WW kid's bike??? Pics wanted.

Discuss light weight issues concerning road bikes & parts.
wallstbear
Posts: 9
Joined: Sun Jun 17, 2018 4:17 am

by wallstbear

I was playing with the idea of building a WW bike for our 5 year old, who recently complained his Giant XTC 20 7 speeder is a bit heavy.

Ran a search and didn't come up with much, so here goes the question: any WW kid's bikes? Pls post what you have.

If you don't have a bike to share, pls feel free to discuss any info related to building a relatively inexpensive (under US$1500?) kid's bike under 7kg. Other than the one below, of course.

Image

by Weenie


alcatraz
Posts: 1240
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Either a small production chinese carbon frame or any alloy frame should be a good start.

What kind of wheels do you expect a 5 year old to ride? 451, 650?

Do you want to put on drop bars?

Kids grow fast. Won't be fun to realise kid's outgrown the bike after 2 years you know.

Sounds like a fun project though.

/a

mattr
Posts: 3759
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

Try islabikes.
They have a pro series.
https://www.islabikes.co.uk/product/bik ... ro-series/

Even the stock ones are seriously light compared to most kids bikes.

mattr
Posts: 3759
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

THis is "comparable" to the giant...........

https://www.islabikes.co.uk/product/bik ... ro-series/

siim
Posts: 55
Joined: Sun Nov 26, 2017 9:37 pm
Location: Estonia

by siim

Orbea's kids bikes have aluminium forks and therefore a relatively light chassis. I got my daughter one and plan to do few upgrades: stan's crest 24 rims on some lightweight chinese hubs, disc brakes (both fork and frame have the tabs), carbon seatpost, handlebar. Already changed stem and cranks. She's happy with it already now of course :)

Geoff
Posts: 5171
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

Yeah, I had the same notion. I actually agree with @alcatraz on this one: they grow too darn fast! In the end, we ended-up getting James a Giant alloy road bike with 24" wheels and lightening it up a bit. It was still heavy, but workable. It really only lasted one season, as kids grow like weeds. It served the purpose of getting him to understand shifting gears in race situations, riding clipped-in, using dropped bars, brakes, etc. Today, he is on an Emonda 650, which should last a few seasons until he is on a 700c bike. The 650c bike is where you can spend a few bucks with some more comfort. We are looking for a set of old Tri tubular wheels.

User avatar
LouisN
Posts: 2437
Joined: Mon Feb 19, 2007 3:44 am
Location: Canada

by LouisN

24" wheels ?
Most of the 24" alloy frames are sensibly the same. Some have aluminium forks instead of steel so a few grams saved.
You can build a nice set of light 24" "old school" tubular wheels, that will save 1-2 lbs right there.
Swap the stock crankset for a light single ring one (BMX like).
Look for older Shimano Sora shifters ( 8 or 9 speed) they have screw adjustments for smaller hands. Combine with older Dura Ace Ti cassette.
For the rest, light bike parts ( brakes, skewers, stem, seatpost, saddle, handlebar) , as stock kids bikes are built with heavy steel peripheral parts mostly.

Be pattient, search the Internet:
Ex.: A few years ago I bought an XS ( 46cm seat tube c-c) 700c Scattante Scandium frameset at 950g with Easton EC90 fork (320g) on Ebay for $300.

Louis :)

Noctiluxx
Posts: 396
Joined: Tue Feb 07, 2017 7:17 pm
Location: Southern California

by Noctiluxx

Canyon sells a tiny 3XS women's endurance bike with 650B wheels. Price and size should meet your criteria although weight is above 8KG's. I guess you can upgrade the Shimano 105 and some components to something lighter down the road.
2018 Bianchi Oltre XR4, (Celeste Matt)
2018 De Rosa SK Pininfarina (Blu)
2017 Giant TCR Advanced SL (Red)
2016 Specialized Allez DSW Sprint (Gold)
2016 Giant Anthem Advanced SX (FS)
2018 Trek Farley EX 9.8 Fatty (FS)

JerryLook
Posts: 110
Joined: Thu Dec 07, 2017 2:18 am

by JerryLook

I have been wanting to build a WW bike for my daughter. She is on a 24” mountain bike right now. I’ll be watching this thread to see what you guys come up with.

Seems like most of the kids road bikes are really heavy, and most of the WW parts I have are too big for a kid to use.

The Diamondback Podium 24 is an affordable option. It’s around 20 pounds. So maybe with some parts swaps get it down to 18 pounds?
2010 Orbea Opal 54cm
6.6kg (14.5lbs)

joejack951
Posts: 434
Joined: Fri Feb 18, 2005 6:50 pm
Location: Wilmington, DE

by joejack951

It wasn't a real weight weenie build but I put together an Orbea 24" wheel road bike for a very small adult relative of mine using a full Tiagra 4700 group (rebuilt the stock wheels with Shimano 105 hubs and double butted spokes). I was amazed at how well the smaller wheeled geometry fit her compared to her other Specialized bike which tried to cram 700c wheels into a tiny frame. The one weight-weenie-ish decision I made was using nice tires, which was a bit of a challenge given the oddball ISO 540mm size. Come to find out Schwalbe makes some pretty nice tires in that size but designated for wheelchairs: https://www.schwalbetires.com/node/2348

Been working fine on her road bike for a few years now. Crap photo:

Image

User avatar
themidge
Posts: 867
Joined: Fri Jan 13, 2017 4:19 pm
Location: yer ma

by themidge

Methinks you guys are overestimating the size of 5 year-olds.
When I was 5 I had a bike with 16" wheels (I think), it had flat bars and was single speed (which saves weight) and I can't recall ever wishing i had an easier gear.
No 5 year old should be on a bike with wheels bigger than 24", and that would be too big a bike or a rather large 5 year old.
When I was 9 I got an old Peugot racer with 24" wheels, which was fantastic, I'd say that's the best time to get into drop bars, earlier is too early :D

To save weight off the current bike though, I'd stick to things that can be carried over to the next bike:
-seatpost, chinese carbon/alloy?
-saddle "
-stem " (kalloy Uno come in short lengths and are very light)
-bars "
-derailleurs, if your 5yr-old needs them at all
-shifters, mtb stye
-chainset, but don't sacrifice a suitably short length for the sake of weight
-cables
-headset

Things to avoid saving weight on:
-tyres, neither you nor your 5 year old want punctures and they're tricky to find anyway
-wheels, not very transferable to a new and bigger bike
-frame, will be grown out of
-chainguard/RD guard, kids' bikes get thrown around a lot

joejack951
Posts: 434
Joined: Fri Feb 18, 2005 6:50 pm
Location: Wilmington, DE

by joejack951

My then-5-year-old on his 7.36 kg Islabikes Beinn 20 Small ($550):

Image

He is almost 7 now and the bike fits him great still. With a longer stem I imagine we'll get another 1.5 years out of the bike.

JerryLook
Posts: 110
Joined: Thu Dec 07, 2017 2:18 am

by JerryLook

That orange Orbea looks pretty sweet
2010 Orbea Opal 54cm
6.6kg (14.5lbs)

wallstbear
Posts: 9
Joined: Sun Jun 17, 2018 4:17 am

by wallstbear

This one looks real solid.
joejack951 wrote:
Thu Sep 06, 2018 12:03 am
My then-5-year-old on his 7.36 kg Islabikes Beinn 20 Small ($550):

He is almost 7 now and the bike fits him great still. With a longer stem I imagine we'll get another 1.5 years out of the bike.

by Weenie


wallstbear
Posts: 9
Joined: Sun Jun 17, 2018 4:17 am

by wallstbear

Thanks all for your input. WW never disappoints. The 4.8kg ISLA looks pretty sick (am not in the UK so may not be easily accessible).

Re kids growing fast, well they don't really grow that fast between 4-10, and beyond that there is really no limit. Some grow half a foot in 3 months especially when they are 12-14.

My son is 5.2 years old and just a hair under 4 feet (118cm for the Euro folks). Kids around us up to 10/11 years old are generally sub-5 feet it seems. Also a lot of adults like running these 20/22 inch wheelers in certain parts of the world. So I am not sweating too much over wheel size for now.



OK, here is how I am going w/ my project. I did quite a bit of research and haven't really seen a good light frame option in this size, so I decided to give the existing Giant a shot first.

It looks like this originally.

Image

Got rid of the kickstand, rear derailleur protector cage (what's the point of protecting a Tourney while I have Dura Ace and XTR ders exposed), decided to keep the chainring guard for now coz it does have some utility and it being plastic is not really heavy.

Then I picked up a knockoff Enve bar for like $30, gave it a few good yanks (I figure if at 185lbs all muslce I can't brake it, my 46lb kid should do fine), cut it short to 48cm, and added a UNO-esque short stem. The combo came to 201g in total.

Voila, 240g saved. Not bad.

Then there's the wheels. The bike came w/ 20 inch 406 wheels and knobby tires with solid steel axles so they weighed around 4kg. It so occurs I have an opportunity to pick up some green 22 inch rims for cheap (apparently there is some surplus wheels from the Goodsmile Racing project ran by some computer game and cartoon company).

Image
Image

These aren't that light at 1700g, but they are interesting. AND GREEN.

Plus they were $40, so whatever. Either way they would be a huge upgrade on the original wheels. If really necessary, I can probably find some 1100g tims for 600g savings.

Seatpost is the fun part. I have had a spare GIANT carbon seatpost from the an early TCR Team ONCE edition. I lost the lower cradle so it's been in the parts bin for like what 15 years??? Anyways, I found a cradle this time and my son's XTC happens to use 27.2 seatposts.

So great, now we can complete the GIANT theme and add some Tour de France flavor. I cut it down to 160g, so that's an instant 150g savings.

I decided not to revamp the drivetrain just yet but may be left for a later date. Also left the tall steerer tube for future needs.

The brakes will be replaced w/ long arm versions as the wheels are getting bigger. The long arm brakes are on the way and should save another 120g off the original ones.

In addition I got some 1 1/8 tires coming in and a lighter cassette on the way too. The complete wheelset w/ tires/cassette should come in at 2.7kg so that's a solid kilogram saved.

Also new pedals are on the way. Not really lighter than the original plastic ones but much smoother/ more functional.

So the unfinished product in the photo is at 7.7kg, so when everything is done, it should be around 8.5kg (19lbs).
XPBK.jpg
XPBK HDB2.jpg
Going forward, I feel the BB area and of course the steel fork are two likely candidates for upgrades. Then there is the drive train. Wonder if I should put my M980 shifter/derailleur on there at some point.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post