Is it the non-German lens? Got caught out with that years ago, they have weird rules about blinding drivers so the domestic market lights have a weird beam pattern.
According to Bikester, it's apparently StVZO approved which I understand be some sort of German traffic law / regulations. Fuck knows, it was cheap and I'm still suspicious :)
Sounds like a German one. TBH I havent actually used that one in anger, but it is just a different beam pattern, it isn't less bright so as long as you set it up right you will be fine. Also, you can compare between the one on your tandem and on the Bowman, please report back!
Is it the non-German lens? Got caught out with that years ago, they have weird rules about blinding drivers so the domestic market lights have a weird beam pattern.