Friday, December 16, 2005

Winterised Cables

Avid Flak Jackets.

The posted delivered a parcel yesterday that'll hopefully contain a solution to my regular cable lubing that now seems to be needed almost every couple of rides. If it doesn't then uphilla with his "recommendation", is in a whole heap'o'trouble !

It's not that I mind a little maintenance, it's just that since the wetter weather arrived my rear der has been snickin' "ghost shifts" on most rides, typically when you need it least.

I guess the main contibutor is that I'm now riding through much gloopier terrain that I used to and all that extra mud and sh!te seems to find it's way into the cable, mainly the final rear der section.

Could it be that perhaps the 5Spot is more susceptible to this problem ? Or its the more direct, rear der cable run on my SRAM ? Which I doubt (tho it may contribute) as I my earlier Shimano rear cable "loop" used to clog up a little on my olMarin.

Oh and I'm also using a slightly larger diameter outer which seems to be allowing more cr@p in to glog the system. During a recent strip down, I found it hard to rethread the inner and after mucho pushing it started to going through the outer. A couple more shoves and it appeared at the other end but after a couple of inches had cleared it then flopped to the side ! It wasn't the inner cable at all, rather grit and mud that had compacted itself inside. Why am I using the larger diameter outer ? Hmmm, I read (somewhere) that it reduces friction as the inner will be free-er, which in turn should lessen ghost shifts. However, Rob came up with a good argument against it; in that the inner isn't as well supported and will cut thru the lining quicker, which'll then increase the friction. Aargh.

You can see from the pic that the Flak Jacket cable outers are fully sealed so any moisture or gloop is now gonna find it very tough to bury itself deep inside. One of the main features over my basic setup are those cable end caps which slim down sugly over the inners. Such a system is employed by top flight Shimano cables and used to good effect by the likes of Rob. The Flak Jackets take this a step further tho by then sliding an outer sheath over the normally exposed cable inners. Thus completing their sealed cable system.

I hope to be fitting these beauty's soon, over the wkend if possible, and I'll provide an update after a week or two's worth of muddy riding. Then we'll see if the theory works !


uphilla said...

Will be interesting to hear how these work out - the ones I have are called 'Drycables', these were offered to me by Chaybo when I bought my Turner. They seem OK, but have not stopped ghost shifting when the weather is wet and muddy.

I think that Shimano XTR cables seem as good as anything - they have rubber sleeves that keep the crud out and are prelubed.

Rob said...

Yeah hopefully this will help, I think it's down to the way the cable routes down the seat stay, dirt and wet will inevitably run down the cable. The red sleeves are perfect for this application.

Agreed re the XTR's, I've tried many solutions over the years but swear by XTR even tho there's plenty that cost more. My F has had the same cables for 10 years + and although not ridden much in recent years it has done plenty of muddy miles. Still shifts sweet as a nut.

The Jek is rather more temperamental with it's 3 runs of outer and fundamentally badly designed cable route but XTR tends to last a couple or 3 years on the rear and virtually permanently on the front. Can't remember last time I changed the front cable though I tend to get them free each time Cannondale replace the broken frame!!

Lube? Good question, I have found assembling stainless cables better with lube but Teflon coated XTR is worse with and last better without. The lube just holds the dirt inside.

Farqui said...

Update; Yesterday, I fitted the rear mech cable and found that the Avid end caps make the outers longer if you cut your new sheath to the same size as the set you've just removed. It seems that the ends caps have approx 4mm section that is filled unlike the basic Shimano end caps. Once I'd shortened the outers to accommodate this "feature", it all came together nicely and is no more complicated to install than standard cables. Albeit that the exposed inner now requires a bright red (yuk) outer to cover 'em.

Chaybo said...

the dry cables use a similiar 'sealed' system as the Avid Flak Jackets, with exception to the fact that the plastic liner runs from shifter to derailleur without interuption.

Uphilla ...... I read on the mtbr forums that you were having some shifting woes. Check the piece of housing nearest the rocker arms and make sure it is not too short ( a nice gentle bend is desired ). Having a short piece of housing there will certainly effect your performance exactly like you describe.

Another possibility is that the teflon cable has gummed up a bit. A slick stainless version may be needed.

option # 3 ... have someone with a Park Dag-1 tool check the der. hanger. Even though the bike is very new, there is still the slight possibility that it could still have recieved large enough of a jolt to knock it slightly out of alignment. It's amazing how easily 9spd systems can be fowled.
(yes, the retro in me still desires to run 8 gears)

nothing more frustratingthan a drivetrain that is fussy.

good luck !


Farqui said...

Uphilla, I've a der hanger alignment gizmo that's currently on loan to Rob. If you'd like to use it then give me a shout.

uphilla said...

Thanks Chaybo, I will give it all a check once the festivities are over, very tempted to put the 8 speed setup off my hardtail on, but will give the current setup a bit more time. Farqui, if nothing else works, will check the alignment - was reminded that I replaced the hanger on my S-works and it made a big difference, but you could see the misalignment by eye. Thanks for the help. y'all

Farqui said...

I've now had a few wet rides since fitting these sealed jobbies and they do seem to work. Although Sundays blat was dry (from above) the trail (below!) was deceptively wet which splattered the bikes with a whole load of goo.

Shifting is still light and accurate and I'll probably really test 'em on a woodland ride this evening - cos it's been raining a fair bit recenty.

Farqui said...

OMG, how muddy and wet was it around Woburn tonight ? It was the worst I've ever seen it. Yet the gears stayed put and didn't ghost shift once. A result. The drivetrain was grumbling a little but that's to be expected with loads a sandy mud being flung about.