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Sentinel - enhanced mountainbike fork seal
https://www.kickstarter.com/projects/258021526/the-sentinel
![photo]()
Did you ever think about your forks performance?
Oil, seals, temperature, dirt, water, sunlight, bushings and the probably most important part: The dust wiper or fork seal ? To be honest, we spend a lot of time with that....
Beginning with dust wipers: they have to fullfill 3 tasks which have conflicting requirements to the applied material. As conventional wipers are made out of one piece, engineers had previously compromised in choosing rubber, which is perfect for compensating for tolerances. Tolerances result from the production process of the forks lowers, a little torsion while riding, and undoubtedly while installation - no one is able to pound wipers into the casting with a precision of 1/10 mm or 0,004 inches, and that is a lot in sealing !
![Conventional wiper made of rubber]()
Conventional fork seal
As some low friction seals on the market did not meet our demands, we wanted to do something new. But for us new meant not to just put a cover over a normal wiper, nor manufacture them as a one-piece part out of a material that naturally provides lower friction to surfaces than rubber. Covers get rubbed off. Harder parts like one-piece polyurethane fork seals cannot compensate tolerances that easy - hard contact pressure on one side but less pressure on the other leads to an inaccurate performance/protection for the fork. We wanted to reach both goals: Lowest possible friction on the one hand and simultaneously a good protection against contaminants.
We thought a lot about this - starting several years ago. But then the idea came up this winter:
The Sentinel wiper was born !
We ran to our patent attorney and registered a patent: Our idea of a fork seal evolution is to introduce materials that are stronger than rubber and therefore provide less friction - i.e. materials which are also used to protect expensive industrial machines. The solution was to snug these naturally a bit "tenacious" materials into a soft sealing body - providing them with a little compensation space. The sealing or wiping function works through the ring tension of our "inserts". So our inserts are not forced to compensate, they are fully floating and completely lateral sealed . Which leads us to choose freely which materials to use. So we can use the best materials available !
Here a section view:
![Section view - body including reinforced core - inserts in grooves with tolerance compensation space - lateral seals protecting each insert]()
![Sentinel exploding view w foam ring]()
![Sentinel ultra low friction fork seal providing a patent pending tolerance compensation insert system. This enables to use materials that provide the lowest friction ever in a fork seal. Final version Top insert and body have the same colour]()
We are running a Kickstarter campaign until 4th of July - do not hesitate to back our project
![Back us today and get a pair of Sentinels]()
Did you ever think about your forks performance?
Oil, seals, temperature, dirt, water, sunlight, bushings and the probably most important part: The dust wiper or fork seal ? To be honest, we spend a lot of time with that....
Beginning with dust wipers: they have to fullfill 3 tasks which have conflicting requirements to the applied material. As conventional wipers are made out of one piece, engineers had previously compromised in choosing rubber, which is perfect for compensating for tolerances. Tolerances result from the production process of the forks lowers, a little torsion while riding, and undoubtedly while installation - no one is able to pound wipers into the casting with a precision of 1/10 mm or 0,004 inches, and that is a lot in sealing !
As some low friction seals on the market did not meet our demands, we wanted to do something new. But for us new meant not to just put a cover over a normal wiper, nor manufacture them as a one-piece part out of a material that naturally provides lower friction to surfaces than rubber. Covers get rubbed off. Harder parts like one-piece polyurethane fork seals cannot compensate tolerances that easy - hard contact pressure on one side but less pressure on the other leads to an inaccurate performance/protection for the fork. We wanted to reach both goals: Lowest possible friction on the one hand and simultaneously a good protection against contaminants.
We thought a lot about this - starting several years ago. But then the idea came up this winter:
The Sentinel wiper was born !
We ran to our patent attorney and registered a patent: Our idea of a fork seal evolution is to introduce materials that are stronger than rubber and therefore provide less friction - i.e. materials which are also used to protect expensive industrial machines. The solution was to snug these naturally a bit "tenacious" materials into a soft sealing body - providing them with a little compensation space. The sealing or wiping function works through the ring tension of our "inserts". So our inserts are not forced to compensate, they are fully floating and completely lateral sealed . Which leads us to choose freely which materials to use. So we can use the best materials available !
Here a section view:
We are running a Kickstarter campaign until 4th of July - do not hesitate to back our project
Author Info:
Member since Jun 10, 2015
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2 Comments
- 1 0
Throwzogthrow
(Apr 12, 2017 at 18:59)
Those after market parts.... it's a slippery slope.
- 1 0
scar4me
(Jun 12, 2015 at 12:38)
Looks slick!
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