Forks...

[jimmy]

I had been noticing on my last several rides, that the bike was becoming difficult to steer. I felt that I had to keep forcing the bike to turn, so instead of a nice smooth turn, it was more a series of straight lines punctuated with some sharper turns.

Not something you want to do in a bunch ride.

I checked my forks, and I could feel that they wanted to return to a neutral position, quiet forcibly so.

So, this afternoon I pulled them out and had a look, there was a reasonable amount of surface rust in a few areas, and some deeper along the length of the steerer. I suspected that this was the fault, as I could feel that it was raised. I checked the bearings, and they were quiet dry, and also had some rust in them. This is probably a result of riding the bike in the wet over the last two years.

I repacked the bearings with new grease (after giving them a good clean), and I lightly sanded the steerer to get rid of any rough patches on it.

Final result, a set of forks that are happy to stay where you want them. Expect me to overshoot a corner tomorrow morning because I will probably be over steering.

I didn't find this to be a particularly difficult or time consuming job, and I would recommend to others to make it maybe a 6 monthly check of the bike. Even if you find nothing wrong, it is better than finding something wrong too late.

James

[weiyun]

Good reminder James. Did you replace the bearing? I understand that there's usually a rubber weather seal that goes on the lower side of the head tube, is it there? Is it damaged? I understand that some keen riders rebuild their bikes every year or two along with a change of cable and other worn components. If you don't take it apart, you'll never find the problem.

[jimmy]

I didn't replace the bearings for the simple reason that I didn't have any.

I recognised that the lower bearing was the worse for wear, and I did consider swapping it for the top one. I think because of the way they are orientated, the top one seems to drain a bit better.

I will probably consider replacing both bearing sometime in the near future. I simply popped the seals out, wiped out what muck I could with a degreaser, and then repacked the bearings with new grease and replaced the seals. I also put grease on the steerer itself as well as around the collar at the top. All in an attempt to keep the water out as best I can.

James

[Tom Rayner]

http://www.sheldonbrown.com/brandt/inde ... ering.html

[jimmy]

Interesting article Tom.

After today's ride, I can attest that the overhaul that I gave the forks and their bearings made a difference. The bike was inclined to corner in a smooth arc, and I was able to again ride no hands, I had found over the last several weeks that I was unable to ride smoothly with no hands, despite being able to do it on the Commuter (with a single pannier on one side).

I have no idea on the cost of the bearings, but mine definitely had very little lubrication in the races, so according to that article, that was probably the issue.

It would be good to know what the cost of replacement bearings are, at least that way it is something to factor into a service every now and again. That bike is now about 2 years old and I have never done that before, I would probably look at replacing the bearings every 12 months or so, if they aren't too expensive. Or simply repacking them every 12 months and replacing them every 2 to 3 years if they are a slightly pricier item.

James

[Kieran]

buddy they should not be more than 2.50 for a complete race.

If you let me know what size you need i can procure some.

[jimmy]

I noticed during the week that the steering was starting to feel "indexed" again. I pulled the bearings out this morning, and the lower one definitely has indexing.

I managed to get it right apart, and you can see the divots in the inner and outer race.

Inner Race



Outer Race



I managed to read the side of the bearings, so I am hoping I can get some this week.

TH Industries1-1/8"
ACB 360 x 450 873#

The zeros are meant to be superscript, so it is 36 degrees x 45 degrees

James

[timyone]

i should do the same deal
mine totally froze up the other day after a ride

[T-Bone]

different type of headset on yours tim. Probably just need to regrease the bearings a little.

[Toff]

You can reduce the chances of dimpliing your headset by peeling the ball bearings out of the racers, and installing them loose.

Jobst Brand had a bit to say on the subject here.

[jimmy]

I spoke to my dad last night (retired plant mechanic). While I can almost certainly get the bearings from a bike shop, I am going to try and source them from a bearing shop. Considering I have done only about 20,000km on that headset, and the bearings have pitting, then he said that the surfaces weren't hard enough.

The front of the bike doesn't have a lot of load on it.

As far as that post goes, I disagree with the first point about the "no possibility of injury or damage with indexed steering". When my steering was indexed, with no weight on the front wheel, it would naturally return to the straight ahead position, I felt like I had to muscle it around a corner. That is a safety issue.

Also, these are cartridge bearings with seals, so while the lubricant can get washed out, it should always be able to get around the balls.

I will report on my success (or failure)

James

[weiyun]

As long as there's no damage to the integrated headset, changing bearing is easy. I understand that if the integrated headset is damaged, then the frame is toast.

[geoffs]

There's alot to be said for Chris King headsets.
They just work....

[jimmy]

I ended up getting the bearings from Steve Hogg at Pedal Pushers. They are a non standard bearing, so you can't source them from a bearing shop.

Not too bad at $25 each.

He pretty much said that 20,000km wasn't a bad life, and after I had bought them my Dad called me up and also advised that I may have had them too tight which could have caused an issue.

When I installed them last night, I went pretty soft on the tension in the head set. This morning, the handle bars had no wobble at about 55km/hr downhill with no hands.

James