Finally decided to drag my TRP caliper into the TRP shop to get the recalled caliper replaced.
What I want to know, is if it’s taboo to replace an inner cable only. My housing looks in good shape, but I worry a bit about where my cable was crimped to the caliper. It’s quite spread/flattened from being crimped, and I wonder if re crimping it could fatigue the cable at all and cause fraying/breakage. There aren’t any loose or broken strands yet though.
I might end up just doing them both. I like the Jagwire that it came with, but replacement is compressionless and I don’t want to deal with cutting that.
Okay, this is weird. UDC specs the TRP with Jagwire Mtn Pro cable/housing, which is compressionless, but I remember when I set up the brake, the housing cut fine, and definitely seemed like regular spiral housing.
I don’t have a Spyre caliper, but it is not normal for the housing to be crimped to the caliper itself. More likely there is a ferule at the end of the housing.
Sometimes the ferules are crimped to the end, but not always. If that’s the case I would trim off the flattened bit of housing, file/grind the end flush, and ream out the liner so that the cable moves freely through it. After that replace the ferule with a decent quality one (especially important with compressionless housing). I like the Jagwire POP ferules, but there are many good ones around. At most you will lose a centimeter of housing by doing this, but you may gain some back depending on the ferule you use. Most housing is long enough that a little trim like this won’t have any effect on the braking.
Naw, my housing isn’t crimped to the caliper, just the cable. My ferule on that end is just slipped on. The only thing wrong with it, is the section of inner cable that has been crimped and I’m wondering if re-crimping it could fatigue it at all.
I will see if I have enough cable/housing to just shorten half an inch or so.
Oh, you’re talking about the cable itself. So, my guess is that you are concerned about the the place where the pinch bolt holds the cable.
First of all, it isn’t taboo to replace just the inner cable. People do it all of the time, even in bike shops. While housing doesn’t last forever it is usually good for a few cables. Unless there is something wrong I wouldn’t think twice about reusing the housing.
Now back to the cable. Cables can be reused, but the crimp you’re talking about is one of the biggest problems in terms of fatigue. If you can afford to trim your housing that will effectively lengthen your cable and move the crimp to a new spot. If you use a new cable you can try impregnating the cable with solder at the end. It does two things: it eliminates the need for a cable end, and prevents the cable from being pinched flat. This makes servicing the cable easier since you can pull it to relube without worrying about getting it back into the housing.
If you do go with the solder it’s nice to leave a little rounded ball end on the cable. You can always file it so that it’s not too sharp if you halve a hard time with the ball end.
Meh, I ended up deciding to just do the cable and the housing. I found some with a reflective stripe, that I like to go with my reflective rim and reflective sidewall.
Actually a bit of an interesting story, I took my caliper back to TRP to get the new one, and they gave me some free cable and housing to go with it. Got home, and the cable has road ends on it (I’m running a mountain lever). Anyway, I got looking around, and thought it’d be nice to get a different color housing to match my uni. I wanted to get some Kool Stop pads anyway (my new caliper didn’t come with any ).
One more question, I’m running an Avid Speed Dial 7 Mtn brake lever, and really like it. When I had the cable off, I noticed how thin the return spring is on the lever. Return is snappy, but are these springs a weak point? I’m just thinking about UPD’s (and all the times I’ve sat there and flipped my lever repeadedly while talking to someone :)), and wonder how durable they are.
Thanks Jtrops. Always there to answer my mechanical questions (and very helpful to boot).
The return spring on the lever is for the lever blade itself, and has no real function outside of that. At one point the caliper springs got so light that they couldn’t return the lever back to its rest position, and so they started putting springs in the levers. With modern slick mandrel drawn cables it is almost unnecessary with most calipers, so I don’t think you have anything to worry about.
I have SD7’s on a uni, and a couple of bikes. I’m not worried about the return springs at all. The weak part of these levers is the lever blades. They are designed to bend, and need replacement after even a small impact. The upside is that you can replace just the blade. The downside is that it’s often cheaper to find the whole lever assembly.
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(and very helpful to boot).