Thursday, February 13, 2014

Ohlins Off Road Steering Damper v2.1 SD502 with SD 534 Mounting Kit

A couple weeks ago I was cruising down a straight sandy trail in the desert at about 40 mph. I hit a half buried soccer ball sized rock that was hidden in the shade of a bush. The bars slammed to the side jamming my wrist and forearm and the bike bucked up tossing me out of the saddle. I managed to recover, but it was almost an unpleasant crash.

I had heard that many guys run a steering damper in the desert specifically to help with this kind of incident. The idea is that it dampens jarring hits like one caused by hitting an embedded rock at speed. And I'd rather spend some bucks on a steering damper than have to recover from a hard fall. So I started shopping.

I quickly found that most steering dampers for dirt bikes mount under the handle bars and raise the height of the bars. I'm pretty short and definitely didn't want to raise the bars. A solution to that is to get flat low rise bars to compensate. I considered GPR v4 stabilizer with that plan. The GPR v4 is advertised to be thin and is designed to not raise the bars as much as other options. But after looking at it, I didn't want to install it and then put the flat bars on; I just didn't like setup.

Most people seem to use the Scotts steering stabilizer, and I noticed almost all of the Dakar guys use the Scotts. Unfortunately it raises the bars even more than the GPR. They do offer an "above the bar" mount, but I like to mount my GPS on top of the bar, and I have some safety concerns about mounting a solid metal stabilizer on top of the bars like that.

And then I found the Ohlins v2.1 Off Road Steering Damper. Now this looked cool and was claimed to mount under the bars without raising them!  There is a also good review on Eastern Dirt Magazine that made me more interested. The only problem was that it was darn expensive. But then I found a distributor offering a great deal as he had some overstock and I grabbed it. For my 2013 KTM 350 EXC-F the proper fitment was the SD502 damper with the SD 534 mounting kit.

The Ohlins 2.1 requires that you replace the top steering stem race with an Ohlins race with an attached post for the damper. With the special race and the thin damper body this makes for a nice tight installation. The negative is that you have to remove the top steering race and install the new Ohlins one. And the new one must be installed with the post perfectly in line with the centerline of the bike. This isn't too hard, but requires some special tools and extra care to not rotate the race during installation. The benefit of all this is a very compact installation with a short rigid post to actuate the damper.

Additionally, for installation on the KTM 350 EXC-F you have to drill and tap the top triple clamp to to fasten the damper in place.

I almost did this all myself, but then decided that instead of buying some tools and spending a bunch of hours that I'd rather let a professional do it. So I took that easy way out. Allen at Fox Engine Works did a great job for me. I should say installing this correctly takes some care. If you are skilled, do it yourself. If you want to have someone else do it, be prepared to pay for a bunch of hours and make sure they are capable of a detailed careful project like this. Your typical wrench monkey might not put it on straight.

I told Allen I wanted to be sure that the bar mounts were installed in their existing location, which was the most rearward position of four possible locations. Installing the damper with the bar mounts in the most rearward location did require grinding the bar mounts just a little bit to clear the damper.

I also needed to put some spiral wrap on the throttle cables and the fuel breather to protect them from rubbing on the sharp edges of the damper.

You also need to be careful to check the steering stops. You do NOT want the damper to stop the steering, you want the steering to hit the frame stops first.

The Ohlins offer two adjustment knobs. The "DL" or Damping Level knob sets the damping when the steering is being turned away from center. The "RTC" or Return to Center knob sets the damping when the steering is returning to center.

In this picture you can see the under bar mount with the plastic Garmin gps mount above the bar. The post from the steering race is completely hidden under the unit.

Here you can see to bolt that fixes the damper on top. The triple clamp needed to be drilled and tapped for this. Ohlins offers adapters for some bikes so the damper can be fitted without drilling. This looks nice and clean but does require careful work

This is a shot showing the adjustment knobs. For enduro use Ohlins recommends the DL to be opened 12 clicks and the RTC to be opened 8 clicks. I noted this on a bit of white duct tape.

After some consideration I decided to install the plastic protector Ohlins provides to protect the cables that run by the damper. Be very careful tightening these to not strip them!

My only concern about the damper is the arm that actuates the mechanism comes out of a thin slot on the underside of the damper. I could imagine sand or dirt jamming that slot. But it is in a fairly protected area of the bike so we will see how that works out. In this picture you can see the underside of the damper with the post mounted to the steering race and the actuating mechanism.

I tried the damper out just turning the bars. With the damping turned all the way open it's hard to tell it is installed. With both knobs turned all the way closed there is real resistance to the steering. (But not as much as the old linear damper on my Ducati Monster; on that damper you could barely turn the bars with the damper fully closed.) The return to center adjuster does really work; if you open that all the way you don't feel any damping when returning the steering to the center. I guess some people want to be dampened more if they are being knocked away from straight, and want to return back to the center more easily.

So far it looks great! A ride test report will come soon.
Ride report:
I got out in the desert for 100 miles with the new Ohlins steering damper. I set it at the suggested settings for enduro; 12 clicks out for the DL and 8 clicks out for the RTC. An a stand with the front wheel in the air you can feel the damping, but it is not much.
Out in the desert I couldn't feel it at all. I bumped the DL to 10 clicks out and even tried 8 and really couldn't feel it. Accelerating over ripples the front end felt really free and loose. Frankly, I was expecting a bit more restriction. Maybe I'll turn it way up and see. ;-)
But regardless of what I feel (or not) in regular use, I'm assuming it will help with a big off center hit to the front wheel. And that's why I put it on there.
I'll have to find somebody with a Scotts to compare.