Grindstone Trail Running Festival - 50K 2025
The forecast arrives five days before the start.
Here you'll find the elevation profile, an estimated finish time based on your UTMB Index and details of the 5 aid stations to plan your nutrition and hydration segment by segment.
What's your time based on your UTMB?
Times estimated by the RAVIT model, learned from real ultra-trail finish times. Enter your UTMB Index (utmb.world) to get a personalized estimate.
Predicted race time based on your UTMB Index® · smoothed times achieved by runners at your level in past editions
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Cut-off times and crew - Grindstone Trail Running Festival - 50K · 2025
Data from the official race rules, checked for every edition. The race rules prevail. Positions are interpolated along the GPX track and are a guide, not official course marking.
What you'll find at each aid station
| Product | Lick Run 1km 9.2 | Wolf Ridgekm 18.6 | Sand Springkm 34.2 | Lick Run 2km 45.2 | Finishkm 52.3 |
|---|---|---|---|---|---|
| Water | available | available | available | available | available |
| Brand products · Näak | available | available | available | unavailable | unavailable |
| Hot meal | unavailable | unavailable | unavailable | available | available |
La feuille de ton assistance pour Grindstone Trail Running Festival - 50K · 2025
L'assistance n'est autorisée sur aucun poste de cette course.
Elevation profile
The course and its aid stations
Grindstone Trail Running Festival - 50K: times, aid-station stops and fuelling needs by UTMB® Index
Between a UTMB® Index of 500 and 800, the estimated finish time on this race runs from 6h42 to 4h13. These times include aid-station stops: they come from real durations between two timing points, and this race's timing does not measure stops separately.
Source| UTMB® Index | Estimated time | Night hours | Carbs | Fluid | Sodium | Cut-off margin |
|---|---|---|---|---|---|---|
| 500 | 6h42 | — | 402 g | 4.7 L | 3,350 mg | +2h17 |
| 550 | 6h03 | — | 363 g | 4.2 L | 3,025 mg | +2h56 |
| 600 | 5h35 | — | 335 g | 3.9 L | 2,792 mg | +3h24 |
| 650 | 5h12 | — | 312 g | 3.6 L | 2,600 mg | +3h47 |
| 700 | 4h44 | — | 284 g | 3.3 L | 2,367 mg | +4h15 |
| 750 | 4h27 | — | 267 g | 3.1 L | 2,225 mg | +4h32 |
| 800 | 4h13 | — | 253 g | 3 L | 2,108 mg | +4h46 |
Figures based on 60 g of carbohydrate, 700 mL of fluid and 500 mg of sodium per hour, "average" preparation and mild conditions (15–25 °C). Above 25 °C, count on roughly 900 mL/h and 700 mg/h. Carbohydrate intake is trained: 60 g/h is a floor, 90 g/h assumes a glucose-fructose blend and a gut used to it.
Measured on the 2025 edition: the field checkpoint by checkpoint
275 starters, 12.7% DNF rate, 5 timed checkpoints.
| Segment | km | Median | Middle half | Measured | Median passage | Still ranked |
|---|---|---|---|---|---|---|
| Natural Chimneys → Lick Run - 1 | 9.2 | 1 h 01 | 55 min – 1 h 07 | 274 | 1 h 00 | 275 |
| Lick Run - 1 → Wolf Ridge | 18.6 | 1 h 16 | 1 h 09 – 1 h 23 | 269 | 2 h 15 | 270 |
| Wolf Ridge → Sand Springs | 34.3 | 2 h 36 | 2 h 16 – 2 h 53 | 268 | 4 h 48 | 268 |
| Sand Springs → Lick Run - 2 | 45.3 | 1 h 52 | 1 h 39 – 2 h 03 | 239 | 6 h 34 | 240 |
| Lick Run - 2 → Natural Chimneys | 52.3 | 53 min | 46 min – 59 min | 239 | 7 h 30 | 240 |
“Median passage” is elapsed time from the start, not a clock time: the clock time depends on the edition.
Where runners drop out. Sand Springs (28) · Lick Run - 1 (5) · Wolf Ridge (2) out of 35 total DNFs.
RAVIT record from the official timing of the 2025 edition, data from September 16, 2026.
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Grindstone Trail Running Festival - 50K over the years
Sources and method
- Time projection — times by UTMB Index are taken from the actual splits of runners in each level band on previous editions of this race, aid station stops included. No formula is used as long as these results exist.
- Trail nutrition — hourly targets for carbohydrate, fluid and sodium follow the commonly accepted ultra-endurance guidance. La Clinique du Coureur — Fuelling in trail running
- Course, aid stations and cut-offs — taken from the event's official rules, which prevail in case of any discrepancy. Official site — Grindstone Trail Running Festival - 50K
Weather for Grindstone Trail Running Festival - 50K
The weather for Grindstone Trail Running Festival - 50K will appear here as soon as the forecast models reach that date, around five days before the start: feels-like temperature, rain, snow, wind and storms, section by section and at your passage time.
Detailed weather for Grindstone Trail Running Festival - 50K, hour by hour on the courseFrequently asked questions
How many checkpoints?
Grindstone Trail Running Festival - 50K has 5 checkpoints: 5 aid stations. Details are in the two tables above.
What's the longest segment without aid?
The one leading to Sand Spring: 15.7 km and 0 m elevation gain. That's the one to load up for first.
How do I find the exact location of an aid station?
The Google Maps icon in the “Access” column opens the aid station's location: handy for planning your crew's routes.
What distance and elevation gain?
Grindstone Trail Running Festival - 50K is 52 km long with 1526 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 5h35 for Grindstone Trail Running Festival - 50K.
What's the weather forecast?
The weather for Grindstone Trail Running Festival - 50K will be published on this page around five days before the start, once the forecast models reach the race date. It will be detailed section by section: feels-like temperature, rain, snow, wind and storms.
Want to stack the odds in your favor for Grindstone Trail Running Festival - 50K?
In 2 minutes, RAVIT generates your complete plan: segment-by-segment time, carbs, water and sodium at every aid station, printable roadbook.
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