Thursday, November 5, 2015

How to replace a headset

Replacing the headset is usually very straightforward and simple, given you have acces to the right tools which you will see in the pictures below. The two main tools are the extractor and the pressfit compressor. Teoretically one can do without these tools, but at risk of damaging the frame. The frame below is a Scott CR1 carbon and I would say that doing this job without the tools a damaged frame would probably be the result. The pressfit tends to sit very hard since the are to a difference from the bottom bracket in aluminium.

The reason for replacing the headset was a rusty lower bearing, the headset startet to bindly shortly after use and that lead me doubt the quality. I continued to use the bike rest of the last season and this, but it got worse and worse affecting the safety, especially noticable during fast decents.


Dismantle the stem in the usual way, first by removing the rings and the top.


Be sure to hold the fork while lossening up the stem to avoid it falling to the floor.


The fork should come loose and it some of the further service might require to dismantle the front break


Top bearing is looking good, almost no rust and do not really need replacement.


Inspect top and bottom to see if there are any wear, cracks etc in the carbon


I purchased a new complete high quality sealed BBB headset, the original Ritchey was not sealed and I believe that could have accelerated the wear and tear since replacing the headset should only be done every 3-5 years. 


This is the pressfit extractor, it enables your to apply force on the pressfit itself and not the frame when hammering down.


Insert the extractor backwards


Be sure that the blades on the extractor engages inside on the edges of the pressfit. If a rubberhammer dont do - use a metall hammer, but be carefull and take your time to avoid damaging the frame


The bearing can usually be removed without forced since they are only held in place by the fork that is now removed. As you can see, the bearing was very rusty and no wonder why it caused binding.


Same process for removing the top pressfit, notice the metall hammer :)


Inspect the inside for reasons mentioned earlier. The white stuff you see inside the carbonframe is normal and are remains after the molding.


Wipe and clean


Notice the remains after the old bearing, this a seal and must be removed since it do not fit with the new bearing.


Removal was in this case hard, since the rust had glued it to the carbon


Careful prying got it moving after a while



There are different oppinions of what to do with the surface between pressfit and carbon. Some say to keep it dry, but I prefer to lube it up - in this case using lithium grease for longevity and resistance to moisture.


New pressfits alligned with the compressor aligned, be careful when tightning up to keep everything alligned.


New lower bearing inserted onto the fork


New top bearing inserted


Insert the spacers and thighten up by hand, be carefull not to tighten to hard. It should now bind when turning and there should be no slack.


There, done!


Go biking!

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