[db3266]

Forgive my ignorance but I have the following question.

I bough a Spesh E5 Diverge, stripped it down and put all my Roubaix running gear on it. Including the wheels. Everything was fine, I put a 42mm tyre on the front to investigate clearance and even though it was tight, the tyre and wheel were perfectly in the middle of the fork.

The Roubaix wheels were DT Swiss 470r’s.

I wanted to upgrade the wheels and hubs, so bought some DT Swiss CR1600 dicut.

Put the rear on and the tyre and it was all perfectly centred in the frame.

Put the front on and the rim was offset significantly to the brake disc side.

Why?

I have re-dishes it, so it is now in the middle of the fork. I also got a friend to put it in his truing stand and it is showing as approx 5mm out of centre in his stand. (I couldn’t do this with the 470r as I didn’t think to take that with me)

Is this normal for Specialized Carbon Fact forks on Specialized road bikes?


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[Lone Rager]

Best not to check wheel dish in a truing stand. Use a dish tool, or flip the wheel in the stand or in the fork to check dish.

If the rim is centered between axle ends, the tire will be in the same position after flipping the wheel in the stand or in your fork. If the tire moves when you flip it, the rim is not centered between the axle ends.

If you flip it and the tire doesn't move, but it's off center to the same side when flipped either way, then it's the fork that's off.

 

[db3266]

Yeah I get all that.

The wheel that come off the Roubaix was perfectly centred in the Diverge Fork.

The new wheel I bought was not and I had to centre it in the fork.

After it had been re-centred, I put this wheel in a truing stand and it had a dish of approx 5mm. We flipped it in the stand to check.

Why did the Roubaix wheel fit?
Why did the new wheel need a dish putting into it?


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[Lone Rager]

You get all that and you have the items in hand, so I would posit you're best equipped to answer the question.

 

[esXso]

I just noticed the same problem but with the R470 DT Swiss hub and wheel from a Specialized FSR29. I tried using a dish gauge to center the wheel but made it off center. Found this thread when I hunted for answers.

I guess these DT front disk hubs are an asymmetrical design.

 

[HTupolev]

No idea where a whopping 5mm would come from, but it's common for there to be a little bit of dish in front disc wheels. Oftentimes the disc-side flange is closer to the centerline than the non-disc-side flange, to make room for the disc.

(And like all dished wheels where the spokes on each side are the same gauge, inflating a tire on the rim will cause the dish to move slightly in the direction of the higher-tension side. But this effect is usually much smaller than half a centimeter.)