Almost always the hole count. A rim and hub have to share the same drilling — a 32-hole rim needs a 32-hole hub, and there is no way around it. The rim is chosen first because it sets the number every other part has to match.

The other common blocker is the spoke head. A Straight-Pull hub takes Straight-Pull spokes and a J-Bend hub takes J-Bend; they are not interchangeable, so choosing the hub narrows the spokes you will be offered.

Yes. Those ratings are advice, not a lock. Recommended is what we would put on our own bike for your riding and weight, Approved will do the job, and Not Recommended means we think you will be unhappy with it eventually — usually too light for the load, or a rim that will not enjoy the terrain you described.

What is genuinely blocked is only ever physical: parts that will not go together are filtered out before you see them.

It follows from your weight, how hard you ride, and what the wheel is for. A light road rider on smooth pavement is well served by 24 or 28; a heavier rider, a loaded tourer, a tandem or an e-bike wants 32 or 36 and the extra material that comes with it.

This is exactly what the weight and effort questions are for — answer them honestly, including gear, and the recommendations move with you rather than with an average buyer.

Brass unless you have a specific reason not to. It is stronger, far more forgiving when a wheel is trued years from now, and it does not seize into the rim the way alloy can once moisture has been in there.

Alloy saves a genuinely small amount of weight — a few grams across a wheel — and is the right call mainly on light race builds where every gram is being counted deliberately.

The rim decides. Some rims are drilled so the nipple sits down inside the rim cavity and is reached through the valve hole; others take a normal external nipple at the spoke bed. Pick the rim and the answer is already made, which is why incompatible nipples stop appearing once a rim is selected.

For most builds, 3-cross is the default for good reason: it handles drive and braking loads well across the usual hole counts. Lower cross counts suit low-spoke-count and lighter builds; the pattern options you are shown are already filtered to what works for your hole count, wheel position and brake type.

If your hub is Straight-Pull the pattern is not a separate choice at all — the flange geometry dictates it, and our builders use the pattern that hub requires.

Spoke length is calculated from the rim’s ERD and the hub’s flange geometry, and we work it out for your exact combination rather than trusting a published chart. If you want to see the maths yourself, the Spoke Length Calculator is the same tool we use at the bench.

When you send us your own rim or hub we measure it on arrival rather than assuming, because published figures and real parts disagree more often than you would like.

Yes. Choose the supply-your-own option for that part and tell us what it is, how many holes it is drilled for, and what condition it is in. You pay the lacing labour rather than the part, and we check the component over before it goes into a wheel.

That is what the required questions are doing. Brake type, wheel size, axle standards front and rear, and the driver your cassette needs — get those four right and the wheel will fit. Where only one answer is possible for what you have already told us, we fill it in and say why.

If you are unsure of an axle or driver, the safest source is your frame or hub manufacturer’s spec page. If you would rather not guess, send us the bike details and we will confirm it for you.

Yes — a tubeless rim still needs the right width tape and a valve to seal against the rim bed, and they are not automatically included with a rim. Add them with the build so the wheel arrives ready to set up rather than one part short.

Lead time depends on what is in stock for your combination and how many builds are ahead of yours. Email or text us with your parts list and we will give you a real date for that specific build rather than a generic estimate.