Weighed the front fork with the MD brake booster, Chris King lower race and the star nut. Let's be a little OCD...
1322 g total weight
-10 g star nut
-17 g King bearing race
Grand total:
1295 g
...but there is room for improvement?
View attachment 693877
Looking at this old Rock Shox catalog scan, the fork I have is much heavier than what is claimed in the catalog. My 1322 grams total vs. the catalog 1043 grams, a 21% difference. If the catalog claimed weight is accurate the brake booster and the billet crown stiffness come with a significant weight penalty (see catalog scan below). I pulled the stem shims off to see if that steerer tube is ferric in any way, like some kind of alloy mixture because there are people out there with SL forks who have steel steerer tubes
...aluminum. I used a strong magnet too. Though on the Weight Weenies website, the weight of the SL fork is listed as 1225 grams 'actual' (Al steerer w/ canti cable guides removed), a 7.5% weight difference. Do I press in a titanium steer tube? At first glance, no, titanium dollars to donuts is heavier than aluminum. However this doesn't consider wall thickness of the current aluminum steerer tube and what is available. I measured the wall thickness of the aluminum tube: about 3.5 mm. From a prior link posted above to a German Tune machinist, he sells a 1 1/8" titanium steerer at 170 mm long and claims 84 grams but does not mention wall thickness; my assumption is about 2x thinner maybe 2.5x.
What is the aluminum steer tube weight though? Using yet another link posted prior in this thread to another German-based website a thread starter has the same fork here along with the Ultimate Machine crown. His fork pre-upgrades weighs 1550 grams WITH a steel steerer tube at 180 mm.
My Rock Shox SL = 1322 grams with Ultimate Machine crown and MB brake booster and aluminum steerer tube
Other guys SL = 1550 grams stock with a steel steerer tube
He then goes on to post pictures of parts on a scale:
1) Ultimate Machine crown = 186 grams
2) Ultimate Machine crown and aluminum steerer tube 170 mm = 345 grams
By deduction I can then infer by his data that the stock aluminum steerer tube = 159 grams
Titanium 170 mm steerer tube = 86 grams
Stock aluminum steerer tube = 159 grams
Reduction of steerer tube = 73 grams
Steel allen head bolts = 10 grams
Steel canti bosses = 22 grams
Titanium allen had bolts = 3 grams
Titanium canti bosses = 11 grams
Reduction of bolts = 18 grams
So it looks like for a lot of money I can reduce about 90 - 95 grams total, simply by switching to a titanium steerer and titanium bolts. In a small pursuit of keeping the fork "blingy", adding a bit more "blinginess" and chasing a tiny bit of grams for the hell of it, this is a good side project for tinkering. I guess I'll order some hardware.