# Just bought Hotrock 24" and i need a source for upgrades



## mjbrox (Jan 6, 2005)

I just bought a 24” hotrock for my 8 year old son. It was used and only $40

The upgrades start now. But I need some up sourcing the best deals 

-	Cassette. Currently it is only 27 tooth on the top, but I am going to order one with 34 tooth 
-	Fork, current fork is seized. Which is find because it was garbage anyway. I was looking at the suntour with air/oil. What other type should I consider 
-	For tires I was going to get some Rocket Rons, Is it worth it to go tubeless?
-	Cranks….. should I mess with the cranks?
-	Bars, stem post. It all steel, but ill find some used stuff to swap out. 

So my big question is, where to buy this stuff and does anyone have stuff for sale?


----------



## jestep (Jul 23, 2004)

Much of this depends on how much you want to put into fixing/upgrading it.

Cassette. Assuming you're sticking with the 7 speed drivetrain, the Shimano HG50 is a good option and comes in 13-34. I would upgrade to the M310 7 speed trigger shifters and replace the cable at the same time. Unless you like grip shifters, kids do much better with triggers in my experience.

Fork. Tough one if you want to keep it cheap. Most budget 24in forks aren't much better than your seized one. Spinner grind and RST F1RST are probably the best suspension options. Rigid 26in forks are usually close to the correct height, but you have to switch the front brake to disc.

Cranks. Wouldn't be the first thing to upgrade. There are good options, there's several threads here in the family section, but I'd do the other stuff first.

Tires. Rocket rons are probably the best ones I've found. If you are somewhere where thorns are a problem, they're not a good tire though. The casing is fairly thin, they suffer from punctures super easily. We haven't had issues with sharp rocks, just thorns. We stuck with tubes. I've heard mixed results on trying to get the performance line rocket rons to work tubless without a ton of sealant.

Bars, etc. For kids this is one area I'd go with chineese carbon stuff except the stem. Just find a aluminum stem of the correct length. Uno are good light ones.

Here's our build if you want to get some ideas. We did rigid to save weight on this one: http://forums.mtbr.com/families-riding-kids/our-24-hotrock-build-novella-version-guide-994732.html


----------



## mjbrox (Jan 6, 2005)

well, i spent $40 on the bike. I figure I can spend $160 on the fork, $100 on the tires, then another $20-$40 on odds/ends. 

Then Ill be under $350 for a decent bike. there is a neighborhood MTBike club for kids that gets pretty serious. If he falls in love with, then ill probably drop serious coin a built bike. 

i need to read through your post again. 

YOu want to sell it?


----------



## the.vault (Oct 11, 2006)

Everything adds money. Kids bike parts cost less than adult stuff.

Spawn Cycles is selling nice wheels, rims and tires. Prices seem reasonable 
https://spawncycles.com/components

I got some 20" Vee tires for my kid. They have 24" version as well, tubless ready. Large volume tire.
https://www.veetireco.com/listings/junior-specialty-crown-gem/

RST also has 24in fork.
The Spinner 300 is available in 24in too.


----------



## mjbrox (Jan 6, 2005)

i cant find anyone selling the RST or Spinner fork


----------



## alexbn921 (Mar 31, 2009)

Cranks you need shorter ones. Going from the 165 down to a 145/150 will make a world of difference.

Tires rocket ron's are the lightest option

Forks old sid's work good

rims and hubs will be crap. alex rims ace20 are the lightest rim option

You have a freewheel rear so cassettes are more of a pain and weigh a **** ton.

all the 7,8,9 speed derailleurs work with 7 speed shifters.

Stem and bars are a good place to save weight as is seatpost and seat.

GL

My boys bike


----------



## jimPacNW (Feb 26, 2013)

I had both the 20 and the 24 for my daughter, I swapped out the bars and seatpost right away with spares I had laying around. Those stock forks are heavy!, on her current 26er bike I went with a chinese carbon 'toseek' rigid fork, -super light and about $80 shipped. She's so lightweight she's not going to break It If figured the weight savings would be better than a squishy heavier fork, but in your case you'd have to convert to disc too. They did make a 'hotrock street' which was rigid, and quite a bit lighter I think. 
I wouldn't go too crazy, your son could outgrow that one pretty quick; I got my daughter off 24s and onto 26 at age 9 and she's pretty average size, lightweight stuff is so much easier to find for 26, she's got a great little rigid 26er now. My advice is to make this one work while you start searching for a 13" frame 26er build.


----------



## the.vault (Oct 11, 2006)

ta


mjbrox said:


> i cant find anyone selling the RST or Spinner fork


I don't know who sells the RST fork.

You can order the Spinner fork direct from the Polish distibutor in Poland, seriously. That's where I got my 20" fork. It was $150 shipped. Check out their facebook page.


----------



## mjbrox (Jan 6, 2005)

the.vault said:


> ta
> 
> I don't know who sells the RST fork.
> 
> You can order the Spinner fork direct from the Polish distibutor in Poland, seriously. That's where I got my 20" fork. It was $150 shipped. Check out their facebook page.


I just be stupid because I can't find that either


----------



## the.vault (Oct 11, 2006)

*Just bought Hotrock 24" and i need a source for upgrades*

Spinner Facebook page
https://www.facebook.com/SPINNER-SUSPENSION-FORKS-307348999289102/


----------



## thesmokingman (Jan 17, 2009)

I have some great condition used kid sized gear you might be interested in.

Thorn 150mm crankset running a blue RF n/w 30t iirc.

Some shoes, two lightly used pairs of shoes, size 7.5 Giro Jacket platform shoes in black and a pair of size 7 Teva Pivot clipless shoes in black. My kid outgrew the shoes before he could really use them.


----------



## Sparkman999 (Dec 19, 2017)

*Just bought Hotrock 24" and i need a source for upgrades*

Does the bike have a freehub and cassette or does it use a freewheel? I'm thinking there's a good chance it's a freewheel, so if you have not done so yet, you may want to check before ordering a replacement.

Sent from my iPhone using Tapatalk Pro


----------



## alexbn921 (Mar 31, 2009)

99.9% freewheel. options are more limited and you will need the tool


----------



## Steve-XtC (Feb 7, 2016)

Just using this as a base... (not because I disagree)


jestep said:


> Much of this depends on how much you want to put into fixing/upgrading it.
> 
> Cassette. Assuming you're sticking with the 7 speed drivetrain, the Shimano HG50 is a good option and comes in 13-34. I would upgrade to the M310 7 speed trigger shifters and replace the cable at the same time. Unless you like grip shifters, kids do much better with triggers in my experience.


If you have the stuff lying around then going 1x10 is an option and you can also put on a 40T expander...



> Fork. Tough one if you want to keep it cheap. Most budget 24in forks aren't much better than your seized one. Spinner grind and RST F1RST are probably the best suspension options. Rigid 26in forks are usually close to the correct height, but you have to switch the front brake to disc.


The F1rst is from experience WAY better than I'd expected. 
That said it's designed as an XC fork... and whilst it does that job very well (certainly at the price) it's less capable as the technical level goes up. We used one for full on DH and it's not ideal...



> Cranks. Wouldn't be the first thing to upgrade. There are good options, there's several threads here in the family section, but I'd do the other stuff first.


OK do disagree a bit here. At least if you want then to pedal the bike make sure the cranks are the correct length or the entire riding position is compromised. If the main use is uplift then it doesn't really matter as they are stood up anyway.



> Tires. Rocket rons are probably the best ones I've found. If you are somewhere where thorns are a problem, they're not a good tire though. The casing is fairly thin, they suffer from punctures super easily. We haven't had issues with sharp rocks, just thorns. We stuck with tubes. I've heard mixed results on trying to get the performance line rocket rons to work tubless without a ton of sealant.


Weird ... the RR's we have seal up on *our* thorns... in fact I doubt I could count the number of thorns that have been sealed.. we have (tempting fate) never had a puncture that hasn't sealed in the RR's... compared to my own (similar Racing Ralphs) where it's always been sharp rocks.

*I'm sure it depends a lot on what your thorns and sharp rocks are. Obviously there are thorns and thorns...* they do soak up a fair bit of sealant the first go.... but they have been super reliable after that for us.



> Bars, etc. For kids this is one area I'd go with chineese carbon stuff except the stem. Just find a aluminum stem of the correct length. Uno are good light ones.


The Chinese bars were so good I ended up putting them on my XC as well... I'd bought 2 sets as I was going to test one set to destruction (at $15). when I got to cutting them though they were much better than I expected...

We got a "Wake Stem" ... short (50mm) very light (without bolts) and about $7 delivered. We only stopped using it because he grew and he's now using a 85mm stem on his XC bike and my own best stem on his Enduro bike...


----------



## mjbrox (Jan 6, 2005)

This is great!!! I found the spinner distributor and I’m ordering the fork now. 

Yea, I’ll buy those 150 cranks. 

Thank you for the heads up about the cassette. 

I’m going to take my sone to a bike shop that sells used parts so that I can get the stem, bars and post. 

Also, I weighed the bike. 31 lbs!!!!!!!


----------



## mjbrox (Jan 6, 2005)

The spinner rep sent me the following, It should fit my hot rock, correct? 

Thank you very much for your email.

We have on stock Grind air 24” in gloss black color. This is version for v-brakes (v-brake pivots) and disc brakes (IS mount).

Just in case I’m sending you photo of available version.



Price including postal priority shipping is 135 USD. If you would like to have the fork sent by EMS, price is 145 USD.

If you’re interested we can deal transaction via paypal.


----------



## the.vault (Oct 11, 2006)

mjbrox said:


> The spinner rep sent me the following, It should fit my hot rock, correct?
> 
> Thank you very much for your email.
> 
> ...


Tell him you got referred my Adam and Michal (with the polish L). That's a picture of my daugther on his facebook page.


----------



## RMCDan (Feb 28, 2008)

mjbrox said:


> i cant find anyone selling the RST or Spinner fork


Trailcraft will sell you one, according to others who have posted here. They may also sell you one of the new Snyper forks that come on the Maxwell. The Snyper is probably a lot better than the RST or the Spinner.


----------



## Steve-XtC (Feb 7, 2016)

RMCDan said:


> Trailcraft will sell you one, according to others who have posted here. They may also sell you one of the new Snyper forks that come on the Maxwell. The Snyper is probably a lot better than the RST or the Spinner.


Depends what the intended use is. The Snyper also has a larger AC from memory. The F1rst works very well as a kids weight XC fork... but its not designed for pointing downhill or big jumps. The Snyper is a lot beefier and more travel... so it's like comparing a SID and Pike or Lyric for adults...

https://www.bike-discount.de have F1rst in stock.


----------



## mjbrox (Jan 6, 2005)

RMCDan said:


> Trailcraft will sell you one, according to others who have posted here. They may also sell you one of the new Snyper forks that come on the Maxwell. The Snyper is probably a lot better than the RST or the Spinner.


The spinner seems like a good deal at $145 shipped. I am pulling the trigger on it now


----------



## NYrr496 (Sep 10, 2008)

How about a plus wheel and fork for the front instead of a so so suspension fork? 

One of my friends just bought his grandson a Scott 24" plus bike with 3" wide tires. Thing is awesome.


----------



## slapheadmofo (Jun 9, 2006)

When my son was on a HR 24", we did a fat (2.8") front tire. Definitely a better/cheaper/lighter option than a suspension fork at the time.


----------



## mjbrox (Jan 6, 2005)

NYrr496 said:


> How about a plus wheel and fork for the front instead of a so so suspension fork?
> 
> One of my friends just bought his grandson a Scott 24" plus bike with 3" wide tires. Thing is awesome.


I considered that but went with the suspension for for a couple of reason.

- Rotational weight will be less on the set up im going with 
- Adding just a fork is less modifications and less $$
- The belief that a large tire does not equate to actual suspension ( but I could be wrong)


----------



## slapheadmofo (Jun 9, 2006)

I didn't do any mods besides taking off the old tire/tube and putting on the new one.
Might not work as well as high-end suspension, but close enough as far as what's available for 24" bikes IMHO.


----------



## NYrr496 (Sep 10, 2008)

I for sure don't believe that a fat or plus tire is equal to a suspension fork but I do feel the performance is superior to the forks they put on most kid's bikes.


----------



## mjbrox (Jan 6, 2005)

NYrr496 said:


> I for sure don't believe that a fat or plus tire is equal to a suspension fork but I do feel the performance is superior to the forks they put on most kid's bikes.


agreed, but a Spinner Grind fork is $145 shipped. I have to replace the existing for anyway, So how much would a new fork, tire and wheel cost? I dont know the answer, but I assumed it would be about the same as the Spinner fork.

Anyway, the whole budget bike build for a kid is enough to make your head spin


----------



## mjbrox (Jan 6, 2005)

my spinner fork is on its way from Poland. $145 shipped. 

March/april are tough riding months in Colorado, so it might be a couple of months before we really get to ride with the new fork


----------



## mjbrox (Jan 6, 2005)

So got the following upgrades

-spinner grind fork
-carbon bar with aluminum stem 
-150mm thorn cranks. 

I pulled all the old stuff and i am comparing weights. I only dropped 470 grams and most of that was in the bars, But the cranks are better length and the fork is air. 

That said, the headset is a mess and bottom bracket is even worse. So those will get replaced 

Holy crap! The wheels are heavy. Can I pull half the spokes? Lol. I guess I need to suck it up and buy some rocket Ron’s, but I’m already $240 into this bike before the bottom bracket. So I’m starting to have buyers remorse thinking I should just got a clearly meerkat


----------



## Steve-XtC (Feb 7, 2016)

On an old Cannondale Race we saved a lot of weight on:
Saddle and Seatpost ...(Saddle was $20 a BMX Race saddle 1/3rd the weight of the stock one, seat post I got a used Ti one off ebay that had been cut short - I don't remember the exact price but something like $15)

If you can find one of these they are cheap, light (186g) and very very tough... he has had the one on the Cannondale for 2 years and when it's washed it still looks new despite a lot of wipe outs. (I thought the kevlar trim was a bit of a gimmick... but it seems to work)

https://www.customriders.com/6309/products/odyssey-junior-seat-black-blue.aspx

I left the headset until it seized ... (about a year with our weather and he now has sealed bearings)

We used the AEST Ti pedals .. (about $35)

BB's, the Shimano UN55 is pretty good and <$20 ... 
The wheels of course were the expensive part as I had spare XT brakes and gearing but after pulling off the 3x8 etc. the bike is under 10k with the RST Airfork.. (depending exactly what's on at any time)


----------



## indianadave (Apr 27, 2010)

Good thing about Specialized, Trek, Etc... They use a lot of the same standard parts that the 26" bikes use.
I built my daughters 24" Trek MT220 with parts out of my spare parts bin, and off the local classifieds and Ebay.
Got a 25.4" carbon bar, (They're cheap since most have gone to 38.1) and carbon seatpost off Ebay. Took a short stem I had already, and milled out some excess material to lighten it up.
The best thing I did was find some Sinz short 115mm (I think) cranks. These can be found used, with some searching.
I also rebuilt the wheels, only using the actual hoop. Swapped in a freewheel cassette, and quick release axles, and laced them only using half the spokes.
Went with a SRAM X9 9 speed cassette and grip shift.
I found small hands have an easier time with grip shifters. She tried my SRAM triggers, and couldn't quite reach with her thumb.
But As many have said. Don't spend a lot. Good thing is, many parts can swap over to a 26" bike.
Took a bike that was almost 45lbs. stock, down to just under 30lbs.


----------



## H2oHouse (Dec 28, 2020)

I like the idea of going with the trigger shifter and the



jestep said:


> Much of this depends on how much you want to put into fixing/upgrading it.
> 
> Cassette. Assuming you're sticking with the 7 speed drivetrain, the Shimano HG50 is a good option and comes in 13-34. I would upgrade to the M310 7 speed trigger shifters and replace the cable at the same time. Unless you like grip shifters, kids do much better with triggers in my experience.
> 
> ...





jestep said:


> Much of this depends on how much you want to put into fixing/upgrading it.
> 
> Cassette. Assuming you're sticking with the 7 speed drivetrain, the Shimano HG50 is a good option and comes in 13-34. I would upgrade to the M310 7 speed trigger shifters and replace the cable at the same time. Unless you like grip shifters, kids do much better with triggers in my experience.
> 
> ...





jestep said:


> Much of this depends on how much you want to put into fixing/upgrading it.
> 
> Cassette. Assuming you're sticking with the 7 speed drivetrain, the Shimano HG50 is a good option and comes in 13-34. I would upgrade to the M310 7 speed trigger shifters and replace the cable at the same time. Unless you like grip shifters, kids do much better with triggers in my experience.
> 
> ...


Sorry for the basic question but looking to do some upgrades on my 8 year olds Hotrock and it looks like you have already done this. We do a lot of trail riding and he struggles with some of the hills so hoping to give him a climbing gear and trigger shifting. I like the sounds of your recommendations above. Do I need a new Wheel/hub for this cassette?


----------



## Klurejr (Oct 13, 2006)

H2oHouse said:


> I like the idea of going with the trigger shifter and the
> 
> Sorry for the basic question but looking to do some upgrades on my 8 year olds Hotrock and it looks like you have already done this. We do a lot of trail riding and he struggles with some of the hills so hoping to give him a climbing gear and trigger shifting. I like the sounds of your recommendations above. Do I need a new Wheel/hub for this cassette?


Have you considered a towie until you can get him a better purpose built kids bike with gears?

Specialized makes subpar kids bikes. I did not realize that until I bought my kid a Hot Walk and discovered cheaper balance bikes came with brakes on them to also teach hand control braking.....


----------



## H2oHouse (Dec 28, 2020)

Klurejr said:


> Have you considered a towie until you can get him a better purpose built kids bike with gears?
> 
> Specialized makes subpar kids bikes. I did not realize that until I bought my kid a Hot Walk and discovered cheaper balance bikes came with brakes on them to also teach hand control braking.....


No - this bike seems well built and has a 1X7 drivetrain but he could really use a larger climbing gear for the terrain we ride.


----------



## indianadave (Apr 27, 2010)

H2oHouse said:


> I like the idea of going with the trigger shifter and the
> 
> Sorry for the basic question but looking to do some upgrades on my 8 year olds Hotrock and it looks like you have already done this. We do a lot of trail riding and he struggles with some of the hills so hoping to give him a climbing gear and trigger shifting. I like the sounds of your recommendations above. Do I need a new Wheel/hub for this cassette?


Depending on if it's a freewheel or cassette, you can get a different range with the same number of gears.
I went from a 9 speed 11-34 cassette to a 9 speed 11-42 (I think) on my bike and just had to use a Wolftooth Goatlink to drop my derailleur down a bit.


----------



## H2oHouse (Dec 28, 2020)

indianadave said:


> Depending on if it's a freewheel or cassette, you can get a different range with the same number of gears.
> I went from a 9 speed 11-34 cassette to a 9 speed 11-42 (I think) on my bike and just had to use a Wolftooth Goatlink to drop my derailleur down a bit.





indianadave said:


> Depending on if it's a freewheel or cassette, you can get a different range with the same number of gears.
> I went from a 9 speed 11-34 cassette to a 9 speed 11-42 (I think) on my bike and just had to use a Wolftooth Goatlink to drop my derailleur down a bit.


Thank you! Just googled the difference between freewheel and cassette and that makes sense. Is it possible to get a Freewheel with a better range of gears?


----------



## indianadave (Apr 27, 2010)

I've rebuilt an old 20" Hotrock and switched the 6 speed freewheel to an 8 speed. It's been a few years, so I don't recall what the range was.
On the 24" Trek, I knew it would be used a couple years, so I put some more work into it. I switched the hubs to a get a cassette, and quick release, so it opened up lots of options. It's got an 8 speed, with the mega-range gear for climbing.


----------



## H2oHouse (Dec 28, 2020)

indianadave said:


> I've rebuilt an old 20" Hotrock and switched the 6 speed freewheel to an 8 speed. It's been a few years, so I don't recall what the range was.
> On the 24" Trek, I knew it would be used a couple years, so I put some more work into it. I switched the hubs to a get a cassette, and quick release, so it opened up lots of options. It's got an 8 speed, with the mega-range gear for climbing.


Thanks!

Looks like Shimano makes a freewheel with a the mega range gear so I think I'll try that vs messing with a new wheel or hub.


----------



## Klurejr (Oct 13, 2006)

H2oHouse said:


> Thanks!
> 
> Looks like Shimano makes a freewheel with a the mega range gear so I think I'll try that vs messing with a new wheel or hub.


Let us know how it goes!


----------

