|Loose nips on Ksyriums||CRM|
Jul 9, 2001 2:35 PM
|I have a relatively new pair of Ksyriums (maybe 15 rides on them) and about 4 or 5 rides ago, the spokes on the rear wheel came loose and the wheel went out of true. It wasn't in response to any major hit or anything, but when I got off the bike, the rear wheel wouldn't even turn because it was up against the brake pad.
I trued it up and it happened again on the next ride. And the next. And the next. I'm at my wit's end. Is there anything I can do to keep the spokes tight so they won't loosen like this? It's the same non-drive-side spokes that keep loosening. Any suggestions???
Jul 9, 2001 2:54 PM
|When you tighten the relevant spokes, you are in part twisting them; then when the a given spoke passes the bottom of the wheel and is partially unloaded, it will unwind in the nipple to straighten itself. The effective overall length will be more and the wheel will be out of true. This is more significant on low spoke count wheels such as these. The answer is to relieve this stored torsion when you're truing, by backing off about 1/8 turn for each 1/4 turn advancement you make.|
Jul 9, 2001 5:39 PM
|First, in order to true a Ksyrium wheel you need two special tools - the special wrench for turing the nipple (now avail. in aluminum - yeah!) and the slotted plastic tool to hold the spoke from winding up - both of which come with each set of wheels. Now assuming that the original poster has enough wheel savy (and one should to mess around with the new low spoke/high tension designs) to use the tools supplied I don't see how spoke windup can be much of a factor. It's an answer to a different question. Also, spoke windup is pretty easy to spot on a large bladed spoke. |
Nipples tend to loosen if there is windup, but will also loosen without windup. Usually low tension is the culprit, but ultimately everything can be done right and they'll still loosen - the thread pitch is a bit course and if the fritctional forces are low enough they will loosen (I've had this happen on mine). Using linseed oil is a traditional treatment for threads, but there are thread locking compounds that are also used (just don't use the permanent red variety). In fact DT Swiss now makes a nipple that comes with a dab of loctite on the threads. I've also seen a version with a nylon ring that works just like a nylok nut.
I'd advise that you first try to hit up Mavic on the warranty - the product isn't performing. If it's too late or you don't want the down time then get your shop to put something on the threads. I've even seen the guys a Wheelsmith grap a pair of dikes and give the nipple a bit of a crimp to keep them from backing off - after they worked on the wheel and it came out of true. Obviously this isn't a good idea for the unique aluminum Ksyrium nipples.
Jul 10, 2001 4:12 AM
|I didn't consider the unique design of the Ksyrium before I posted my response. Anybody want to say 'Forum pact"?...
I didn't know that Mavic made proprietary tools for the K which would prevent wind-up occuring; but given that spokes are still loosening, I can only imagine that it is a problem in the design. Flat, aluminium spokes spell trouble to me because they're so flexible... beyond this, I don't know.
I maintain however that the only cause of spoke loosening in a regular wheel is latent spoke twist. A spoke is like a long strain bolt; under normal use, the nipple is always preloaded, and can't turn; only if the spoke was totally unloaded would the nipple be free to turn as a response to vibration or whatever, and this doesn't happen to anything but severely under-tensioned wheels.
I've heard that Wheelsmith used to crimp nipples before; they also used to tye and solder spokes before it was shown that this is a pointless activity, and I heard recently that they also used to hold a spoke in pliers whilst tightening the nipple in order to prevent twist, until it was shown that this doesn't work either. Nobdy's perfect, not even the venerable DT who gave us Revolution spokes which have virtually no resistance to twist, and now threadlocked nipples in admission of this fact.
|Correct, sorry...||grz mnky|
Jul 10, 2001 5:12 PM
|>Flat, aluminium spokes spell trouble to me because |
they're so flexible... beyond this, I don't know.
Actually the aluminum spokes are so beefy that they are similar or have less flex than a SS spoke. What the aluminum lacks in material properties is made up for with a beefy section design.
Most folks aren't having problems with Ksyrium spokes loosening up, although I had a replacement one come loose - gonna use some "monkey mung" if it loosens again. I got into the whole replacement thing as the result of a crash. Until that time things were bomber. I'll probably send the wheels back for a factory overhaul during the off season.
No doubt - if twist is present you're going to have problems. However, you can still have properly tensioned and non-twisted spokes come loose. Had it happen after Wheelsmith repaired a wheel for me - it was a crappy (Trek) Matrix rim. At the time the guy claimed that the rims are fairly soft which allowed the properly tensioned spokes to go slack. Kinda funny that Trek had bought Matrix, but now they're gone and we have Rolf in their place.....hmmmm.
|say grz mnky, did you see....||keith m.|
Jul 10, 2001 12:28 PM
|my spinergy rant dedicated to you about two weeks ago on the general message board? If not, go look it up, you may find it ammusing.|
|You're Scaring Me!||grz mnky|
Jul 10, 2001 3:39 PM
|Dunno if I should go looking. :-) I guess there's a big difference between "dedicated to you" and "directed at you".... |
Been on some forced vacation - you know, use all your vaction then take time off w/out pay as the hgih tech companies try to keep from doing further layoffs. I typically don't use the computer at home - I'd rather play outside and get greasy. The Mrs. only lets me in the house around feeding time, after passing "hand inspection."
|Found It!||grz mnky|
Jul 10, 2001 4:22 PM
|Finally found it over in the "general" section, but had to page through everything by author name - I guess I'm glad your name isn't "William M.".... |
Interesting info about the hub failures. It's not that I hate Spinergy per se, I just find it rather amusing for them to make all the amazing claims for a particilar design, then come out with totally new product within 12 mos. and more amazing claims. Kinda like being "most improved" 3 years in a row or the kids in Lake Wobegon all being "above average". If the product were truly great you'd kinda expect a manufacturer to stick with it for a while, instead of dropping it in their first year, repeatedly. Heck, if you like their stuff just wait six months for supergo.com to start blowing it out at half off (along with women's dresses.....opps!)
Now looking at it from and engineering perspective I can find lots of fault with many of their "new and improved" designs. Ultimately there is no free lunch in either the engineering or the business world. Everything comes at a trade off and the rest of your competition is not likely to be a bunch of dopes. The real dopes are the ones that think this. I guess I have the opinion that they are not much more than modern day snake oil hucksters of the bike industry. If their current "product XYZ" is so great, how come they keep changing things? Sure their is a time and a place for radical designs and if you're a world class time trials rider maybe they have an edge in this narrow segement - besides if they pay you to ride their stuff are you really going to turn them down unless you have a better deal?
There is no excuse for the crappy customer service, but then Mavic isn't exactly winning any awards either. I'm pretty happy with the Ksyriums, but wouldn't even consider using their similar MTB products (Crossmax USST, etc.) if I have to pay for them. I figure there is one thing for certain in the MTB world (at least for me) - I'm going to damage rims, no ifs ands or buts. You've gotta be able to rebuild/repair/rplace the wheel easily and economically. Can't let something like a taco'ed wheel ruin your week in Moab or some other place. I also won't use the C'dale Lefty fork for the same reason. How do you re-rim the front wheel on a hub with an axle that is an intergal part of the fork? You need a special tool and do you want to carry one with you or hope the LBS in the sticks has one? Our LBS (non'C'dale dealer) has one hanging in the service area awaiting parts. Looks like the guy taco'ed the wheel while driving around town with his jazzy new bike on a trunk mounted rack.
Ultimately I think it does pay to be a little skeptical and not believe all the marketing hype that gets shoved at us. heck, in most companies the marketing and engineering types don't even like each other. I also find fault when some product gets glowing reviews in a glossy mag and follows with a full page ad. It's pretty well known in lots of industries that if a mag slams a product then the advertiser pulls out. I want to see things proven, I want to know they're robust desings, and if someone makes a claim I want to see the data.