Stippling could be a good technique to use as it allows for strong tonal work whilst still keeping simplicity.
Tatto Ideas 2017 - Geometric Beasts by Kerby Rosanes...
The early R50/5 was virtually indistinguishable from the R60/5 and R75/5. This is the 1970 US R50/5 with higher handlebars. BMW Group Archives
'69 Honda cb 100
BMW gendarmerie nationale
BMW R27 | Retro Motorcycle
vintage honda motorcycles - Tìm với Google