# Another 16" Hotrock Build



## HighFlyingMama (Apr 4, 2011)

Mine can't touch Demo9's awesome build, but here's what we just built this morning for our daughter's 3rd birthday.  It's definitely a work in progress.

I bought the 2009 16" Specialized Hotrock for $40 from Bay Area Schwinn in Pasadena, TX. It was pretty whooped, but would have served several more kids as-is.

Current mods:
Haro low-rise bar with AME mini grips on a Sinz mini 40mm stem
Cane Creek Headset with 1 1/8" - 1" headset reducer
Redline Flight R6 aluminum 20" fork
Redline rear wheel
18T freewheel
40T Sinz chainring
120mm Sinz cranks, drill pressed 40g lighter with Sinz pedals
68/107mm Euro BB with aluminum American-Euro bottom bracket converter
Rattle can Krylon Rich Plum and Watermelon with Rustoleum sparkle clearcoat.
UNI seat with cut down seat post

Right away, it needs new tires, straight handlebar, the padded Crupi/THE padded mini BMX seat and ...something else that I'm forgetting.

In the end, it'll get disc brakes and three speed freewheel with short cage derailleur. And probably better paint. That's planned for late summer. We worked it out in the shop a few days ago, and know how we're going to do it. But, we've already blown the bike budget, and at just-turned-3, she can wait a few months for gears. 

We ran into issues last night with our primer, so the paint didn't come out as well as planned. :-(

Here's the album. If you don't do FB, let me know and I'll post them here. 
https://www.facebook.com/media/set/?set=a.10150652152231383.450980.680686382&type=1&l=7fa631f3da


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## Duntov1967 (Jan 14, 2012)

*>>Rattle can Krylon Rich Plum and Watermelon with Rustoleum sparkle clearcoat.<<*

Bangin!!


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## Demo9 (Nov 20, 2006)

Awesome build. Love the crank mods. Sounds like you have it pretty figured out. What are you going to do for the caliper mount mount and rear hub?


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## IAmHolland (Jul 8, 2010)

nice build.

curious to know how many cans of paint and clear each, and how long it took to strip and paint?


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## indianadave (Apr 27, 2010)

Pretty sweet bike.... Why'd you ditch the V-brakes though?


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## HighFlyingMama (Apr 4, 2011)

Thanks everyone! She's so thrilled with it, I can't even say. I can't wait to see how she does with it this weekend. My son's racing at Warda, TX, so I'm sure we'll be taking it along.

Demo9, since we don't have a TIG welder, we will mock up the mount and have a shop weld it on, front and rear. That's the plan...mind you, we have never dealt with disc brakes before so I am sure it will be something of an adventure! I wasn't too clear, in my OP. Sorry. We only worked out an option for the rear hub, not the discs. We are eyeballing the Redline hub with a custom 3 speed and v-brakes, nothing solid yet, though we're taking suggestions. Discs will come as we learn more, if we get to that point. I'm hoping to. 

iamHolland, We didn't strip. It had pretty good original paint, so we just thoroughly sanded and gave it an alcohol rub. Then, we used 1.5 cans of Rich Plum, 1 of Watermelon and almost 2 of sparkle clearcoat. It was 20 minutes between each coat, per instructions. Two coats of primer, four coats of color, four coats of clearcoat. (Plus an extra go at the whole deal on the frame, as it got dropped in the grass after three coats of color.  ) Prepping frame with grinding off all tabs, filing smooth, sanding, etc. took about 2 hours. Painting all parts took all day, on and off, working on other bikes in between paint.

indianadave, The 16" Specialized is a coaster brake only bike. It never had V-brakes. It only has a hole in the frame for a U-brake mount. If the disc idea doesn't work, we will probably weld up some v-brakes mounts.


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## indianadave (Apr 27, 2010)

Doh! I knew that... So what was it you ground off?
how much weight do you think you took out of the cranks? I've got a set on my girls 20" Hotrock. They're pretty light already.
I'm going to a swap meet tomorrow, and am going to be looking for some goodies for both my girls bikes... Especially my oldests 24" GF Tyro. It's a tank, but she loves it and won't trade it for the 24" Hotrock hanging on the wall in our garage... Maybe if I paint it up like yours she would...


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## HighFlyingMama (Apr 4, 2011)

We weighed cranks before and after. There is 40 grams of aluminum laying next to the drill press. I really don't like those Sinz cranks, honestly. But, they're the only ones that come short enough for her at 120mm. (Her first set on her race bike was 115!).

If you're looking for GOOD, lightweight cranks for a kid, check out the Answer/Speedline (two brand names, same exact ones) cranks. They're $, but super light, nice geometry and resell well when you're done with them. My son runs them on his BMX racer. There are even lighter ones, but then you're up in the $400+ range.
https://www.jrbicycles.com/storefront/index.php?act=viewProd&productId=604
https://www.jrbicycles.com/storefront/index.php?act=viewProd&productId=3658
I also like the AC Mini LE cranks. Those are a pretty good cost to weight ratio.

I cut off a bunch of tabs:
two 1/2" square tabs for the chain guard 
one thick 2" square plate behind the bottom bracket for mounting the kick stand.
one 2.5" long tab by the drop out for the coaster brake assembly.

Good luck at the swap! There was one here yesterday, but we missed it.


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## indianadave (Apr 27, 2010)

For the price, I'm pretty happy with the Sinz... I also had trouble finding any others short enough.
I am keeping a balance between money and performance on my kids bikes... They don't ride ompetitivly, so it's hard to justify spending a lot... especially when I want to upgrade from my 12 year old Trek someday... LOL


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## HighFlyingMama (Apr 4, 2011)

I hear you on budget issues. 
We have 115s, 2 sets of 120s, and 135 Sinz, so yeah, I can't hate them too badly!! lol
We maintain some sort of reasonable cost with the kid bikes, but not as much as we should. Trouble is, we enjoy working on them. 

I just upgraded to a 1999 Gary Fisher Aquila from a 97 Diamondback Sorrento. Bought it from hubby's copilot, who upgraded to a 2012 Rockhopper. lol The kids get all the goodies. The only reason I even upgraded was to ride with my son though, so in my case it makes sense. If it was "my" hobby though, I'd be riding better equipment, I'm sure.


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## indianadave (Apr 27, 2010)

Wish I could get my wife involved on our mountainbike hobby. It's all I can do to get her to ride around town with us occasionally. It's awesome to see a mom this involved!


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## dantheman762 (May 12, 2007)

*Which year Hot Rock to buy?*

Hi everyone,

This might be the coolest build thread ever. I'm looking to buy my little guy a used 16" Hot Rock, but wondering if they changed the specs over the years and which year(s) to look for. Weight is my primary concern. I've been trying to find this info, but it's been difficult.

Thanks for any info any of you can offer.


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## adamm3 (Mar 26, 2007)

@mama. What is the axle to crown on that redline fork?


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## Shayne (Jan 14, 2004)

A-C on the 20" R6 fork is ~320mm


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## HighFlyingMama (Apr 4, 2011)

Thanks Shayne, I was just about to go google it. I am pretty sure all of ours are cut down, but don't know, right off. Would have to dissassemble to verify top of steer tube.

As for what years are like this one, the 2007 was the start of this frame being used. BikePedia - 2007 Specialized Hotrock 16 Boys Complete Bicycle

The one in 2006 looks a little different, (ignore paint and graphics!) Look at the top tub shape, primarily. BikePedia - 2006 Specialized Hotrock 16 Complete Bicycle


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## cboyd1974 (Sep 7, 2012)

This is a great thread. My youngest son is 8, but is the size of a 5 year old.Since my older son moved up to a 26", I am moving him up to the GT Stomper. He is a bit stretched out on the bike so I need to order him a new stem. Do you have any other suggestions? 

Did drilling the cranks make it any weaker? I am thinking since it is for a smaller kit it should be ok since they really don't put a ton of stress on it.


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## chrisjmcqueen (Oct 19, 2010)

This thread and some others inspired my to customize a hotrock.

I put the cupri racing seat on my sons 16", its great


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## Dave88LX (Aug 29, 2007)

Background of my local bike shop looks nothing like that! Damn! :eekster::skep:


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