# Specialized Hotrock 24 Build



## bendermike (Oct 17, 2011)

My 8yr son was ready to step up to a 24" bike from his Trek Superfly 20". After some research on these boards and other reviews, I decided to buy a Hotrock 24 off Craigslist and build it up to a light weight rig. He likes to ride with me and has competed in a few XC races held locally (and WON!!). And anything I can do to support him and build his interest in the sport I love is well worth the time and money to me.

There have a been a couple extremely helpful threads:
http://forums.mtbr.com/families-riding-kids/help-me-lighten-scott-scale-rc-jr-947948.html
http://forums.mtbr.com/families-riding-kids/24-disc-wheelset-960020.html
http://forums.mtbr.com/families-riding-kids/specialized-hotrock-24-parts-weights-930965.html

While these were excellent threads especially the info Mark194 provided, I wanted to get more detailed in the existing parts and the cost benefit for the replacements. The constraints were the $250 paid for the used 2014 Hotrock and keeping total budget under $1000. If I was in a position to spend more I just would have gone with the sweet Trailcraft rigs that have the best geometry for kids IMO. So I kind of geeked out creating the spreadsheet below, I took pictures of each of the take-offs (except the bar & stem waiting on their replacements first) if anyone is interested.

I'm trying to get below 20lbs which appears pretty achievable with the starting weight of 25.5lbs.








The picture below is for the starting bike, I will post the finished product in the next few weeks. Cheers


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## stom_m3 (Jun 28, 2011)

Good list. Might as well get the Ti bottom bracket. It's about $90 and will save you another 70g. You can get them from Dan's Comp or Jr. Usually they will have 15% off which will make the difference even smaller. Do a search for coupon code. I'll also check to see if I have one.


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## GrayJay (May 16, 2011)

You still need to add brakes to your cost & weight sheet. The stans rims do not have brake track for the stock rim V-brakes.


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## GrayJay (May 16, 2011)

Couple of options to consider for weight and cost savings on your project (at the expense of more time on your part);

stay with V-brakes (lighter and cheaper since you already have them). Cut the rims out of the existing wheels and re-build them into a lighter wheelset using lighter hubs and fewer spokes;
http://forums.mtbr.com/families-rid...40lb-rider-need-help-891768.html#post11024330 
Use the $ savings from reusing the rims/brakes to get some even lighter road bike hubs (if you are not using disks). 80gr front road hubs would make a nice light wheel! Road Hubs

Opportunity to save another 200-300gr on a 24"fork by shortening an older 26" fork;
http://forums.mtbr.com/families-riding-kids/suspension-fork-shortening-932945.html


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## bendermike (Oct 17, 2011)

Thought I'd post some update pictures. As the bike sits now with all parts, Stans sealant, etc it is 20lbs 10oz. I still need to replace the seatpost and bottom bracket which should knock another 11oz off getting it below 20lbs. 













RST F1RST Air Fork works amazing







Action Shot


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