You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
The Suntour Junior XCT is a good option. Cheap and square taper with removable chainrings.
It's not much cheaper than a SRAM S600 but it's 152mm and hence can't be shortened above 130ish (if that)
I'm assuming most kids first 24 inch they are towards the smaller end of 24 and not just about to move onto a adult XS bike... so 152mm is ridiculously long if the kid is just moving into 24er or about right if you are pretty much eeking the last out of a 24er size or XS adult size) so [b]if you are going to the effort of changing cranks [/b]... it seems worth it to do it properly... The SRAM's (or I got an old pair of Alivio's for £10 + post off ebay) also have a decent square taper fit for JIS.... whereas Suntour seem neither JIS or European.... and are £33 free P&P instead of the £25 ish with P&P
When I switched to the SRAMS/Alivio's we knocked about 5mm off the BB length over the Suntour.... (and UN55 BB's are pretty cheap weight upgrades over stock anyway) Not only did it save quite a few grams but the square taper fits properly....
If your kid is 5' then you can get proper cranks in NX at 155mm ...
Given its disk ready why not ???
The wheel was for a Hoy Bonaloy bike which is not disk ready. He's fairly light and the v-brakes do a good job of stopping him.
Balls - stevextc are you saying that I won't be able to re-use the BB on the bike with that Suntour chainset? Didn't realise there were different kinds of square taper (assumed the crank/spindle interface was standard)
I bought the Suntour XCT cranks in the amazon link above and use them with a shimano square taper BB, which fits perfectly. Great for £22. Although i then ditched the chain rings and fitted a superstar NW and bashguard (to stop the school trousers getting caught!!).
I understand that if everything is perfect we'd all have different length perfectly fitting cranks, but as most people are riding around with the wrong length cranks any way why not let the kids join the party......
Which BB ads678? (apologies if you've already mentioned this in the thread!)
Ta
Balls - stevextc are you saying that I won't be able to re-use the BB on the bike with that Suntour chainset? Didn't realise there were different kinds of square taper (assumed the crank/spindle interface was standard)
You can try it.... on the kids Cannondale the axle was too long when I replaced the Suntour with either Alivio or SRAM S600.... but both fit much better on the UN55 ...
The one that came with the Cannondale was some chinese thing.... UN55'sd are only a few quid.... (£16 quid at Halfords at the moment) so it's not the end of the world... you can get the cheaper Shimano sq taper cheaper.... but like I said... if you are going to the time/expense on everything else then it seems sensible to spend the extra few quid and do it right.
The Suntour never seemed to really "fit" the square taper.... It worked but it felt like it was not quite right when it was fitted .... and seemed a bit like it fit because the alloy is softer than the steel.... so given enough torque it seemed to go on...
The wheel was for a Hoy Bonaloy bike which is not disk ready. He's fairly light and the v-brakes do a good job of stopping him.
Ah, makes sense....
The pull of disks for me was really not about stopping power.... I just hated the squeak as soon as the wheel was 1mm out of true and also riding mainly at Swinley the mud/grit on the rims....
It was also a pain taking the wheels on and off as with the brakes adjusted so they worked the whole cable had to be undone everytime I took the wheels off... (and it soon starts getting tatty)
I just got annoyed on his 20 ... so when we looked for his 24 disk brakes were top of MY list ...
Now he has them he says "the other brakes don't work" but he has just got used to the modulation on hydraulics and 1 finger braking.... but he'd never complained BEFORE he tried disk.... 😀
BB for the suntour crank is 118mm wide
Which BB ads678? (apologies if you've already mentioned this in the thread!)
Can't remember the exact one as it was one out of the spares bin sorry. It was probably a UN55 though...
Shameless link to my classified ad:
[url= http://singletrackmag.com/forum/topic/carrera-blast-24-bike-split-for-dads?replies=1#post-8451401 ]Classified Ad - Blast 24 Bike Split for dads[/url]
Happy to help anyone on here with bits as required - contact details in advert.
So, chainline woes.
The original bottom bracket on my Blast was destroyed when the LBS took it off with an angle grinder so I had to resort to STW hive mind when replacing, which said 118mm square taper. I kept the original 7 speed wheel but went 1x at the front and the chainline seemed acceptable.
Yesterday I swapped the rear wheel for an Islabike Creig wheelset with a 9-speed cassette. Now the chainline appears to be too tight for the bottom gears (as far as I'm aware, the freehub got longer on the inside so the bigger gears are where there used to be empty space in 7-speeds) as the chain is trying to fall off the top of the lowest gear constantly and the straight chainline is somewhere around 6th or 7th gear.
Now I'm cursing square taper brackets as I can't just fiddle a spacer to adjust the chainline. Before I either attempt to eyeball it, or do some dubious maths, does anyone just know what size bottom bracket I'd want to get the correct chainline with a modern cassette?
Now I'm cursing square taper brackets as I can't just fiddle a spacer to adjust the chainline
IIRC - if you can find an old Race Face one you can do this by threading the cup in to position the BB in the required place.
[img] http://www.retrobike.co.uk/forum/download/file.php?id=188336 [/img]
had no problem with a 118BB and a 10sp cassette etc also no problems with a 113mm BB with low profile crank either.
measure the chainline and see if its 50mm
Having taken delivery of stevextc's shortened alivio cranks, I fitted them to an ex-Mrovershoot's 68x111 bb. And I reckon it's about right.
Maybe it would take a few mm shorter, and just mount the ring on the outside of the crank? Is that possible?
Have had an initial try at getting the creigg wheel up tubeless too - it's now got a tube in 😉
Yeah our creigs have tubes in too...
Okay so yes, the chainline is exactly 50mm. I guess that's not the problem then. After a quality 30 minutes fiddling with the limits it's mostly behaving now.
Do you know if the 7 speed cassette has a spacer so that I could change it to a 9 speed cassette without changing the hub?
Do you know if the 7 speed cassette has a spacer so that I could change it to a 9 speed cassette without changing the hub?
Assuming you're talking about the stock blast wheels there are two types I've come across; the earlier bikes with the white deep section rims have a 7spd cassette - you can take one cog and spacer out of a 10 spd cassette to make a 9spd that fits, using a 10spd mech and shifter works well.
The later bikes with black rims have joytech hubs that take a 10spd cassette as standard.
I wish I'd known that when I did up my eldest daughters bike as I ended up buying wheels from superstar for that one, the one I've just finished for my youngest has the better wheels.
[url= https://c1.staticflickr.com/5/4170/34119455430_3b61751ba5_z.jp g" target="_blank">https://c1.staticflickr.com/5/4170/34119455430_3b61751ba5_z.jp g"/> [/img][/url][url= https://flic.kr/p/TZ28oW ]IMG_0893[/url] by [url= https://www.flickr.com/photos/18854590@N00/ ]mike_gee32[/url], on Flickr
[url= https://c1.staticflickr.com/5/4164/34119456100_4db1114b35_z.jp g" target="_blank">https://c1.staticflickr.com/5/4164/34119456100_4db1114b35_z.jp g"/> [/img][/url][url= https://flic.kr/p/TZ28Au ]IMG_0921[/url] by [url= https://www.flickr.com/photos/18854590@N00/ ]mike_gee32[/url], on Flickr
[url= https://c1.staticflickr.com/5/4182/34344244232_6c7c22bddf_z.jp g" target="_blank">https://c1.staticflickr.com/5/4182/34344244232_6c7c22bddf_z.jp g"/> [/img][/url][url= https://flic.kr/p/UjTegW ]IMG_0908[/url] by [url= https://www.flickr.com/photos/18854590@N00/ ]mike_gee32[/url], on Flickr
It's a 7 speed as standard with white wheels, I'm wanting to change for a 9 speed cassette, shifter and mech that I have lying around.
My Blast is earlier than the one with white rims: black rims and really bad disc brakes. 7 speed hub. Now swapped for Islabike Craig wheels.
Right off to tinker in the garage!
[url= https://s24.postimg.org/h6vb1qrox/IMG_0378.jp g" target="_blank">
<img src='https://s1.postimg.org/msvnr9dcb/IMG_0499.jpg' border='0' alt='postimage'/>
[url= https://s9.postimg.org/u8xy6g9jv/IMG_0501.jp g" target="_blank">
Before and after!
Thanks guys, gears changed, and hydrolauc discs fitted and little man loves it!
Superstar just mailed me to say that their 24" Crests are back in stock so if you want a proper pimp wheelset then that's the place to go: 24" Crest mk3 rims, Switch hubs. £290 the set and 'wheelz' discount code might knock more off.
First ride out on it since the upgrade, he loves it!
Looking good!
Worth all the hassle I bet?! 🙂
Not really much hassle, I had all the parts from old bikes and it took about 2 hours to sort. It was well worth it.
Ross - where did you get the Islabike wheels from?
Islabikes: I phoned up and asked for a Creig 24 wheel set.
Thanks Ross, are they much lighter than the original wheels?
I didn't it actually weigh them! More importantly they were not covered in rust and don't have a 7-speed hub... they're not Stans Crest levels of light but they're not 300 quid a pair either.
In case anyone is still reading this as they're doing a build, another thread here has mentioned that Evans now sells the cranks that they use on the Hoy bikes:
https://www.evanscycles.com/pinnacle-hoy-bonaly-24-chainset-EV252535
What size chainring bolts did you use on the suntour cranks when you swapped to a single ring?
Swapping the cranks on my daughters 20" Luna and going with a 32t up front.
I put a the 32t on the middle and a bash on the outside so used normal bolts. If you don't put a bash on then you'll need shorter bolts I expect.
Thanks Ross was it a 104 ring you used?
Yeah, Suntour XCT Jr cranks are 104BCD, so Raceface chainring and bash.
[url= https://c1.staticflickr.com/3/2873/33448019051_bce9f95dba_c.jp g" target="_blank">https://c1.staticflickr.com/3/2873/33448019051_bce9f95dba_c.jp g"/> [/img][/url]
Great thread. I'm thinking a year ahead and considering starting getting together everything for a build with my son (I realise it's utopian in my head but will end up with shouting)
These Carrera's do seem like a really good starting point and I would aim to get it down to <11kgs. Seems like sorting the wheelsets+tyres, fork and changing it to a 1x10/11 can pretty much get there. Problem is that the costs mount so quickly - especially the wheelsets + £150 on a RST First, I don't know if I'd be financially better off looking for a second hand Isla Creig or something!
Focusing on the wheelsets - I'm trying to search for a Alexrims MD19 supplier - seems like that's what comes on the genesis core and weighs 390g so not too much more than the crests, might be a goer if its cheap enough. Anyone able to point me in the right direction?
I tried contacting Alex direct and had no joy what so ever - European distributor would only deal with trade.
Ended up getting a set of the Superstar Stan's wheels in the sales.
Same story here for another set of Alex rims, so many models are trade only and you just can't find them.
Top picks so far are Crest's in the regular Superstar sale (assuming they actually have the stock), or Islabike Creig wheelsets (£100 for wheels, tubes, and a cassette).
The Isla ones sound like a bit of a no brainer in comparison.
Did you manage to weigh them?
If anybody wants to proper pimp up a kids bike I’ve got some 165 Carbon FSA race cranks in the garage I need to sell
165mm are too long for a kids bike
mrbigglesworth, sorry no I never did weigh them. When I'm next in the garage I'll take the front off and weigh that, but it will be a built wheel + rotor + tube + Rocket Ron tyre + a little of Lanhydrock's best mud.
Thanks rossburton. Should help give us idea - do you know what rotor and tube - can try to look up the weights (without being too much of a weight-aholic, it is useful to get an idea!)
Isla Creig 24 front wheel plus tubes plus muddy Rocket Ron plus Avid 160mm rotor plus pimp purple skewer from eBay: 1.5kg.
Scale up as appropriate for rear. 🙂
Ballpark - So the rotor is probably just over 100g (G2 160mm is 106g), rocket ron 445g, tube around 165g if also schwalbe 24 inch and skewer c.100g. That makes the wheelset itself around 700g. Superstar quote the crest front as 721g, though that might include the skewer so not much in it at all. Seems like an excellent find and may make this cost effective after all!
Does anyone know if the 'Luna' decals come off as the boy and girl bike look identical except for the colour scheme and decals (and seen a cheap luna near me!)
Just get us stripped and powder coated - cost me £30 to have my lads done.
Where did you get the powder coating done for that cost?
Superstar Stan's wheel set weighs just over 1.5kg:
[img] 
[/img]
[url= https://www.flickr.com/photos/156402205@N05/36742811553/ ]Superstar Stan's build - super lightweight![/url] by [url= https://www.flickr.com/photos/156402205@N05/ ]Chris Wood[/url] - [url= https://play.google.com/store/apps/details?id=com.dariogf.flickr2BBcode_lite ]Flickr2BBcode LITE[/url]
For comparison the wheels that came on my Blast were 900g (front, hub/spokes/rim) and 1.1kg (rear), and the tyre/tube was another 1kg [b]each end[/b], so both wheels ready to roll weighed 4kg.
mrbigglesworth - Member
Where did you get the powder coating done for that cost?
I had it done at [url=h http://www.bournespowdercoating.co.uk/ ]Bournes Powder Coating - Birmingham[/url].
(Wrong thread!)
Those stans are lighter than the numbers I was working off on Superstars (which reckon the set is 1623g, 721g front, 902g rear).
Again, doing some rough maths here, but adding on 2 tyres (+445+445), tubes (+165+165), 2 discs (+100+100) gets you to 2.97kg. Taking the isla front wheel at 1.5kg, assume the rear one is 1.7kg gets you to 3.2kg. So probably 200-250g in it between the sets of wheels? And another 250-300g to the stock wheels.
Does make me wonder if its worth a new wheelset, instead focus on changing the tubes, tyres, discs and cassette. Are the stock wheels robust enough?
(Ta for the powder coaters name too).
if they're ETRTO 520, spa have some kinlin rims here: https://www.spacycles.co.uk/m2b0s116p2336/KINLIN-Nb-R-24%5C-inch-Rim that look like good value
I'm continuing to look at this, but costing it is looking a bit ugly! Seems like its around the same as just getting a decent condition second hand isla and I'm not sure that the components would be any better.
Anyone know if a SID dual air 26 inch fork mess up the geo/ride noticably? And how much it would cost to get one of those adjusted to cope with a kid's weight?
A2C is about 400mm on the blast so as long as the forks are within that area shouldn't be an issue.
Do you have more than one kid? Full monty blast rebuild is never going to be good value on 24'' wheels that they'll soon grow out of, but it helps if you can pass it on.
mrbigglesworthMember
I’m continuing to look at this, but costing it is looking a bit ugly! Seems like its around the same as just getting a decent condition second hand isla and I’m not sure that the components would be any better.
Depends if you want a project or not - a secondhand isla is certainly easier and prob cheaper in the long run, but I guess it's about doing it for its own sake and building a great bike for your kid. [I rebuilt one but drew the line at new wheels].
Well I'm about to do it all again... got my parents to buy a 24" Blast close to them that was "for parts" (knackered mechs, maybe a bent hanger) and a steal at £30. It can sit in the garage until my daughter is starting to grow out of her 20" bike then I'll decide whether to do up the new Blast for her, or bump my eldest up to 26" and give her the old Blast (fixing up the blast to sell at a profit, obviously).
I totally do appreciate there is the whole project aspect and again, maybe rose tinted spectacles, but the prospect of building it with my son and him showing interest!
I do have two boys, so it could be reused twice as a 24 inch bike, and might be able to further use some of the parts in the second ones following bike (potentially 26 inch fork, derailleur, brakes..)
Thanks poah for the info, a 63mm adjusted SID is around 434m I think - so difference of around 34mm. I suppose with the angle that is going to increase the front of the bike by around an inch?
(I'm looking at the SID as it seems to have been suggested in other threads and understand you can change the oil so it is better for lighter weighted souls.)
The Isla will have better but not great components fitted ()unless you got the Pro it's a question of which ones (if any) you keep and if what you want to end up with is the Isla or will you then be modifying.
How much do you enjoy tinkering vs want to buy off the shelf.... ? Tinkering with kids bikes is expensive but less expensive than adult ones... but building with your kids is very rewarding.
The other options to look out for a pre-modded bike already to do what you/he needs....
But then that's the main question ... what is it they need now vs a years time?
Most stuff will be transferable if you don't go for absolute weight weeny 12 spoke wheels for example and your only paying extra for the used frame if you change later.
It all depends what you and Bigglesworth Jnr end up riding. The type of riding we do has changed a lot over the year and a bit on the 24. Most of that was initially driven by what was close but changed into what we enjoy as his skills and fitness also progressed.
Depending what this is you might go more towards the Isla (XC) or more towards a more trail Geo.(or we ended up going to FS).. or stick with the Carrera.
On forks ... the RST F1rst is probably the best off the shelf kids XC fork.(it works well out of the box for kids weights in XC and anything where adsorbing big air isn't the priority).. with some mods the SID can be a great Enduro Fork and is certainly more capable of adsorbing bike park sized jumps and drops... but I'm not convinced even though its lighter and more sophisticated it would be better for XC. Its a bit like trying to mod a Pike or Lyric for adult XC use IMHO...
Thanks again for the input. As you say there are quite a few unknowns in that what we ride might end up changing. The building aspect is certainly a draw, as I would like to capture his interest in something like that.
I wonder - as I'm on a fairly steep learning curve on bike components maybe I'm not thinking about the right components - which is why I have trouble matching it up to an Isla. Broadly I was thinking as the following to go on a powedercoated carrera frame: RST First 24 air fork, Isla wheelset with Rocket Rons, Clarks M2 hydraulic brake set, X5/GX2.1 10sp rear derailleur, the Hoy 140mm cranks with a UN55 118m BB, otherwise balance of reasonably priced cost effective bar, stem, saddle, post etc. Think that should be <11kg and bit over £500 with most components new but shopped around for best prices. Anything there that is naff/or where a better similarly price option exist?
My method was to source most parts from here and eBay, plenty of people shedding perfectly good parts as they upgrade. eg my son's bike has practically unused Deore brakes from someone upgrading their new bike, and they have good reach adjustment so fit his hands. Biketart are selling the Madison youth trail saddle for a tenner on eBay.
Assuming my youngest gets her own 24" bike before my eldest is tall enough to need a new frame I plan to moving almost everything over to a small 26" frame apart from wheels and fork, and I'm pretty confident a Blast frame with 24" wheels and a carbon fork will sell easily on here...
I am looking into starting a similar project and have been reading with interest.
Like mrbigglesworth I am debating between a project and just buying an Islabike.
For me it looks like the project is going to win out for the following reasons:
-I can respray the frame a bespoke colour without effecting the resale value much.
-If I keep all the original kit I can put it back on the project to sell and put the upgrades on the next project when this is outgrown.
-It will be great fun to do all this tinkering with the little one's help, should be some great parent/child time.
-Some of the upgrades would cost nothing as I already have them as spare parts from my bikes.
Respraying it is definitely a draw, pretty sure that would capture my little one's imagination, picking/making decals too!
I floated it past my wife yesterday, was quite surprised when she didn't shoot the idea down. In fact, she's just started reading Flying Fergus to the little one which is quite on topic.
As Ross said you can pick most of the bits up cheap either on here or ebay.
My lads 24" blast will probably end up around £500 as I splurged on the Stan's wheels.
But it will be going to my younger daughter in the not too distant future.
Just sorting a small 26" frame for my lad so we can build his next bike - he's joined the cycling & maintenance club at school (they've go there own MTB track in the grounds too) so hopefully that'll enthuse him a bit more to get involved in the build.
What else did you spec on the bike dirkpitt?
My issue is that as far as I can see stans wheelset plus rst fork = £450 - and I don't have any other bits around, so by the time the rest is added the cost is going to get much higher.
Most of the kit is second hand or stuff I had in the spares box.
It's got some Shimano M365 brakes I picked up of a guy at work for £20.
SRAM X5/X7 shifter 7 mech off here for £20.
Shimano 11-42t 10sp cassette from Bike-Discount.de £30.
Suntour XCT Jr crankset from Amazon £30.
Forks are some 26" Fox Float 32's with 80mm travel - picked up locally for £50.
@rossburton - what size BB did you go with when switching to single ring?
The crankset I swapped it for was a triple so I didn't want the chainline to move. I needed a new bottom bracket anyway (the LBS had to use an anglegrinder to get it off...) and they're 118mm apparently.
118 for the suntour crank
Thanks chaps. That's what I have at the moment and swapping to single ring. So if I put the n/w in the middle position it should be ok?
Yeah just put the single on the middle and that neatly means you can put a bash on the outer. Go 32t on both and it's super neat.
I'm still super-confused how one is meant to know what axle length to use, pretty sure the cranks never said 118mm on them anywhere.
Quick question on the frame. Seems like the newer carrera frames are a little different that slightly older ones. One of them has a little extra tube piece under the saddle. Any view on one frame being better than the other. Or lighter etc?
Or are there any other donor frames worth considering?
Don't think there is any major difference - I suppose the tab from top tube to seat tube looks more 'Enduro'.
As for other frames I don't know - didn't really look at any others as the general consensus was the Carrera frame was fairly light.
That seems to be consistent with what I've generally seen. Sifting through one thread, found a reference to a Poison Zyankali - £100 for the frame and around 1600g , so prob better to stick with the blast frame and spend money on other things.
Hmm, a few hesitant ebay clicks and I have a frame sitting in the garage. Guess I'll go down the building route!!
Next stop wheels....
Such a shame that photo bucket managed to skrew up a lot of the pics on this thread. 🙁
Was just on the Isla website and noticed that they've changed the Creig to be 11 NX speed and 11kg (instead of 10 speed and 10.5kg).
Wondering what people think of that - have those with little ones found a 11-36 10sp cassette sufficient (which is what I was thinking of using) or have they found instances when 11-42 would be required - and if so when?
I'm thinking 11-36 will be sufficient for most needs throughout the lifetime of the 24 inch bike (which he will be in around this time next year), maybe a bigger range on the next 26 inch bike down the line...
my 7yo has a 20in wheel isla and she can just about fit on it but because of the relative power of the rider to the size of the bike she's constantly in the lower(st) gears so the lower you can get the ratio they will use it, especially as they get tired - better to have it and not need it than be found wanting and have your child lose interest at the furthest point from home