Light(ish)weight Pompetamine

They're tubeless ready, not tubeless only. If you're looking at saving weight (where it matters most) on a budget, I would definitely be looking at a tubeless setup.

Pacenti CL 25 rims come to a similar price and (claimed) weight but with a wider profile, which would be beneficial if you're running wider tyres.

If you're looking to go cheaper and lighter still, you could look at some eBay hubs. These would work out around £90 cheaper and (claimed) 50g lighter than the hope hubs Tester posted. However, the hope build is more likely to be a wheels-for-life setup, whereas these would simply be a wheelset to use until you've got more money to replace them if (when) they fall apart. I'm sure they'd be more than up to the required use anyway.

Something like this would save around £25 and a little bit of weight over your Ritchie stem depending on length (mine is 90 or 100mm and came in at around 115g IIRC)

It's the little things like this that add up to a decent cost/weight saving, but at the end of the day, you've got to ask yourself how long you expect these parts to last and stretch/shrink your budget/expectations accordingly.

Iower, thanks for your input - extremely helpful.

I'm certainly looking at this as a long-lasting bike, and kind of hoped my spec was pushing in that direction. I'm trying to go for quality where I can - within reason - and am stretching the budget to make sure I get something light-weight, but also built with decent parts. Last I checked, the weight was just under 8.5kg, albeit without cables, BB or sprocket. Finished bike will hopefully be below 9.5, but will have cost over £1k, which is more than I'd planned.

Wheel suggestions are extremely helpful. I haven't used tubs since I ran them on my road bike as a teenager (MANY years ago) when they were nothing but a pain. I realise going tubeless may save a couple of hundred grams, but I think I'd still rather use tubes unless there are other compelling arguments for going tubeless. I hadn't realized notubes were tube or clincher compatible - I'll give them a re-look.

I'll also check your stem - agreed, lots of 20g savings make a difference.

Thanks again

Jules