# 20" Custom Build Project



## Jordan300 (Jul 26, 2008)

So after reading about and seeing pictures of all the custom kids bikes. I pretty much have no choice but build my own.

My son is currently on a 16" Scott Voltage Jr. He is 4yo and small for his age. He probably won't be ready for the 20" for a year or two. I've been buying a part each month or so.

This is the bike I started with.


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## Jordan300 (Jul 26, 2008)

I got it at a yardsale for $40. Took it right home and stripped all the parts off.


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## ProjectMayhem (Aug 23, 2013)

Good start. Your workshop looks awesome too.


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## Jordan300 (Jul 26, 2008)

Thanks, I spent about 2 years of being more "into" my shop than I was actually riding. No bike upgrades just tools and shop stuff. Now I'm paying more attention to my bikes now that I have all the proper tools.


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## NYrr496 (Sep 10, 2008)

That's gonna be a cool little bike. I built my son a Gary Fisher Precaliber 20" very much like that. 
The 24" he's on now also started out used. Bought it as a complete, perfect bike and ended up using only the frame.


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## Jordan300 (Jul 26, 2008)

After I stripped everything off I started hunting for new parts. I've never been keen on the weights of stuff. But it's lots of fun weighing everything and searching for the lightest parts.


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## Jordan300 (Jul 26, 2008)

I busted out some aircraft stripper and stripped all the paint off the frame.

It worked perfectly, I've stripped several frames before, this one was practically effortless.









Next is to send this off to the powdercoater. Might not happen right away but my son has asked for fire engine red.


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## ProjectMayhem (Aug 23, 2013)

I like seeing your project thread because we are at the same stage (apart from mine is 16inch). I really must start my own thread - just ordered a pile of bits. The original plan of having it ready next spring/summer has been blown out of the water by my impatience! The bike will be ready before the boy is big enough...


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## Jordan300 (Jul 26, 2008)

I am right there with you. I had planned to do this really slow. My son isn't even turning 5 until December. I wanted this to be for his 6th birthday but I just can't help myself.

I was thinking of re-routing my focus to his 16 inch Scott Voltage jr and do some up grading there too.

.


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## GrayJay (May 16, 2011)

Jordan-
Got a weight of the bare frame?


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## Jordan300 (Jul 26, 2008)

Yeah the frame weight is 2lb 15oz.


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## Jordan300 (Jul 26, 2008)

Stripped the paint off the rims.

I think I'll send them to the powdercoater with the frame.


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## Jordan300 (Jul 26, 2008)

Pulled the trigger on some Sinz 135mm cranks. They are a tad longer than I wanted but I got a good deal on them.


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## GrayJay (May 16, 2011)

Did you get ISIS or square taper? By the time he is ready for a 20" frame, I would suspect that 135mm length cranks will be fine and should probably last until you bump him up to a 24" or XS 26" frame. 
One slightly counterintuitive thing I realized when trying to fit kids on bikes is that longer cranks allow for a lower seat height at same leg extension. Kids seem to really want to be able to stretch and reach the ground with their feet while seated/resting, a slightly longer crank helps to accomplish this so can make them more confident about being able to get stopped/started from the saddle.
One thing that irks me about most 20" frames is that the bottom bracket height is often so high (usually has negative BB drop relative to the hubs), it is almost as-if they used the bottom-bracket height spec of an adult frame meant for 175mm cranks, ignoring that shorter cranks are less suspectible to pedal strike at a lower BB height. 

As long as you are powdercoating the frame and rims, might be cool to also powdercoat the crank arms to match. 

What are your plans for a 20" fork?


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## Jordan300 (Jul 26, 2008)

I got the Isis.

I think he'll grow a bit too so it should be a good fit.

Good insight about the seat height, I'll remember that.

The fork is my biggest issue right now. I'm really really leaning towards getting this








But it's like $150 so that's the big obstacle.


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## GrayJay (May 16, 2011)

Jordan300 said:


> The fork is my biggest issue right now. I'm really really leaning towards getting this
> But it's like $150 so that's the big obstacle.


If the expense is a consideration, I really wouldnt bother with this carbon fork. While it has a visual bling attraction, this carbon fork also has a hefty 210 pound rider weight limit and is made to pass current adult DIN standards, subsequetly it weighs 750gr (1.5 pounds)! For comparison, cheaper 700c adult road carbon forks weigh less than 400gr and non-disk aluminum BMX 20" forks can be bought that are much cheaper and weigh only 1 lbd. (see Redline R6 Aluminum Race Fork at Danscomp) You could likely even start with a lightweight CrMo BMX fork and braze-on a disk mount that would produce a lighter disk fork than the carboncycles fork. I suppose the ultimate project would be to DIY build a kiddie capable carbon fork that is <300gr. Probably not something that any mass-manufacturer is going to offer since it would be too fragile for adult weight, big liability.


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## Jordan300 (Jul 26, 2008)

Yeah, I'll start looking in to that. Thanks


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## ProjectMayhem (Aug 23, 2013)

Those forks would look really good though...


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## Jordan300 (Jul 26, 2008)

I know, right! I have an internal battle between spending the cash on that fork because it would just complete the bike so well, and going another route that might cost less and look differently from what I how envision it should look like.


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## bme107 (Jul 23, 2008)

I have that fork on my son's XS 26er because it can be found in the correct AC and it's got lots of clearance between the legs with a light weight. I justified it, and most of his bike, by selling all sorts of his old baby/little kid stuff on ebay and craigslist. Used that paypal money to get the new fork. Was all "internet money" that was previously justified or gifts over the course of many years.


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## Jordan300 (Jul 26, 2008)

Good Idea! I have tons of stuff I can sell. 

:thumbsup: (On the plus side, that'll be off my wife's radar):thumbsup:


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## Jordan300 (Jul 26, 2008)

Just got the frame back from the Powdercoater.

It looks amazing.
I also got the Rims and Brake levers in white. Can't wait to finish.


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## ProjectMayhem (Aug 23, 2013)

nICE!


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## paulski1966 (Jun 10, 2013)

Looks great - what colour did you have it powder coated in the end.


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## TigWorld (Feb 8, 2010)

That's going to look great when you get it together.


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## Jordan300 (Jul 26, 2008)

Thanks. The color I got was gloss red. I'm really happy with how it turned out. Now I'm going to start putting it together. Still need to build the wheels. Don't have a rear shifter yet. Also need the fork.


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## Jordan300 (Jul 26, 2008)

I put some of the parts on today. Also got some of the decals on. Tell me what you think.

I also went to a local Bike swap meet. I found some carbon handlebars, and the Red XO 9spd shifter that I had been searching for.

Still haven't pulled the trigger on the fork yet. I took your advice and sold a bunch of stuff on ebay, I have the money to buy it. Just gotta do it.




















That's just a seat post holding the handlebars on.


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## Jordan300 (Jul 26, 2008)

Just placed the order for the fork. I should have it in a week.


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## ProjectMayhem (Aug 23, 2013)

Don't finish it too soon or your son won't be big enough to ride it


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## Jordan300 (Jul 26, 2008)

That couldn't be truer. I try to have him help me with everything when I install it, we have lots of fun in the bike shop. My boys love riding their bikes, I might get a little resistance from him to give up his 16". No matter. It can sit as long as he wants to wait.


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## ProjectMayhem (Aug 23, 2013)

I think that's great that you get him to help. I must admit I do my bike stuff after the kids go to bed. My excuse is that I'm still learning and need the peace and quiet to concentrate. But I will be able to teach them as they grow.


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## Jordan300 (Jul 26, 2008)

OH yeah, most of the real wrenching happens after bedtime. But i'll get him to pump up tires or turn the hex wrenches once the bolts are loose enough. But I did get the fork in the mail. It is absolutely gorgeous. I want it to stay beautiful. I was thinking, I have a big extra piece of this 8mil crankskin material. I might cut it and cover the stanchions.


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## ProjectMayhem (Aug 23, 2013)

Oh wow, you got your dream forks  

I do have 13 year old as well who does help - we will be building him a bike next...


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## Jordan300 (Jul 26, 2008)

Yeah, it took a lot of effort to click that button and order it. I sat at my computer for quite a while before I took a deep breath and pulled the trigger. It helped that BME107 told me to sell some random stuff on eBay to raise the money. That totally did it for me.


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## GrayJay (May 16, 2011)

Is your wheel tensioned yet? From the picture, it looks like the rim is far off-center from the fork, needs more tension on the disk-side spokes, get the rim centered between the fork blades.


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## Jordan300 (Jul 26, 2008)

No, Not tensioned yet. I actually brought the bike to work with me today and just dropped it off at my LBS down the street to have them tension the wheels and cut the steerer tube for me. It was very cool seeing the shop guys reactions to it. They'll call me once it's finished. Then I'll put the tires on and it's done.


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## bme107 (Jul 23, 2008)

Jordan300 said:


> Yeah, it took a lot of effort to click that button and order it. I sat at my computer for quite a while before I took a deep breath and pulled the trigger. It helped that BME107 told me to sell some random stuff on eBay to raise the money. That totally did it for me.


Out with the old and in with the new! We just did a massive pre-chirstmas purge of old toys and I've got 6 listings up right now, with more in the cue. Also in the last 3 weeks I've sold a 16" Fuji and Trek trail-a-bike on CL. By spring I plan on getting that 20" fork for my daughter.

For my son I just wrapped the legs with black electrical tape so he didn't tear up the CF. Not pretty, but it's been working since August. My daughter wants more color on her black bike so I realized that Plati-dip would be the perfect solution. Rubberized, spray on at home, easily removed protection. Comes in lots of colors.

Crankskins would probably work. There is also that clear 3M plastic sheeting you apply to cars to protect from stones/bugs.


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## Jordan300 (Jul 26, 2008)

*Here we go. 18lbs 15oz*


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## TigWorld (Feb 8, 2010)

Very nice!!!


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## GrayJay (May 16, 2011)

Big transformation from start to finish, the low spoke count wheels came out looking great.


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## ProjectMayhem (Aug 23, 2013)

Brilliant!


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## Jordan300 (Jul 26, 2008)

He is definitely too small for it yet. He looks really stretched out on it. So I guess he'll keep riding his 16" for a while longer.

He really loves it though.


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## Jordan300 (Jul 26, 2008)

My buddy asked me why I put the specialized sticker on it. I figured I'd post it here too. My son had to have a bike like "just like Daddy's" He was super stoked when the stickers arrived.


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## ChaosCelt (Feb 4, 2013)

Awesome thing about that build is in a month when he suddenly is too big for it you have a ton of good parts (hubs, brakes, mech, cassette, bars and what not) to swap to a bigger frame.


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## GrayJay (May 16, 2011)

ChaosCelt said:


> Awesome thing about that build is in a month when he suddenly is too big for it you have a ton of good parts (hubs, brakes, mech, cassette, bars and what not) to swap to a bigger frame.


Problem is that so much time gets invested in sourcing all the components and putting them together, if you just part out the bike when the kid has outgrown then you loose all the added value of having built the wheels, picking and assembling all the components. It would be nice to keep a customized bike functional and find someone that appreciates the complete bike and is willing to pay for the added value rather than parting out, otherwise it just reverts to being another $50 used frame.


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## ChaosCelt (Feb 4, 2013)

I could see that point as well, but depending on what parts you got for the build it makes the cost of upgrading to a larger bike much easier to handle. That and if he's anything like me there is still the box of original parts.


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## Jordan300 (Jul 26, 2008)

Yeah I'll be able to reuse this for my youngest once he grows out of it, then my niece if she shows any interest. But then I'd much rather find someone who can appreciate all that I've put into this project.


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## CJH (Apr 21, 2004)

Jordan300 said:


> He is definitely too small for it yet. He looks really stretched out on it. So I guess he'll keep riding his 16" for a while longer.
> 
> He really loves it though.


If you have a moment can you measure the effective/horizontal top tube? I found one for sale but it's too far away for me to go measure without being fairly certain I want it. Have a few lingering questions in my head.

Thanks.



NYrr496 said:


> That's gonna be a cool little bike. I built my son a Gary Fisher Precaliber 20" very much like that.
> The 24" he's on now also started out used. Bought it as a complete, perfect bike and ended up using only the frame.


Same question for you. Do you know or can you measure the horizontal top tube?

Thanks.


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## Jordan300 (Jul 26, 2008)

So it's been about 6 months since I finished building this. He started riding it this week. He really likes it.


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## NYrr496 (Sep 10, 2008)

Awesome.


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## NYrr496 (Sep 10, 2008)

CJH said:


> Same question for you. Do you know or can you measure the horizontal top tube?
> 
> Thanks.


Sorry, CJH. I Just saw this. On the 24" Gary Fisher Tyro, the top tube is 18 3/8" from the back of the head tube to the front of the seatpost.


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## jblockers (May 16, 2009)

Very cool. Which disc brake mounting adapter did you use and what size rotors?


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## Jordan300 (Jul 26, 2008)

Anyone who still reads this thread. I'm ready to sell his bike, any one have experience selling bikes on here?


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## NYrr496 (Sep 10, 2008)

Jordan300 said:


> Anyone who still reads this thread. I'm ready to sell his bike, any one have experience selling bikes on here?


I sold my son's 24" bike to someone on here. I hadn't put it up for sale or anything, it was just taking up space. We made a deal, he took it and I boxed the bike up and shipped it off. He contacted me a few days later angry that the derailleur hanger was bent. I felt stupid for not taking it off before shipping. I guess I shouldn't feel too bad.
I sold the whole bike, minus the 26" Manitou coil fork what I had into the rear wheel.


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## tofubeats (Dec 10, 2021)

Thanks for your description, it inspired me a lot! Let me share how I ended up with the same frame 8 years later.
I had the surprises: the frame was pretty heavy with 1578g, space for 140mm rear disc only, the 350mm axle to crown fork to replace (I used a 310mm carbon fork first, now it's a 410 mm rst) and the 132.5mm rear axle spacing, having to fight with it every time to fit the rear wheel...


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## thomcom (Nov 9, 2015)

Thanks for sharing your follow up! Here's my 20" Gary Fisher Precaliber


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## NYrr496 (Sep 10, 2008)

Cool little Fisher! Same exact frame as my son's. My son is 18 now and as big as me. It's patiently waiting for the first grandkid to come along and ride it. My wife's other son (my stepson) is going to become a dad next June. Few years...


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## thomcom (Nov 9, 2015)

Thanks! I also did a 24' model for an older child. Good idea hanging on to yours, you're not going to find a better one for the right age range. Thanks to the rear brake mount you can upgrade these things to Trailcraft level easy, with pretty much the same or better geometry.

I struggled a bit with getting the seat to mount as far forward as I could on this bike, idea being of steepening the seat angle. I'm particularly impressed with the RST SPEX, it has very little stiction for a tiny fork. All I had to do is build a 100x15 20" wheel to use it.  It has MT200 brakes, which I don't love, but I'm not sure that 8 year olds need to learn 1 finger braking yet? What's your opinion on that?


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## tofubeats (Dec 10, 2021)

thomcom said:


> Thanks for sharing your follow up! Here's my 20" Gary Fisher Precaliber
> 
> View attachment 2013698


That's a similar build, wow!
I'm ok with the mt200 brakes, more then enough. Was grown up on canties 😅

Wasn't aware of RST SPEX, could have shaved 7mm off axle to crown, and add 20 mm of suspension...

I was really annoyed changing the axle to crown and the geometry as such, yeah I was put the saddle forward as much as possible, too. In my next build I'm putting a lot of attention not to change the original geometry.


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