Wheel stiffness vs comfort: where ride feel comes from

The evidence here is moderate: real tests, but not many of them. 9 sources, listed at the end.

What the tests say

Most of the figures below come from a wheel maker (SILCA) and independent wheel-test sites, not peer-reviewed studies. The one peer-reviewed study is in Sports Engineering (Lépine, Champoux and Drouet).

Two different stiffnesses. Wheels have radial (vertical), lateral and torsional stiffness. Lateral stiffness, especially at the front, affects handling¹.

Vertically, wheels barely move. Roues Artisanales measured front wheels at about 1,500–2,500 N/mm, meaning it takes 150–250 kg to deflect them 1mm. That deformation is too small to matter for comfort². SILCA’s springs-in-series analysis puts the system in order:

• Wheels are 5–10 times stiffer than the frame and seatpost.
• The frame and seatpost are 2–5 times stiffer than the inflated tire.
• So the tire is “the softest spring in the entire bicycle system”³.

Because the softest spring dominates, halving wheel stiffness improved overall system compliance by “just under 2%”, which slight overinflation would cancel. The spread between the stiffest and softest frame categories was worth less than 1 bar of tire pressure³. A 2020 vibration study found tire filtering substantially reduced vibration above 10 Hz⁵. A 2025 field study found lower pressure and wider tires reduced vibration at the bars and seatpost⁶.

Partial counterpoint. A 2015 Sports Engineering study (Lépine, Champoux and Drouet) tested several bike components using a factorial design. It found the handlebar and fork dominated vibration at the hands, while “the wheels and frame” dominated at the buttocks⁴. It’s unclear from the published abstract whether tires were held constant, so wheel construction may matter more for seated comfort than the springs-in-series view suggests. That’s one study, and the question is unresolved.

What sets lateral stiffness. Damon Rinard’s tests (115 N lateral load) found⁷:

• Stiffness barely changes with spoke tension unless a spoke goes slack.
• Rear wheels were 40–60% more flexible than similar fronts, mainly because front hubs have wider flange spacing.
• 650c wheels were about 25% stiffer than 700c.
• Straight 2.0mm spokes were about 11% stiffer than 2.0/1.45mm butted spokes.
• Radial lacing (“elbows out”) was about 13% stiffer.
• An inflated tire added only 5–8%.

Wikipedia’s summary says more spoke crossings reduce lateral and radial stiffness, and that the angle between spokes and the wheel’s center plane (the bracing angle) is the most significant factor¹. Rinard also stresses that stiffness “is not wheel strength”⁷. Roues Artisanales suggests minimum lateral stiffness by rider weight: about 30 N/mm for 60–70 kg, 35 N/mm for 70–80 kg, and over 40 N/mm for riders above 80 kg. That’s a wheelbuilder’s guideline, not a study². Mavic engineers, quoted secondhand, said 29” MTB wheels were 39% less stiff than comparable 26” wheels⁸.

Carbon vs alloy, and spoke count. BikeRadar’s 2026 buyer’s guide calls carbon the standard for performance wheels where stiffness, weight and aero matter. It says higher spoke counts are stronger and more durable, with a weight and slight aero penalty⁹. The same guide says “the deeper a rim gets... the harsher the ride”⁹. That conflicts with SILCA’s analysis and Roues Artisanales’ vertical-stiffness data²³. No controlled test compares comfort between carbon and alloy rims.

The numbers

• Front wheel vertical stiffness: about 1,500–2,500 N/mm²
• Wheels are 5–10× stiffer than frame/seatpost, which is 2–5× stiffer than the tire, so wheels are roughly 10–50× stiffer than tires³
• Halving wheel stiffness improved system compliance by under 2%³
• Rear wheels 40–60% more flexible laterally than fronts⁷
• Radial lacing about 13% stiffer, and straight 2.0mm spokes about 11% stiffer than butted⁷
• Suggested minimum lateral stiffness: 30, 35 and 40+ N/mm for 60–70, 70–80 and 80+ kg riders²

Myths and disagreements

• “Deep carbon rims ride harsh.” Vertical wheel stiffness is dwarfed by the tire’s²³. A harsh ride might often trace back to tire choice or pressure. Controlled data is lacking either way⁹.
• “Tighter spokes = stiffer wheel.” Only if spokes were going slack⁷ (see).
• “Stiffer is stronger.” Stiffness and strength are different properties⁷.
• Disagreement: SILCA’s analysis says wheels barely affect comfort³. A peer-reviewed factorial study found wheels and frame dominated vibration at the buttocks⁴. Test setup and frequency range probably explain some of the gap.

What to change for comfort

• Chasing comfort? Change tire width and pressure first. It’s the largest, cheapest lever³⁶.
• Heavier riders or hard sprinters: prioritize lateral stiffness, especially at the rear. Look for wide flange spacing, adequate spoke count and fewer crosses¹²⁷.
• Judge “compliance” marketing skeptically unless it comes with test data³.
• If a wheel feels flexy, check spoke tension for slack spokes before blaming the rim⁷.

Sources