[Bender]

What is the difference between the formula B4 and B4 SL? Is TI hardware the only difference? Also what model years have advantages and disadvantages? I will likely be using custom TI rotors as well.

 

[bhsavery]

what custom rotors? Weren't some other people doing that? I thought it didnt work out. Wore the pads or something.

 

[Duckman]

03 B4SL used to be made from mag and used highend alum bolts for the caliper breakdown, frame to caliper, and master cyc/bar clamp bolts. No such offering now. The 04-05s are alum and use a heavier csp system not unlike Hayes. 03s used 160/140mm rotors, which I prefer. alas...04-05s are 160mm both ends.

03 SLs with Stans alum rotor and ti/alum rotor bolts. Nothings lighter.

03 B4Pros. Same casting except made from alum and slightly diff sufface machining. Steel bolt kit also(altho this set has the alum SL bolt kit. Also were 160/140mm.

Note 140mm rear. Sweet.

The 03s were plauged with airleaks around the mastercylinder because of "too-light" of duty parts used around the caps. Many many were warrantied and replaced with retro-kitted 03Pros(a rather large and prob overkill set of parts) from Thor, including mine. Both ends failed after 4-5 races. My 03 Pros have been flawless and the feel is perfect imho.

04/05 are great brakes...only heavier then the 03s, alho they are still fractionally lighter then Magura SLs.

Duck

 

[bhsavery]

good info, how much heavier is a set of pros and could they be retrofitted with lighter bolts to bring them down around SL weight?

 

[Duckman]

About 22gms heavier..total. Still THE lightest out there.

edit:Now that I've remembered, I think its only 12gms.

 

[bhsavery]

wow so you could defintiely bring that down with bolt tuning

 

[Bender]

Thanks for the great info Duckman! One stupid question though. 03 was the first year these were produced correct?

By chance does anyone have the specs for disc brake mounting? I need to know the distance apart the holes are and such.

 

[Duckman]

I'm talking about the 03 Pros, not the current model.

 

[Ole]

03 B4SL used to be made from mag and used highend alum bolts for the caliper breakdown, frame to caliper, and master cyc/bar clamp bolts. No such offering now. The 04-05s are alum and use a heavier csp system not unlike Hayes. 03s used 160/140mm rotors, which I prefer. alas...04-05s are 160mm both ends.

03 SLs with Stans alum rotor and ti/alum rotor bolts. Nothings lighter.

03 B4Pros. Same casting except made from alum and slightly diff sufface machining. Steel bolt kit also(altho this set has the alum SL bolt kit. Also were 160/140mm.

Note 140mm rear. Sweet.

The 03s were plauged with airleaks around the mastercylinder because of "too-light" of duty parts used around the caps. Many many were warrantied and replaced with retro-kitted 03Pros(a rather large and prob overkill set of parts) from Thor, including mine. Both ends failed after 4-5 races. My 03 Pros have been flawless and the feel is perfect imho.

04/05 are great brakes...only heavier then the 03s, alho they are still fractionally lighter then Magura SLs.

Duck

Pro+ have aluminum bolts, and weigh ca 60g more than SL pr pair. Pro have steel bolts, and weigh considerably more. For 2005, B4 Pro+ are available with 160/140, or 160/160. Pro is sitll only 160/160, but with the change of the rear caliper half from Post Mount to IS, you can still have 140mm in the rear.

Ole.

 

[Duckman]

Well heck..I woulda sworn I read that only 160mm rears are avail now over at the Brake Forum and such. My bad then. Same deal with the bolts. Hmmmm.....

One would think the newer Pros would indeed be measureably heavier since they now have 14 bolts...all steel.

 

[Ole]

Oh no!

Duck

What is it I see? You've got the original steel housing ends on all three pictures! They weigh almost 20g each, the aluminium ones you fit when you cut the cable are only 5g or so. Shame on you!

Ole.

 

[rhys]

whats the difference between b4sl and b4sl +?

I just shipped my 03 b4sl brakes to thorsten and he replaced me with, i guess the newer version, which is the b4sl plus. Whats the difference between the b4sl and b4sl +? does it have the same problematic inernals? or formula addressed the problems with the b4sl and made the plus better? What i noticed was a slight increase in weight.

 

[STS]

What is it I see? You've got the original steel housing ends on all three pictures! They weigh almost 20g each, the aluminium ones you fit when you cut the cable are only 5g or so. Shame on you!

Ole.

the original steel ones weight 9gr each (with a little part of tube), and the Aluminum ones are 6gr each. Not so much difference...

 

[1speed_Mike]

I just shipped my 03 b4sl brakes to thorsten and he replaced me with, i guess the newer version, which is the b4sl plus. Whats the difference between the b4sl and b4sl +? does it have the same problematic inernals? or formula addressed the problems with the b4sl and made the plus better? What i noticed was a slight increase in weight.

I had some B4s, B4 SLs and then B4 SL+s. The B4 SL+s were a mid-year release (no longer available). I *believe* the only diffs between the SLs and SL+s is the use of a metal torx screw in the master-cylinder (SLs used plastic, which had a tendency of stripping or breaking), and some other metal hardware, and the use of alloy instead of magnesium for the caliper/master-cylinder. My B4 SLs weighed 631g/set (uncut) or 614g/set (cut). The B4 SL+s weighed 697g/set (uncut) or 681g/set (cut). Both offered excellent power and modulation. Plus, they come backed by Thorsten!