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Hi all, I feel like a bit of an idiot here but... I am looking at upgrading some bolts to lighter weight and also some blue ones..
M5 x 10 - Does this mean it needs a 5mm hex key and the thread itself is 10mm in length or something else?

For example, Thomson stem bolts what are they?

What bolts have you guys changed on your bikes?

Also, where should Ti bolts and Al bolts be used?

Cheers
 

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There are a couple things regarding bolts
Metric
example:
M5x1x10

M5 = (diameter of the threads...aka a M5 will barely fit in a 5mm diameter thru hole)
1 = pitch, this is the distance between the thread peaks
10 = length from the tip to the bottom of the head
 

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SUBLIM8er
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All about bolts (Author: Nino)
M5 x 6 means:
M5 is the size of the thread in millimeters: here it`s 5 millimeters of outside diameters.
6 refers to the length of the thread in millimeters: here it is 6 millimeters.
So M6 x 15 for example means a 6 millimeter diameter thread which is 15 millimeters long.

BOLT TUNING:

Aluminium Titanium
Chainring bolts − 30 g − 15 g 2x5 pcs
− 24 g − 12 g 2x4 pcs
Crank fixing bolts − 15 g − 10 g
F-derailer − 5 g − 2 g 2 main bolts
R-derailer − 10 g (ca.) − 4 g (ca.) hanger bolt, cable stop bolt, pulley wheel bolts
A-head cap bolt − 4 g − 2 g M6x20 mm
Bottlecage bolts − 7 g − 4 g 4 pcs M5x10 mm (Al = 3 g / Ti = 6 g / Steel = 10 g)
Brake lever bolts − 5 g
Canti brake bosses on frame − 8 g 2 pcs (typical steel bosses weigh around 24 g)
Canti brake bosses on frame − 6 g 2 pcs (Manitou Ti: 12 g / RockShox SID steel: 18 g / Manitou steel: 21 g)
Stem − 5-10 g 4-6 pcs
Seatpost − 3-8 g (ca.) 1-2 pcs
V-Brake canti bolts − 11 g − 6 g 4 pcs M6x15 mm
V-Brake cable fixing bolts − 5 g − 3 g 2 pcs M5 or M6x8 mm
V-Brake brakepad fixing nuts − 10 g 4 pcs M6
V-Brake brakepad carrier bolts − 8 g 4 pcs (Ti = 12 g / Steel = 20 g)
Ti bolt-on axles instead of QR − 70 g typical steel QR levers 120 g, bolt-on axles Ti = 48 g / steel 65 g
Cassette Lockring − 10 g Steel 14 g / Al 4 g
Pedals − 10 g my Corratecs had 8 steel bolts
Pedal axles − 70 g

The only place you need the added strength of Titanium is at the stem and the seatpost.
All other bolts can be out of Aluminium which is also a lot cheaper than Ti.

Carbon (savings over aluminium):
A-head spacer − 6 g / 10 mm (Al = 10 g / 10 mm , Carbon = 4 g / 10 mm)


V-BRAKE TUNING:
CrMo Ti Al Max. saving
4 Canti-bolts M6x15 mm 16 g 10 g 5 g − 11 g (Al)
4 padcarrier bolts 20 g 12 g − 8 g (Ti)
4 pad fixing nuts M6 14 g 9 g 4 g − 10 g (Al)
2 Cable fixing bolts M6x8 mm (Avid) 8 g 5 g 3 g − 5 g (Al)
Total possible savings: − 34 g


Example for maximum possible BOLT-TUNING on a MTB:
ALUMINIUM:
Chainring bolts (2x5pcs) -30 g / (2x4 pcs) –24 g
Crank fixing bolts -15 g
F-derailer (2 main bolts) -5 g
R-derailer (hanger bolt, cable stop bolt, pulley wheel bolts) ca. -10 g
A-head cap bolt (M6x20 mm) -4 g
Bottlecage bolts (4 pcs M5x10 mm) –7 g ( Al = 3 g / Ti = 6 g / Steel = 10 g)
Brake lever bolts –5 g
V-Brake canti bolts (4 pcs M6x15 mm) –11 g
V-Brake cable fixing bolts (2 pcs M5 or M6x8 mm) –5 g
V-Brake brakepad fixing nuts (4 pcs M6) –10 g
Cassette Lockring –10g (steel 14 g / Al 4 g)

TITANIUM:
Seatpost clamp bolt –3 g
Canti brake bosses on frame (2 pcs.) : -8 g
Canti brake bosses on fork (2 pcs) -6 g
V-Brake brakepad carrier bolts (4pcs) -8 g
Stem (4-6 pcs) 5-10 g
Seatpost (1-2pcs) ca. 3-8 g

Total possible savings: ca. 150 g

Remember:
Titanium is about 1/3 lighter than steel.
Aluminium is 1/3 the weight of steel and ½ the weight of Titanium.
Carbon is about ½ the weight of aluminium


This was put together by nino some time ago. Good info. for starters.
 
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