A customer dropped off a Fulcrum Speed 40 rear wheel with us.
The image above is after the work was done,
but the rear wheel had noticeable wobble.
Since the customer themselves could clearly see the wobble,
I predicted before even looking at the wheel
that a spoke was probably bent
and causing lateral runout at that point—
and I was right.
↑The spot I fixed
↑The spoke I replaced
Before doing that, I inspected the front wheel, and it had perfectly centered centering—almost unnaturally so. There's a "depth" to how perfect centering can be, and with this level of precision, I asked if we had a history of inspecting this one before. Turns out we did. For the rear wheel, except for the nipple on the replaced spoke, I only slightly turned two nipples on either side of one of the quiet spots, and once I applied the centering gauge after straightening the lateral runout, it was dead center. On rear wheels, a few years after inspection they sometimes drift slightly to the right, but still.
Both wheels had tires mounted, but I removed them during the work to apply the centering gauge properly. For the front wheel, I only barely turned one nipple, so the work basically amounted to just removing and reinstalling the tire. Since there's a history of this from before, I didn't charge for labor this time to avoid double-billing. I didn't take photos, but for the rear wheel I replaced the outer bearing on the freebody and added grease to the hub's USB bearing.
Now, about those tires I removed and reinstalled:
They were Vittoria Corsa Control tires.
The center tread is a slick with grooves,
and the sidewalls have four wood grain patterns cut into them.
I wonder if people actually lean the wheel over far enough to use that last wood grain pattern,
but in that sense the IRC Formula Pro has a similar pattern.
The rule is to mount the tire so that the front-to-back line and the wood grain patterns on either side form an arrow,
following the rotation direction, but:
Wood grain pattern
Wood grain middle pattern
Wood grain middle-middle pattern
Wood grain middle-middle-middle pattern
Like this, with each wood grain pattern, the theoretical mounting direction reverses. If you only lean the wheel over to about the third wood grain middle-middle pattern, it would actually make more sense to mount it backwards against the last wood grain pattern. But does this tire have a specified rotation direction?
Actually, it does.
The markings are located on top of the flattened fourth wood grain pattern, so the text and arrow in the image above are sitting on top of the third wood grain pattern. Therefore the rotation direction specification is the same as the general interpretation of the wood grain pattern.
With a pattern like this on the tire and dual labels, the rotation direction specification doesn't seem obvious, so I'd guess plenty of people are mounting it backwards from the specification. In fact, on this front and rear wheel set, the rear wheel was mounted backwards. Whether mounting it opposite to the spec actually makes a performance difference is questionable though.
In the image above, there's "THAILAND→", but that's not pointing toward Thailand as a direction—
it's just "MADE IN THAILAND" followed by an arrow.
The image above is after the work was done,
but the rear wheel had noticeable wobble.
Since the customer themselves could clearly see the wobble,
I predicted before even looking at the wheel
that a spoke was probably bent
and causing lateral runout at that point—
and I was right.
↑The spot I fixed
↑The spoke I replaced
Before doing that, I inspected the front wheel, and it had perfectly centered centering—almost unnaturally so. There's a "depth" to how perfect centering can be, and with this level of precision, I asked if we had a history of inspecting this one before. Turns out we did. For the rear wheel, except for the nipple on the replaced spoke, I only slightly turned two nipples on either side of one of the quiet spots, and once I applied the centering gauge after straightening the lateral runout, it was dead center. On rear wheels, a few years after inspection they sometimes drift slightly to the right, but still.
Both wheels had tires mounted, but I removed them during the work to apply the centering gauge properly. For the front wheel, I only barely turned one nipple, so the work basically amounted to just removing and reinstalling the tire. Since there's a history of this from before, I didn't charge for labor this time to avoid double-billing. I didn't take photos, but for the rear wheel I replaced the outer bearing on the freebody and added grease to the hub's USB bearing.
Now, about those tires I removed and reinstalled:
They were Vittoria Corsa Control tires.
The center tread is a slick with grooves,
and the sidewalls have four wood grain patterns cut into them.
I wonder if people actually lean the wheel over far enough to use that last wood grain pattern,
but in that sense the IRC Formula Pro has a similar pattern.
The rule is to mount the tire so that the front-to-back line and the wood grain patterns on either side form an arrow,
following the rotation direction, but:
Wood grain pattern
Wood grain middle pattern
Wood grain middle-middle pattern
Wood grain middle-middle-middle pattern
Like this, with each wood grain pattern, the theoretical mounting direction reverses. If you only lean the wheel over to about the third wood grain middle-middle pattern, it would actually make more sense to mount it backwards against the last wood grain pattern. But does this tire have a specified rotation direction?
Actually, it does.
The markings are located on top of the flattened fourth wood grain pattern, so the text and arrow in the image above are sitting on top of the third wood grain pattern. Therefore the rotation direction specification is the same as the general interpretation of the wood grain pattern.
With a pattern like this on the tire and dual labels, the rotation direction specification doesn't seem obvious, so I'd guess plenty of people are mounting it backwards from the specification. In fact, on this front and rear wheel set, the rear wheel was mounted backwards. Whether mounting it opposite to the spec actually makes a performance difference is questionable though.
In the image above, there's "THAILAND→", but that's not pointing toward Thailand as a direction—
it's just "MADE IN THAILAND" followed by an arrow.