Best Bike Split

Best Bike Split (BBS) is a race pacing planner for cyclists and triathletes, founded in 2013 by operations research PhD Ryan Cooper and Rich Harpel, acquired by TrainingPeaks in 2014, and bought back by its founders as an independent company in 2022. Its core engine is mathematical physics modeling: simulating aerodynamic drag (CdA), rolling resistance, gravity, and race-day weather to turn power profiles and course files into per-segment optimized variable-power race plans. 150K+ members and 250K+ race plans worldwide, with adoption by WorldTour teams including Lidl-Trek and EF Education-EasyPost.

Core Features

• Race time prediction: a physics engine solves aerodynamic drag, rolling resistance, and gravity forces; official accuracy of about 2–3% with accurate inputs
• Variable-power pacing: computes optimal power targets for every climb, descent, and flat segment (NP/IF/TSS three models) rather than a simple FTP percentage
• AI Assistant: a GPT-3.5/4-based Q&A assistant answering race plan, training, and nutrition questions (premium tiers)
• AI Workout Builder: generates personalized structured training plans from natural-language prompts (premium tiers)
• Course and weather modeling: Course Builder auto-detects bridges, tunnels, and road surfaces; multi-point weather forecasts along the course and fine-tuned Crr
• Device ecosystem: full integration with Garmin/Wahoo ELEMNT/Karoo/TrainingPeaks/Zwift; plans go straight to the head unit for real-time execution

Pricing Free tier (1 race plan + basic analytics); Athlete $19/month or $119/year (about $10/month); Coach $49/month or $299/year; Athlete Plus/Coach Lite tiers at $149/year. AI features are included in all premium tiers, and the free tier needs no credit card.

Who It's For Best for: serious triathletes with power meters (Ironman/70.3), time trialists, road/Gravel riders, plus coaches managing multiple athletes and professional teams. Less suitable: recreational riders without power meters and purely indoor casual users — the feature set is over-provisioned for them.

Strengths and Weaknesses Strengths: physics modeling is the de facto standard in the race-pacing niche, with heavily battle-tested prediction accuracy (TJ Tollakson planned 279W and rode 278W to a record; the 2014 world championship prediction for Wiggins was off by only about 9 seconds), INFORMS Edelman Award recognition, and thorough ecosystem integration. Weaknesses: steep learning curve (you need to understand FTP/CdA/TSS/NP), predictions depend on input quality and drift when weather changes suddenly, $119–$299/year pricing is high, coverage is limited to cycling segments, and there is no native app.

AI Authenticity Note The core engine is mathematical physics modeling and optimization algorithms, not machine learning or large models — moderate-to-low AI content. The confirmed AI features are premium paid modules: AI Assistant (late 2023, GPT-3.5/4) and AI Workout Builder (March 2024). The accurate framing is 'physics modeling first, AI as an add-on.'

Risk Notes Subscriptions auto-renew by default, there are no refunds on termination whether active or passive, the liability cap is low (1 month's fees or $10), and jurisdiction is forced to Austin, Texas; uploaded content is granted a perpetual royalty-free license; the service collects heart rate, FTP, and weight data but is not bound by HIPAA. Predictions are not medical advice — on race day adjust for fueling, traffic, and how your body feels rather than executing the plan mechanically.