Hi to all, I am rebuilding a BMW R100RS mono of ’88. The build is almost finished. Now I noticed that it is not possible to turn the rear wheel when it is in gear and clutch is engaged when ignition plugs are removed. When I try to turn the wheel, I feel some play (assuming that this is the play on the hole rotating part up to the blocking part). At both ends of the play I feel resistance building up. It does not feel like play and then 100% blocking. The motorcycle is resting on the engine with rear wheel hanging over the table. Diagnose: 1) Wheel spines free when in Neutral, or in any gear when clutch is disengaged. Conclusion: Brakes, rear differential, drive shaft and transmissions are free. 2) Motor spines free when in Neutral, or in any gear when clutch is disengaged. Conclusion: Crank and cam is free, checked chain and alignment, all is correct. 3) Clutch is working correct to me, removed transmission to inspect, but cannot identify an issue. Here is some information about the works done on the engine and transmission. Cylinder head rebuild, new rod tubes, new engine gaskets, new chain + tensioner, new clutch. Rear swing arm has been removed. Rear differential removed and opened it to inspected due to blocking rear brake axle. Anyone as an idea, a tip? thanks!