Bought a frame only and Di2 groupset offer from Westbrook. Arrived promptly in lots of boxes, spent many hours assembling the bike and finally plugged the battery in to configure Di2 - and nothing, dead as a dodo! Spent more time dismantling to check my work - still dead. Rang Westbrook who were very helpful on the phone but couldn't help. Further research discovered that Di2 needs all components to be running same firmware. Built at different times will mean different firmware possibly which is probably the cause. Shimano authorised service centre were useless and local bike shops didn't have the PC interface equipment to update. So all electronic parts were removed and posted back for an update that in my opinion should have been performed / ensured before original dispatch. I've wasted many hours of my time on a very confusing problem (I'm new to Di2). It has spoiled what as an avid cyclist was an exciting purchase and I've missed using my new bike on my weekend ride. Only time will tell if things work out but at the moment I am beginning to regret the significant investment I've made. Anyone buying Di2 BEWARE your gear may need a PC update before it will work, finding someone local who can do this will be your challenge and do not look to Shimano for help as they will not offer any. They are happy to ship the gear and reap the rewards but have not ensured countrywide support. You could spend a further £200 and buy the interface to do it yourself!! So in summary, great product and price. Swift dispatch and excellent telephone help from the shop but very disappointing that they did not ensure firmware match, if they don't know about these things as installers and sellers - who does!! Shimano UK support - useless!!