BMX Sizing
 

  You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more

BMX Sizing

7 Posts
4 Users
0 Reactions
168 Views
Posts: 1070
Full Member
Topic starter
 

My soon to be 12 year old says he’d like a BMX. He’s been doing a bit of jumping on his MTB lately and rode a mates BMX the other day so has decided they are the shizzle. I can’t really argue with N+1, even for a 12 year old, and if he’s spending more time riding I’m happy. So we are contemplating part funding one for him, currently looking on pinkbike for second hand.

According to size charts he’ll need a 20” frame, up to 20.5” with room to grow. I’ve seen one relatively close by that might fit the bill, but it’s 20.75”. Is this a massive deal? An extra 15mm reach may not be ideal but will it affect him that much? He’s very much learning so bike handling is important, I’m just not sure how much difference this will make. Presumably a bigger frame “just” means longer reach, but is standover etc the same?

Thanks


 
Posted : 23/10/2022 10:33 am
Posts: 10942
Free Member
 

A friend who builds frames for BMXers and who favours dirt jumps is pretty anti new skool geometry unless your very skilled and capable of pulling off real tech back to back tricks in a skate park. It's just far too twitchy and nervous. Far better to have something more stable. All the size guides target shorter bikes to you by height, my friend was pretty confident you can go a bit longer for stability and grace in the air, he is also anti crazy short chain stays and super steep head angles. I hope this helps you navigate the maze of sizing & geometry.


 
Posted : 23/10/2022 10:53 am
Posts: 8750
Full Member
 

Almost all BMX's have 20.5" top tubes but no, less than an inch either way makes zero difference especially to a 12 year old on New Bike Day.

They're all tiny so standover height isn't really a concern.

Have you seen the Mafia bikes website? 2 for 1 on most bikes last week.


 
Posted : 23/10/2022 11:59 am
Posts: 1070
Full Member
Topic starter
 

Thanks both, I might explore this one on pinkbike then. I was quite surprised at the different options with sizing and geo, things have obviously changed a lot since I had my Raleigh Tuff Burner circa 1982.

sharkattack - no, hadn't seen the 2 for 1. Figured we'll get better value second hand, and there's no way I can justify a BMX for me (because if it's 2 for 1 then one of them would have to be for me!).


 
Posted : 23/10/2022 1:12 pm
Posts: 10942
Free Member
Posts: 4954
Free Member
 

.25" on a bmx is quite a bit. Unless he is massive I would try and keep to 20.5. I am just shy of 6'2" and ride a 21" as a around park bike, if I was building a pure trail machine I would go 21.25 or 21.5.


 
Posted : 23/10/2022 2:40 pm
Posts: 8750
Full Member
 

The difference between 20.5 and 20.75 is 6.3mm and we're talking about a 12 years old's first BMX. He'll have the same experience on either bike.

I was trying to be encouraging and not get bogged down in minute details. Leave that to the middle aged MTBers.


 
Posted : 23/10/2022 3:15 pm
Posts: 1070
Full Member
Topic starter
 

Appreciate the thoughts folks. Agree with the 6mm won’t matter sentiment - more important is colour, has it got pegs, will he look cool 😊

If his older brother is anything to go by he’ll be hitting a growth spurt in about…… 10 minutes time and will be 4 inches taller by January 🤣


 
Posted : 23/10/2022 3:57 pm

6 DAYS LEFT
We are currently at 95% of our target!