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Suspension Fork Hop-Ups
By James Sharp
Mountain bike forks have come a long, long way since the days of the Mag21s and original Manitous. The chassis are stiffer, the travel plusher and there is just more of it--lots more of it. Damping systems have become more tunable, making modern forks react to small ripples as well as bigger hits. Even though you may think you have the perfect fork, there are often a few niggling items that tend to bug. Or, maybe you bought last years fork, only to have this years “must have super-mega-stable-platform” fork come out and make yours obsolete. Sheesh, it's almost like the computer industry any more. Fortunately, there are some smaller companies out there that can help out a rider who needs to make his fork better. We have had a chance to put some time in on products from two of these: Enduro Seals and Stratos USA. The guinea pig fork for both of these modifications was a ‘03 Fox TALAS RL. While it's a good fork in its own right, it didn't have the latest platform damper technology and the seals leaked like a sieve.
Enduro Seals
Stratos ID
Enduro Seals
 Real World Cycling is a small company that sells fork seals and wipers--not very glamorous really. What their products lack in flash, they make up for in well thought out design. The wipers are made out of polyurethane. Unlike rubber, polyurethane doesn't flex. This means that dirt can't make the wiper flex out, so they keep the dirt, dust and grime out better than the stock wiper found on many forks. If it's so great why don't the manufacturers do this? Because the polyurethane doesn't flex, it has to be made to tighter tolerances than rubber wipers. Because of this, they are harder to manufacture. The fit is tighter on the stanchion, and does require some break in. Once broken in, however, they run smooth and do the job well.
In addition to the wipers, the kit includes inner oil seals. The seals replace the foam ring and do a much, much better job at keeping the oil in the fork, and not running down the leg. We also threw the Enduro Seals on a Manitou Black fork, though the kit for the Black only contains the wipers.
On both the TALAS and the Black the wipers went without too much trouble, though they are a tight fit. The seals on the Fox dropped right in. The Enduro Seals website gives very good instructions, with pictures, so that even a novice will have an easy time of it.
To date, we have had zero issues with the Enduro Seals. None, nada, zilch, not one. Period. We haven't felt an increase in stiction and we have seen a noticeable reduction in the amount of fluid leaking past the seals and wipers. Previously, we would have had enough leaking out to pool on the wipers, now we just get a dirty ring on the stanchions. In the case of the Black, we replaced the mini-boots that would never stay put with the Enduro Seals wipers and have had no issues there, either.
Summary: Who needs Enduro Seals? Everyone. At $23, or less, they are an inexpensive way to increase the life of your forks fluid and internals. They are made for just about every popular fork, and are backed by a company that knows the meaning of customer service.
For more information, contact:
Enduro Seals
www.enduroforkseals.com
Phone: 877-ENDURO-1
Stratos ID
 Stratos has been around since 1995, making shocks and forks for bicycles as well as motorcycles and other off-road vehicles. Though better known for their freeride and downhill offerings, they have some products that are pretty unique. They are one of the few companies to offer a tandem specific suspension fork and they are the only company to offer an inertial damper cartridge as an aftermarket kit for non-Stratos forks.
Inertial dampers are not new. In fact the design that Stratos licenses comes from the motorsports industry. Like all inertial dampers, the ID cartridge relies on a mass to turn off or on the compression damping. The laws of physics state that an object at rest wants to stay at rest, unless acted upon by an outside force. This is why you can pull the tablecloth out from underneath the silverware without upsetting a spoon. The inertial damper works on the same principle, but Stratos has added a twist. The mass in the ID cartridge is the brass colored bit in the picture. It rests on the spring below and fits into the X-Chamber immediately above the mass. The X-chamber is the key to the ID's success. The mass is the silverware and the rest of the fork is the tablecloth. As the fork encounters a bump, fluid is forced into the X-chamber. As the mass begins to compress the spring, remember that the mass wants to stay put as the rest of the fork moves upward, the fluid pressure in the X-chamber slams the valve completely open. This makes the fork react to bumps faster than if the fork relied on the mass movement alone. Not only does the valve open faster, but as the fork settles down after a bump, the venturi effect of the liquid moving back into the X-chamber, the negative pressure sucks the mass back into its seat in the X-chamber, closing the valve very, very quickly.
What this all boils down to is that the ID cartridge reacts faster than any other inertial damper on the market, and it settles down faster than any other inertial damper on the market. That is the bit that is patented; Stratos is the only mountain bike company that can use the fluid to speed up the process. That should be enough, but Stratos goes one step farther is making the effect of the valve adjustable. It doesn't have to be an on/off switch. One key market for the ID cartridge is in downhill forks. I can see you asking yourself, who wants a lockout on a downhill fork? They don't. But the ID can be tuned to just increase the compression damping a bit to resist brake dive, something that plagues big travel forks. It's a case of having your cake and eating it too. A soft fork that soaks up small ripples and big hits equally well, while resisting brake dive as you hit the binders hard coming into a corner. Our ID was set up with an “almost” lockout, meaning that it was stiff enough to behave as a lockout, but the fork moved a bit when hammering out of the saddle. Immediately the benefits of reduced brake dive became apparent and allowed us to run 10psi less in our test TALAS. By doing that we had a fork that really was the best of both worlds, stiff when we wanted it (mostly) and plush when we needed it.
Overall the quality of the travel on our TALAS guinea pig remained the same as stock, which is a good thing since we feel that the Fox damper is very good to begin with. The ID cartridge doesn't have adjustable compression damping, but does have rebound damping adjustability with a very usable range. The only issue that we had was that the TALAS feature didn't work quite as well. Dial down the travel and the fork shortened without a hitch, but extending the travel required a stop and physically pulling on the fork to extend it. This occurred regardless of where the rebound was set. Full fast or full slow netted the same results. Our other complaint wasn't really against the cartridge, since it works as claimed, but rather with the technology. I am a lockout proponent. I feel that every fork with more than 3 inches of travel should come equipped with some sort of lockout, downhill and freeride forks excepted. The thought of having a fork that does that bit for me seems like a great idea, in theory. Imagine, hammering on the single track and you make a sharp right hand turn and the trail immediately goes up. You stand to hammer, since you don't have time to shift, and the fork is stiff, though not rigid, and you make the rise. No fumbling with levers or slowing down. That is how it works. The problem is the rest of the time when you might not want the lockout, even though the trail is smooth. Or, and this is a bigger problem, your once balanced bike isn't anymore. Before plunking down the $250 for the latest technology out there, you have to ask yourself, "Is this going to make my bike behave in a bad way?" There were times during the review period when I wished that I could turn off the inertial part of the damper and just run the fork open all the time.
Summary: Inertial dampers are here to stay. The ID cartridge carries the best of this technology in a package that is retrofitable to many forks out there (see their website for details). I would recommend this cartridge as an upgrade to anyone riding a hardtail; be it racer, singlespeeder, all day epic rider or weekend warrior. I am more leery of recommending this to someone riding a full suspension bike without a test ride. If you are looking for an inertial damper fork, look no farther, but know that it might make your bike unbalanced.
James Sharp is a contributing editor for GearReview.com specializing in mountain biking.
For more information, contact:
Stratos USA
109 South Quarantina Street
Santa Barbara, CA 93103
Phone: (805) 966-2509
www.stratosusa.com
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