Wild Dog Adventure Riding

Technical Section => Make / Model Specific Discussions => Suzuki DR & DRZ => Topic started by: Alphat on July 14, 2015, 12:35:55 pm

Title: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Alphat on July 14, 2015, 12:35:55 pm
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.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Matie spero on July 31, 2015, 10:14:17 am
bedonnerd!

Jy moet meer post soos die maak!

Sal jy my asb n copy van die sheet stuur.

Matiespero
@
gmail,com

ek moet ook in die nabye toekoms my furke en shock diens, sal graag meer met jou wil gesels siende dat ek nog nooit so iets aan gepak het nie!
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: ZA on July 31, 2015, 10:49:46 am
Brilliant!! Ek wag al lank vir so tegniese post. Wat weeg jy  met jou kit op?
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Alphat on August 03, 2015, 02:45:02 pm
Thanks Matie Spero and ZA. I reckon a bit more fiddling with the suspension and it'll ride like a KTM plastic!  :biggrin:

@Matie Spero: I have emailed you the spreadsheet as requested.

@ZA: I weigh about 88kg all kitted up.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 03, 2015, 05:36:00 pm
Thanks Matie Spero and ZA. I reckon a bit more fiddling with the suspension and it'll ride like a KTM plastic!  :biggrin:

@Matie Spero: I have emailed you the spreadsheet as requested.

@ZA: I weigh about 88kg all kitted up.
You're a light weight Alphat!🙀

In general the DR is under sprung and under damped.

Beefier springs and emulators are required.

Your mods are a cost effective solution, that should work for your weight Alphat.

I am nearly a 100 kgs without gear and luggage, and some of our DR friends even more!

We will need to beef up the springs, but could utilize the damping option.






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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 03, 2015, 05:42:48 pm
My current DR 650 suspension research revolves about transplanting a few suspension components from this donor!

(http://images.tapatalk-cdn.com/15/08/03/d1189f6d3128ff901a38efddef365de2.jpg)


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Alphat on August 04, 2015, 09:14:16 am
My current DR 650 suspension research revolves about transplanting a few suspension components from this donor!

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What donor bike is that? A DRZ400?
I've heard of guys using DRZ forks very successfully and it's something I'd like to investigate.

Let us know how this transplant works out.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: superfoxi on August 04, 2015, 10:13:24 am
I wouldn't recommend using higher viscosity oil in a modern bike shock - rather use the correct 2.5W oil and re-valve the shock to give it more damping. I am using a 8.3KG/mm spring (100kg rider+ luggage for Angola trip) with re-valved shock. Works very well.
I didn't like those flimsy front forks too much and transplanted a set of WP48mm forks and triple clamps. Also had to re-valve, shorten and re-spring the forks. Feels like a real motorbike now. :ricky:
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 04, 2015, 12:11:56 pm
Jip. DRZ 400. 👍


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: superfoxi on August 04, 2015, 05:24:23 pm
The DRZ forks should work well. Not sure if the rear shock would fit. The DR650 shock is very long.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: StuartC on August 04, 2015, 05:37:51 pm
I'm trying to find an early 90's  KTM (Pre PDS)shock for my DR
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 04, 2015, 05:47:00 pm
The DRZ forks should work well. Not sure if the rear shock would fit. The DR650 shock is very long.
They do use it. Think its 1/2 an inch shorter though. Needs a beefier spring.

Not sure about the revalve. Has high/low speed damping and rebound adjustment.

Bottom shock mount is narrower than the DR. Mods on ADVrider.

Maybe better to revalve the DR shock and fit new spring?

Will one have to fit other springs to the DRZ forks? 100kg rider?

With the DRZ's forks having damping and rebound adjustment, will the valving be sufficient for the heavier DR?


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 04, 2015, 05:48:48 pm
Does anybody know the origin of this rear shock?

(http://images.tapatalk-cdn.com/15/08/04/ff79eab6a78edf58e709fc2c36a9844c.jpg)(http://images.tapatalk-cdn.com/15/08/04/3cac74da33bc31c793cca0e73a9ed2c0.jpg)


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 04, 2015, 05:49:54 pm
More pics...

(http://images.tapatalk-cdn.com/15/08/04/91e674c6ecc6bb75a7e69ed28b63efa2.jpg)(http://images.tapatalk-cdn.com/15/08/04/1de18cb5c53c708785b453f2f78e7955.jpg)


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: superfoxi on August 04, 2015, 08:12:18 pm
I'm trying to find an early 90's  KTM (Pre PDS)shock for my DR

I have three of those older non - PDS shocks. But they are all too short  :(
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: superfoxi on August 04, 2015, 08:24:19 pm
The DRZ forks should work well. Not sure if the rear shock would fit. The DR650 shock is very long.
They do use it. Think its 1/2 an inch shorter though. Needs a beefier spring.

Not sure about the revalve. Has high/low speed damping and rebound adjustment.

Bottom shock mount is narrower than the DR. Mods on ADVrider.

Maybe better to revalve the DR shock and fit new spring?

Will one have to fit other springs to the DRZ forks? 100kg rider?

With the DRZ's forks having damping and rebound adjustment, will the valving be sufficient for the heavier DR?


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The 1/2 inch shorter shock might work for shorter riders - but then the forks also have to be shortened or converted to the short setting. The linkage ratio is around 3:1. That means that the 1/2 inch shorter shock will lower the back around 1.5 inches...

Re-valving the stock shock seems to be the easiest and cheapest option. The only problem is that it doesn't have a rebound adjuster and the valving must be rather accurate for the spring rate that you are using.

The DR400 forks might be a little bit too long - but they can be shortened easily. The spring rate will also be way too low for the heavier 650 + 100kg rider. But you could either get the right springs or shorten the stock springs slightly (if you have to shorten the forks anyway)  to achieve a higher spring rate (can be calculated). The range of adjustment should be fine - worst case the forks have to be re-valved slightly.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 04, 2015, 08:34:50 pm
If possible I would actually prefer to increase the bike's clearance slightly. The DRZ shock will then not be an option.

If I send you the DR650 rear shock, will you be able to supply the correct spring and valve it accordingly?

If yes, the cost via PM will be appreciated.👍


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: StuartC on August 04, 2015, 10:38:57 pm
I'm trying to find an early 90's  KTM (Pre PDS)shock for my DR

I have three of those older non - PDS shocks. But they are all too short  :(
what length are they?
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Kykdaar on August 05, 2015, 08:11:13 am
If I send you the DR650 rear shock, will you be able to supply the correct spring and valve it accordingly?

If yes, the cost via PM will be appreciated.👍


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Can you let me know as well please?

I weigh around 125kg's and place considerable sag on the rear shock. I am not into hard core riding anymore, but I would like a (much) stiffer rear spring to compensate for my bulk ;D
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Ganjora on August 05, 2015, 08:16:45 am
if i recall correctly i got an upgraded spring from procycle,
here's a nice tuturial: http://www.procycle.us/info/guides/dr650/shock-build.html (http://www.procycle.us/info/guides/dr650/shock-build.html)
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Kykdaar on August 05, 2015, 08:42:33 am
if i recall correctly i got an upgraded spring from procycle,
here's a nice tuturial: http://www.procycle.us/info/guides/dr650/shock-build.html (http://www.procycle.us/info/guides/dr650/shock-build.html)

Thanks D, but working on shocks is like the dark arts or voodoo to me. This is one job I would rather give to the professionals.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: lecap on August 05, 2015, 10:47:11 am
If I send you the DR650 rear shock, will you be able to supply the correct spring and valve it accordingly?

If yes, the cost via PM will be appreciated.👍


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Can you let me know as well please?

I weigh around 125kg's and place considerable sag on the rear shock. I am not into hard core riding anymore, but I would like a (much) stiffer rear spring to compensate for my bulk ;D

You should get a stiffer spring for the rear shock. Ideally also re - valve the damper.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Alphat on August 05, 2015, 10:59:03 am
If I send you the DR650 rear shock, will you be able to supply the correct spring and valve it accordingly?

If yes, the cost via PM will be appreciated.


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Can you let me know as well please?

I weigh around 125kg's and place considerable sag on the rear shock. I am not into hard core riding anymore, but I would like a (much) stiffer rear spring to compensate for my bulk ;D

Hey Superfoxi, I'm also very interested in the cost of revalving the shock and the forks. Especially to improve rebound damping (a very weak point with the DR). Please PM to me as well or post approximate prices here.

Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Alphat on August 05, 2015, 11:08:22 am
I wouldn't recommend using higher viscosity oil in a modern bike shock - rather use the correct 2.5W oil and re-valve the shock to give it more damping. I am using a 8.3KG/mm spring (100kg rider+ luggage for Angola trip) with re-valved shock. Works very well.
I didn't like those flimsy front forks too much and transplanted a set of WP48mm forks and triple clamps. Also had to re-valve, shorten and re-spring the forks. Feels like a real motorbike now. :ricky:

Hey Superfoxi, Ja, I agree this is definitely not the best way to do things but it gives pretty good results and very good bang for your bucks. I do want to upgrade the pretty basic stock forks when a suitable set comes along and revalve the shock (please send me the approximate cost for this too).

Out of interest, why wouldn't you use higher viscosity oil in a modern shock?
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Kykdaar on August 05, 2015, 12:26:38 pm
If I send you the DR650 rear shock, will you be able to supply the correct spring and valve it accordingly?

If yes, the cost via PM will be appreciated.👍


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Can you let me know as well please?

I weigh around 125kg's and place considerable sag on the rear shock. I am not into hard core riding anymore, but I would like a (much) stiffer rear spring to compensate for my bulk ;D

You should get a stiffer spring for the rear shock. Ideally also re - valve the damper.

Thanks LeCap - ja, I should stop pimping the bike for a while and make the real important upgrades :thumleft:
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 07, 2015, 06:46:56 am
Superfoxi
 
Please remember to PM myself, Kykdaar and Alphat the estimate for the rear shock's revalving and spring upgrade. 👍


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: superfoxi on August 07, 2015, 10:07:27 am
Superfoxi
 
Please remember to PM myself, Kykdaar and Alphat the estimate for the rear shock's revalving and spring upgrade. 👍


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Yes, I will PM you on the weekend. Having a hectic week at work and no time for anything else at the moment...
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 07, 2015, 12:58:46 pm
Superfoxi
 
Please remember to PM myself, Kykdaar and Alphat the estimate for the rear shock's revalving and spring upgrade. 👍


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Yes, I will PM you on the weekend. Having a hectic week at work and no time for anything else at the moment...
Great! Thank you!


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: superfoxi on August 10, 2015, 09:17:20 pm
I'm trying to find an early 90's  KTM (Pre PDS)shock for my DR

I have three of those older non - PDS shocks. But they are all too short  :(
what length are they?


Sorry, only saw your post now...
They are 386mm and 390mm long and look like new.
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: superfoxi on August 10, 2015, 09:28:50 pm
Superfoxi
 
Please remember to PM myself, Kykdaar and Alphat the estimate for the rear shock's revalving and spring upgrade. 👍


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Yes, I will PM you on the weekend. Having a hectic week at work and no time for anything else at the moment...

PM's sent...
Great! Thank you!


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Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: Kykdaar on August 10, 2015, 09:36:30 pm
Got it thanks :thumleft:
Title: Re: DR650 Suspension Set-Up - Highly Recommended Mods
Post by: chopperpilot on August 12, 2015, 09:38:54 pm
Replied to my PM.


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