Boring but necessary question for the mechanically inclined. Really appreciate your time in answering, here goes…
OK, so I’ve been commuting and training and just happily rolling around on my KH 36 for a few months, racking up 75 miles or so / week, and I’m just wondering what I need to do for spoke health in the long term. This morning I noticed a single finger-loose spoke which i tightened a bit just to bring it in line with the rest. I chatted briefly with the guy at my LBS who’s a wzard wheel builder, and he said he could take a crack at checking and tensioning the spokes, but I’m wondering what I should be aware of with this larger diameter and what’s recommended for maintaining a strong, true 36er wheel. I haven’t had any issues with the wheel; this question concerns proper preventive maintenance. :o
Thanks again.
I read somewhere that if a guy at your lbs tensions the spokes you should make sure that he doesn’t test tension by plucking them. It would work, but since he will be used to smaller wheels he will want them to sound higher pitched and possible over tighten them.
My wheel d00d apparently uses some fancy device that measures spoke tension, so getting them even shouldn’t be a problem. I’m just wondering if / when it’s a good idea to have him do his thing…
I’ve tensioned over 1/2 dozen 36er wheels with this:
http://www.parktool.com/product/spoke-tension-meter-tm-1
Only 1 wheel did I ever have problems and it was due to defective spokes. They broke several inches from the J bend.
When a wheel is properly tensioned and stress relieved it is good for a long time. I’ve been able to run years with minimal maintenance.
If using the TM-1 a reasonable setting for a 36er with a Stealth or Stealth 2 rim seems to be about 22.
It is a good idea to have the wheel tension set evenly. It will prolong the life of the wheel immensely. All my bike and uni wheels get a full check and tuneup as soon as I get them. New wheels sometimes have less than stellar builds. Getting them to a consistent reasonable tension and stress relieved properly takes some practice, but it is definitely worth learning how to do.
It makes you popular with other local uni riders for sure.
What tension does this “22” represent in kgf?
Greetings
Byc
For 2.0 spokes, about 85 kgf according to the Park Tool page:
http://www.parktool.com/blog/repair-help/wheel-tension-measurement
VERY good info, UG, others. Thanks! 
Yes, I agree. Very good information. Thank you! I believe I will be stopping at my LBS on the way home to buy a TM-1. I bought a second-hand original Coker a couple months ago and haven’t yet dared to fiddle with the spokes.
Ah, thanks for the link to the conversion table (did read this sometimes in the past but forgot).
I have the spoke tension on my 36" set to something around 110kgf, according to an iPad-App called Tensioner. The App translates frequncy into tension (when provided thr right information about spoke length, thickness and material).
Also used a guitar tuner for some time. (Can’t remember the note i used to tune it too, will have to measure it again).
Greetings
Byc
coker spoke tension
With the help of a b*ker buddy I thought I would tune up the wheel of the Coker big one that I got off the forums. Is 22 the recommended tension on the park TM-1 for the newer coker rim?
85kgf is fairly conservative for modern rims. The tension window is normally between about 85 and 110kgf. The problem with 36er wheels is accidental over tensioning. A lot of expert builders tension by feel, and with super long spokes they will deflect more at any given tension than shorter spokes. This makes a tension meter very useful on Coker’s.
So, the short version: 22 would be okay, I would go to 24 (107kgf). This will give you a slightly stiffer wheel, but more importantly spoke movement due to the natural stress/release cycle will be minimized. Really you will be fine anywhere within that range, try 23;)
Thanks jtrops I will give it a try tomorrow.
Thanks for that info, I just received my TM-1 too which I’ll use on the second hand 36" I just bought.
It’s a QX_Series with disc brake but I find the wheel is not centered in the frame. It looks like the rim is centered on the hub, but since the hub is not symmetrical, the tire appears to be off set. I was waiting for the ParkTool before trying to shift the rim a bit.
First I would check to make sure that it is the wheel which needs adjustment by putting it in your frame backwards. If the offset moves to the other side it’s the wheel, if not it’s the frame.
Once you’ve determined for sure that the wheel dish is off set the disc side spokes at the correct tension for your rim. Then adjust the non disc side spokes to correct true and dish. You will find that the disc side has more tension due to the higher bracing angle. So you want to make sure it’s not greater than what the rim can handle. So, all adjustments should be made on the non disc side. Don’t be surprised if the spokes end up in the 16 or 17 range on the tm1.
Is there a problem with first loosening the spokes on the disk side, then tightening the spokes on the other side ? If both sides are tensioned in the ballpark of what they should be, this would keep the overall tension similar to what it was. I’m talking about 1/4 turns here…
I should start by saying that this feedback was about tension, and not dishing. I included the bit about dishing because having different tensions on different sides of the wheel may seem incorrect to someone who doesn’t work with wheels much.
In your scenario you would end up with a rim offset to the non disc side, in other words the rim wouldn’t be centered between the bearings. In wheels with asymmetric dishing the disc side will be under higher tension than the non disc side. By adjusting dish via the disc side spokes you run the risk of over tensioning those spokes, and possible rim failure. By setting the tension on the disc side first you are establishing a baseline that is within the limits of the rim, and then the non disc side spokes will have lower tension. It is not uncommon for the non disc side to have a tension value 40-50% lower than the disc side. The strongest asymmetrically dished wheel will have the high tension side at the limit of the acceptable tension range for the rim.
Thanks for this post. I’ve built my 26 and 29 wheels from parts and have had no problems with them at all. The only wheel I bought was the 36 and I have had doubts about its factory build.
I’ve read 22 somewhere else… This confirms.
That actually makes perfect sense to me, but I hadn’t thought of it that way in my head up until now. Thanks
So does tightening the spokes on the non-disk side lower the tension of the spokes on the disk side? (assuming a wheel built properly)
On a properly built wheel, meaning that it is dished and true (and evenly tensioned), you won’t find it necessary to make such a dramatic adjustment to the dish.
If you start with a symmetrically dished wheel (rim brake only):
and then adjust the dish so that the rim is no longer in the center,
and you make this adjustment only by adding tension on one side,
you will find a gain in tension on the side that you didn’t touch.
If you have an asymmetrically dished wheel and you re-dish to put the rim in the middle of the flanges you will have the same scenario as above. If you instead reduce tension on the disc side as you add tension on the non-disc side you will find in the end that the rim is centered in the flanges, and the overall wheel tension is even on both sides. The rim won’t be centered in the bearings anymore though.
Good tip about swapping the wheel to check the offset. I’ll try this over the weekend.
The guy who sold me the 36" (he only covered about 200miles on it) told me that he checked the spoke tension once in a while, and that it is something every unicyclist should do now and then. I think that what might have happened is that he put the same tension on both sides, feeling spokes by hand, not using anything to measure the tension. And ended up putting the same tension on both sides, though originally the non disc side was looser than the disc side.
I checked a few spokes and they were all in the 24 region on the ParkTool TM1. So that’s probably him, trying to take good care of his uni, who ended up offsetting the wheel by about half an inch.
I was thinking that I’d start undoing a quarter turn on the spokes on the opposite the disc, then adding a quarter turn on the disc side until I get the rim centered. Having read all of the above, I now realize that I’ll have to check the tension closely as I do that.