Headset bearings on a Giant Rapid?

[moo]

Is there any particular type/brand/model I should be buying?

 

[rusty bearing]

There are many different bearings so I'd usually drop the fork out and see whats what. If its a sealed bearing the size and angle is usually marked on it. If it's a ball race you could replace the whole headset for a better version or install correct size ball bearings.

 

[moo]

They are sealed.

TH Industries 1-1/8th, 45" x 45" 170

Does the 170 number have any meaning, or is it just a part number?

From the reading I've done so far it appears 36x45 is the standard angle, which explains why I can't find any reasonably priced 45x45 bearings.

 

[accountantpete]

45 x 45 is the normal bearing angle.

First step is to go to the Cane Creek headset finder and pump in your details.

They suggest IS42 type headsets as per http://www.chainreactioncycles.com/cane-creek-40-series-is42-integrated-headset/rp-prod115639

Alternatively you can measure your existing bearings.

eg 41.8 (OD) x 28.6 (ID) x 6 mm and search to see if you can get individual bearings cheaper.

see http://www.edgesportsuk.com/store/index.php/popular-products/headset-bearings-11-8-is42-28-6.html

The thing to bear in mind is that the bottom bearing has a slightly wider ID to go on the crown race so ideally you need two different bearings. 28.6 ID up top and 30.0 ID at the bottom (making sure that you have the 45x45 angles). Also make sure that the depth of the bearing is the same - this is vital.

 

[moo]

Thanks for the help guys. Just ordered an FSA Orbit CE headset from Planet X for £15. All specs seem to match with the Cane Creek suggestion (IS42/28.6 | IS42/30). Cheaper than buying 2 bearings individually. Worst case scenario we will have to fit the whole headset.