Ruegamer dual pivot brakes, looking pretty before dismantlementI started a topic about 2 years ago as straessis (I have a lot of aliases - and the copyright reads 'Hiiragi Kagami', just in case you were wondering) about these brakes. The calipers weigh 119.3 (F) + 117.0 (R) = 236.3g, and the pads weigh 34.3 (F) + 34.4 (R) = 68.7g. So, they weigh a total of 305.0g. Don't be mistaken, they are light for dual pivot brakes: slightly lighter than Dura-Ace 7800 (~317g), and slightly heavier than Dura-Ace 7900 (~295g).
Ruegamer dual pivot brakes, after dismantlementBut, KCNC is lighter at 168.0g (with Koolstop brake pads) for dual pivot brakes, although there seems to be a consensus that they have weak stopping power. Ti2 Racing makes another pair at 224g. I am very particular about the modulation of braking power: the purpose of this project is to get a more powerful pair of brakes with comparable weight.
At the same time, I'm not very particular about heat dissipation from the brakes - I don't live in a mountainous region, so there's no need for a long duration of braking. Hence, I'm OK with carbon fiber brake pad holders, which don't dissipate heat as quickly. Other users may find Zero Gravity brake pads more suitable here.
Without modifying the main body of the brakes, I have to start with 212.7g. There is a chance that I'd change the central pivot bolt, which makes up for a lot of mass, for an aluminium option. But I haven't figured out how to dismantle that part. So my initial target for this pair of brakes is 250g, with Swissstop yellow pads for heavy performance. I'll also keep the existing spring which I find really strong.
At the same time, I'm not very particular about heat dissipation from the brakes - I don't live in a mountainous region, so there's no need for a long duration of braking. Hence, I'm OK with carbon fiber brake pad holders, which don't dissipate heat as quickly. Other users may find Zero Gravity brake pads more suitable here.
Without modifying the main body of the brakes, I have to start with 212.7g. There is a chance that I'd change the central pivot bolt, which makes up for a lot of mass, for an aluminium option. But I haven't figured out how to dismantle that part. So my initial target for this pair of brakes is 250g, with Swissstop yellow pads for heavy performance. I'll also keep the existing spring which I find really strong.
More hardware removed.
Size comparison with 150mm Vernier calipers
Brake clasps.
Weight of some additional hardware.As you can see, I can change the above parts to aluminium:
- dual pivot stud x2
- mounting stud x2
- mounting bolt x2
which would save about 6.3~6.4g. I'll opt for BTP carbon pad holders with Swisstop yellow pads, which start at 37g (extra weight saved from gluing on the brake pads rather than using mounting bolts). This saves another 31.7g.
BTP uses titanium bolts in the front, with most likely aluminium washers. Using drilled washers or nylon ones, another 1.0g can be saved. The titanium bolts will probably be M5x15 - meaning I can save another ~2.0g by changing them to aluminium.
I originally intended to use these aluminium brake clasp bolts (they save about ~4.5g), but I realized that I can do away with these bolts AND the brake clasps if I changed the mechanism for securing the cables: using the Powercordz cable clasps (M5; for Campagnolo), which weigh 3.9g. That means, I save another (4.0+2.1-3.9)=2.2g!
- dual pivot stud x2
- mounting stud x2
- mounting bolt x2
which would save about 6.3~6.4g. I'll opt for BTP carbon pad holders with Swisstop yellow pads, which start at 37g (extra weight saved from gluing on the brake pads rather than using mounting bolts). This saves another 31.7g.
BTP uses titanium bolts in the front, with most likely aluminium washers. Using drilled washers or nylon ones, another 1.0g can be saved. The titanium bolts will probably be M5x15 - meaning I can save another ~2.0g by changing them to aluminium.
I originally intended to use these aluminium brake clasp bolts (they save about ~4.5g), but I realized that I can do away with these bolts AND the brake clasps if I changed the mechanism for securing the cables: using the Powercordz cable clasps (M5; for Campagnolo), which weigh 3.9g. That means, I save another (4.0+2.1-3.9)=2.2g!
Aluminium brake clasp bolts. M5x10! Quite short, actually.So... I'll save at least 47.7g, which makes the brakes weigh 257.3g. I could also do away with the adjusters (3.9g), but they are considerably light for that size, and I don't want to compromise on the functionality of the brakes. Maybe I'll think of something with the central pivot bolt.
M4x10 socket screw/stud.
M6x6 socket screw/stud.
M4x4 socket screw/stud (major diameter measurement).
M4x4 socket screw/stud (length measurement).So, after careful adjustment, and double-checking the unthreaded lengths and deliberating where to use dome/countersink/parallel socket head bolts, I just have to wait for a huge shipment package from Pro-bolt: including the electrode fasteners for my cyclotron project; and wait for Bernhard (BTP) to reply Eric's email (he needs a front derailleur clamp, so I'll share shipping with him).
This is a fairly simple project for me. Easier than the Avid brake tuning project, which took me about 50 hours. The Avid brake project saved a larger percentage of the weight... and more importantly, had a difficult surgical procedure for transplanting the aluminium pivot sleeves. The most difficult part with the current project is figuring out the exact measurements of the hardware - and I'm done with this part, fortunately. So... I don't think I'll take more than 2 more entries to finish the coverage of this project.
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