What is the average diameter (external and internal i.e I'd like to know the thickness of the tube) of aluminium tubing on a mountain bike or BMX ?What about steel tubing?
There is no standard diameter or thicknessSome bikes use butted tubing (meaning the thickness is variable to be thicker where it requires strength and thinner where it can safely save weight)Along with variable sizes, manufacturers use different methods for bending and forming (hydroforming, roll forming, stretch bending).and different attachment methods (welding, brazing, lugged attachments)Some companies use gussets to beef up welded jointsOthers use a different method to ensure a strong weldsorry for the long winded response, but there is no standard size for Al, Ti, or steel framesOn top of that some will use a different size tube for each part of the bike, like my Cannondale has a top and seat tube that are the same, but the downtube is different, the stays are different, the headtube is different, the fork is different.
On a track, you ALWAYS have metal against metal; in the links between each track, on the hubs, on hatches, and generally all over the thingMost probably is just normal wearing of any number of metal-on-metal, and I would not worry unless they get much larger and/or change in any significant wayStart to worry if you see hand sized and above pieces come pealing off the sides or elsewhere.
something is chewing it's self up dudeIt could be many things.god I hated driving those POS things! LOL
