BB30 -> GXP adapter - what's going on here?

[02gf74]

My understanding is that a BB30 -> GXP adapter fits into the bearing fitted to the BGB30 bottom bracket (see here: https://www.amazon.co.uk/Wheels-Manufac ... B003TOUUYK - these are delrin inserts.

so what is going on with this one - it has additional bearing races fitted - any ideas?
http://www.ebay.co.uk/itm/301853605189? ... EBIDX%3AIT

 

[hamster]

if I understand it right the Amazon one is a reducer that fits into the BB30 inner race to allow the slimmer shaft to fit. The second is a complete press-fit and reducer unit that replaces the BB30 bearing.

 

[02gf74]

I would have said that too except they look identical to me.

I contacted the seller and response was "no need to remove the bearing" which implies the ebay one fits to the bearing and has an additional bearing. (it seems most strange). :?

 

[mechanical_vandal]

I would have said that too except they look identical to me.

You shoulda gone to specsavers, they are different diameters, one is one piece, the other multiple pieces, including a bearing.

As already suggested, Amazon one fits into the BB30 bearing to alter the ID, eBay one is a complete replacement unit.

Neither of these will do anything to alleviate the problems that come with bb30 though, you really want something like the Praxis adapter that screws together/expands.