Cruizin’ not too far from home, my wheel suddenly locked up and sent me on my way without Diet Coker. It was dark so I couldn’t immediately figure out what had happened. But when I picked up my uni to turn it upside down, one side of the wheel fell from the bearing holders. I had broken one of the main cap bearing holder bolts. A quick search later revealed the culprit. The bolt head had sheared off cleanly.
I hope it was nothing more than a faulty bolt but I’ve been noticing some spoke creak recently and think my spokes may not be tight enough. This formerly John Kovachi built wheel has been upgraded to a Bruce Edwards built wheel after I changed out the hub. Upgraded? Yeah right, my wheel building skills (or lack thereof) and quality control are non-existent compared to J.K.'s. I don’t think I ever got the spokes tight enough and wonder if I was creating some stresses in the uni that contributed to the bolt failure. I’ll check tomorrow and tighten up the wheel.
Of course most of the fault lies with the fact that I’ve developed Furniture Disease over the years, you know, the one that causes one’s chest to drop into the drawers.
Meanwhile, it was a short one block back to the house. One replacement bolt later and I was up and rolling.
Yikes! Someone else mentioned in passing in another thread that they had a similar bearing cap bolt failure. Maybe those bolts are not quite up to the task for heavy or aggressive riders.
Is there a stainless or higher grade version of that type of bolt available?
I’m not too keen on having a bolt break on my Coker while I’m riding.
Bruce, you’re scaring me! When I think of the pounding my Coker bolts have
taken on the offroad rides and races I’ve done… and mine are coming up on
4 years old. I don’t think it could be the spoke tension unless the wheel
was really wobbling. Maybe you just had the nuts on too tightly? How many
miles did it have on it?
Glad you’re not hurt,
Nathan
“yoopers” <yoopers.dtyeb@timelimit.unicyclist.com> wrote in message news:yoopers.dtyeb@timelimit.unicyclist.com…
>
> Cruizin’ not too far from home, my wheel suddenly locked up and sent me
> on my way without Diet Coker. It was dark so I couldn’t immediately
> figure out what had happened. But when I picked up my uni to turn it
> upside down, one side of the wheel fell from the bearing holders. I had
> broken one of the main cap bearing holder bolts. A quick search later
> revealed the culprit. The bolt head had sheared off cleanly.
>
> I hope it was nothing more than a faulty bolt but I’ve been noticing
> some spoke creak recently and think my spokes may not be tight enough.
> This formerly John Kovachi built wheel has been upgraded to a Bruce
> Edwards built wheel after I changed out the hub. Upgraded? Yeah
> right, my wheel building skills (or lack thereof) and quality control
> are non-existent compared to J.K.'s. I don’t think I ever got the
> spokes tight enough and wonder if I was creating some stresses in the
> uni that contributed to the bolt failure. I’ll check tomorrow and
> tighten up the wheel.
>
> Of course most of the fault lies with the fact that I’ve developed
> Furniture Disease over the years, you know, the one that causes ones
> chest to drop into the drawers.
>
> Meanwhile, it was a short one block back to the house. One replacement
> bolt later and I was up and rolling.
>
> Bruce
Thanks, Nathan. No, no unpleasant boo-boos from the incident. I had just gotten started when the wheel locked up so I sort of ran off the front.
The bolts were not too tight. I have corrected many a unicycle in our club with overly tightened bolts so I think I do a good job there.
I’m not sure the wheel wasn’t wobbling. If the spokes weren’t properly tensioned, isn’t there a chance that the wheel may have flexed from side to side and put more force on one bearing pocket than the other?
As far as miles on the Diet Coker, I may still be counting in yards.
Absolutely, if you promise to share the results back here. Send me your address and I’ll ship it out to you. I don’t have the head but it may not be too hard to find in the daylight.
Surely in normal riding these bolts shouldn’t be under much strain? The uni sits on the bearings because the top half of the bearing clamp is that shape. (Simplistically) all that the bottom half of the clamp does when you’re riding on the flat is stop the wheel dropping out of the top half if you go over a bump or kerb.
My guess is that the bolt was done up slightly too tightly at some stage in its life.
nathan@movaris.com writes:
>Bruce, you’re scaring me! When I think of the pounding my Coker bolts have
>taken on the offroad rides and races I’ve done… and mine are coming up
>on
>4 years old. I don’t think it could be the spoke tension unless the wheel
>was really wobbling. Maybe you just had the nuts on too tightly? How many
>miles did it have on it?
>
>Glad you’re not hurt,
> Nathan
If he didn’t have the nuts too tight before, I bet his nuts are pretty
tight after that UPD!
But seriously, that has to be the scariest way to fall off a Coker. My
god, I’m going to have nightmares.
Seems to me that the scariest way must be on a street crowded with traffic, in some busy city, going the wrong way, distracted, no pads or helmet, with expensive electronics in my hand…
