I just picked up a Grom Hit this winter, my son isn't big enough for it yet, but he still tries to ride it. I wish I had seen the lil shredder bikes first.
Kids DH bike
- Thread starter Kntr
- Start date
No she is still riding it and will be for a few more years.Has your daughter outgrown hers yet? Looking to sell????
The FSR Grom Hit is a better bike IMO and is big enough and adjustable enough to last a long time. My daughter only rode a 20" wheeled bike for 2 years, when she was 5 and 6. She started riding the 24" wheeled Gromhit when she was 7. It was big but doable. She is 9 now and riding soooo well.
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Yeah, my boy is smaller, will be 7 in august, but in the long run it was a better investment, just for now it's a bit big.
He's still pumped to ride. Hoping to take him on fathers day weekend.
I still need to get with you about tuning the original fork when I put it back on the bike. For this year I am going to go with the shorter travel fork I swapped on.
He's still pumped to ride. Hoping to take him on fathers day weekend.
I still need to get with you about tuning the original fork when I put it back on the bike. For this year I am going to go with the shorter travel fork I swapped on.
hard to tell in this photo, the bike is way to big but he refuses to leave it at home, but he's still pretty small. Here he is on a Kona Hula. His big hit is a little bigger then the kona
It hit me on the head again, hard, this weekend, that I HAVE to build a mtb for my daughter.
She is 6 and rides with us on some easy crap, she is actually pretty decent when she does ride, but she only rides a couple times a month, whatever.
She is on a 20" wheel specialized something-rock, Vbrakes, 6 speed, single ring front and the bike is SOOOO heavy. I'd imagine the 3 secrets to weight reduction are Fork, Wheels, Frame eh? no sense getting some sick carbon bar, stem, etc...if I am still going to have a heavy ass main parts.
So frustrating the selection of decent bikes, I saw that ventana 20" bike at sea otter, but the price was wicked gnar.
She is 6 and rides with us on some easy crap, she is actually pretty decent when she does ride, but she only rides a couple times a month, whatever.
She is on a 20" wheel specialized something-rock, Vbrakes, 6 speed, single ring front and the bike is SOOOO heavy. I'd imagine the 3 secrets to weight reduction are Fork, Wheels, Frame eh? no sense getting some sick carbon bar, stem, etc...if I am still going to have a heavy ass main parts.
So frustrating the selection of decent bikes, I saw that ventana 20" bike at sea otter, but the price was wicked gnar.
Don't go carbon anything on a kids bike... they wreck.
I got my kids Gromhit around 31 lbs with DH tires. The bars are Stylo world cup strait, Thompson post, SDG ti-Fly seat, and Juicy 7 brakes. She rode a roller last night that I've seen some adults walk down. As soon as school is done, we ride a lot more.You will be amazed how heavy some of the peripheral parts are. Things like 400 gm bars and seatposts. You can get a 200 gm aluminum bar practically for free. You probably have a fleet of old race bikes you can scavenge from. My daughter's Scott that is a few pages back lost pounds and the only parts I bought for it were the rimes, tires and chainguide. Everything else came from a bike I was never going to ride again.
I just realised I've never posted in this thread!
My lad is now 12 and he's progressed through a small dj frame with 24" wheels, an original spec big hit grom - 24" wheels and then 26", a Kona stinky for 5 minutes (chainstays waaay too long for a small bike), and now a small Bottlerocket - initially short shocked, now stock shock length with offset bushes, a longer fork and slacker headset cups.
This is the second year on the Bottlerocket and it'll probably be a small DH bike after this.
My lad is now 12 and he's progressed through a small dj frame with 24" wheels, an original spec big hit grom - 24" wheels and then 26", a Kona stinky for 5 minutes (chainstays waaay too long for a small bike), and now a small Bottlerocket - initially short shocked, now stock shock length with offset bushes, a longer fork and slacker headset cups.
This is the second year on the Bottlerocket and it'll probably be a small DH bike after this.
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Stik - been there, so frustrating!! So difficult... BMX till they are at least 10 - makes life so much easier and less expensive!! MTB world is not for kids or girls ;-)
My girl asked to go with momma to the BMX track when she was 5, she rolled around the track, thought it was fun, went back 3 times and when some kid in clips couldn't unclip in the finish straight, he slammed into my daughter, big pile of dust-she never went back! haha She likes riding MTB much better, but she's still pretty lazy, wants to go for a little trail ride maybe 2 times a month.
Yesterday, last minute she said she wanted to race with me at our local night series, over the hump...so we threw her stuff in the van and we all headed out after work. My 6yr old girl was the first place girl out of all the girls, and first kid out of boys and girls in the under 10 category, she was pumped and said she wanted to do it again, so who knows, maybe racing will make her stop being lazy. I will be perfectly happy if she never wants to race DH! haha Such a fun vibe at that overthehump series, she gets snocones, sees friends, plays on the playground, etc.
Yesterday, last minute she said she wanted to race with me at our local night series, over the hump...so we threw her stuff in the van and we all headed out after work. My 6yr old girl was the first place girl out of all the girls, and first kid out of boys and girls in the under 10 category, she was pumped and said she wanted to do it again, so who knows, maybe racing will make her stop being lazy. I will be perfectly happy if she never wants to race DH! haha Such a fun vibe at that overthehump series, she gets snocones, sees friends, plays on the playground, etc.
The stock cranks on the Gromhit are 165mm. They are a little long and they will hit rocks... a lot. I got smaller HT pedals and this helped a ton. Sinz makes shorter cranks if you want to swap them out. My daughter was about 4'2" when she started riding the Gromhit.
The pedals are perfect for small feet. Ill get her a regular pair in a few years.
This was my daughters first real ride on her bike. You can she was pretty small. I put on a SDG race seat and a Thompson seatpost so she could lower the seat another inch. The bike lost almost a pound too. The stock seat and seatpost are HEAVY. I also swapped the Specialized 2.3 tires for Kenda 1.9s. The tires were a lot lighter and the sidewall was smaller so it lower the bike about 1/2".
You can see the smaller tires in this pic. You can see from her smile she was hooked.
The pedals are perfect for small feet. Ill get her a regular pair in a few years.
This was my daughters first real ride on her bike. You can she was pretty small. I put on a SDG race seat and a Thompson seatpost so she could lower the seat another inch. The bike lost almost a pound too. The stock seat and seatpost are HEAVY. I also swapped the Specialized 2.3 tires for Kenda 1.9s. The tires were a lot lighter and the sidewall was smaller so it lower the bike about 1/2".
You can see the smaller tires in this pic. You can see from her smile she was hooked.
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Thank you Kntr, that's a great news. My son is just short of 4', but I don't expect him to ride the bike till next season, 2013.
How did your girl find it at that height, was she able to put foot down and reach ground when stopping?
I have frame only, not whole bike. So have to build it up from scratch. I'll definitely be putting BMX cranks on it, either Sinz or Answer 140-145mm, not sure yet...
Good idea with the smaller tires, but did she puncher them a lot?
If you have any more tips for the bike, I would be more then happy to hear them.
Many thanks
How did your girl find it at that height, was she able to put foot down and reach ground when stopping?
I have frame only, not whole bike. So have to build it up from scratch. I'll definitely be putting BMX cranks on it, either Sinz or Answer 140-145mm, not sure yet...
Good idea with the smaller tires, but did she puncher them a lot?
If you have any more tips for the bike, I would be more then happy to hear them.
Many thanks
She could put her feet down after I put the lower seat, seatpost, and smaller tires on. She has never had a flat and she runs her tires at 20psi.
Sinz 150mm cranks
Thompson seatpost
SDG ti-Fly seat
Truvative flat Stylo XC bars
small Ruffian ODI lock on grips
small HT pedals
Schwalbe Moe Joe single ply tires
I agree with everything Kntr has said, seatposts that you can slam in the frame, low profile seats, smaller single ply tyres are all big helps when they are starting out and "just" fitting a proper mtb. And yes 165mm cranks are too long when they are first on a 24" bike - but its what I and plenty of others have used out of convenience.
My lads bike was a running parts change as I kept making it "feel" a bit bigger, if you plan on doing the same then dont be too precious with the parts you choose as they wont be there for long!
Bars, forks, wheels, shocks, frames - were all replaced as he grew. Usually I made one change at a time as that helped it always feel like his bike and helped him learn to set up his own bike and he now has a good idea what various changes do to a bikes handling.
He also got used to being "uncool" at races as he would have skinny xc bars or whatever, but he tended to silence any kid who gave him sh*t by letting them ride his bike around the carpark. As an adult dh racer you shouldn't have any issues with measuring sag and balancing front and rear suspension and all the rules still apply when kids are involved! You just need to hunt up light springs and lighten the rebound damping enough to suit.
My lads bike was a running parts change as I kept making it "feel" a bit bigger, if you plan on doing the same then dont be too precious with the parts you choose as they wont be there for long!
Bars, forks, wheels, shocks, frames - were all replaced as he grew. Usually I made one change at a time as that helped it always feel like his bike and helped him learn to set up his own bike and he now has a good idea what various changes do to a bikes handling.
He also got used to being "uncool" at races as he would have skinny xc bars or whatever, but he tended to silence any kid who gave him sh*t by letting them ride his bike around the carpark. As an adult dh racer you shouldn't have any issues with measuring sag and balancing front and rear suspension and all the rules still apply when kids are involved! You just need to hunt up light springs and lighten the rebound damping enough to suit.
Kntr, thanks for the link. I have seen the MR01T pedals under different brand, and I was planning on using something like that. It’s good to know they are working well for your girl.
weedkilla, thanks for confirming the info. Sure, it’s not about how cool he looks, it’s about how well the bike fits him, so XC flat bars were on a shopping list from the beginning for sure.
I have been looking at growth charts (if he stays the same percentile), I expect him to have that bike for about 4-5 seasons, before he outgrows it, and can have XS or S size full on DH bike. So I am planning that some of the parts will have to change through the lifetime of the bike (bars flat to risers and narrow to wide, stem 35 to 50, cranks 135 to 155, spacer above/bellow stem, and tires as he gets more aggressive with his riding etc) to allow the bike to grow with him, so to speak.
Yes, its good thinking, getting him involved in setting his own bike up, I will do that.
I have couple more things I would like to ask, how did the kids find the air suspension? Were you able to make it supple enough over small bumps?
And did any of you change the rims, or build other 24" wheels? I have hard time finding 24” 32 holes light and strong rims. Best rims I can find are Sun Envy, with 36 holes at 521g.
weedkilla, thanks for confirming the info. Sure, it’s not about how cool he looks, it’s about how well the bike fits him, so XC flat bars were on a shopping list from the beginning for sure.
I have been looking at growth charts (if he stays the same percentile), I expect him to have that bike for about 4-5 seasons, before he outgrows it, and can have XS or S size full on DH bike. So I am planning that some of the parts will have to change through the lifetime of the bike (bars flat to risers and narrow to wide, stem 35 to 50, cranks 135 to 155, spacer above/bellow stem, and tires as he gets more aggressive with his riding etc) to allow the bike to grow with him, so to speak.
Yes, its good thinking, getting him involved in setting his own bike up, I will do that.
I have couple more things I would like to ask, how did the kids find the air suspension? Were you able to make it supple enough over small bumps?
And did any of you change the rims, or build other 24" wheels? I have hard time finding 24” 32 holes light and strong rims. Best rims I can find are Sun Envy, with 36 holes at 521g.
Nope, never found any rims lighter than about 500 grams, but when he could get away with a 500gm tyre there was plenty of weight to save there. Even tubes vary pretty hugely.
I never got a kids bike down to a weight I would want to brag about, but I could certainly build one lighter than a 20" pseudo MTB that they had ridden before and they were stoked at that.
Air suspension.....honestly it isnt great. Service the air can, lube all the seals and do it regularly.
Its either that or hunt ebay for light second hand springs or when internet stores have sales a lot of their odd size stuff is actually what you want. I had some custom springs wound along the way, maybe not for my lad, but I've built a couple of others for friends.
What is worth doing is hunting for pre pro pedal era shocks, the increase in low speed compression damping is not required for such small body weights. There is still a Fox Vanilla RC in my lads bike at the moment. The best air shock I built was a Manitou Piggy back airshock, I threw away the SPV valve and put in a light shim stack. That was a beautiful thing in a small Kona Howler that is now on its second Jnr Pilot. It had a 2002(ish) Jnr T on the front converted to 5" travel, custom springs. I think the whole bike had a total value of about $300 but it just turned out perfectly for a kids DH bike.
I never got a kids bike down to a weight I would want to brag about, but I could certainly build one lighter than a 20" pseudo MTB that they had ridden before and they were stoked at that.
Air suspension.....honestly it isnt great. Service the air can, lube all the seals and do it regularly.
Its either that or hunt ebay for light second hand springs or when internet stores have sales a lot of their odd size stuff is actually what you want. I had some custom springs wound along the way, maybe not for my lad, but I've built a couple of others for friends.
What is worth doing is hunting for pre pro pedal era shocks, the increase in low speed compression damping is not required for such small body weights. There is still a Fox Vanilla RC in my lads bike at the moment. The best air shock I built was a Manitou Piggy back airshock, I threw away the SPV valve and put in a light shim stack. That was a beautiful thing in a small Kona Howler that is now on its second Jnr Pilot. It had a 2002(ish) Jnr T on the front converted to 5" travel, custom springs. I think the whole bike had a total value of about $300 but it just turned out perfectly for a kids DH bike.
I think the rear air Fusion shock on the 08-09 FSR Gromhit is perfect. I can change air pressures as she grows. I also took the front spring out of the Marzocchi front shock. Marzocchi told me this was the best route for her weight. It works great and Ill throw the spring back in the bigger she gets.
Make sure to get good hydraulic brakes though. Their small hands and fingers make it hard to pull cable disc brakes.
Make sure to get good hydraulic brakes though. Their small hands and fingers make it hard to pull cable disc brakes.
I think I will probably leave the Xfusion shock, it's unusual size, so would be more difficult to change.
And I will probably try to find Fox 32 vanillas on ebay, as they dont make them anymore. I still have some time to find a good deal...
Yes, he will have hydraulic brakes for sure. What size discs is your girl using?
And I will probably try to find Fox 32 vanillas on ebay, as they dont make them anymore. I still have some time to find a good deal...
Yes, he will have hydraulic brakes for sure. What size discs is your girl using?
She is running 7" rotors. Probably overkill but they work great.
Avid (and I'm sure others) make a 140mm rotor - lighter, and harder for them to bend when they crash, which is more of a concern the smaller the wheels they're running. Also, if you use adjustable cable pull levers (like Avid or Shimano) you should be able to set up a set of cable discs they can pull. My 5 year old daughter can pull the Avid bb7's on my dirtjumper. For weight savings, though, hydro is the way to go.
And tubeless is another good way to save some rotating weight and give them a little more cushion.
And tubeless is another good way to save some rotating weight and give them a little more cushion.
Yes they do, but I don't think I will be going 140mm rotors. May be on 20" bike, but 24" DH/AM bike I would rather it be bit heavier, then let him overheat the brakes half way down the mountain. I would prefer him to be safe, then sorry. The weight of the bike is only 2ndary objective, prime objective is fit and function.
Yes, I am thinking about going tubeless, not 100% sure about that yet. But may go that way and see how he gets on. I can always put a tube in if it does not work well for him.
Yes, I am thinking about going tubeless, not 100% sure about that yet. But may go that way and see how he gets on. I can always put a tube in if it does not work well for him.
Not that I have first hand experience, but a couple of friends have gone down the route of 24" BMX cruiser rims that are light and pretty durable. Also they use those DJ saddle/seatpost combos that are wicked light and you can slam it really into the seat tube.
This thread has got me so excited about my son riding bikes. I have to keep reminding myself that he's not super daring and I shouldn't be an overbearing dad. He took a while longer to get comfortable without the training wheels (he's 6.5), but once he got rid of them he's been gangbusters wanting to ride his bike. I picked up a new proper helmet and gloves for him last night, and he was so psyched about it. I could barely get him to leave the bike shop when we were done. He really wants one of the Trek or Specialized 20" mountainbikes when he outgrows his Haro BMX. I will have no issues spending the money on better bikes because he's about to have a little brother and every bike we buy will have a second life down the road. The last thing he said to me last night was that he wished he could ride to school (right down the street), and the first thing he did this morning after eating cereal was to suit up and go ride in the driveway. Bikes rule! Thanks everyone who's posting in this thread. Keep me in mind when your kids start to outgrow their GromHits 
Hopefully I'll need one at some point when my peanut gets big enough for 24s.
Hopefully I'll need one at some point when my peanut gets big enough for 24s.
I love this thread as well! My little one is only four but is having a blast on his 16" pit bike...we're doing the kids DS race at Whiteface and will shuttle up to the pump track as well this summer....Looking forward to fun for many years ahead.
EDIT: thus far, this bike (wethepeople seed) seems to be a great 'transition bike' - freewheel, hand brakes, scaled down lever size/cranks (140 mm) and pedals.
EDIT: thus far, this bike (wethepeople seed) seems to be a great 'transition bike' - freewheel, hand brakes, scaled down lever size/cranks (140 mm) and pedals.
How big is your son? He looks older than 4 in that shot.
My daughter is 5 (but small for her age) and just moved up to an Intense micro mini bmx. She loves it, but will still be on her hotrock 16 for skatepark riding until she completely outgrows it. It's a lot easier for her to throw around.
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weedkilla, I have just re-read your post, and picked one more thing I am missing in my as small as possible Gromhit build. I could use offset shock bushes, to lower the bike.
iRider, the Sunline rims are BMX cruiser rims. As far as I could find there were no 32 holes, sub 500g cruiser rims. I would be very happy if anyone could tell me otherwise. DJ rims can be found in 32 hole, but are also very heavy. The BMX seatpost-seat combos are good, but I don't think they go to 30.9mm seatpost, so no good for Gromhit unfortunately, Hotrocks yes.
Lex, how tall is your boy? Couldn't he ride Hotrock 24? My son is 5.5 and can ride it already on flat terrain, not off road yet...
iRider, the Sunline rims are BMX cruiser rims. As far as I could find there were no 32 holes, sub 500g cruiser rims. I would be very happy if anyone could tell me otherwise. DJ rims can be found in 32 hole, but are also very heavy. The BMX seatpost-seat combos are good, but I don't think they go to 30.9mm seatpost, so no good for Gromhit unfortunately, Hotrocks yes.
Lex, how tall is your boy? Couldn't he ride Hotrock 24? My son is 5.5 and can ride it already on flat terrain, not off road yet...
Yep, offset bushes are easy and cheap and the way dh bikes are going by the time our kids are on full size bikes head angles will be about 50 degrees! Better get used to low and slack now I figure!
Just do the normal measuring to make sure nothing will hit, particuarly as I'm pretty sure its 6mm shock hardware so you can offset it a fair way.
Dont be afraid to use a shim to get that seatpost you want to fit, I've done it and its all sweet.
I've used these plastic ones, but I'm sure everything from coke can onwards works.
http://www.chainreactioncycles.com/Models.aspx?ModelID=43707
Just do the normal measuring to make sure nothing will hit, particuarly as I'm pretty sure its 6mm shock hardware so you can offset it a fair way.
Dont be afraid to use a shim to get that seatpost you want to fit, I've done it and its all sweet.
I've used these plastic ones, but I'm sure everything from coke can onwards works.
http://www.chainreactioncycles.com/Models.aspx?ModelID=43707
Nice vid! My kid's about to turn 5. He has a big torso but so-so length legs - he barely has enough standover height on the 16". Because the bike is scaled down, I also think that shot tends to make him look like he proportionally on a 20". If we get into BMX, a micro mini will be the thing. Right now, he's curb bashing and doing some trail riding - wanted something a little beefier.
My son is only four feet tall. I had him sit on the Hotrock 24 and it was way too big. When he's a little more confident we'll get a 20 and it will last him quite a while I think. His little brother is due any day now so any bike he gets will get more use later.
She says she really wants to race, so that's why we got the micro mini. The video plays funny thru this site, on youtube it's not so jumpy, and you can see how she grabs the brakes at the top and whips the bike around - that's what I meant to show. I'd still like to pick her up a longer 16" bike for park riding when she outgrows the other one. Her micro mini is about 2.5 lbs lighter than her HR16, tho - that's like me taking 12 lbs off my bike.
weedkilla, I was thinking about putting 120mm fork on for the first season, instead of 130, to drop the front of the bike, I know that would steepened the HA a tiny bit. The offset bushes would fix the HA (and may be slacken it bit) and lower it even more.
I know the BB will be low, but with 135-145mm cranks and small pedals it shouldn't an issue, I think?
I know the BB will be low, but with 135-145mm cranks and small pedals it shouldn't an issue, I think?
Fair enough, both Rockshox and Fox have travel adjust spacers available. A second hand float or revelation is an easy way to have a light fork and easily adjustable travel and spring rate.
Obviously U-turn and Talas is an option.
I think those early Vanilla Forks had a travel adjustment option, similar to a 40 where you could shuffle some spacers from the spring preload to the top out bumper.
Obviously U-turn and Talas is an option.
I think those early Vanilla Forks had a travel adjustment option, similar to a 40 where you could shuffle some spacers from the spring preload to the top out bumper.