Dished or dish-less?

[Once A Hero]

When setting about getting a rear wheel built up, how do you determine the amounting dishing required if the frame isn't present?

I've found a few times now that when I've gotten wheels back from the builder that they need different dishing to that which they have been built with. In both cases the frame wasn't present during or discussed prior to the build, and I don't want to fall foul of the same problem on my next set of wheels. Surely you don't have to take a frameset in when getting wheels built?

 

[hamster]

The only thing necessary is the OLN of the frame (typically 135mm except for modern stuff or 130 for the very old).

Then you calculate spoke lengths and set up your dishing gauge accordingly.

 

[benjabbi]

Dishing is usually done relative to the hub, to centralize the rim between the locknuts. If the frame has an offset back end like a Pace then this is taken into account in the spoke calculation with the centre to flange dimension. If the centre to flange is say left 30mm right 20mm but the frame is offset 5mm to the driveside then the centreline shifts 5mm to the left on the hub giving c to f dimensions of 25 left 25 right which gives you equal spoke lengths and a dishless rear wheel. The builder would need to know this before starting.

 

[pete_mcc]

So few frames built to suit a dishless wheel that it really shouldn’t be an issue. 99.9% of frames will just require a centred wheel so the builder shouldn’t have any issue.
So unless you’re building for a Pace or a Bradbury Manitou I wouldn’t really worry, but if you’re getting wheels with varying degrees of dish then I would question the builders ability

 

[FluffyChicken]

Re:

It's easy to check if they dished it central (as above, pretty much every bike will be).
Just turn it around, rim should be in the same spot.


If it's not, then it's dished wrong.
OR your axle has a problem in the frame.

If it is properly dished, then your frame has a problem.

 

[Once A Hero]

If the frame has an offset back end like a Pace

How do I determine if a frame has an offset back end?

So few frames built to suit a dishless wheel that it really shouldn’t be an issue. 99.9% of frames will just require a centred wheel so the builder shouldn’t have any issue.
So unless you’re building for a Pace or a Bradbury Manitou I wouldn’t really worry, but if you’re getting wheels with varying degrees of dish then I would question the builders ability

One of them was my Pace so that makes sense.
The current wheel which appears wrong in the frame is on my '90 Kona Explosif - could that require a dish less wheel?
If anyone has a list of frames requiring dish less wheels that would useful to see.

It's easy to check if they dished it central (as above, pretty much every bike will be).
Just turn it around, rim should be in the same spot.
If it's not, then it's dished wrong.
OR your axle has a problem in the frame.
If it is properly dished, then your frame has a problem.

I'll check this, but it's definitely a bit left in the frame at present.

 

[bantamsuper]

Mystery prob I've just measured seat stay to rim there's 6mm difference. Does this mean r-wheel should have an offset?
Frame 96 Kona Kula 8 speed XT hub Rims XM317(originals X217)

PS: it came to light with difficulties in setting up rear (XT) v-brakes

 

[FluffyChicken]

No, frame is normal.
Either whelk is build with an offset
Or frame is bent
Or stays are just not equal at that point..
Test the wheel, see above...

 

[jonthefish]

Like Fluffy C says flip wheel over drive side to non-drive to check.
I had similar issue with an Explosif frame and it was the rear triangle that was out of alignment. Sheldon Brown's string test will tell you if misaligned (scroll down to "checking alignment (symmetry)"

Bicycle Frame/Hub Spacing

A bicycle frame and fork should match the wheels that are to be used in it. Older bicycles used narrower spacing, but older frames can often be spread out to match more modern wheels.

www.sheldonbrown.com

 

[Tootyred]

For my 2 pence worth....yes, probably a bent frame as said above.

I would suggest you buy this download....its even got jig plans....i built one from here and its better than anything this side of cast iron!

Its £9. Lots in it for new and old hands.

And has acess to a great, simple, spoke calculator.

Wheel Building and Spoke Lengths for cycle wheels

Wheel Building and the Spoke Length Project. A total package for serious wheelbuilders.

www.wheelpro.co.uk