ATDS and Suspension Settings

Hello all! It has been quite a while since I updated the blog. Hope that everybody’s been well and enjoying their bikes!

New Rear Spring

Since the last write up, I have meddled with the rear shock and suspension setting some more. The biggest change was the replacement of the rear shock’s spring to a softer one. The original spring had a spring rate of 8.5kg/cm. According to Race Tech’s spring rate calculator, the rear shock should have a spring rate of about 8kg/cm. The 8.5kg/cm spring rate is for a rider weighing about 98 kgs! I was 30 kg lighter. No wonder I had a hard time setting up the rear shock and had to increase rebound damping all the way to 22 clicks.

This was the heavier spring that came originally with the Bitubo shock.
This was the heavier spring that came originally with the Bitubo shock.

I went to the local Bitubo dealer and ordered the softer spring. It made a difference straight away. The bike was much more comfortable to ride. With the new spring, I had to change some settings to the bike’s settings. After some trial and error, I came up with the following:

These were the initial settings for 40psi rear tyre pressure.
These were the initial settings for 40psi rear tyre pressure.

You can see straight away that the damping for the rear shock has been adjusted to more reasonable and sensible levels. I also softened the front fork’s compression from 8 to 10 clicks to make the bike more comfortable. The rebound was softened to 6 clicks out to match. Overall the bike now is more settled in the turns but does not turn as quick or sharply.

New Tyre Feature – ATDS

Recently, I discovered a new feature on my Pirelli Angel ST. It is called the ATDS – Automatic Tyre Deflation System.

As you may recall, the lovely rear Pirelli Angel ST tyre was quite a magnet to nails. The rear tyre was punctured twice and had to be patched. The tyre has recently started to leak slowly again recently. Total mileage as of now is about 18,000km. I could not find any new metallic additions in the rubber and can only conclude the tyre patches are probably where the slow leaks are occurring. From the look of the tyre, there could be about 2000km or so left. The tyre drops about 1 psi every day and so I would have to pump it up every 2 to 3 days. Otherwise, everything seems fine.

Actually my tyre does not only attract nails but friends from the insect world as well. Of all tyres on all the bikes in all the world, you walk into mine...
Actually my tyre does not only attract nails but friends from the insect world as well. Of all tyres on all the bikes in all the world, you walk into mine…

It was because of this new tyre feature that I made a pleasant discovery. I have long suspected that the manufacturers recommended tyre pressures were too high for the rear tyre. Suzuki recommended 42psi for the rear tyre for both solo AND 2 up riding. Common sense would tell you that there should be a difference in tyre pressures – less for solo and more for 2 up.

Well, due to the new ATDS feature, I took the opportunity to try different settings on the rear shock with lower tyre pressures. I found that as the rear tyre pressures go down, increasing the rear compression damping makes the bike handles better (compensates for the increased movement and lower height?). The interesting thing is that at around 36-37psi and with compression damping at 14 clicks out, the bike is relatively comfortable over bumps and feels very much in control. I have been able to ride to both the tyre’s edges. In fact for solo riding, I kind of prefer the lower tyre pressures over the 40 psi one (though that works too, bike just feels a bit different).

After the discovery of the ATDS of the tyre, the new settings for use with 38 psi for the rear tyre.
After the discovery of the ATDS of the tyre, the new settings for use with 38 psi for the rear tyre.

Wear and Tear

In the interval since my last post, the ignition switch went poof! and the main fuse also decided to follow its friend a month later. Just before that, the ball joint of the gear shifter lever sheared off as I engaged it into 1st gear. Good thing that I was at the car park just ready to go off. God was looking out for me. Thank you!

Clunk! And then a dangling feeling at the feet.
Clunk! And then a dangling feeling at the feet.
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s