I have a 2004 Varadero ABS model. The issue is that in second gear under hard acceleration it feels like the chain jumps or the clutch slips for a second then re engages then jumps again. I have replaced the chain and sprockets, also changed the rear carrier bearing as it had collapsed. Renewed the clutch actuator and push rod too. Doesn't happen in any other gear and if I'm gentle on the throttle is ok in second, just if I start to accelerate. Any ideas?