Isle of Man TT winners Peter Hickman and Michael Dunlop have begun their delayed test schedule of the new BMW, after both missed the Silverstone British Superbike test on Monday.
Hickman and Dunlop are both set to race the brand-new S1000RR BMW in the Superbike and Superstock races at this year's TT, with the former also campaigning in BSB on the bike in Smiths Racing colours.
Both missed the BSB tests at Monteblanco and Portimao last month due to the Smiths and Tyco Racing teams taking late delivery of the new S1000RR.
They had expected to be ready to make the final official BSB test on Tuesday ahead of next weekend's season-opener, but were forced to abandon those plans, and have instead carried out private running.
Double TT winner Hickman has been a regular in BSB since '06, and has finished the last two seasons inside the top five of the championship.
During the '19 TT launch event, Hickman told Autosport the newness of the S1000RR already put him on the "back foot" coming into the new year without the delays in testing.
As well as Hickman, his BSB team-mate and former MotoGP rider James Ellison was also forced to miss the Silverstone test - though both completed some laps on the BMW at Le Mans last week on the Dunlop Test Team bike.
Both were at Cadwell Park on Wednesday for a shakedown of the new bike, and have resumed their private testing programme at Rockingham today.
Dunlop and the Tyco team - including its BSB runners Chirstian Iddon and Keith Farmer - have also begun its delayed testing schedule at Bishopcourt in Northern Ireland. Dunlop has also completed running at Kirkistown.
The Silverstone test was topped by McAMS Yamaha runner Jason O'Halloran, who fired in a 54.372s lap of the National circuit late in the final session of the day.
MotoGP convert Scott Redding completed the top 10 on his Paul Bird-run Ducati Panigale V4 R, 0.558s off the pace and a place behind former Ducati World Superbike rider Xavi Fores on the Honda.
TT regular Dean Harrison will campaign his second full season in BSB for the Silicone Engineering Kawasaki team, having first made his debut in the series in the latter stages of '17.
The double TT winner was 1.8s off the pace on his ZX-10RR in 25th on the test timesheets, with fellow road racers James Hillier [Bournemouth Kawasaki] and Padgetts Honda's Conor Cummins 24th and 30th as the continue their TT preparations.
Hillier will also contest rounds of the National Superstock Championship this year, while three-time TT podium finisher Lee Johnston will race in the Supersport series.
Johnston was present at the Silverstone test with his Ashcourt Racing Yamaha R6, and was 35th on the combined STK, SSP and GP2 timesheets.