bmx cranks for a youngster

souter

The 7 year old is hitting his knees off the handlebars on his ancient 14" bike so I popped down to rothar.ie to get him something bigger.
Dad has a bit of a nostalgia moment and ends up getting juniour a fairly bog standard bmx (apollo mx 20.3, I suspect it is a generic halfords yoke) with pegs and spinny around front brake cables.
There are a few days wait to collect the new bike so Dad is upselling bmx by showing various Danny McAskill videos.
Kid collects bike and isn't doing said tricks. Dad has bruised shins from pegs and wondering if this was such a good idea.
Question, the frame of the bike seems a fine size but the cranks are definitely more appropriate for someone older than 7, can these be reduced (I reckon they are c. 17cm)?
I had a cursory scan of various websites, but inclusion of bmx in any search seems to assume semi-pro level of expenditure.

Harrybelafonte

I'm guessing the cranks you were looking at were expensive cos they were 3-piece cranks?

Rider Inseam Crank Arm Length
20" 140 mm
21" 145 mm
22" 150 mm
23" 155 mm
24" 160 mm
25" 162 mm
26" 166 mm
27" 171 mm
28" 175 mm
29" 177 mm
30" 180 mm
31" 182 mm
32" 185 mm
33" 185 mm
34" + 190 mm

souter

Would indeed, also can't find any < 17cm.
Bearing in mind the whole bike cost e80, any ideas where to look for cranks that are a) cheap b) < 17cm, c) fit the axle/bb/crankshaft/bit in the middle.

Harrybelafonte

Probably Rothar again, or see if they have an 18inch bike for him?

kona

Becareful, Cheap bikes are usually 1 piece cranks. AFAIK they only come in one size. You could get a 3 piece but this would require pressing in BB cups and new bearings etc and possibly a new front cog.

kona

souter wrote: »

Would indeed, also can't find any < 17cm.
Bearing in mind the whole bike cost e80, any ideas where to look for cranks that are a) cheap b) < 17cm, c) fit the axle/bb/crankshaft/bit in the middle.

There is a shop in greystones that sells BMX all the kids go there to get their fancy bits, as much as Im told about it, I do not have a clue what the name is.
Perhaps try G1 skate supplies on connell street?

Id imaging 170 is quite common, the issue is that BMX have Massive BB shells. Otherwise ya be laughing, you could stick a MTB crank on.

Harrybelafonte

kona wrote: »

There is a shop in greystones that sells BMX all the kids go there to get their fancy bits, as much as Im told about it, I do not have a clue what the name is.
Perhaps try G1 skate supplies on connell street?

Id imaging 170 is quite common, the issue is that BMX have Massive BB shells. Otherwise ya be laughing, you could stick a MTB crank on.

www.theeboardroom.ie ???