# Need help fixing up Specialized Hotrock 20 6 speed



## imero (Aug 6, 2011)

I just bought a 2006 Specialized Hotrock 20 6 speed dirt cheap on Craigslist. My son is super excited that he's getting a "real" mountain bike.

Unfortunately, it needs some work. Besides super worn tires, the bash guard is broken and both the upper and lower roller chain guide are missing. I've attached a photo of the damage.

I'm going to see if the LBS stocks or can order the chain guide. Has anyone found the chain guide online? Does anyone know if it's possible to replace the bash guard? I'm wondering if I've stepped into a money pit.

Any suggestions as to how I can get the bike up and running without spending a too much money?

Thanks.


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## rollis (Feb 24, 2007)

I removed my son's chain guides on his Specialized, he hasn't lost his chain yet and he's a little shredder. I'll be upgrading his crankset in the very near future, you can have his take off (great shape) if you haven't found one by then.


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## Aresab (Mar 27, 2007)

I don't think the bashguard is anything to worry about unless it can cut him. The chainguard looks in tact, just missing the rollers, bolts and nuts. That should be cheap and 20" tires are readily avaiable. I doubt you'll need to sped much to get he bike rolling. My experience is the chainguard is worth it if you are doing trails. If you doing path rides, not so much.

Oh, and Jenson USA has some roller kits, you may have to make it fit, but they are 9 bucks a pop. They will have bearings where the stock are just bushings, at least they were on my son's 08.


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## imero (Aug 6, 2011)

thanks rollis.



rollis said:


> I removed my son's chain guides on his Specialized, he hasn't lost his chain yet and he's a little shredder. I'll be upgrading his crankset in the very near future, you can have his take off (great shape) if you haven't found one by then.


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## dmboarder (Jan 13, 2011)

I took the rollers off my boy's Hotrocks, too. They each have a 9 speed rear gear and chain drop has not been an issue. I'd leave them off.

You can relace the crank with a Sinz unit, if you like. However, I changed it on one bike and not the other and they both ride about equal.


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## CheesePuff (Apr 20, 2010)

Checking with the LBS would be a good idea. They probably have some used parts which you can use.


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## rollis (Feb 24, 2007)

For the time being I would at least round the sharp edges off the cracked portion the bash ring. If you can wait a month, I'll just send my son's old one to you in the mail for free as mentioned earlier. Oh... and remove that kickstand if he's jumping or riding aggressive.


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## imero (Aug 6, 2011)

I'm going to take the dremel to the bash guard. Sent you a pm.



rollis said:


> For the time being I would at least round the sharp edges off the cracked portion the bash ring. If you can wait a month, I'll just send my son's old one to you in the mail for free as mentioned earlier. Oh... and remove that kickstand if he's jumping or riding aggressive.


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## indianadave (Apr 27, 2010)

I've upgrade my daughters hotrock 20" with a Sinz BB and crankset. I left the chain guide off, and she's been riding it and hasn't dropped the chain yet. I didn't even shorten the chain yet after going to a smaller front chain ring. She rode some singletrack yesterday, and was hitting the downhills faster than ever, and still never had a problem with the chain.

Just curious. How long are the crank arms on that bike? My girls were way to long for her legs, so I switched to some 115mm arms. Do a search for "daughters firts mountain bike" for my upgrade thread.

If you decide not to switch the whole crank assembly out, I'll send the chain gaurd from ours to you... free.


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## imero (Aug 6, 2011)

I believe the crank arms are 140mm. However, I won't be getting new cranks anytime soon.

I'm glad to hear that folks are riding without the chain guide without any problems.

I'll make sure to read your thread.

Thanks.



indianadave said:


> I've upgrade my daughters hotrock 20" with a Sinz BB and crankset. I left the chain guide off, and she's been riding it and hasn't dropped the chain yet. I didn't even shorten the chain yet after going to a smaller front chain ring. She rode some singletrack yesterday, and was hitting the downhills faster than ever, and still never had a problem with the chain.
> 
> Just curious. How long are the crank arms on that bike? My girls were way to long for her legs, so I switched to some 115mm arms. Do a search for "daughters firts mountain bike" for my upgrade thread.
> 
> If you decide not to switch the whole crank assembly out, I'll send the chain gaurd from ours to you... free.


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## NYrr496 (Sep 10, 2008)

I put Sinz cranks on my son's 20" bike with a 34 tooth chainring, an aluminum bash guard and a small, plastic and stainless inner guard to prevent the chain from falling inward. The name is escaping me at the moment. I also installed an old hub, 8 speed cassette and XT shifter I had layin' around. Bike works sweet and is actually useable on the trails now.


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## Aresab (Mar 27, 2007)

I forgot to add 1 item to my post above, I upgraded my son's 08' Hotrock 20 to a 34t megarange 7 speed (from the stock 6 speed) freewheel and Alivio trigger. It was very usable in the trails, but it was not too good without the chainguard. Even setup that way, we still had a few chaindrops, but it was worth it. Now he's on a small 26er with 24 inch wheels. Staying 6 speed, should be much better the way you have it. You've got a lot to look forward to!


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## gibbons (Oct 23, 2011)

I got my son a Hotrock years ago, and put a BMX crank with 2 rings sandwiched on it. Then a front derailleur, and it was good to go. Easy and actually worked for climbs at Moab.


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## dieseldork (Oct 20, 2011)

AWESOME thread. I bought a hotrock for my son for $100 of craigslist, and it has turned out to be a basket case. I ended up stripping the bike completely down, having it sand blasted, painted, new forks, etc...  I've replaced everything but the drivetrain and wheels. Out of money now, so am on the hunt for cheap cranks. 

THanks for the good suggestions.


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## indianadave (Apr 27, 2010)

dieseldork... Post some pics!!!


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## dieseldork (Oct 20, 2011)

Moved my pics to their own thread. Felt bad about hijacking this one.


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## chollaball (Apr 8, 2005)

i know this is an old thread, but hoping someone could help me with instructions for getting the chain guide back on. It came off when I pulled and serviced the bottom bracket, and I cant figure out how to attach it again.

Thank you.


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## albanach2000 (Oct 10, 2012)

Tagging along in this thread - can't post my own as a new member :/

I also just picked up a 20" hotrock for my kid. I want to upgrade the drivetrain and replace the handlebars, but need some part recommendations.

I know many folk here have done these upgrades before. I'd be really really appreciative if folk can recommend parts for me to get. Goal is to make the bike a bit lighter and to give her some easier gears. I'd like to keep the cost down where possible, but also want the bike to last a couple of years. Can I do this for $150 or thereabouts? The handlebar and stem I can get from Performance using points.

Can anyone recommend parts for the following? I don't have anything lying around to use.

I'm presuming upgrading the rear cassette means a whole new rear wheel. There's another thread for 20" rims, so no worries there. What about the hub?

For the rear cassette, I know she needs an easier gear. Should I be thinking 7 speed or 8? Can anyone recommend a cassette? Is a megarange the way to go?

Rear derailleur thoughts?

Can I leave the cranks alone? Hopefully I can save some money by doing so.

Shifters - I want rapidfire type shifters. What's reliable and affordable?

Do the brake leavers need replaced? I presume I don't need to worry too much if they do and just get something from the LBS.

Performance Bike look to have a half decent alloy handlebar so I'll likely get that. They also have an adjustable stem. Will the be helpful as my daughter grows, or is it just added weight and more to go wrong?

Is there anything obvious I'm missing?


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## NYrr496 (Sep 10, 2008)

albanach, I used older XT 8 speed stuff on my son's 20" bike because I had it. You can probably find stuff on Ebay. 
I used a cassette with a 34 tooth large cog. Paired up with a 34 tooth chianring and 20" wheels, he could climb walls.


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## indianadave (Apr 27, 2010)

Albanach,
Any 25.4 handlebar will work. You can pick up carbon 25.4 bars on Ebay really cheap. I got one for my girls Hotrock. Not sure what year yours is, but my daughters had waay too long of crank arms. I swapped to a shorter Sinz cranks, and ended up replacing the bottom bracket also. The original bearings were toasted. I'm surprised they even turned. I also found by swapping to a smaller from chainring, that the stock 6 speed rear gears are fine for now. She does tend to use the lower 3 gears the most on our hilly trails around here.
The original brakes are sufficient to stop a little kid, but I swapped some Avid Speed Dials I had laying around from my old bike, and now she can stop on a dime. I was also able to adjust the levers farther in for her small hands.
Also, after replacing the shifter cables, my daughter has no trouble shifting with the gripshifters. I think the stock cable corrodes, and that is what causes problems for most. I think she'd have more trouble reaching thumb shifters. Post a pic of your bike.


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## cakemonster (Sep 30, 2012)

indianadave said:


> Albanach,
> Any 25.4 handlebar will work. You can pick up carbon 25.4 bars on Ebay really cheap. I got one for my girls Hotrock. Not sure what year yours is, but my daughters had waay too long of crank arms. I swapped to a shorter Sinz cranks, and ended up replacing the bottom bracket also. The original bearings were toasted. I'm surprised they even turned. I also found by swapping to a smaller from chainring, that the stock 6 speed rear gears are fine for now. She does tend to use the lower 3 gears the most on our hilly trails around here.
> The original brakes are sufficient to stop a little kid, but I swapped some Avid Speed Dials I had laying around from my old bike, and now she can stop on a dime. I was also able to adjust the levers farther in for her small hands.
> Also, after replacing the shifter cables, my daughter has no trouble shifting with the gripshifters. I think the stock cable corrodes, and that is what causes problems for most. I think she'd have more trouble reaching thumb shifters. Post a pic of your bike.


I have a 16 hotrock and want to put on sinz cranks. What BB size does it take 68 x 113 like a mini?


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## indianadave (Apr 27, 2010)

This was 3-4 years ago, but that sounds about right... My daughter is on a 24" Trek now. 

I wouldn't assume a 16" has the same size. Best thing to do is measure it. It is really easy to measure.


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