Light replacement bearings for FSA Orbit c-33 44E?

Discuss light weight issues concerning road bikes & parts.
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octave
Posts: 94
Joined: Sun Jan 15, 2017 8:47 pm

by octave

hello everyone,

i am working on shaving some weight off a new build, and i would like to replace the headset bearings and conical spacer. the stock headset is the FSA Orbit C-33 44 E ( tapered 1 1/8 to 1 1/4, 45 degree angle). here are the specs (not the exact one, but it is the cyclocross variant that has the same measurements, just different conical headset spacer) :

http://shop.fullspeedahead.com/en/files ... 45d46a829/

can anyone point me in the right direction for a light set of bearings to replace it? i am having a hard time figuring out what exactly i need to replace it with based on the FSA exploded diagram...

upper needs dimensions of 41.8 (outer) X 30.5 (inner) x 8 (height) ?
lower needs 46.8 (outer) X 34 (inner) X 7 (height) ?

what does this translate to in headset speak? is the upper IS42? and the lower IS47?

i was poking around and found a Pro Headset SL that would work for the top, i think (http://www.starbike.com/fr/pro-upper-headset-sl/), but the SL bottom does not have the right size, unless i have completely misunderstood things (http://www.starbike.com/fr/pro-lower-headset-sl/). the SL bottom only comes in IS42, IS 52 and ZS52...

in any case, the Pro SL was just one i stumbled across. does anyone have any suggestions?

thanks!

o

motorapido
Posts: 263
Joined: Fri Jul 30, 2010 7:08 pm

by motorapido

I thought FSA only did an 1 1/8 and 1 1/2 alloy light weight bearing,

SL Alloy ACB Bearing 36°×45° 1.5" (TH-073, MR110R) 51.8mm x 8mm

the 1 1/8 is available in 2 versions,

FSA SL Alloy ACB Bearing 45°×45° 1.1/8" TH-870
New Super Light ACB bearing with alloy housing
38% weight saving over steel bearings
Contact Angle 45°×45°
Height 8.0mm
ID 30.5mm
OD 41.8mm
Type ACB
Type Cartridge
Type MR042R

FSA SL Alloy ACB Bearing 36°×45° 1.1/8" TH-873
New Super Light ACB bearing with alloy housing
38% weight saving over steel bearing
Contact Angle 36°×45°
Height 6.5mm
ID 30.2mm
OD 41.0mm
Type ACB
Type Cartridge
Type MR054R

but Tredz seem to list a 1 1/4" as well

https://www.tredz.co.uk/.FSA-SL-Alloy-A ... cQAvD_BwE#

by Weenie


octave
Posts: 94
Joined: Sun Jan 15, 2017 8:47 pm

by octave

ah ha yes! that is the lower that i would need. the 1 1/8 would be the upper... i had found the FSA SL at Fairwheel, too, but it is out of stock for the lower. FSA plays nice and gives the exact measurements i need, but i can't figure out what i would need from, say, Extralite.... can anyone help?

thanks for the link and the specs on the FSA SL, motorapido!

o

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