I went on a ride a few weeks ago, and had a lil fall on my back, now after a few days my coxix thing looked like it swelled up ... left it a few days and seemed to get worse and worse .. ended up near enought fainting due to the pain, so went to a walk in centre it wasn't due to my riding it swelled up, i had a ingrowing hair, and it created an absis ... so of i went to ane to have it sorted, it realy FFFFFFIN hurts they had to drain the absis out, and now i have a fanny looking hole on my back, which needs to heal inside out it is a common thing this, so if you have a lump, you might have the same problem, get it checked out ... i can put pics up, but only if you want to see it, its not all that nice really sorry to jon too who brought ,y bike of ebay, i promise i will get it posted asap, really sorry mate ....