Upgrading/swapping out parts on kid's bikes

*Sorry if this should go on a different forum, but this is my first visit here. So If it needs to be moved, Mods please feel free to.*

This is my first post here and I wanted to pose a few questions to all of you. While I have been mountain biking off and on for almost 30 years, and then the last 10 years I've been pretty much strictly a road guy, I have never been that much of a bike mechanic. But, now that my kids are both on two wheels, plus my wife and I it is just starting to seem more financially responsible to start doing more myself. Anyway, what I am currently looking at is my youngest daughter's mountain bike (a 20 inch Haro Flightline). We were given it a few years ago when my older daughter was starting to outgrow her first box store first bike. It was actually already a pretty old bike at that point having gone through three girls before my daughter, but it was free and it has never really been treated badly at all. So, I swapped out the old shifter, the cables, brake pads, chain and grips and called it good. (The one part that I have wanted to change but haven't been able to find a replacement for is the stupid suspension fork.)

Well, my youngest is not as big, or strong as her sister was at that age, so I'm looking for ways to lighten the bike. Any suggestions? I would really love to get a rigid fork for it, but I can't seem to find any. I've also been wondering about options for the crank. I'm thinking of swapping out the bars, seatpost and saddle, but are there any other things I could do? Wheels? If so, builder? Brand? Do you all know any good sites or stores?

Thanks for taking the time to read (and maybe answer) this.

Cheers!

 

The problem with kids' bikes are twofold:
- kids outgrow them, so paren't aren't particularly inclined to pay for good stuff that'll be discarded in a year.
- a scale thing. For adults, the same wall thickness tubing, fasteners etc that make a bike easily buildable also happen to make it about suitably strong. If you build a kid-sized bike, you either have to retool a whole production line to deal with thinner stuff, or accept that it'll be disproportionally heavy.
One of the few who make a decent effort of scaling down are:https://www.islabikes.co.uk/ and they charge accordingly.
Once you start swapping steel for aluminum and aluminium for carbon fiber, you'll sink more money into parts than you paid for the bike in a heartbeat.
As for the fork, check out the axle-to-crown measurement on 20" BMX forks. There might be one that's close enough to use. You might need to swap in a U-brake(and another brake lever), but that's a doable fix.
If those seem too short, look at 24" rigid forks. Some creativity required to get a brake to line up, but doable.
https://www.ebay.com/sch/Forks/177815/i.html?_fsrp=1&_sop=15&Type=Rigid&For%20Wheel%20Size=24%22
Rigid forks in the lower price range have fairly thick walled tubing. If it was me, I'd cut the dropouts off and re-weld them higher up w/o hesitation.
TBH, you'd probably get most from your money by picking some narrower tires and swapping in a crank with shorter arms and fewer teeth.

 

Been there and totally agree with everything said and discussed above. As an avid biker across all disciplines, three kids posed a lot of challenges to both my wallet and 'freedom'. My solution was to take them with! I was fortunate enough to have a sponsorship with Kona (who makes an impressive line of kids Mt bikes) for a few years but after a few free bikes for the kids my conscience got the better of me so I began modifying as each kid grew. My crowning achievement was a Kona/K2 Frankenstein I created for my daughter so she could join me on road rides. I put the entire front end (fork, bars, etc.) from her Kona Hula onto my wife's K2 Mod 5.0. Actually worked but after a long fast downhill, my daughter ratted me out to my wife with a tale of horror and fright! NET: you can find really affordable used kids bikes on Craigslist.

 

I guess my question is how much will all the upgrades cost? In most situations it will cost you more to do the upgrades than it would to buy another bike, and if that's true in your situation for a few more dollars you can get a decent new bike. And if you do go the new bike route I would find a bike that doesn't have a suspension fork, those type of forks on low cost bikes are pure trash, they don't work right, won't last long, takes away the ability to put more power to the rear, and replacement forks will cost more than the bike did. I know that Giant sells a really nice bike for a kid called the XTC jr 24 lite, I'm sure there are others too that could fill the niche.

 

Hey Froze. As you know, there are three routes to go. NEW. Repair/Upgrade. USED. Having to equip three kids taught me three things. Always get new if it's 'FREE' or on pro deal. Repair/upgrading saves money and makes Dad a hero in the short term BUT the time and $$ to keep on this path can be a pain. I recommend USED bikes for kids. Most parents buy new and the kid does NOT use the bike! Rare to find a kid who rode their bike into disrepair. So you can score great deals locally or online. AND kinda cool to recycle used bikes.

 

I hear you Crankn...no pun intended...well maybe! Anywho, I don't subscribe to buying kids under 9 years of age anything nicer than a Walmart bike because the kids when they're that young trash them by crashing and leaving them out in the rain, not to mention outgrow them fast, so it's $69 bikes for them. But I did buy my oldest grandson when he was 9 a Giant that cost me $320, it's not a bad bike in fact it's a decent bike for an older kid, if the rear derailleur or some other component fails I wouldn't mind upgrading that, but I won't go crazy doing that, maybe go up to the next level, maybe two levels depending on price. That Giant is the only childs bike that will be still operational to be handed down to the next kid, Walmart bikes are now made so cheap they're lucky to make it through the first kid! I remember when I had my kids and bought Walmart bikes for them I could hand down one to the other, not anymore, I'm almost constantly tightening loose stuff or recently a pedal broke off so I replaced the pedals on those bikes, which is ok since they only cost $69. Fortunately this is the last group of kids I'll ever have to buy Walmart bikes for. And those $69 bikes aren't any worse than their $150 ones!

 

Ha. Well now you got me! Yeah, I must be getting old? I also remember when all bikes had a certain structural integrity to them. The only new bike I've purchased from a big box was a Schwinn Cruiser for my mentally disabled bro. Crazy how long it's lasted for $120! He clocks in at 6'5" and 270! But that's been years.

 

And with any big box retail store bike like Walmart, when you get the bike home you have to go through the bike with a fine tooth comb, checking to make sure all nuts and bolts are tight, the wheels are trued, hubs and bottom bracket are lubricated along with the chain, make sure the headset is adjusted correctly, make sure the brake pads are aligned...well you get the idea, that's a lot of work for a cheap bike but that's where this world has taken us.

 

Thanks for your responses. I have to agree with you Crankn, used is absolutely the way to go with the kids. My only problem is that I live in a rather remote part of Japan, and there simply isn't any kind of used market around. Even checking sites like ebay is hard because by the time you factor in shipping costs you might as well buy new.

Anyway, like I said the biggest issue is just that my youngest daughter is not as big or strong as her older sister was. But, there is is still a bit of time before she will get on that bike regularly, so I'll keep looking and see what I can find. Again, thanks!