DR650 Suspension Set-Up - Highly Recommended Mods

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Alphat

Pack Dog
Joined
Nov 1, 2012
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Location
Johannesburg
Bike
KTM 990 Adventure
I thought I'd share my experiences on setting up the suspension on my 2001 DR650SE. This is, in my opinion, the best value for money mod you can do on the DR and has completely changed the characteristics of the bike offroad. It went from a wayward pogo stick to a big plastic in feel.

Firstly, when I bought the bike I found that it has aftermarket springs in the forks and on the shock. I'm not sure what these are but they are heavier than stock. The fork springs are also shorter than stock at 504mm uncompressed compared to the stock 548mm. These heavier springs made the lack of rebound damping that the DR suffers from even more pronounced and the ride was harsh and bouncy. It was clear I had to do something.

Shock
I mixed up some shock oil from Silkolene Pro RSF 5W and 10W to get an approximately 7.5W (Calculated viscosity of 37.29 cSt @ 40degC) shock oil and replaced the old oil with this.
I then set the rider sag to 64mm (approx 1/3rd of total travel). This required 13mm of preload on the spring.
I set the compression damping to 5 clicks.

Forks
I mixed up some oil for the forks with a viscosity of 40 cSt @ 40degC and changed the fork oil with this. Oil level was adjusted to 150mm from the top of the tube.
Preload was set to 7mm using thick-wall PVC tube.

Once all this was completed I took the bike for a ride at Dewildt (Copshop to 3-Fences Shop and back) and was amazed at the difference. I could hit whoops and small jumps with confidence and had a great ride. Even managed to chase down some guys on plastics at one stage ;)

Next Steps
Since I am quite an aggressive rider I will be increasing the shock preload to reduce the rider sag to about 55mm and changing the shock oil to a slightly heavier blend of 40cSt @ 40degC for even better rebound damping. I will report back after the next ride.

Notes:
1)  The actual viscosities of same weight suspension oils can vary considerably between the various manufacturers. Refer to the attached pdf for some actual viscosities of common suspension oils.
2)  I have created an Excel spreadsheet to calculate the viscosity of suspension oil blends as it is not a simple linear relationship. PM me if you would like a copy.
3)  Don't use fork oil in your shock as the viscosity index is too low to perform properly at the high temperatures a shock can reach.
 

Attachments

  • Suspension - Comparative Oil Weights Table.pdf
    212.8 KB · Views: 34
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