I have recently been configuring an Ohlins rear shock to my bike. It’s the TTX22 9.5×3.0 model. What I have discovered is since the length of the OEM FastAce shock is 10.5 inches the loss of one inch can come into play. The rear ride height is obviously less which in turn increases the trail of the front. By how much I have not measured. How much does it affect the handling? For me it is no slower in steering or more stable downhill. I will say that they feel of the rear shock is just as amazing as it was when I changed from the RST forks to the Dorado’s. It’s plush. I had to do some calculations to see just how losing approximately 1″ of travel affects the bike:

I fabricated this measuring tool to see how much travel occurs in each shock before complete compression occurs where the rear tire hits the seat fender. Keep in mind that I am using Shinko 244s which are about one inch taller in profile than the OEM knobbies. The line marked “Fast Ace” s where the fully extended OEM shock reaches. The line to the left of that is the Ohlins fully extended. The line furthest to the left is where the measuring tool reaches when the bike is fully compressed.
Here my homemade tool is installed in place of a shock for measurement.
The OEM 10.5 inch shock yields 3″ of stroke before the tire impacts the fender. The Ohlins reaches 2.25″ of stroke.
The linkage, bushings and nylon shims. I recommend that these be inspected and regreased about every 1k miles depending on your conditions.
I’m 180lbs in gear and took the bike over bumps and small jumps. As you can see I still have at least an inch of travel left before hitting the bottom out bumper. One other issue is the 10.5 inch OEM shock gets VERY close to the linkage on full extension. As the shock compresses it moves AWAY from the linkage.
This is where I do most of my testing. I did NOT go off the larger jumps for testing!
I’m running the 502 lbs pound spring and have set my preload to 25% of total travel.
The manual scissor lift in the foreground allows me to adjust the bike to whatever height I wish in small increments. Perfect for measuring just where tire to fender impact occurs.
The black lever is the high speed compression adjustment. The blue knob is the low speed compression. At the very bottom is the rebound adjuster. At full compression of the bike NOTHING in the linkage collides with other parts of the frame/linkage/swingarm. The ONLY impact that occurs is frame to tire and upper linkage to my fender mud guard. Lowering that mud guard will solve that issue.
So during my road racing days I worked with an Ohlins tuner. I’m working with some of their guys to figure out just what I need to do to increase the length by an inch. It may be a new dog bone in the linkage. But for now I’m using the 9.5 inch Ohlins after determining that nothing catastrophic will occur should I bottom out the shock. I don’t plan to do bottom out jumping until I can measure and ensure that the tire will not impact the fender on landing. But until then I just can’t give up the incredible plushness and control of the Ohlins.

Because the Ohlins shock I purchased off of eBay for my bike is a 9.5” and the OEM is 10.5” I needed to have a shock tower extension custom engineered and produced. A few folks have asked me why I didn’t just buy a 10.5 inch Ohlins or a Fox shock. I tried to find an Ohlins 10.5″ TTX22, but could only locate new ones which are 700.00 plus a spring which is another 100.00. I got my 9.5″ one for 397.00 delivered. Plus the 10.5″ Ohlins has a shock plunger length of 3.5 inches. The 9.5″ Ohlins has a 3″ plunger travel. After measuring the maximum travel of a shock plunger is 3.1 inches before the rear tire impacts the subframe. (based on my Shinko 244s which are about 1″ taller in profile than the OEM tires) So I would have to have added a spacer under the shock bumper to avoid having too much travel. Not a big deal, but combine that with an additional 400+ bucks in cost…no thanks.

My OEM shock was the FastAce model. All Sur Ron shocks are 10.5 inches eyelet to eyelet on center.

And although many folks like Fox suspension parts, I’m very familiar with Ohlins from my racing days. So I went with what I know.

I found a craftsman near my home and Gerard measured and designed it out of billet aluminum. It is engineered in such a manner where no flex or movement occurs. Remarkable. After having used the shock now for 12 hours of riding, I will simply say that it has transformed how the bike handles on choppy downhill sections as well as through off camber turns. It feels much more planted on both accounts and in general. Now the front and rear tires react in a similar fashion keeping contact with the ground without a pounding feeling or chatter over bumps large or small. The Dorado’s are now matched in the rear with the Ohlins. Prior to replacing the rear shock, the smoothness and contact of the front end highlighted the weaknesses of the rear suspension.

Gerard measuring and designs the shock tower extension. He transferred all of that into his CAD program.
The little Sur Ron attracted quite a bit of attention at Gerard’s shop when I went back to install the shock tower extension. Loads of questions.
As you can see his engineering of the shock tower extension is well executed.

So what’s different than the OEM shock? Most folks may think that suspension just makes the bumps more smooth. Of course that is ONE of the aspects of suspension. But the aspects of the Ohlins is its ability to make going faster easier and safer is one of the best aspects. Being able to get on the throttle sooner coming out of a turn, reducing arm pump because its high speed damping are all things that are great about the shock. If you’re primarily riding on the street or smooth surfaces, then I would not recommend the effort or money to replace the rear shock.

For any of you who may have purchased the same shock as I’ve bought I’ve placed a link to the user manual below.

Ohlins_DTC_TTX22 Manual

5 Comments

  1. Hi Mark
    I am seriously impressed by by your website! I thought of the sur ron more like a toy bike but now I’m intrigued and will probably purchase one. Thanks for that marvellous page! Cheers from Mallorca Spain

    • Hey Andreas, thank you for stopping by and letting me know you appreciate the site. The ENTIRE reason I took the time to build it was to support the Sur Ron Community worldwide. I was formerly an admin for the Private Sur Ron Facebook group, but I just cannot stomach Facebook’s business practices so I deactivated my account. Obviously you’ve read through my site and know how enthusiastic I am about this new device which in my mind has not existed before, not in this way. If I travel to Spain I will ping you to meet in person. Take care!

  2. 4sure…when in Mallorca give me a ring 😉

    • I’m 180 in gear and use the 502 lbs spring.


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