The DR650SE's are noted to have soft and under damped suspension components for all but the lightest riders. Old style non-adjustable damping rod type forks and a compression damping and spring pre-load only adjustable rear shock keeps the DR650 off-road heroics in check. Fear not! There are some pretty cool options for the stock DR suspension. One of them, of course, would be to take the components to one of the many performance suspension experts that do this type of work. You can also buy the parts and DIY!
While the best option is to upgrade both the springs and dampers both front and rear, if you are on a budget try replacing the springs front and rear with ones for your body weight and riding style and putting in some nice fresh 10 weight suspension oil.
Links that can help Edit
- Race Tech has a list of suspension goodies and services for the DR650
- Cogent Dynamics (www.motocd.com) offers this awesome DR650 shock upgrade
- Jesse at Kientech Engineering offers the Eibach fork and shock springs
Procycle offers front and rear suspension "kits" http://www.procycle.us/bikepages/dr650.html#suspension
- Ricor Intiminators
- Kouba Link has a has a nice write up on how to change a shock spring on the DR650.
Forks and triple clamps from other bikesEdit
Some decide to replace the stock 43mm forks with better ones from other motorcycles. Some of these will also have heavier springs than the stock .400 kg/mm springs and may not need new springs. First up are late model forks that will also require the triple clamps as they are a different diameter stancheon, or inverted.
This upgrade can be done at a net $0 cost if you take your time buying/bidding on parts, the stock forks/wheel should sell for what you paid for your DRZ forks/wheel. The spring rate for the DRZ400E and the DRZ400S is 0.44 kg/mm, the E model has better damping though. I like the DRZ forks because they are intended for higher weight bike loads. PM me on the ADVRIDER forum if you want the original pics. I've been riding my upgrade now for about 1.5 years and I'm very happy. Also consider the DRZ rear shock upgrade.
- [http:// http://www.thumpertalk.com/forum/archive/index.php/t-555780.html RM250 inverted forks and triple clamps]
- DR 650 fork swap with 05-07 RMZ 450 forks
43mm forks from other bikesEdit
An even easier option is to find 43mm forks from other bikes that will slide straight into your DR650 triple clamps. Some bikes with 43mm forks include the XR600, DR350, early model RM125 and RM250, and 1986 to 1988 CR125 CR250 CR500 models. The conventional forks from the 1983 to 1988 RM125 and RM250 options are the easiest, as with a bit of work you can keep your stock front wheel, disc and speedo drive in place. These will slide straight into your DR650 triple clamps. They are a longer fork, but you can slide them down into the clamps to get closer to the original setup. Your front wheel, axle and speedo drive will all fit perfectly. However, you will need to make a caliper adapter plate to position your caliper correctly for the 290mm disc of the DR650. Otherwise, you will need the orginal RM125 or RM250 front wheel and settle for the 250mm disc. The spring rate for the RM125 forks is usually around 0.33 kg/mm and the RM250 springs are 0.35 kg/mm so you will definitely want to fit stronger springs.
Modifying the existing DR650 forksEdit
The most basic cheapest mods? Replace the 5w fork oil with 10w for stronger damping. Some riders have experimented with 15w, some report good results while others say the bike will shudder on fast corrugations. Others have also mixed their fork oil for a 12.5w as a compromise. The forks should compress around 25-30% of their travel when you sit on the bike; many riders find they sag more than this so add preload to the forks. You can remove the very heavy existing steel preload spacers on top of the springs and replace with PVC tubing. Experiment with the length of this, many riders report that making these a half inch longer than the stock ones works well. Heavier riders can also ramp up the preload on the rear spring to get the right amount of sag. Please note, increasing preload does not increase your spring rate, it only achieves the right amount of sag!
If you are on a strict budget, a possible option is to cut and reduce the length of your springs by 10% which will increase the spring rate to 0.44 kg/mm, and make your preload spacers correspondingly longer. Read more about this here. Another budget option that is debated is increasing the level of your fork oil; this reduces the amount of air in your forks so on compression this makes your forks stiffer so acts in a similar way to stronger springs (although at a different rate). Some argue against this due to the increased strain on fork seals. Read more about this here.
Your next option is to look at stronger springs which aren't very expensive so well worth looking at. Racetech have a handy calculator here for working out the spring rate to suit your weight and riding. For better damping (especially rebound damping) look at installing either emulators or intiminators. Emulators are slightly cheaper, but need the forks dismantled and are more work to install. Read more here.
DR650 rear shock modsEdit
For the vast majority of riders the rear shock is underdamped and undersprung. Here are your options, working from the cheapest to the most expensive / work intensive.
The most basic cheapest mod is the highest damping setting and increase the preload on the spring - as per the forks, The rear shock should compress around 25-30% of its travel when you sit on the bike. Of course this does not make the suspension any stiffer, but at least it should correct the excessive rider sag for most riders.
The next mod would be to remove the rear shock, and replace the 5w rear shock oil and replace with 10w rear shock oil. This thread has lots of information on this mod. This will provide increased damping and lessen the pogo stick effect of the stock suspension. It should cost around $20 for oil and the same again for recharging the shock with nitrogen. Please note, the stock shock has insufficient rebound damping so you may need to work out a compromise e.g. go up to a 15w shock oil and have harsh compression damping, but at least some rebound damping.
The next mod costs more, and involves the above but includes a stiffer rear spring. Racetech have a handy calculator here for working out the spring rate to suit your weight and riding. However, once you spend the money on a rear spring (around $10 to $150) it makes sense to revalve the stock spring and not bother with trying to make the stock valving work. Click here to see step-by-step instructions on installing a Gold Valve setup (about $170).
ProCycle also has a replacement shock kit that is very easy to install and comes with a beefed up shaft and Race Tech Gold Valve. You also get a new spring setup for your weight and riding style.
Next mod? If you don't feel like doing it all yourself, suspension specialists will rebuild your shock for you with a better spring, revalving, and optional recoating of the shaft etc.
The most expensive mod is to buy a complete aftermarket rear shock like the Ricor or the Cogent. There are also a budget DR650 rear shocks from the United Kingdom that can be purchased via Ebay, such as the Hagon and Hyperpro. It's likely you will just get what you pay for, so do your research first if considering a cheap aftermarket shock.
If you like messing around, you can adapt shocks from other bikes to suit the DR650SE, the most common seems to be the DRZ400 rear shock which has better damping with rebound and compression adjustments, but you'll definitely need a stiffer rear spring - the stock one is even softer than the DR.