Helmets & Gear
MIPS helmets explained
MIPS is a slip layer inside the helmet that lets the shell move a few millimeters against the head during an angled impact, reducing rotational force on the brain. It is a real addition rather than marketing — but it is not a substitute for correct fit, and a well-fitted plain helmet beats a loose MIPS one.
What it is
A standard helmet is designed for a straight-on impact: the foam crushes, and the energy that would have gone into the skull goes into the foam instead. Real crashes are rarely straight-on. A head usually hits at an angle, and part of the energy becomes rotation.
MIPS — Multi-directional Impact Protection System — is a low-friction layer between the head and the liner. Nutcase describes it as sliding 5 to 15 mm in any direction on impact, which is the mechanism: a few millimeters of slip absorbs some of the rotational energy that would otherwise reach the brain.
The alternatives
Bell fits Mips Evolve, which integrates the slip plane into the retention system rather than adding a separate liner — less weight, fewer parts. Lazer builds KinetiCore into the EPS foam itself, using controlled-crumple blocks to do the same job without a separate layer.
All three are addressing the same problem. We are not in a position to rank them against each other — we do not run impact tests, and we are not going to pretend otherwise.
Does a kid need it?
Our honest read: it is a worthwhile addition if it does not push you into a worse-fitting or heavier helmet, and it is far less important than the three things below.
1. That the helmet fits. A loose helmet rotates on the head regardless of what is inside it.
2. That your child wears it every ride. Compliance beats specification, every time.
3. That it is certified for their age. Under five, the CPSC extended-coverage requirement matters more than any slip layer.
What it costs
MIPS versions typically carry a price premium over the same helmet without it, and add a small amount of weight. Both are real. Whether that trade is worth it is a family decision, and we are not going to pretend there is a single correct answer.
What we would do
Buy the best-fitting helmet in your size band. If two fit equally well and one has a rotational system, take that one. Do not buy a MIPS helmet that fits worse than a non-MIPS one, and do not spend the helmet budget on MIPS if it means skipping the fitting process that actually determines whether it works.
The picks
Every figure below is the manufacturer's own published spec, linked to the page we read it from. We have not ridden these bikes and the cards say so — here is how we choose.
Quick picks — sorted by head size
| # | Product | Best for | Head | Price |
|---|---|---|---|---|
| 1 | 45–53 Top pickGiro Scamp MIPS II The XS covers a 45–49 cm head and carries the CPSC certification for age 1 and up with extended rear coverage — the combination most toddler helmets miss. | Toddlers and preschoolers | 45–53 cm | |
| 2 | 47–57 Bell Sidetrack II MIPS 320 g in youth size with a visor and Mips Evolve — the value pick once a child is past five and riding further than the driveway. | School-age riders | 47–57 cm | |
| 3 | 50–56 Lazer Nutz KinetiCore 250 g and 12 vents, with rotational protection built into the foam rather than added as a separate liner — the lightest helmet in this registry. | Hot-weather riding | 50–56 cm | |
| 4 | 48–56 Nutcase Little Nutty MIPS Toddler (48–52 cm) and Youth (52–56 cm) sizes with MIPS, in the graphics kids actually agree to wear — which is most of the battle. | The helmet they'll actually wear | 48–56 cm |
n/p = the manufacturer does not publish that figure. We do not fill in a number they never gave.
Top pick — Toddlers and preschoolers
Giro Scamp MIPS II
The XS covers a 45–49 cm head and carries the CPSC certification for age 1 and up with extended rear coverage — the combination most toddler helmets miss.
| Head size | 45–53 cm |
|---|---|
| Brakes | — |
| Frame | In-mold polycarbonate shell, MIPS liner |
| Brand says | XS is CPSC certified for age 1 and older; S for age 5 and older |
What works
- XS 45–49 cm, S 49–53 cm — two sizes across the whole toddler-to-kid range
- Extended rear coverage on the XS
- Roc Loc Jr. dial fit with a pinch-guard buckle
What doesn't
- MIPS versions cost more than the plain shell
- Dial fit systems can loosen and need re-checking
Hands-on status: Researched from published specs · Giro — Scamp MIPS II
#2 — School-age riders
Bell Sidetrack II MIPS
320 g in youth size with a visor and Mips Evolve — the value pick once a child is past five and riding further than the driveway.
| Head size | 47–57 cm |
|---|---|
| Brakes | — |
| Frame | In-mold polycarbonate shell, Mips Evolve |
| Brand says | CPSC certified for age 5 and older |
What works
- Universal Child 47–54 cm and Universal Youth 50–57 cm
- 320 g in size Y, light for a helmet with rotational protection
- Removable visor for trail riding
What doesn't
- CPSC certified for age 5 and older, so it is not a toddler helmet
- Universal sizing is less precise than two distinct shells
Hands-on status: Researched from published specs · Bell — Sidetrack II MIPS
#3 — Hot-weather riding
Lazer Nutz KinetiCore
250 g and 12 vents, with rotational protection built into the foam rather than added as a separate liner — the lightest helmet in this registry.
| Head size | 50–56 cm |
|---|---|
| Brakes | — |
| Frame | EPS with integrated KinetiCore rotational protection |
| Brand says | CPSC certified for age 5 and up |
What works
- 250 g published weight
- KinetiCore rotational protection integrated into the EPS
- 12 vents, which matters in summer
What doesn't
- One size, 50–56 cm — too big for a toddler
- EZ Fit auto-adjust gives less manual control than a dial
Hands-on status: Researched from published specs · Lazer — Nutz KinetiCore
#4 — The helmet they'll actually wear
Nutcase Little Nutty MIPS
Toddler (48–52 cm) and Youth (52–56 cm) sizes with MIPS, in the graphics kids actually agree to wear — which is most of the battle.
| Head size | 48–56 cm |
|---|---|
| Brakes | — |
| Frame | Hard outer shell, crumple-zone EPS, MIPS liner |
| Brand says | Complies with CPSC 16 CFR 1203 |
What works
- Two sizes cover 48–56 cm
- MIPS across the range
- Designs kids pick themselves, so it gets worn
What doesn't
- Skate-style shell runs warmer than a vented road shape
- Heavier than an in-mold helmet
Hands-on status: Researched from published specs · Nutcase — Little Nutty MIPS
Questions parents actually ask
01What is MIPS and does my kid need it?
MIPS is a low-friction layer that lets the helmet shell slide a few millimeters against the head in an angled impact, reducing rotational force. It is a genuine addition, but correct fit and consistent use matter more.
02Is a MIPS helmet worth the extra money?
If it does not compromise fit or push the helmet out of budget, yes. A well-fitted non-MIPS helmet beats a poorly fitted MIPS one.
03What is the difference between MIPS and KinetiCore?
MIPS adds a separate slip layer inside the helmet. Lazer's KinetiCore builds controlled-crumple blocks into the EPS foam itself. Both target rotational impact forces.
Sources
Read next
- Helmets & GearBest kids bike helmetsFive helmets, compared on head size and certification.
- Helmets & GearKids helmet size chartHead circumference to helmet size, in one table.
- Helmets & GearHow to fit a kids bike helmetFour steps, two minutes, and the shake test that proves it.
- Helmets & GearWhen to replace a kids bike helmetAfter an impact, after a growth spurt, after damage.