I flexed the steel rim on my original stock Coker pretty badly the last couple of times I rode it. Now I am extremely apprehensive to ride it aggressively (which I feel compelled to do every time I ride) until I get the rim tightened and trued because I know it’s a Taco waiting to happen!
I called my local bike shop today to find out how much it would cost to get the rim trued… and they told me they couldn’t true it for me because the 36" rim wouldn’t fit in their truing stand! Is this a common problem? Are most truing stands incapable of handling rims this size? I assume there are some stands that are available that can handle a 36" rim… are they less commonly available (or in use at bike shops)?
Try telling them they can clamp your frame in the repair stand and then use the frame as a truing stand.
Never happened to me, I don’t own a coker, and if I did, I would true it.
Try riding aggressivley on the airfoil. If I was you, I would ride the AF exclusively to get used to it and sell the steel cheap to get someone interested in cokers.
> Try telling them they can clamp your frame in the repair stand and then
> use the frame as a truing stand.
What he said. The truing stands I am familiar with do not accept
unicycle wheels because the hubs are different from bicycle hubs.
They should still be able to do a good job for you, provided the rim
isn’t trashed.
I haven’t worked on 36" wheels, but I know they sound different (lower
tone when plucked) than smaller wheels at the same tension. It might
be a good idea to remind them to use a tensiometer.
Your frame is an excellent truing stand. Using cable ties or some other simple devices as indicators you can true up a wheel with a reasonable amount of precision. But first think about what has happened.
Ideally, before your wheel was built, you could have laid the rim on a flat floor and it would lay flat…it would not show any warping. After what you (and myself as well as many others) have done to this type of wheel, if you unlaced it now and laid it on the floor it would be warped. That means that to make it straight you will have to apply some amount of uneven spoke tension. Maybe alot of uneven spoke tension.
On my wheel, I used a piece of wire attached to one of the frame legs as an indicator and found out where it was warped using the rim (not the tire) as the reference. I got it straight (flat in one plane) and centered (it didn’t change radial position with rotation) by picking which spokes to tighten or loosen. Then I centered the wheel in the frame by tightening all the spokes on the required side because my spokes seemed too loose.
I retrued the wheel after riding it about 40 miles. It is nicely trued and I rode 23 miles on the Chilly Hilly bike ride on Bainbridge Island and have commuted another 100 miles or so. But I don’t trust it at all any more because the spoke tension is obviously and noticably uneven. Also, I have the stock hub which is really too narrow for this wheel. If the spokes are too tight or too loose it could taco just hitting a bump. I have a wheelset on order with the wider hub. I hope you do the same.
One mechanic that I’m friendly with did true it for me in the repair stand… so I guess I can try and go back there when he is around.
I have been riding aggressively on my airfoil (almost exclusively) and I have gotten a lot more used to it… but I’ll never sell my steel rim Coker - I’m actually looking to buy other people’s steel rims (cheap :D) when they upgrade to an Airfoil.
Different rims have there pro’s and con’s and even if I’m the only Coker rider in the universe to feel this way… I prefer my heavier, more flexible steel rim Coker over the Airfoil for certain types of riding situations… even if I can do the same maneuver just as well on the Airfoil.
Physics is physics… and from my (extremely limited) knowledge of the subject: greater weight = greater flywheel effect… which is something that I feel is a big advantage for certain types of riding.
Thanks Harper… your knowledge and insight is much appreciated (as always)! Do you have a steel rim wheelset on order or an Airfoil wheelset? If steel, was your choice based solely on economic factors… or was there some other reason you chose the steel rim? Also… which wide hub are you getting - the 100mm (center flange to center flange distance) hub or the 71mm (center flange to center flange distance) one?
“harper” <harper@NoEmail.Message.Poster.at.Unicyclist.com> wrote in message news:harper.1mmipw@NoEmail.Message.Poster.at.Unicyclist.com…
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> I retrued the wheel after riding it about 40 miles. It is nicely trued
> and I rode 23 miles on the Chilly Hilly bike ride on Bainbridge Island
> and have commuted another 100 miles or so. But I don’t trust it at all
> any more because the spoke tension is obviously and noticably uneven.
> Also, I have the stock hub which is really too narrow for this wheel. If
> the spokes are too tight or too loose it could taco just hitting a bump.
> I have a wheelset on order with the wider hub. I hope you do the same.
>
>
Thanks Harper, I had, purely from the Physics of it guessed that a wider
hub would probably be advisable for a coker, and that a retrued bent wheel
would probably have an uneven spoke tension. It is good to hear from an
expert that this is in fact correct. Nicely put, and in such a way that it
is meaningful to us all.
The video shown elsewhere in this thread is quite an eye opener.