Electric Mountain Bike Suspension: Forks, Shocks and Handling Benefits

Electric Mountain Bike Suspension: Forks, Shocks and Handling Benefits

Dialing in electric mountain bike suspension enhances handling and control while also boosting comfort over challenging terrain.

Suspension fork and rear shock choices require careful consideration of the additional forces produced by powerful eMTB motors and system weight.

We’ll compare aspects like fork travel, spring types, chassis designs, brands, tuning ability, and frame integration to help select optimal electric mountain bike suspension.

Overview of eMTB Suspension

Electric motors allow mountain bikes to go faster and farther into demanding terrain. Suspension becomes even more vital to absorb impacts and maintain traction for confidence, stability and control.

Suspension types found on eMTBs include:

Front suspension forks – Telescoping units attaching to front axles with 50-150mm of travel to compress over bumps and provide front wheel control.

Rear shocks – Mounted between the frame and rear wheel swingarm, they provide 50-150mm of rear wheel travel in response to forces and terrain.

Full suspension eMTBs combine front forks with rear shocks for maximum bump absorption and traction. Hardtails have only fork suspension.

eMTB Suspension Challenges

Electric assist adds unique demands on mountain bike suspension:

Increased weight – Heavier motors and batteries mean forks and shocks must handle greater static and dynamic loading forces.

Powerful forces – High torque motors dramatically affect acceleration, braking, and climbing traction compared to human power.

Higher speeds – Faster downhill and cruising speeds demand responsive, progressive suspension and damping control.

Advanced terrain – Added capability allows hitting rougher trails requiring more travel and adjustment range.

Rider weight range – Wide variances in total eMTB system weight with rider aboard necessitates greater tuning flexibility.

Frame integration – Suspension must work in harmony with eMTB frame design and motor placement for seamless power delivery.

Quality eMTB suspension meets these challenges while retaining efficiency, low maintenance, and long service life.

eMTB Fork Types

Here are the main eMTB fork options by configuration and travel:

Cross country forks – Shorter travel optimize climbing efficiency over speed. 100-120mm of smooth travel aids control without compromising efficiency on mellower trails.

Trail/All-mountain forks – Balance climbing and descending well. Offer 130-150mm travel for handling moderate terrain at speed while remaining maneuverable.

Enduro forks – Prioritize control and bump absorption on rowdy descents. Provide 160-180mm travel for high-speeds over extremely rocky, rooted terrain.

Downhill forks – Maximize stability at reckless speeds down steep grades. 190-200mm of plush travel soaks up huge hits and charges.

Match your eMTB fork travel range to the type of terrain you plan to ride based on desired riding dynamics.

eMTB Rear Shock Types

Key attributes differentiating eMTB rear shocks include:

Stroke length – The amount of wheel travel delivered on compression. Typically 40-75mm for short travel eMTBs, up to 150-170mm for downhill bikes. More stroke absorbs bigger hits.

Shock dimensions – Overall length and stroke dimensions must integrate optimally with rear frame layout and suspension kinematics.

Mounting – Shock mounts via eyelets or trunnion tabs. Size and configuration affects leverage.

Reservoir – External fluid reservoirs allow cooling and dedicating more fluid to damping control rather than suspension movement.

Ample shock travel, matched frame integration, effective damping and cooling allow surviving rugged downhill runs and huge jumps even with the added forces of eMTB motors tormenting rear suspension designs.

eMTB Fork and Shock Brands

Leading suspension makers crafting products specifically for eMTBs:

RockShox

The Pike and Lyrik eMTB forks offer stout 32-37mm chassis with offsets optimizing eMTB handling. Their Super Deluxe shocks feature tuning to pair perfectly with motors.

Fox

Fox 36 forks and Float shocks dialed for eMTBs offer ultra-adjustable GRIP2 damping and robust stanchions plus custom valving to manage electric power delivery.

SR Suntour

More accessible suspension like Suntour Auron and Durolux forks and Rux and Triair shocks configured for eMTB use provide great value and performance.

Bosch

Bosch produces their own eMTB-tuned suspension pairings to integrate optimally with their motors and power curves under their Smart Suspension initiative.

X-Fusion

Affordable yet capable products like the Trace and Sweep offer proven eMTB suspension performance on a budget.

Leading brands adapt their reputable suspension designs and technologies specifically for eMTB applications. Trusted names provide confidence.

Key eMTB Fork Features

Quality forks for eMTB use should contain:

35+ mm stanchions – Large, rigid fork legs prevent twisting under eMTB forces.

Shortened offset – Offsets around 44-51mm (vs 51-56mm on regular MTBs) quicken steering response ideal for eMTB handling.

High-volume air spring – Allows tuning spring rate for total eMTB weight. Prevents harsh bottom out.

Robust compression damping – Controls forces from high eMTB speeds and heavy landings. Prevents fork diving.

Adjustable rebound damping – Tunes return speed for traction, comfort, and stability. Custom eMTB tunes available.

Downhill boost spacing – Provides stiffness and space for wide plus tires on aggressive eMTB builds.

Axle options – Torque caps, bolt-on axles, and stiffening braces improve axle stiffness.

Rigid, highly tunable forks allow eMTBs to charge hard without deflecting under electric motor forces or heavier weights.

Key eMTB Rear Shock Features

Desired attributes for full suspension eMTB rear shocks:

Adjustments – Separate low speed compression and rebound dials allow extensively fine tuning damping feel.

Air volume spacers – Let riders modify spring curve progression to prevent harsh bottom outs.

Damper cooling – Heat-dissipating shock bodies, external reservoirs, and cooling fins prevent fade.

tfivalving – Special compression and rebound port shapes refined for eMTB loads and velocities.

Frame fit – Required shock dimensions and mounting configurations vary. Integration is vital.

Reduced friction – Slick coatings and modern seal materials improve small bump sensitivity and traction.

Reliable seals – Keeping oil and air sealed is crucial to longevity with all the grinding forces eMTBs produce.

Boost shock resistance to fluid breakdown, heat, and leaks while retaining sensitivity. Custom eMTB tuning ensures seamless power delivery and handling.

eMTB Hardtail vs Full Suspension

Hardtail eMTBs have suspension forks only. Full suspension models add rear shocks:

Hardtail

Pros

• Lighter weight
• Lower cost
• Simpler maintenance

Cons

• Harsher ride
• Reduced traction and control

Full Suspension

Pros

• Increased comfort and stability
• More rear wheel traction
• Additional bump compliance

Cons

• Added weight
• Higher price
• Extra complexity

Evaluate your budget and performance needs. Full suspension provides big handling benefits for aggressive eMTB riding. But hardtails offer lighter simplicity.

Suspension Fork and Shock Sizing for eMTBs

Matching your eMTB’s fork travel and dimensions to the rear shock optimizes bike handling balance:

• Travel – Run fork travel as close to rear wheel travel as possible – i.e. 150mm fork with 140mm rear shock rather than mismatched lengths.
• Offset – Optimize front/rear weight distribution by using equivalent fork and rear center offsets.
• Mounting hardware – Ensure suspension mounts, pivot points and axles provide adequate stiffness and rotational control.
• Wheel sizes – Pair appropriate fork offsets and lengths with rear wheel diameters. Fat bikes need extra long forks.
• Chassis dimensions – Diameter, length, stroke size and other dimensions must integrate with frame and motor spec.

Mismatched suspension component sizing leads to unbalanced ride dynamics. Seek suspension engineered in tandem for each eMTB model for optimal handling and power delivery.

Suspension Fork Adjustments

Quality eMTB forks offer external adjustments to tuning feel:

Compression – Controls fork compression movement. Increase to limit dive when braking or landing. Decrease for more sensitivity over small bumps. Lets riders dial rebound based on total bike weight.

Rebound – Adjusts fork extension speed after compressing. Faster rebound provides more traction but decreases stability. Slower rebound offers more control. Optimizing rebound makes a huge difference based on rider weight preferences.

Air pressure – Adding or releasing air pressure sets overall spring resistance and sag. Typically set 15-20% of travel. Higher pressure for heavier loads.

Volume spacers – Add spacers to reduce air volume, increase spring rate, and create more ramp up near bottom out. Removes harsh end of travel feel.

Adjust your eMTB’s forks to balance plushness on square edge hits and mid-stroke support while maintaining traction for confident control in rough sections.

Rear Shock Adjustments

Key features allowing eMTB rear shock tuning:

Rebound – Controls the rate the rear shock extends after compressing. More rebound damping slows return for stability. Less creates traction but allows kicking.

Low speed compression – Adjusts compression damping at slower shaft speeds for sensitivity over small bumps, chatter, traction.

High speed compression – Tames damping at higher shaft velocities for big hit control. Prevents packing down and harsh bottom out. Crucial for heavy eMTB landing forces.

Air pressure – Sets overall spring resistance based on total weight. Lower pressure provides more sag.

Air volume – Reducing air volume makes the spring curve more progressive nearer bottom out to avoid harsh impacts.

Tune your rear shock to maximize grip and small bump compliance while preventing bottoming out on large hits. Adjustments allow optimizing your eMTB suspension for riding style and weight.

eMTB Suspension Setup Tips

1. Set appropriate sag

Referring to manufacturer guides, use air pressure to achieve 15-20% sag measured while seated in riding position. Lighter riders use less pressure.

2. Balance front and rear

Even out front and rear sag percentages by adjusting pressure. Unbalanced suspension is detrimental.

3. Test rebound speed

Bounce aggressively to test if rebound is too fast (bike bucks up) or slow (bike packs down). Adjust dampers until smooth.

4. Dampen compression

If fork or shock easily blows through travel even with proper sag, increase compression damping.

5. Check for bottom out

Does a sharp clang or jerk indicate harsh bottom outs? Increase compression or reduce air volume.

Take time to properly set up your eMTB’s suspension. It makes an enormous difference maximizing control, comfort and handling capabilities so you can push harder.

Why eMTB Suspension Differs from Standard MTBs

Suspension for electric models differs from standard MTBs in a few key ways:

• Heavier weight – eMTB forks and shocks need more stiffness, damping range, and spring capacity for the additional weight.
• Power tuning – Special eMTB valving profiles manage the explosive forces produced under motor assist.
• Progressive leverage curves – eMTB suspension kinematics utilize more linear ramp ups for support against big hits and motor torque rather than initial plushness.
• Reduced anti-squat – Less anti-squat allows eMTBs to extend their suspension easily to maintain grip when applying power.
• Softer tuning – Lower air pressures compensate for heavier overall e-bike weights to retain bump sensitivity.
• Tuned-for-motor frames – eMTB suspension integrates intimately with frames, pivot points and motor placement to maximize power delivery.

While based on similar technology, eMTB suspension requires special design considerations to perform ideally under electric power.

Diagnosing eMTB Suspension Issues

If experiencing problems, systematically diagnose your electric MTB’s suspension:

• Visual inspection – Check for damage, leaks, loose fasteners or missing clips. Ensure nothing is loose or broken.
• Sag settings – Verify sag is properly set based on total bike/rider weight. This affects overall suspension function.
• Smoothness – Cycle fork and shock through travel by bouncing bike. Any stiction or binding indicates need for service.
• Noises – Listen for knocks and clunks that could signal loose parts or damage.
• Oil leaks – Evidence of leaking fluid indicates failed wipers or seals needing replacement.
• Fade – Do fork or shock seem to lose effectiveness after prolonged use? Overheating oil can reduce damping.

Don’t ignore any odd sounds, changes in function, or noticeable issues – have your eMTB suspension inspected promptly to avoid further problems.

sagSigns Your eMTB Suspension Needs Servicing

Monitor and address these potential indicators of needed fork or shock maintenance:

• Loss of smooth travel
• Excessive stiction or binding
• Visible damage or cracks
• Annoying noises on compression
• Fluid leaking from seals
• Fading performance after prolonged use
• Inability to hold set pressure
• Excessive top out clunking

Typically forks and shocks require lower leg oil changes or rebuilds every 50-100 hours of use. But intense eMTB riding may necessitate services 2-3x more frequently.

Periodic professional servicing ensures your suspension lasts and performs like new. Don’t wait until problems arise.

Conclusion

Dialing in eMTB-specific suspension creates a more capable bike by increasing control, comfort, traction, and handling precision across challenging terrain. The right forks and shocks maximize stability and bump absorption to allow pushing your e-bike faster and harder. Matched suspension enhances overall eMTB ride dynamics. Don’t settle for underperforming or mismatched components. Work with suspension specialists and your local shop to optimize suspension for your eMTB riding style and frequent trails. The results will improve your experience dramatically so you can focus on the fun of piloting cutting edge electric power on scenic natural trails.

eMTB Suspension FAQs

What is the best eMTB rear shock?

Top options include the RockShox Super Deluxe, Fox Float and Ohlins RXF eMTB-tuned shocks. Match shock size, mounting, and tune to your bike model.

Do eMTBs require more fork/shock maintenance?

Yes, the added forces require about twice the service frequency compared to standard mountain bikes. Every 50 hours is ideal.

What is the benefit of a coil shock for eMTBs?

Coil shocks offer very linear, consistent feel and can be tuned via springs for ideal mid-stroke support. But air shocks are lighter and easier to adjust pre-ride.

Should my fork and rear travel match on an eMTB?

As close as possible. Mismatched lengths lead to unbalanced handling. Stick within 10-20mm front to rear for best dynamics.

Do eMTBs need special brake pads?

Yes, eMTB-specific brake pads better handle repeated heavy braking on descents. Sintered metallic compounds withstand heat and wear best.