Went and picked up an older version of a Carrera Blast last night so I can do the usual STW Dad thing of getting it better and lighter. It came sans saddle and seatpost, so what size do I need? I popped a 27.2 in there last night but it waggled about a fair bit before tightening up. 30.9 was too big and I can’t imagine it being something in between – that would just be weird.

Also looking for some lightweight 36 hole disc hubs if you know of any. Around £50 for front and rear would be nice.

My eldest has a Carrera blast. Off came the bars and stem, on went some (hand sprayed) old alu ones, lock on grips, changed the forks (how much did they bl00dy weigh!) with some 26″ dual air rebas, pumped loads of -ve pressure to shorten them (next service will have the internals changed a little). Want to change the wheels and crankset next as that’s where a lot of weight hiding.. Easton 27.2mm seat post fitted fine btw. LX hydraulic brakes and trigger shifters rather than the clarks mechanicals and horrid grip shift, much better for small hands.

It is a 27.2 seatpost – doubt you’ll find any hubs significantly lighter for £50 but have a look on eBay for mobster hubs from aus, the run about £70 for a pair

Does it have Clarks CMD-7 cable disc brakes? I don’t know if my daughter’s bike had ones from a bad batch but they were useless, the worse brakes I’ve ever used. They were immediately replaced with Avid BB5s before I would even let her ride it.

Standard bars were also far too wide for a 9 year old, so were replaced with lightweight flat bars cut down to about 540mm

I saved a chunk of weight by swapping out the steel ringed crankset for a SR-Suntour XCT JR, fitting a 30T narrow wide and dropping the mech and rear shifter in the bin.

Thanks chaps. I’ll stick the 27.2 back in then.

Plan is swap the forks for a set of RST F1rst that I got 2nd hand off here (although surprised at how ok the stock RST Capa felt), then put on my old set of XT brakes along with new wheels, cranks, a Renthal stem that I happen to have lying around(!), some chopped down flat bars, 2nd hand XT 10 speed mech and shifter, etc.

For the wheels I’d like to use the Alienation Deviant rims, but they’re only 36 hole in the 24 inch size. I’ll check out the Mobster hubs, so thanks Poah. I’ve mostly been looking at lower end Novatec hubs that weigh in around 700 grams for the pair. It’d be nice to get something down at 600 or less.

Is the plan simply to keep the frame, and if so is it something decent? Or did I miss what you were swapping that for?

Nope, pretty much swapping everything. I only bought it for the frame really, but hopefully will get enough back on the parts to effectively give me a free frame. Bought it for £40, so should get close. Seems to be a common strategy amongst STW Dads. 😀

D771/772 3in1 hubs are the a decent weight. And I’d spend the extra for crest rims too

I’ve just picked up some lovely carbon bars on ebay that someone had cut down to “unsellably narrow” back in the day. Cost me a tenner plus about £3, I reckon they’ll take 200g off the weight of LittleMissMcs bike.