bmx cranks

Spindles are the middle part of your cranks that go through to bottom bracket. 48 spline is just how the the crank arms lock on to each other. 19mm is one of the most common, it is the diameter of the spindle, they also come in 22mm and Fit has 24mm cranks.

And yes you should be able to upgrade.

you could get the profile cranks but you would need the whole set like spindle and everything. 8 spine is stock crap 19mm and 22mm? idk ones bigger than the other lol spindle bolts just hold the cranks together..

Thanks guys.helped a lot

The spindle is what the cranks hold/clamp on to. It spins..

The splines are kinda like little teeth for the cranks to hold to. Cranks are also splined on the inside for that specific spindle. Some spindles have 48 (teeth) others less.. like 16 splines for example.

Spindle bolts screw into the spindle itself, after the cranks are installed. They're just bolts.. they keep your stuff tight.



Here is a pic of two different sized spindles. They're measured in circumference. 19mm would be the smaller (skinnier) compared to a heftier 22mm spindle.(19 and 22 are the most common sizes) When buying a new crank set, you have to take into consideration the size of your bottom bracket bearings. The bottom bracket is the part of your frame that holds the bearings.. which hold your spindle.. which hold your cranks.

So if you happen to buy a 22mm crank set then you would need bearings which are also 22mm to accommodate that 22mm spindle.