I don't know how common a problem it is but I found that my rear Showa shock had lost a lot of its preload adjustment range. Of the original 20 turns (40 clicks) only the last 10 were doing anything.
After a bit of thought and a couple of hours work I was able to recover the full range of adjustment giving about 5mm more preload at max. This makes quite a difference to the rear ride height specially two up.
If anyone is interested I can post the procedure and pics to show how to do it.
Nige
Recovering Showa Pre load adjustment
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Harry Lime
- Member
- Posts: 549
- Joined: Fri Feb 20, 2004 9:01 am
The following can be done on or off the bike
Checking if you have a problem.
1. Fully preload shock.
2. Check the gap between the bottom of the aluminium preload housing and the upper edge of the spring seat. This was about 4.5 mm on mine.
3. Unwind preload counting turns until handwheel goes free. This was about 8 turns, 16 clicks on mine.
4. Check the gap between the bottom of the aluminium preload housing and the upper edge of the spring seat. This was about 1.25 mm on mine.
5. Continue unwinding the preload handwheel counting the remaining turns. This was about ten turns / 20 clicks . I don’t know what they were like new but this is potential preload/ride height that has been lost.
If you have plenty of gap at maximum preload 8-10mm and only one or two free turns on the handwheel then you probably are best off leaving things alone.
If like mine you have lost most of your adjustment then you could try this.
It should only take a couple of hours.
1. Remove shock from bike.
2. Ensure preload is set to minimum.
3. Hold the shock securely on its side with the preload handle pointing down.
4. Remove the Phillips screw from the preload housing. A small amount of oil may leak out.
5. Using a foot pump and airbed adaptor to blow into the screw hole. If you get a good seal and pump hard you will hear the preload piston move.
There will now be a considerable air gap above the oil in the preload reservoir which needs topping up.
You can’t just pour the oil in as the hole is so small the air can’t get out.
I used a large syringe and attached a football inflator. This fits easily in the hole lets the oil in and the air out.
Once full put the screw back in.
Now screw in the preload. Mine has about a turn of lost motion then it loads up the remain 17 turns are pure preload.
At full preload the gap is now about 10mm.
Checking if you have a problem.
1. Fully preload shock.
2. Check the gap between the bottom of the aluminium preload housing and the upper edge of the spring seat. This was about 4.5 mm on mine.
3. Unwind preload counting turns until handwheel goes free. This was about 8 turns, 16 clicks on mine.
4. Check the gap between the bottom of the aluminium preload housing and the upper edge of the spring seat. This was about 1.25 mm on mine.
5. Continue unwinding the preload handwheel counting the remaining turns. This was about ten turns / 20 clicks . I don’t know what they were like new but this is potential preload/ride height that has been lost.
If you have plenty of gap at maximum preload 8-10mm and only one or two free turns on the handwheel then you probably are best off leaving things alone.
If like mine you have lost most of your adjustment then you could try this.
It should only take a couple of hours.
1. Remove shock from bike.
2. Ensure preload is set to minimum.
3. Hold the shock securely on its side with the preload handle pointing down.
4. Remove the Phillips screw from the preload housing. A small amount of oil may leak out.
5. Using a foot pump and airbed adaptor to blow into the screw hole. If you get a good seal and pump hard you will hear the preload piston move.
There will now be a considerable air gap above the oil in the preload reservoir which needs topping up.
You can’t just pour the oil in as the hole is so small the air can’t get out.
I used a large syringe and attached a football inflator. This fits easily in the hole lets the oil in and the air out.
Once full put the screw back in.
Now screw in the preload. Mine has about a turn of lost motion then it loads up the remain 17 turns are pure preload.
At full preload the gap is now about 10mm.