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in 1977 Verot-Perrin (makers of Stronglight branded products) made a change in the way the dentition was cut on their chainwheels
in that year they launched four new models: 104, 104bis, 105 & 105 bis
these received the new design of cutting teeth from both sides of the stock
existing models such as 49D, 99 & TS continued to have their chainwheel dentition cut from one side of the stock only; model 93 was discontinued, being superseded by model 105
when working with these sets with the 122BCD for example one sometimes finds that someone has mixed the two types of dentition cutting on the same set. this effects the spacing between chainwheels.
from the images provided in this case i find it difficult to determine if all three chainwheels have their dentition cut the same way
difference in this case is more likely due to incorrect spacer being used
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