They are steel, so you (or I :devil could shave another 4-5 grams with tiOk here's the deal: bolts are 3mm allen bolts and its metal. In other words, they are quite small, that explains the low weight as well.
No, just from where the bar starts to taper, its no biggie.
It's not okay when the ads say 100mm/100g and on ritchey's website it claims 110mm at 103g. I've weighed 2 100mm and they were both 109 grams.100mm at 109g is ok but there are plenty of stems at that weight. The Ritchey is supposed to be stronger and it is easier to find than the alternatives.
There is one other option - an Ibis stem with Ti tapered head bolts from Tom.I have a 70mm @ 91 grams, a 80mm @ 93 grams, so a 100mm should be around 97 grams.These are dirt cheap @ $45.00 and very strong. Ibis specs this stem on their AM HD Mojo bike.Syntace F109 at 100 mm is claimed to be 113 g
So it is comparable. The ritchey one is probably the lightedt mass produced 31.8 mm clamp stem on the market currently.
Only way to go lighter is if you go to 25.4 or you pay big dollar for boutique stuff like extralite.