Suspension break-in - why your new bike changes after 5 hours

What actually breaks in

Fresh suspension is artificially harsh and then artificially soft: seals and bushings bed in (friction drops sharply over the first 2-3 hours), shim stacks seat, and springs take their initial set (quality springs settle up to ~1% of free height - that alone moves sag a few mm). Source: Click Suspension spring physics - high; bedding-in timeline: tuner consensus - medium.

The documented effect (real numbers)

Keefer on the 2025 KTM 450 SX-F: the stock setting (10.5 bar, comp 12) was right when new but "once broken in (post 6-7 engine hours) this setting was too soft for most" - the tested baseline moved UP to 10.8 bar and 2 clicks firmer. Same pattern on the 250s: KTM ships 10.5 bar for break-in, 10.6+ after. If your new bike felt great on day one and vague in week three, this is why. Source: Keefer 450/250 MX baseline articles - high.

The workflow

1. Ride the first 2-3 hours on factory settings - do NOT chase the harshness of hour one with clickers.
2. After break-in: RE-CHECK SAG (the spring set has moved it), reset preload to target.
3. Air forks: re-check pressure cold before every ride anyway (ambient temperature swings move it substantially) - and expect to run ~0.1-0.3 bar more than the delivery setting after break-in. Source: Keefer + AER owner practice - medium-high.
4. Only NOW set your personal baseline (weight/skill adjustments, LAISA suggestion) and start your notes from here.

Rule

First impressions of new suspension are not data. Hour five is.