06:55:36 PM »
Yeah, it might come to that.  I don't yet have the tools for cutting cables, but it seems like a good investment - especially as the kids get older and start using their bikes more often.

I contacted the company that imported our bike and their advice was: remove the cables (including brake cables), soak them in motor oil and then re-insert them.  The oil will prevent any moisture from accumulating and freezing the cables.

That sounds messy but fairly inexpensive.  Does that seem wise or crazy to those of you with more experience? I tried looking at Sheldon Brown's page on cables (http://sheldonbrown.com/cables.html#lubrication), which seems to say that bikes used in wet conditions would generally benefit from a bit of oil even if the cable manufacturer recommends against it.

This is my first season of winter riding and, although this latest episode is a bit frustrating, in general it has been way more fun than I had expected!

the fixer

  • Handlebar Stache
  • *****
  • Posts: 1037
  • Location: Seattle, WA
Re: Help - my shifter cable has frozen stuck
« Reply #3 on: November 13, 2013, 11:42:10 AM »
Motor oil seems like a bad idea, there's lots of detergents in there that can damage the non-metal parts of the cable housing.

Unfortunately the best chemical to use, Tri-Flow, is not something you'd want to buy in sufficient quantity to be able to soak the cable in. But you might be able to saturate the area where the cable comes out at the highest point with the stuff, then let it slowly leak in there. It won't be as effective as a full soak but it might work.

If you do manage to get the cable unstuck and it still looks okay, I'd recommend using a grease like you'd use in a bicycle hub to coat the cable with. Run it through the housing, hook everything back up, then clean as much of it off any exposed bits of cable as you can. It's overkill for most applications, but if you managed to get the cable stuck inside the housing once, your riding conditions are probably severe enough to justify it.

aglassman

  • Stubble
  • **
  • Posts: 165
  • Age: 33
  • Location: Milwaukee, WI
    • Milwaukee Maven
Re: Help - my shifter cable has frozen stuck
« Reply #4 on: November 14, 2013, 08:56:22 AM »
I am having the same issue.  I'll try out the motor oil suggestion because I don't really care about the cable housing. I'll post an update if this works!

scottydog

  • Stubble
  • **
  • Posts: 132
  • Location: Montreal
Re: Help - my shifter cable has frozen stuck
« Reply #5 on: November 14, 2013, 11:13:59 AM »
I've never been so happy to be biking in +1 degree (Centigrade) weather. :-)  The shifter was back to normal for this morning's daycare/school run, and after that I dove in.  I decided to try bearing grease because I already have some on hand, whereas I would have had to go out to buy some motor oil.  When I disconnected the cable, about 1-2 tbsp of water came out almost immediately.  Then I used my bike pump, with one of the needles used for inflating soccer balls, to blow air through the housing; initially there was some vapour but it soon dissipated.  I inserted a new cable (found in my box of bike repair stuff) into the housing, applying bearing grease to the cable before it went in.  The grease is quite viscous, and I was afraid it might actually impede shifting, but once I got everything back together I found that the return spring in the gear is more than strong enough and it shifts nicely.

Thanks to the fixer for your advice!  Good luck aglassman!  My tendency has been to overanalyze things, and it feels great to just do it and know that I can do it again quite easily if I have to.

GuitarStv

  • Senior Mustachian
  • ********
  • Posts: 13116
  • Age: 37
  • Location: Toronto, Ontario, Canada
Re: Help - my shifter cable has frozen stuck
« Reply #6 on: November 18, 2013, 11:27:33 AM »
I'm glad you got it working again.  I like to hit my winter bike cables with some chain lube a several times over the course of a winter.  It does seem to help prevent the shifters from freezing stuck in the cooler weather.  Thicker lube/grease can be a problem when it gets down to -20 and below, I find it tends to get gummy and feel weird . . . works fine for most of the winter though.

scottydog

  • Stubble
  • **
  • Posts: 132
  • Location: Montreal
Re: Help - my shifter cable has frozen stuck
« Reply #7 on: November 26, 2013, 07:54:54 AM »
So, 2 weeks later I can say that the bearing grease works for a certain temperature range, but yesterday morning it was only down to -12 degrees C and the shifting was erratic.  It wasn't frozen, but sometimes it would shift and sometimes it would seem to get stuck between gears.  This morning the temp was back up to the freezing mark and it shifted just fine.  I don't have a chance to really dig into this for a few weeks, so I'm going to try leaving it in 4th gear which is good enough for small trips around the neighbourhood.

Once I have a chunk of time to work on it again, I think I'll try getting some tri-flow from MEC.  I'll use degreaser to remove the bearing grease and try coating the cable with tri-flow instead.  GuitarStv, if you see this, do you have a different chain lube that you prefer?

GuitarStv

  • Senior Mustachian
  • ********
  • Posts: 13116
  • Age: 37
  • Location: Toronto, Ontario, Canada
Re: Help - my shifter cable has frozen stuck
« Reply #8 on: November 26, 2013, 10:13:54 AM »
I get a big bottle of white lightening wet ride chain lube (purple bottle) from my bike shop and it'll last me all winter long.  It seems to do fine in the cold (well, down to around -20 is probably the coldest I've done).