Re:
Ambrosio rims are most likely to be found on road bikes where they are widely used .
However the mtb rims you have are clearly low end/budget rims best suited to road/
gravel track/towpath use at best
' are they any good ' ? well if they are still usable after 25 years I think you can't complain ,
however they were never very good from the beginning . And by this I mean that they are
not a particularly strong design
Generally speaking in terms of relative strength , rims without eyelets are entry level ,
rims with single eyelets and possibly box section are next, rims with double eyelets and box section are best
The way the rims are ' joined ' is another factor contributing to strength . On your rims the
join is clearly visible indicating a pegged joint . On better rims the join is welded and virtually
invisible
Going back into mtb history , Charlie Kelly notes that 26" alloy rims ( from Ukai/Araya ) first
became available in mid 1979 . He used lighter weight Ambrosio rims in 1980 for a ' century ' race