06/17/2026
ISR Announces Expansion of the 225 Tillotson Class to All ISR SnoCross Affiliates
Clarification As part of this change, 8-Year-Olds in the Transition Class will be discontinued .
They will be able to race in the new 225 Tillotson Class .
EAGLE RIVER, WI — International Snowmobile Racing (ISR) is pleased to announce the expansion of the successful 225 Tillotson Class to all ISR-affiliated SnoCross organizations beginning with the upcoming racing season.
Following a successful two-year trial period with the Canadian Snowcross Racing Association (CSRA), ISR has approved the class for use throughout the broader SnoCross community. Participating organizations are expected to include ISOC, Midwest Snocross, Northern Power Race Park/Michigan Snocross Series, SCMX, and other ISR SnoCross affiliates.
The 225 Tillotson Class was developed to provide racers 7 to 12 years of age and their families with an affordable and competitive entry-level SnoCross opportunity. Built around a primarily stock 200cc chassis package with limited modifications, the class focuses on controlling costs while maintaining competitive, exciting racing. Approved changes include the engine, exhaust system, and gearing as outlined in the ISR SnoCross Rulebook.
Throughout the CSRA evaluation period, the class demonstrated strong participation, close racing, and a cost-effective platform for young racers transitioning into SnoCross competition.
"This class has exceeded expectations during its evaluation period," said ISR officials. "The participation numbers, affordability, and level of competition demonstrated during the CSRA trial have shown that this is a positive step for the future of our sport. We are excited to offer the same opportunity across all ISR SnoCross affiliates."
As part of this transition, 8-Year-Olds in the Transition Class will be discontinued .
They will be able to race in the new 225 Tillotson Class .
ISR believes the addition of the 225 Tillotson Class will strengthen the sport's developmental ladder, create new opportunities for young racers, and help continue the growth of SnoCross racing throughout North America.
"We are very excited to move this forward and hope the entire racing community embraces these changes. This class provides another opportunity for young racers and families to become involved in SnoCross while keeping costs manageable and competition strong."
225 Tillotson Class – Exceptions to 200 Stock Class Rules
The 225 Tillotson Class shall conform to all ISR 200 Stock Class rules unless specifically modified below.
ENGINE
Required engine: TPP225RS-02 Tillotson sealed engine equipped with the approved snow conversion package (Part -2-RK).
Recoil rope must exit through the OEM location.
DRIVE
OEM primary and secondary clutch springs and rollers must remain stock.
14-gram primary rollers are prohibited.
Drive gearing may be changed from the stock 2.95 ratio to approved aftermarket 2.38 ratio gears (Part ).
SKI SUSPENSION & STEERING
Handlebars and handlebar risers may be replaced with commercially available components.
A handlebar pad is mandatory.
Skis may be changed from stock.
Aftermarket front shocks are prohibited.
Ski widening devices are prohibited.
TRACK SUSPENSION
OEM rear shock must be retained.
Aftermarket rear shocks are prohibited.
Dual front limiter straps are permitted.
IGNITION & ELECTRICAL
OEM wiring harness may be removed.
Tether switch and kill switch must remain installed and functional.
An optional rechargeable battery may be used solely to power the brake light and OEM handlebar warmers.
Battery must be securely fastened to the belly pan.
FRAME & BODY
Bulkhead reinforcement is permitted.
Tunnel reinforcement is permitted.
Complete technical specifications and class rules are available through the ISR SnoCross Rulebook.
ISR Affiliate Resources
ISR SnoCross Rules: https://isrracing.org/rules/snow-cross/
ISR: https://isrracing.org
ISOC / AMSOIL Championship Snocross: https://snocross.com
Midwest Snocross: https://midwestsnocross.com
Northern Power Race Park / Michigan Snocross Series: https://northernpowerracepark.com
SCMX Snocross: https://scmxsnocross.com
CSRA Snocross: https://csrasnocross.com
