stapfam

Down to the LBS today to drop in a couple of wheels for trueing. Not mine I hasten to add but from people that know I understand bikes.

First one is a rear wheel off an old Tourer. 7 speed freewheel 700C wheel but Noname hub and an Arraya rim. Boy did it feel heavy in comparison to mine. This rim was well and truly out. Hit a pothole apparantly and it just went. No wonder the rim went as the spokes are as limp as wet spaghetti. I asked a few questions of the rider and he has had the bike in the family for 15 years or so and has just inherited it. It may be 15 years old but seeing the lack of wear on the tyre- I doubt it has done 1,000 miles. It is retruable but I had a lecture from the wheel builder about getting wheels checked on a frequent basis. Not even my wheel but he made the point that a wheel sitting on the wall or on a bike for a couple of years will lose tension in the spokes. Try and ride it and you are asking for trouble. So just a warning to those of you that buy secondhand bikes--Before riding too much -- get the wheels retrued and the spokes retensioned.

Second one is on My Son-in-laws bike.----AGAIN. He commutes 20 miles a day at Time trial speed. He is a bit on the heavy side and has powerfull legs. Once again he has "Bent" a spoke on the rear wheel. This wheel was only trued a couple of weeks ago so it is was not a "Duff" wheel to start with. Except it is not just a "Bent" spoke- It is a cracked rim.

These are the OM wheels and it will not be worth rebuilding. The Hub is just a cheap one and at the cost of a new rim and rebuild- I know I can get a better wheel for just a little more money online. Well no need as I got a good deal from the LBS on a Mavic Aksium that I know is indestructable.

So moral on this is to look at the rebuild costs before a major wheel re-build. With cheap online prices it may be cheaper to buy a new wheel than rebuild.

Dan Burkhart 

If the spokes lose tension sitting idle, or hanging on the hook, it does not speak well of the builder. That sounds like nonsense to me.
Checking tension on new wheels or 2nd hand wheels new to you is good advice however.

lhbernhardt

Spokes losing tension just sitting there sounds to me like pure rubbish! What forces are acting on the spokes to make them lose tension when they just sit there? Perhaps we should submit this to Jobst Brandt? But I won't do it, I don't want to get totally flamed!

Luis

howsteepisit

It is rubbish. Although its not a bad idea to have things like spoke tension checked periodically, the mech just threw in some extra to encourage that. I hate that, just the facts sir works for me.

I do know that back in the 70s and early 80s it was not uncommon to get machine built whells that had virtually no tesion on them, it was standard faire at the shop I worked at to have to add 2 turns of tension on each spoke in addition to trueing.

CACycling

Recently bought a couple of new in box 1992 MTBs last spring. Spoke tension was perfect and they were true out of the box after all those years.

BigBlueToe

I bought a spoke tensionmeter. It wasn't too expensive. In the spring, or before a tour, I check the spokes. Usually I find one or two that are a bit tighter or looser than the rest. A few quarter-turns of the spoke wrench, a little truing, and the wheels are good to go. For someone with my wrenching skills, the tension meter was a really good investment. (So was the Park truing stand.)

stapfam

Tension anything and over a period of time it will stretch- Doesn't matter if it is a lump of plastic or a Spoke. And this is confirmed by my "Spare" Tandem wheels that I had trued and tensioned 3 years ago. 3 years ago they were perfect and sounded the same as the main wheels that I had done at the same time. Just gone down and checked them and they are not as taught as I would like them. Don't sound loose in any way- but definitely not as though they have just come from the builder.

Not many will have a spare set of wheels sitting on the wall for that long but the "T" no longer does the long enduros that I used to do and I have been lucky with the lack of damage done to the main wheels-----So far. These are top rate rims- top rate spokes and top rate Hubs and well proven for quality. Take the situation of poorer quality parts and Tensioned spokes will pull into the rim and hub aswell as stretch.

So from my experience and the advice of my builder- Check your wheels on a regular basis.

And the other set of wheels I have--The original OM ones from the OCR are sitting on the wall aswell. They were ridden for 6 months and were trued and retensioned after about 100 miles. Only about 2,000 miles on them but "IF" I were ever to use them again- they would need retensioning before use. No twang to the spokes when plucked- just a dull thud.

lhbernhardt

Sounds reasonable. OK, like they say, "one measurement is worth a thousand expert opinions." We need an experiment. I've got some old wheels sitting around that I never use. Suppose I check the spoke tension with my Wheelsmith tensionometer this weekend, and then check the tension at various intervals over the next couple of years? I really think the amount of stretch will be negligible, especially if you check the percentage elongation specs of the steel used to make spokes. Likely oxidation of the material will have a more significant effect as far as turning a twang into a thud. Otherwise, I would be retensioning the wheels I normally use more often. I'm using two sets of wheels fairly regularly right now, and they haven't been retensioned since I built them last year.

Here's an anecdote: Back in the 1970's I had some track wheels built. They were highly-tensioned and tied and soldered. I stopped using them around 1980. When the indoor Burnaby velodrome opened up around 1995, I started using these wheels again. So the wheels were sitting there for about 15 years. I didn't retension the wheels at all, but they were just as tight as when I left them, and I'm still using them! But then, track wheels will pretty well last forever (no brake track, no rain/dirt/grit). I think they will start breaking spokes when the steel crystallizes/becomes too brittle due to oxidative effects or whatever (I have broken 1 or 2 spokes, so they must be under sufficient tension)

I think we need a metallurgist to chime in here! (what do I know?)

Luis.

BluesDawg

I checked mine. What do you think?

lhbernhardt

Yeah, definitely has sat around too long. Maybe you should get another one? - L.

kr32

Whacked, a little super glue and maybe some duct tape.

Velo Dog

This is pure speculation, but there's a lot of energy stored in a wheel. I can't remember the numbers, but each spoke is under quite a bit of tension, and in my case nearly everything has 36 spokes. Might be enough to stretch the metal over time, or to distort the rim around the nips.
For sure, I know i've had well-built wheels loosen as they sit over the winter.

EDIT: I just googled "tension bicycle spokes," and one site said it can be "as low as 80 Kfg or as high as 230 Kfg." Kfg means "kilogram force," and a kilo is 2.2 pounds, so 200 Kfg might be 440 pounds. But I dunno how to put all that together so I can say, "There's as much energy stored in that wheel as in two gallons of gas" or something. Same Web site said the weakest point is always the rim, and I've had many nips pull through. Nothing lasts forever, and I'm guessing a wheel leaning against a wall will eventually lose tension.