[Closed] Dads. Building the nice 24" Wheeled MTB for your Kids - Crank info and Build

Looks good.

I did an equivalent using an alloy Identity Dr Jekyll, started with 24's and then went to 26's when he got taller.

Found some 2.4 Racing Ralphs too, less than 500g and ran them tubeless.

Just wanted to add:

Final Drill hole for the pedals on the crank was performed with a 13mm drill bit. As the pedals are imperial 9/16th in my case, it is recommended that you use a 33/64" drill bit - equivalent to 13.1mm. I used 13mm without issues at all.

I did however, used 3 stage 9/16th 20tpi taps, 1st, 2nd plugs to cut straight treads and a final to cut the treads correctly - these I got from an engineering company in West Yorkshire via ebay. £15 for left and Right.

Looks brilliant. Nice job.

Thanks

Why does it say trek on the frame and fox on the forks?

You'd be surprised at how effective a proper suspension fork is for kids. I think I got Lewis's blast down to under 23lb with a suspension fork and pedals.

What was the total budget, weight of donor bike?

Bike looks great!

You could run an old 28mm stanchion SID (pre 2007).

These only weigh 1.3kg, and 80mm forks can be knocked down to 63mm easily.

New bushes cheap from DFS

Change the damper oil for a lighter weight oil for the lighter rider.

These will obviously grow with them into 26 wheels.

http://faqload.com/faqs/bicycle-components/suspension/rst-f1rst-air-24-versus-28mm-rockshox-sid

http://faqload.com/faqs/bicycle-components/suspension/rockshox-sid-race-2001&template=29

Looks spot on and I'm half way through the same thing. Where did you get the wheels / rims from.?.

I'll just leave [url= http://www.xxcycle.com/sr-suntour-xct-jr-t202-junior-crankset-black,,en.php ]this[/url] here if anyone's looking for kids cranks at a decent price.

Op, who did you get the crests from? Jra?

I'd intended to revamp my lads 24" Hotrock but have revamped a 26" model with a 12" frame instead. He's borderline big enough for it but he likes it.

[url= https://c1.staticflickr.com/1/682/31742680723_aac472e2b8_k.jp g" target="_blank">https://c1.staticflickr.com/1/682/31742680723_aac472e2b8_k.jp g"/> [/img][/url][url= https://flic.kr/p/QmZx5F ]Rowan's Hotrock[/url] by [url= https://www.flickr.com/photos/takisawa2/ ]pten2106[/url], on Flickr

I'm sure someone else did something similar about 6 months ago, also rigid forks with fox stickers.

Yeah, I'm sure I've seen that exact bike before. Strange. Still don't like the trek and Fox stickers.

If you fancy some sus forks then these are really good; plush and tunable. I run them on my daughter's Cube 240.

https://www.bike-discount.de/en/buy/f1rst-air-24-mtb-suspension-fork-black-51499

[img] [/img]

LDC make some nice, short cranks. Quite pricey new (70ish quid) but plenty of s/h options.

Nice build - like the colour. You could have gone for something more exciting than Trek though, the world was you oyster 😉

Nice info on the crank shortening. I was about to shorten some (or get a mate who already had the necessary tools to shorten some!), but ended up going for 150mm Thorns, which were short enough (and really nice cranks too).

Need for sus depends a lot on where most of the riding is happening. It was a priority for me, but those Exotic forks look great (light, simple, etc)

Looks nice.
Did something similar for my lad.
Still need to swap the cranks though and also got some shimano hydraulic brakes, SRAM shifters & mechs to upgrade the current Deore combined cable brake/shifter set up.

[IMG] [/IMG]

Would like some lighter wheels but the cost is pretty high.

dirkpitt74 - what fork is that and I'm guessing you lowered it?? F80? Looks like the A-C height works...

Yep F80's. Didn't lower it, just set the sag a bit lower.
A-C works OK it's only slightly longer than the original forks.

I posted again, as I hope it may help someone in the future, due to my new learned Knowledge with shortening cranks and knowledge of which cranks can be shortened.

I've never came across a post on the web that mentioned Shimano Zee's as a possible set of cranks that you could physically shorten i.e. they are not hollow forged, and have enough AL to drill and tap for pedals - so you now have a choice of which cranks you can fit with a light BB.

In addition, I found a BMX set that are exactly the same build as Shimano Cranks (2 piece and 104BCD), so you can run a Light Shimano Hollow Tech II BB, but the cost was very prohibitive for me at £165. They are Bombshell Ratchet 2 Piece Cranks and you can get them at 140/145mm lengths if you are flush enough to buy them - Zee's can be picked up for £70 or as in my case £23 second hand.

Decals were the choice of my lad....I've got a trek (among others) and he likes it... So for him they are amazing - tried for Santa Cruz but he declined - ads678 - Member there you are mate - so you can bore off about how you don't like them in every post I put.

Stans Crest came from:

http://www.tritoncycles.co.uk/components-c9/rims-c123/stans-notubes-ztr-crest-24-rim-p11098

dirkpitt74 - Member - Those forks look the MINT - Like the 'FOX' decals on yours pal!!!

drliamski - Member - Weight of Donor bike was 13.45Kg and Budget was £495, However this will be for both my son's as I have a 5 (nearly 6 year old) on my 8 year olds 20" Islabikes Beinn for the next 2 years or so, so in my eyes money well spent + I'll get to build a 26" small frame when the time comes - already looking forward to that.

Cheers

Op how tall is you lad my boys are 6 and 7 but still use there 16 inch wheeled bikes, not been out much due to house moves but I don't think they would get on a 24. Have you u a pic of him on the bike so I can see if it looks massive cheers.

@ruffride:

He's 131cm mate and is really growing into the bike. He's out grown the Beinn 20, and I'd took him to Evans Cycles to have a go on the Hoy Bonaly 24 and the LBS to have a ride on the Cube 240 and they fit nicely, so decided on the build, He was about 128cm at that point (Summer 2016).

ads678 - Member there you are mate - so you can bore off about how you don't like them in every post I put.

Suit yourself, consider me bored..... 😐

Ok cheers both my boys aren't that tall so I may still try an build a sweet 20 inch

Suit yourself, consider me bored.....

Nice one, no need to post on this again then.

Dont underestimate how building a bike like John's will get you saying just one more bit to go!

I got the cranks for my son's bike from the States from somebody who had shortened them but never used them. They are Sram S600 so would be interested to know the difference in weight compared to the Saints?

I'm now embarking on building up a 26" wheel bike based on a small Cannondale frame.

Spec so far based on ebay, stw classifieds and sales -

Cannondale F800 frame
Sid forks
Novatech hubs in red
Superstar Carbon XC rims (£70 for the pair in their sale!)
SLX brakes
XT 1x10 transferred from his current Core bike.

My son is currently 143cm so not sure if the Cannondale will be a bit too big come March when he is 10 but the Genesis Core that he is riding is starting to look a bit small.

On the look out for a short stem, narrowish carbon bars and carbon seat post if anyone has some?

Hi i was in a similar situation to the OP a few years ago. Decided to build a better spec isla Crieg 26.

Bought a complete Kona fire mountain 14" and sold everything off it.
Fitted mostly decent kit from my parts box 1 x 9 XT
Mavic cross ride wheels
Some very light flat Spesh bars
A new 50mm stem from china
Glow in the dark pedals from one one
Avid elixir bekaes with braded lines
100 mm fork rockshox revelation alloy with steerer keep the weight down.
The only thing I couldnt get around were the short cranks. So I bought those from Isla bikes.

[URL= http://i307.photobucket.com/albums/nn298/Turner5spot20/fec275a3-7c95-4a60-9bbd-fcc9f1da0815_zpsko6rrofi.jp g" target="_blank">http://i307.photobucket.com/albums/nn298/Turner5spot20/fec275a3-7c95-4a60-9bbd-fcc9f1da0815_zpsko6rrofi.jp g"/> [/IMG][/URL]

NorthCountryBoy - Member

The Kona looks fantastic!!

curvature - Member

The SuperStar rims are a bargain - they'll be so sweet when buit up.

I'll get some photos of the Shimano Zee cranks up, they are rough at the minute, but it will show the progression of the time and effort on them... I'll weigh them when I've lobbed off the excess length.

ruffride - Member
Ok cheers both my boys aren't that tall so I may still try an build a sweet 20 inch

If you are after a quality 20" frame, I spotted this [url= http://www.ebay.co.uk/itm/252738230904 ]Charge cooker 20" frame[/url] on eBay earlier, for £40!

I would have snapped it up, but my eldest is 7 and likes her pink hotrock 20, hence I am onto planning her next bike (24") and browsing threads like this one for inspiration...

Nice one, no need to post on this again then.

Not quite sure what I did that was so wrong, I only commented that i'd seen the bike before in another thread (that i'm pretty sure i didn't even post on) and said that I didn't like the stickers! I wasn't the only one either. If you can't take a bit of criticism, don't post pictures on a public forum!

I've also built up a bike for my 8 year old son, from a carrera blast frame and proper bike parts. We took it out to Les Gets last summer and gave it a proper test, so I can vouch for the RST F1rst air forks if you ever fancy going for suss forks rather than rigid.

That charge frame is a bargain.

[quote=NorthCountryBoy]

Hi i was in a similar situation to the OP a few years ago. Decided to build a better spec isla Crieg 26.

Bought a complete Kona fire mountain 14" and sold everything off it.
Fitted mostly decent kit from my parts box 1 x 9 XT
Mavic cross ride wheels
Some very light flat Spesh bars
A new 50mm stem from china
Glow in the dark pedals from one one
Avid elixir bekaes with braded lines
100 mm fork rockshox revelation alloy with steerer keep the weight down.
The only thing I couldnt get around were the short cranks. So I bought those from Isla bikes.

I did something very simlar with my lads bike. Bought a 2012 Kona Fire Mountain and stripped it back for a ready for a red powder coat. Upgraded gears to SLX 1x9 and bought a set of Superstar 24" wheels with a view to change back to 26" when he started to outgrow the bike.

[img] [/img]

Me and him heading up to Gregs hut on Cross Fell.

He has a new set of wheels on now so should get another year or two out of this bike, although I am tempted to upgrade the fork.

Regarding kids forks - the RST F1rst looks like a good bet (along with used sids or the F80's as above).

In my searching - the cheep'est I've found is:

[url= https://www.aliexpress.com/item/24-inch-mountain-bike-lock-adjustable-ultra-light-aluminum-alloy-tube-rst-disc-V-brake-mtb/32708796973.html?spm=2114.40010308.4.2.3arz5G ]https://www.aliexpress.com/item/24-inch-mountain-bike-lock-adjustable-ultra-light-aluminum-alloy-tube-rst-disc-V-brake-mtb/32708796973.html?spm=2114.40010308.4.2.3arz5G[/url]

Is this site a scam - or ligit?

Let me add some 24” wheeled full sussers to this thread, these were outgrown a couple of years ago so can't remember exact spec, and indeed changed it over time;

[img] [/img]

First bike is a modified Carrera Blast with X-Fusion rear air shock (especially short <150mm)
Fox FL80 forks painted white dropped to 50mm travel (a whopping 1Kg lighter than the standard fork!)
Hydro brakes and trigger shifters
Standard Blast wheels, crank, 1.9 Schwalbe Black Jacks

[img] [/img]

Next is a 14.5” Trek Fuel frame with Fox Float rear air shock, this was quite a light frame by FS standards
Rockshox SID 28mm forks, X-Fusion dropper, hydro brakes and trigger shifters, 155mm cranks (later used Suntour XCT JRs with bashguard)
Alexrims 24” ACE with Shimano hubs and 2.1 Schwalbe Black Jacks set up tubeless using a 20” BMX tube as a rim strip

SR-Suntour XCT JR 152mm cranks with removable rings (i went 30t N/W with 10spd 11/36 cassette) £21.62: https://www.amazon.co.uk/d/Sports-Outdoors/Kettenradgarnitur-SR-Suntour-T20242-Z%C3%A4hne-schwarz/B0029MP3AO

I'm currently in the process of sourcing some Alex ACE 24" rims they are approx 400g.

Not bad at all and should be a nice wheel set on a very cheap ebay bargain (new) Bontrager 10speed hubs - £23

On the shortening of the cranks, are you not better at fitting a threaded insert?

You can get a crimped type which pretty good.

johnski15 - Member

I'm currently in the process of sourcing some Alex ACE 24" rims they are approx 400g

I think you might struggle with that one.

ACE20s were out of production and stock last year when I asked.

qwerty

SR-Suntour XCT JR 152mm cranks with removable rings (i went 30t N/W with 10spd 11/36 cassette) £21.62: https://www.amazon.co.uk/d/Sports-Outdoors/Kettenradgarnitur-SR-Suntour-T20242-Z%C3%A4hne-schwarz/B0029MP3AO

I picked a set of these up a while back for my lads bike but not fitted them yet - didn't realise you could remove the rings.

How do you get them off?

Kind of on topic - has anyone taken a punt on the specialized riprock 24? Can't decide if it's a gimmick or a good idea.

I picked a set of these up a while back for my lads bike but not fitted them yet - didn't realise you could remove the rings.

How do you get them off?

Standard 5mm hex head = triple rings off and i fitted a SuperStar NW 30t ring instead, also used a shorter square taper BB to help out with chainline.

Had a look at the Riprock but still a bit big for my two so blinging their 20" bikes currently. Riprock looked like fun but I'd change the twist shift from a trigger and put some cheap hydraulic discs on it, maybe check the weight of the inner tubes as well.

I looked at the Riprock for my lad, it weighs 30lbs.

I ended up ordering the Saracen Mantra 2.4 that is apparently 23lbs, but it's not arrived yet so I haven't weighed it.

Mantra 2.4 does look awesome, doubt it'll quite be 23lbs but air forks, hydro, narrowide ring. Most kids bikes need a few upgrades but the Saracen looks good from the go.

I'll be removing the post, stem and bars and giving them a weigh. I suspect it might be quite easy to lose some mass from those with minimal outlay.

23kg kids are prime candidates for the Light/Cheap shelf at CRC.

poah - Member
johnski15 - Member
I'm currently in the process of sourcing some Alex ACE 24" rims they are approx 400g
I think you might struggle with that one.

POSTED 4 DAYS AGO # REPORT-POST

Got a contact for Alex in Germany he's off out to Taiwan in March and has said he'll bring me a pair back. Just getting the price sorted.

Cheers

Boys 20" now running bars stem combo from the spares box, figure wider bars and better tyres and brakes might make them a bit more usable in proper stuff as smaller wheels start to struggle a bit.

Got a contact for Alex in Germany he's off out to Taiwan in March and has said he'll bring me a pair back.

Looked at the riprock. In fact ordered it then cancelled it. Decided too heavy and also my soon to be 9yo is at the upper limits for 24" bikes. I have a green Pinnacle Kauri 26 in the garage, boxed up till his birthday, with a short 40mm stem and superstar yellow lock ons with green rings. All set for mid April.

I got mine from Hendrik in Germany, paid £30 posted for the pair. were abour 410g each and the wheels weighed in at 1705g (F800g, R905g) with DB spokes and superstar switch evo hubs ( Novatec D881SB front and D882SB). His current wheels are crests with D771/D772 hubs and DB spokes weigh in at ~1480g

johnski15 / poah; I'm in the market for some 24" rims too. Could you send me Hendrik's email over as I'd happly take a pair of rims off them.

Or group dadstrackworld24"rimbuyin.com?////??

On my final email to Hendrik I did say that there's a good market for ace20s out there. Imagine if someone in the factory nailed together some 350g 24" rims for 20 quid or so, they'd corner the market (stan's being 80 quid apiece!).

FWIW I got the DP17 in 24h flavour, 43 ish euro delivered for the pair.

Hendrik.tafel@alexrims.com.tw

Cheers - I'll email and let you know how I get on. They currently list 2 sub 400g 24" rims on their site.

Yep that's the guy - we should import a s41t load of them and begin a business

Looked through the Alex site for some 20's. Their md25 shows as 350g in the youth section which would be great, but 440g in other sections. Plus it's not available anywhere based on a Google search.
I seem to remember I had issues finding Alex product last time before I ended up with a set of Deviants in 32h
Would like some 25mm inner 20" rims at 350g that's for sure as I cannot find the 300g deviants anywhere now.

I've never came across a post on the web that mentioned Shimano Zee's as a possible set of cranks that you could physically shorten i.e. they are not hollow forged, and have enough AL to drill and tap for pedals - so you now have a choice of which cranks you can fit with a light BB.

Holy cow.... HT II here we come

What an inspiring thread! Top Dadding.

Has anyone done anything similar with a 20" Wheel bike?

My lad is 6 in June and currently fancies a Hoy Bonaly 20, but this thread is making me wonder if there's better options. (That charge frame would have been great!)

EBay/Gumtree is awash with 20" wheeled bikes, giant/ridgeway/specialized/etc, search local (barely anyone wants to post a bike), set a budget limit and stick to it.

£50 got me a pink hotrock last year, I have done the following mostly from the spares bin:

-Front hub axle converted to QR, rear wheel Re-hubbed with claris 9speed (130 OLD), being able to whip the wheels off for mini road trips is invaluable.
-Bars changed to cutdown EA30s.
-Foam BBB Loc-ons
-Avid FR7 (I think) brake levers, kept the original tektro V-brakes, fresh pads they're pretty effective brakes.
-A velo VL5062, kids specific saddle which I was quite impressed with.
-9speed 12-30 HG50 cassette
-Tiagra mech
-Initially I fitted an LX shifter, she didn't get on with it, so I found a SRAM rocket halfpipe Gripshift on fleabay for pennies and she's much happier.
-New BB
-I pulled apart, cleaned and lubed, then took a spring out of the Suntour fork to try and achieve some sort of useful function, but they're still too stiff.

Still to do:

I have some cheap old cranks ready for shortening (already got the drill/taps) just need to get round to actually doing it. And a 30t N/W ring...
And I'll be getting some better tyres eventually, spesh stock ones are OK still, more volume might improve longer ride comfort (whinge) factor...

This bike is currently being used by My 7.5 old, her younger sister will inherit it so it's a pretty worthwhile investment and will probably come up cost neutral in the long term despite not being an isla...

I am keeping an eye on these threads and local ads for the next bike in the chain (24")...

Question for the collective;

How deeply held is the opinion that their first 24" bike should have discs? It's one of the appeals of the carerra blast/lunacy/detonator/solo frames but I am not sure my eldest's riding will ever quite demand discs, maybe when she's 26" sized, but I have noticed carerra also do some kids 24" hybrid bikes with aluminium frames, which look like they'd maybe still clear a 2.0" tyre and work out lighter given the same parts bin treatment...

I have some cheap old cranks ready for shortening (already got the drill/taps) just need to get round to actually doing it. And a 30t N/W ring...

Just drill really slowly.... or the alloy melts.(and you don't want that on the last drill).. and the last (13mm) is tricky when its comes out but I just clamped the cranks to a piece of spare wood

How deeply held is the opinion that their first 24" bike should have discs?

In retrospect ... absolutely in our location and riding!