Fork Service

The Problem

The oil and filter change was coming up and I decided finally to do something about the fork. You see, after the Ohlins springs and valves were fitted into the forks, I noticed that the rebound damping adjuster only had a maximum of 6 turns out from full in. I made a check with GSXR owners online and they confirmed that there were more than 6 turns. In fact, a K2 owner informed me that there should be 16 clicks in total.

Prior to that, I have studied the workshop manual carefully and suspected that the problem probably lie in one of 2 places. One, the distance of the top of the lock nut to the top of the damper rod was probably incorrect. It should be 11mm and I suspected that the distance was more than that. The other likely issue was when the workshop reinstalled the top cap, the mechanic did not adjust the rebound damping adjuster all the way out as the workshop manual instructed.

What pissed me off was that I gave the Ohlins mechanic a photocopy of the relevant instructions with highlighted sections to him. That was 2 years ago.

This time, I also gave the instructions to my mechanic (another one) and explained the problem to him. At the same time, I asked him to do a fork oil change.

Well they say history repeats itself. This is the 3rd time my fork service screwed up again.

After taking back the bike, the rebound damping adjuster were now giving me 16 clicks adjustments. Great. However, after a few days, I realised that the bike was not using more than half the travel. Even when I wound down the preload to their softest settings, the fork would not compress more than half travel.

Immediately, I suspected that they were overfilled with oil. Or to put it another way, the air gap from the surface of the oil to the top of the fork stanchion was set incorrectly. I had a similar experience with my old FZR1000 EXUP. I sent my mechanic a text message and initially wanted to send it back to him. However, with a long weekend coming up, I decided to try doing it myself. To do it right, some things you just have to do it yourself.

Scrapper Modification – Dremel Saved the Day

I had the spring compressor and the piece goes between the lock nut and the top of the spring spacer fabricated from the time when I had my FZR1000. I thought they would work as well.

The Diva without her legs.
The Diva without her legs.

Out came the wheel and forks with the top cap loosened. The spring compressor worked alright, but looking at the metal piece that goes between the lock nut and the top of the spring spacer, I knew that it was too thick. I got my dad to help and it just could not go in as I could not compress the spring enough.

I thought for a bit and looked around my dad’s cupboards and found some metal scrapers. The metal was thin but the material was stainless steel and I decided to bring out the dremel and cut a slot in it to use as the wedge. I estimated that a 11mm width (actually 10mm would be better) would be enough and made the cut and ground the edges down. The dremel saved the day because there was no way I could cut the piece otherwise.

The forks with the cap opened. The fabricated spring compressor was on one of the forks. At the base, you can see that special tool to fit between the lock nut and the spacer. However, it could not fit as it was too thick.
The forks with the cap opened. The fabricated spring compressor was on one of the forks. At the base, you can see that special tool to fit between the lock nut and the spacer. However, it could not fit as it was too thick.
A 11mm or so cut into the stainless steel scrapper saved the day. If I were to do it again, I would cut a 10mm width only.
A 11mm or so cut into the stainless steel scrapper saved the day. If I were to do it again, I would cut a 10mm width only.

The modified scrapper worked and we took the cap and spring off. As suspected, the forks were overfilled with oil. The right one had 46mm of air gap and the left had 56mm. The air gap should have been 90mm. No wonder the forks would not compress.

After taking out some oil, re-measuring the air gap, lock nut space distance and setting the rebound all the way out, fixed it back. After putting all the stuff back together, the bike was better to ride. The rebound clicks I have now were 13 clicks each. Still more than enough because I need only 1 or 2 clicks from the factory setting.

I will use the dremel to trim off the tip of the screw in rods of the spring compressor. They work better with them cut off. When I asked for this to be fabricated, I did not know how big the holes were in the spacer of the FZR1000 and made a taper to accommodate various hole sizes. It turns out that they are not necessary.

The tapered ends were not necessary and also hindered the work. I intend to cut the ends off with the dremel.
The tapered ends were not necessary and also hindered the work. I intend to cut the ends off with the dremel.
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