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Fox Suspension Rebuilds Parts – Mountain Bike Suspension Rebuilds

Over the past 30 years AMF Motorsports has been in the suspension business. Original owner Steve Havness (who is now the lead technician) has traveled the world rebuilding, testing, and custom valving shocks. From working as a lead suspension engineer for McLaren, to Nascar, Indy and WRC, you can say Steve “has seen it all” in the world of aftermarket shocks.

For 2017 we decided to apply our knowledge, equipment and resources to another division in the world of suspension; mountain bikes. Current owner Andrew Wallace has been involved in mountain biking since it’s beginning stages, and has seen the industry evolve over the past 20 years. “Technology has progressed immensely in the mountain bike industry, especially suspension. The fundamentals involved in a $15,000.00 set of rally car suspension are now available for your mountain bike”, Wallace notes. High and low speed compression, preload, high and low speed rebound, bottom out control, custom valving and spring rates; these are terms that were only in the automotive world for a long time (for top tier products), now they are available in almost any industry for your shocks, including mountain bikes.

So Andrew and Steve sat down and went to the drawing board. Andrew’s passion and understanding of mountain bike suspension combined with Steve’s three decades of suspension knowledge had the potential to make something special, and it has. Not to mention Andrew is an active weekend warrior at New England’s local Downhill Mountain bike parks, so test and tune development and feedback was readily available,  it all made sense and was destined to fall into place!

In photos; Andrew of AMF enjoying some hang time.

Our rebuild services and procedures are all you can expect. Cleaning, inspection, new seals, o-rings, and fluids, reassemble test and ship back to the customer. If you want to bring your entire bike in, we can take the suspension off for you and install it once it’s complete as well (if you are local). One thing that sets AMF apart from many other companies who rebuild Fox mountain bike suspension is our Dyno. Many offer what they refer to is a “function test”, or “hand dyno test”. Essentially compress the suspension, make sure the adjustments work, and send it on its way.

We decided to add on an additional feature/ service that we apply to our automotive suspension tuning and services; a shock dyno. We have not one but two SPA shock dyno machines in house here at AMF. What does that mean for the customer who sends in their suspension to AMF? It means the customer gets a full run through of all their adjustments on our dyno, with the compression and rebound data recorded and transcribed into a dyno graph. It helps us solidify everything is correct, and allows the customer to have access to data that they otherwise would be unable to obtain or view. This tool is crucial for solidifying the suspension is working correctly, and also allows for feedback when it comes to custom valving and tuning your suspension with different shims and spacers. Utilizing this tool gives us the ability to change the way the shock works and functions based on the needs and riding discipline of the customer, without even taking it out of our service stations. All in all, whether it is a complex custom Fox suspension revalve, or a standard fork suspension rebuild service, our shock dyno yields and guarantees better results, hands down.

Here are a couple of summaries from some recent MTB suspension services we performed here at AMF for Fox MTB forks and rear shocks.

Fox Front Fork Service – Mountain Bike Fork Rebuild

This Fox 40 was due for new seals and just felt a tad fatigued. It was certainly ready for a rebuild. We serviced this fork utilizing some OEM Fox seals, and well as the OEM specified Fox fork oil. This rebuild for Fox 40 went smoothly!

This customer was local so they opted for us to take the fork off, and reinstall it for them once the rebuild was complete.

Fox OEM seal kit, and the suggested Fox 20wt Gold fork oil. This is a special low friction formula that is proven and highly recommended. We can also use other brand fluids and seals per customer request.

Fox suggests rebuilding most of their forks every season, or if you’re lucky and get to ride a lot each season,every 125 hours. Keep in mind riding conditions can change these suggestions. Environments that expose the suspension to elements such as mud, sand, and excessive dirt can cause your seals to wear or fail faster than what is considered normal.

This fork featured the low friction Fox Kashima technology. A beautiful and functional feature that they offer for their top tier suspension products. Below are the standard Fox fork rebuild services we offer. For custom work, please contact us for a quote:

  • Complete inspection of fork
  • Complete tear down + reassembly
  • Cleaning of entire fork, internal and external
  • New o-rings and seals installed, new travel indicator installed
  • Worn or broken parts replaced- additional charges may apply
  • New fluid
  • Suspension adjustments and functions formally tested
  • Dyno
  • New decals available upon request for additional charge
  • Starting at $150.00

Link to website here:

Fox Rear Shock Service:

This customer wanted a rebuild, and a stiffer spring. Running a Trek Session 9.9 he wanted to go from a 450 to a 500lb spring. We installed a Fox 500lb spring, and a full Fox seal kit. We can also provide mountain bike shock rebuild services for other mountain bike brands as well!

Any of the shims that show signs of wear are to be replaced. All the shims are removed and fully inspected/ measured to make sure they are within spec and in usable condition. Replacement shims are available if needed.

 All laid out; disassembly of all components and a thorough cleaning for inspection are crucial to a succesful rebuild of your suspension.

Another cup of joe please. No that is not coffee! As you can see this shock was in great need of our services, that fluid is supposed be be red. A suspension rebuild for Fox suspension, or any suspension system is very important and should not be neglected.

Going on the dyno!

Here are the results of this shock. Valving as is came from Fox, after a AMF overhaul.

Standard rebuild services include:

  • Complete inspection
  • Complete tear down and reassembly
  • Internals and externals thoroughly cleaned
  • seals, o-rings, and fluid replaced
  • broken or damaged parts replaced- additional costs may apply
  • Nitrogen gas fill
  • All functions of shock tested
  • Dyno
  • New stickers available upon request for additional charge
  • Starting at $125.00 + shipping

Link to website here:

We service Fox mountain bike suspension for all disciplines including: dirt jump, cross country, trail, enduro, downhill and free-ride. For more information on our Fox mountain bike suspension services please email or give us a call during our business hours at 603 256 6800. As mentioned, we offer, mountain bike shock rebuilds, fork rebuilds, suspension rebuilds, & more. We also offer new suspension for those looking to upgrade their current forks or rear shocks. We ship and service USA and Canada.

Keep an eye out for us next time you are at any of New England’s mountain bike parks, we are rider owned and operated!

More information on Fox Service Plans:

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