[Closed] Carrera Blast 7 Cassette/Hub Help.

The 7 speed will be a cassette not freewheel.... not interchangeable

New wheel (will happen at some point if she enjoys the bike)

I'd either stick with 7/8 OR upgrade the wheels TBH....

Someone stripped a blast and weighed it... it was lighter than a "big name frame" by 100g..

To be fair the 100g could go either way.... but the point is it's a nice frame ruined by components. (like many kids bikes)

The Blast/Luna wheels are also insanely heavy as I remember.

you could take the money saved and buy some nice wheels....(then you can do 9-10 or 11) or wait but I'd say starting off with the heavy freewheel wheels your going to end up spending a lot more.

(I speak from experience:  Jnr's FS ended up costing a lot less than his HT... despite me sticking on brand new SID's because I just went for the wheels and drive chain straight off)  On his HT I ended up spending a lot on things that later got thrown away/upgraded ... like £80 on some wheels that were better  than stock but still over twice the weight of £200 wheels from superstar

Even then POAH was selling some good 24's at the time and I faffed about... I should have snapped them up at the time.

Obviously stuff in the spares bin that can be used is good... but not when it involves spending a lot of money to use it.

I had the same issue on my daughters Cannondale, I wanted to make it 1x9 but it only had a screw on freewheel at the back. A decent 24 inch rear wheel with Disc mounts and a proper freehub is pretty hard to come by so I ended up taking a deore rear hub from an old wheel and getting a local wheel builder to build it onto the original 24" rim. Cost of spokes and labour was about £40.

You will also need a special tool to take off the screw in cassette, so factor that into the costs of messing around with the original setup against just binning it!

I had the same issue on my daughters Cannondale, I wanted to make it 1×9 but it only had a screw on freewheel at the back. A decent 24 inch rear wheel with Disc mounts and a proper freehub is pretty hard to come by

The Cannondale probably came with the Alex rims... these are about 1/3 of the weight of the Carerra ones...(assuming it's a Race 24)

Even after spending money on the hub and spokes the carerra rim is still a boat anchor.

Raleigh sell a 24" rear you can get for about £40....  but its not very nice.

Proper 24" disc hubs are very easy to come by if you have a credit card or spare money in your current account.... The wheels are out there... it's just a case of saying F*** It... and somehow finding the cash.  Obviously selling a child is counter-productive so you need to find something else to go without or sell.

Spokes, Rims and Hubs all cost the same irrespective of size... it's more a matter of having the readies and being prepared to spend them.

e.g. £200 will get you Stans Crest on decent hubs from Superstar and £400 will get you a VERY nice set with Stans Crest Mk 3 with CX-Ray on D771/D772..(loo for Foxenhole on eBay) . which is an absolute bargain in context.  (What adult wheels can you get of that quality for £400)

My kids race wheels cost about £300 but I got the spokes at £1 each instead of £3 each and the rims for £50 instead of £70 ... they are lighter than my £1800 (retail) carbon 27.5 wheels ..

His £200 Enduro/DH wheels have standard spokes and are just marginally heavier than my carbon wheels...

Note:  His lighter wheels are stronger.... I just can't afford to replace them which is why he has the heavier wheels for DH... and they still weigh less than a DH tyre!

When I did my son's Blast I phoned up Islabike and bought a spare wheelset for a Creig 24 for £100 (light enough, modern hub).  Apparently they're asking for a photo of the bike now though...

Oh and regarding 7-speed vs 9-speed, my Blast had a "normal" Shimano splined cassette on a 7-speed freehub which is the same shape but shorter, so if you could remove some cogs a 9-speed cassette should fit on.  I've heard others have had screw-on though, so you'll have to take the wheel apart to see.

I wouldn't faff with 7-speed as it is arse though.  I went 1x9 with 32 x 11-32 which so far has covered everything.

Thanks for the advice.

I definitely wont be changing the wheels at the moment so if i cant fit the 9 speed or get it working ill stick with the 7 speed . My long term plan is to get some hope hubs and crest rims and get them built. The hubs can then move up bikes when she outgrows the 24". I have a small giant trance for when she is ready for a 26".

I'm going to have a proper look at the hub tonight and see whats what, The cassette is in pretty good condition so worst case it can stay. The bike looks like it has barely been ridden just left sitting.

On another note i have just ordered some suntour 150mm cranks. They have a 104bcd and i have a few narrow wide rings i can choose from. Just need a bottom bracket as the old one was corroded dropped apart when i took it out.

7 speed works fine on the blast with a trigger shifter - you can get a decent cassette with a 32 which is big enough.

I took our 9 nearly 10yo kid round Landegla at the weekend on his modified blast - great ride, but he's visibly too big for it after about a year of riding. The 24 is just a bike for the short term (unless you have other kids). That's not to say you shouldn't roll out nice wheels, as quality is quality, but it's worth keeping in mind the timeframe you're working with.

You should be able to either use a 9/10 speed cassette directly on the freehub or use a 10 speed cassette with one cog and spacer removed depending on which wheels were fitted - I've built up two lunas (the girls version of the blast) for my daughters, the first had deep section wheels with a 7 speed freehub and needed the butchered 10 speed cassette, the other had joytech hubs with standard 9 speed hub and used a 7 speed cassette and spacer.

https://singletrackworld.com/forum/topic/my-carrera-blast-24-rebuild/page/4/#post-9285992

It looks like I may be in luck.  I had a proper look last night and it’s a standard shimano looking freehub but the 7 speed version. I have fitted a 9 speed xt cassette with the last but one sprocket and spacer removed. The jump doesn’t look too bad so as long as it shifts ok i doubt she will notice. The original wheels are not as heavy as I expected. They are not light but from some of the threads I have read I expected worse. The original tyres are heavy so I will change these. maybe some rocket rons.

I have also sorted the brakes  a friend donated some fairly new avid elixirs which will do for now until I probably give her some hope x2’s off one of my bikes

My next task is to try and drop the Fox forks. They are 120mm standard and I have run them at 100 in the past with the clip on spacers. Any idea how low they can go? I’m thinking 60 or 80mm.

On our Luna, I ended up rebuilding the rear wheel onto a new 10sp Shimano hub. Didn't save much weight but it was cheap as re-used spokes and rim! Standard wheels are fairly weighty (2.2Kg) but as mentioned lots of weight saves available elsewhere for much less money than a set of bling wheels.

Ours is running a suntour 152mm chainset (amazon) with 30t NW, SRAM 9 speed rear mech and shifter, Shimano hydro brakes, Retro RST XMO (26") air forks, Orange hot rod bars (blast from the past?), Schwalbe Table Top tyres - now 25.4lb so not too bad!

Likely to be up for sale in the next 6 months or so as youngest moves towards 26"...

Hopefully some inspiration here

https://singletrackworld.com/forum/topic/the-24-inch-custom-build-thread/

lots of weight saves available elsewhere for much less money than a set of bling wheels.

Indeed, but a bit of googling has yielded these rims:

https://www.condorcycles.com/products/condor-24-mtb-rim

460g claimed weight is pretty competitive for 24" rims, especially at £20 each, so you don't have to chuck £300 at a SS/crest wheelset...

I've ordered a pair and shall report back once I have received them...

Cookeaa. Do you think these will save much weight over the original rims?

Im tempted as i have some xt hubs i could use but think i will wait and get some hope hubs and crest rims to save a big chunk of weight instead of a little bit. The originals don't feel too heavy and mine are in really good condition now i have cleaned them up.

I have made more progress tonight. Im doing a dry fit before getting it powder coated. The suntour cranks were delivered and i fitted them to an old 110mm wide shimano un71 bottom bracket that i never got round to throwing away. That thing did thousands of miles in all weather and still spins perfectly. I have also fitted the mech and shifter and put a cable on and the shifting seems really good. The jump across the missing gear isn't bad at all. It may be different under load but it works well on in the stand. The brakes are also fitted, this took a bit of work as none of my adapters were the right size. It took a few tries with various rotor sizes, mounts and washers to get them right. I ended up keeping the original rotors as the diameter fit well and were a bit lighter than the avid ones of the same size.  Next i want to drill out the cable guides to run the brake hoses and maybe a full length gear cable. Ill probably grind off the redundant front mech cable guides for neatness.

For reference the Crest 24" rims are 310g each.  I'd be able to tell you what the stock rims on my Blast were but the book is in the garage so I'll dig that out tomorrow.  Looking forward to the review of them, especially if you try to get them up tubeless.

This is for a from scratch build so I've no existing wheels to replace or scrounge parts from, I don't know the Blast wheelset or the rim weights for comparison, I would guess the condor's are at least 100g lighter though.

460g isn't super light for a rim in general, I've got lighter (narrower) road bike rims on some of my bikes, but many of the of the 'Decent' 24" rims I've looked at have been intended for DJ bikes and tend to be getting on for 600g (Some are more), these Condors are pretty basic rims, 18mm internal width should be adequate for 2.0 - 2.2" tyres and most importantly they're cheap...

Spank do a version of their Spoon 28 rim in 24" specifically for kids bikes, which is about the same weight I think, but they're more expensive (they do come in some nice colours though).
I think you can pick up Airnimal Rims from Spa cycles and off of Ebay for a reasonable price, intended for their folders (do make sure they are 507mm ETRTO) they're a reasonable weight (sub 500g?) I think.
And then there's the 24" Crests which are lighter (sub 350?) but rare as rocking horse droppings and really quite expensive for an aluminium hoop for a kids bike...

For the build she's getting my old Hope Bulb rear hub (Weight weenies has that at around 380g, I need to confirm), I've had a cheap old OEM front hub from ebay (hoping it's going to be under 200g) plus a nominal ~350g allowance for spokes, I believe it should be possible to build them up around 1800g for the wheelset without too much effort/cost, the main thing being the outside circumference (the rim) isn't too heavy.

Superstar's crest 24" wheelset build claims to be around ~1600g for the pair (IIRC) which really shouldn't be too hard to achieve with such a light rim and relatively short spokes...

So I'd have to spend another ~£200 to save about 200-250g from a pair of wheels for my daughters bike, it's not really worth the spend (YMMV)...

The spank rims are 490g each and depressingly don't come in black with hot pink decals.  They are actually certified as tubeless ready though..

"Certified tubeless" you say? I've yet to meet a rim that can't be set up tubeless with some tape and a bit of perseverance, the thing is going to be finding a 24" tyre I can persuade to play, I've seen no TCS/UST/TR 24" tyres available...

About a Decade ago as an experiment (Before I had kids to assemble bikes for) I managed to get pair of wire bead 24" DMR Moto RT/Digger running with "Ghetto tubeless" split 20" tubes. those were rideable and after a few rides and quite a bit of extra sealant top-ups they would stay inflated for extended periods...

Currently I'm eyeing up 2.1" Schwalbe Tabletops and/or Blackjacks maybe but I'd better get the wheels built before I worry too much about which tyres to fit...

And then there’s the 24″ Crests which are lighter (sub 350?) but rare as rocking horse droppings and really quite expensive for an aluminium hoop for a kids bike…

They are the same price as a Crest in any other size ... so in that way they are actually cheap since the market size is much smaller.

How much someone wants to spend is a different matter ...

Having messed about and ended up spending more money in the end my view is somewhat binary... either "do or don't do - there is no try". (To quote Yoda)

What I mean is there is no real point sticking expensive rims on crap hubs.

However, if someone does decide then the rocking horse poo but means they are easy to resell.

Superstar’s crest 24″ wheelset build claims to be around ~1600g for the pair (IIRC) which really shouldn’t be too hard to achieve with such a light rim and relatively short spokes…

Yeah they use plain gauge spokes and are currently using the heavy fuel rear hub.  WE have a set we use for DH with DH tyres (bought with one of Superstars discounts) so the weight of the front Maxxis is more than the wheel so not too bothered about weight!

If someone does want light wheels then:

According to eBay seller based on choice of spokes: with Novatech D771/D772

32/32H Total wheelset weight around 1420g for the Leader version, 1380g for Sapim Race and 1300g for Sapim CX Ray,

Lightweight option (all CX-Ray) Total wheelset weight around 1250g for the 24/24 spoke version and 1290g for the 28/28 spoke version with 15mm front and QR rear.

Prices are ... well high... but I got everything discounted

If your not in a rush I got my Rims for £50 each (vs £70) Merlin as I remember

Spokes I got reduced to £1 from Planet X each (from £3) so £64 (vs £192)

Hubs I paid around £50 (from Australia but arrived in a week or so ... it took much to get all the spokes at £1 each)

So total price was £214 + my time and they weigh in just under 1300g with tape but no cassette.  

So I’d have to spend another ~£200 to save about 200-250g from a pair of wheels for my daughters bike, it’s not really worth the spend (YMMV)…

As you note 200-250g rotating weight is not the same as 250g elsewhere and the rims are the largest part of the rotating mass (after tyres) because they have the weight rotating more.

On my kids Cannondale we actually dropped 200-250g on the saddle (£15) .. and another 200-250g on the seat post (Used and cut Ti one off eBay £15) and another 250g on bars and stem (£15 / £5) .. We saved nearly 500g on one tyre!  (Weirdly the two apparently identical stock tyres were something like 600g and 900g..)

The Stans are from memory 23mm internal.  Either way we can run and do a 2.5" tyre (on his DH wheels) !!! Not only that but Jnr can actually get it to seat tubeless by himself with a basic track pump and valve core removed.  (This isn't particularly useful as I still fit the tyre and remove the valve core but it demonstrates how well they work tubeless)

The D772 is 270g vs the Hope 380g.  The Hope is a way better hub... but the D772 is more than strong enough for kids weights.  It doesn't SOUND as good though!

OK so I could save more like 4-500g for another £200 if I really put in the effort...

But I think it's a degree of "seriousness" thing; my daughter's wheelset is going to cost about what you spent on spokes alone for your lad.

Of course if I bought her an off the peg wheelset for that sort of money it'd weigh over 2kg.

And ultimately she's not a "serious" rider so a 1300g, £200+ wheelset would simply be overkill...

60-90 quid will still build a lighter, better pair of wheels than you get off the peg...