Set-up & adjustments · 79Bike · Sur-Ron · Talaria
Electric dirt bike suspension set-up: sag, preload, rebound and compression
Most electric dirt bikes leave the factory set for an "average" rider of about 70–75 kg. If you weigh 55 or 95 kg in kit, the bike is not working in the right range: it bottoms out, bounces or feels harsh. Sag is the foundation; rebound and compression come next.
What is sag?
Sag is how much the suspension compresses under the bike's weight, then with the rider in riding position. It puts the suspension in the right part of its stroke: low enough to follow dips, with enough reserve to absorb hits. The usual target is 25 to 33% of total travel for rider sag (about a third at the rear, slightly less at the front).
Measuring rear sag
Pick a fixed point on the frame or subframe, vertically above the rear axle. Measure axle ↔ reference point:
- A — rear wheel off the ground (bike on a stand or lifted by two people).
- C — rider in full kit (helmet, boots, pack) standing on the pegs, someone holding the bike upright.
Rider sag = A − C. Compare with the manufacturer's wheel travel to get the percentage.
Correct it with preload
Too much sag: add spring preload (preload collar on the shock). Not enough: reduce it. Work in small steps (half to one turn of the collar) and measure again. If you need a huge amount of preload to reach the target, the spring is wrong for your weight: a stiffer (or softer) spring is the real fix, not an extreme setting.
Fork rebound and compression
Adjustable forks (FastAce ALX33RC on the Falcon Pro, preload/rebound/compression-adjustable fork on the Falcon GT) use click adjusters. Before changing anything, record your baseline: gently screw each adjuster fully in while counting clicks, then return to the original position.
- Rebound: return speed. Too open and the bike pogos and bounces; too closed and the suspension packs down over a series of bumps.
- Compression: resistance to compressing. Close 2 clicks if the fork dives under braking or bottoms out; open it if it transmits too much from roots and rocks.
Change one setting at a time, by 2 clicks, and test on the same section of trail.
Balance front and rear
A balanced bike sinks evenly when you push down on the pegs standing up. If the front dives much more than the rear, steering gets nervous and the bike falls into corners; if the rear squats, the front goes light and the bike runs wide on exit. Don't forget tyre pressure, which is part of the suspension.
Tools you need
- Tape measure or ruler
- C-spanner or drift for the preload collar
- Flat screwdriver (adjusters)
- A helper
- Notebook to record clicks
Step-by-step procedure
- 1
Record the stock settings
Count rebound and compression clicks from fully closed and write them down, along with the preload collar position.
- 2
Measure A
With the rear wheel off the ground, measure the vertical distance from the axle to a fixed point on the frame.
- 3
Measure C
Rider in kit standing on the pegs, bike held upright: measure the same distance. Sag = A − C.
- 4
Adjust preload
Add preload if sag is too high, reduce it if sag is too low, in small increments, then measure again.
- 5
Set rebound
Push hard on the seat and let go: the bike should come back up briskly and stop without bouncing. Adjust 2 clicks at a time.
- 6
Fine-tune compression on the trail
On a known test section, close compression if the bike bottoms or dives, open it if it feels harsh on small hits.
- 7
Record the final set-up
Write down your final settings and tyre pressures: that is your baseline for future rides.
Useful genuine parts
In stock, shipped in 3–10 business days.
FAQ
My son weighs 45 kg and the bike is too stiff. What can I do?+
Back preload off to the minimum and open compression and rebound a few clicks. If sag is still too low, a softer rear spring is the right fix. Ask us for the right part for your model.
Does suspension need maintenance?+
Yes: clean the fork tubes after every muddy ride and watch the seals (oil on the tube = seal to replace). A fork oil change about once a year is recommended for regular use.
Do settings change in L1e-B road mode?+
Road mode limits speed and power, not the suspension. For mostly road use, slightly softer compression improves comfort.
Key takeaways
Always start with sag, write down every click and change one setting at a time. Good suspension set-up is often the cheapest comfort and safety upgrade you can make.
Need a hand?
Our workshop in Toulouse Sud (France) services 79Bike, Sur-Ron and Talaria. Send us a photo or video of the problem.
Related guides
These guides are for information only. If in doubt about a safety-critical part (brakes, steering, wheels), have a professional do the work. Always follow the manufacturer's manual.