Loading Race For You
Loading page content.
entries openBog Dog Running
Grim Reaper 40
The Grim Reaper series
Next edition: Saturday, 22 May 2027 – Sunday, 23 May 2027Grimsthorpe Castle PE10 0LY, England
Four marked laps of the undulating Grimsthorpe Castle estate course on grass trail, woodland, limestone track, estate road and disused railway.
Start · approximate postcode area. Approximate race area. Check the organiser’s website for the exact start and race-day directions.
Location evidence
Preserved researched current-edition startLocation explicitly contains this postcode; no finish or organiser address was searched or substituted. Reuses completed source research; this pass extracted the public postcode from saved startLocation and does not claim a fresh event-page check. Applies only to listed editions. Geographic postcode centroid remains approximate. Postcodes.io postcode centroid: approximate postcode location, not exact start. Apply only to listed editions where applicability is explicitly bounded.
Event/venue postcode: PE10 0LY
Location checked 2026-09-14.
Official race site (opens in a new tab)
Optional device-only history; never synced to your account. Shared-device users can leave it off.
Distance40 mi
Ascent671m*
Climb / km10.4m
Cutoff27h
Cutoff pace25:10/km
TechnicalityUnknown
Entry£90
FormatLooped
Next edition
22 May 2027 – 23 May 2027
This is the most relevant confirmed edition currently held for the permanent race family. Edition-specific facts should still be checked against the final organiser instructions.
Edition archive
This is the only edition currently stored for this race family. Earlier verified editions can be added without changing the permanent race URL.
Check the official race source (opens in a new tab)Race For You difficulty
3.6/ 10
Moderate
Moderate input evidence · 68% evidence coverage
The main recorded demands are balanced overall demands. Course difficulty and cutoff pressure describe different challenges: more approachable terrain can still require a demanding pace to beat the deadline. Neither score assesses your personal fitness, safety or readiness.
Scoring details and version
Difficulty V2's separate time-limit modifier adds 0.00 points here and is capped at 0.70; a broad limit cannot erase extreme intrinsic demand. This is independent of the public Cutoff Pressure V2 band. Evidence coverage describes the recorded inputs, not prediction accuracy or your likelihood of finishing.
Weather, conditions and individual preparation can change the real difficulty significantly.
How the score works Distance, weighted 30 percent3.5 out of 10
Climbing, weighted 25 percent2.2 out of 10
Technicality, weighted 15 percent5.5 out of 10
Accumulated burden, weighted 17 percent2.8 out of 10
Exposure & support, weighted 13 percent5.7 out of 10
Course analysis
What shapes this race
Expect forest trail that may change character in wet conditions.
trailforestroadmixed
Climbing density
10.4m per km
A more useful comparison than total ascent alone: it shows how consistently the course asks you to climb.
Cutoff analysis
Lower pressure
To finish inside 27h, the raw average required is 25:10 per kilometre (40:30 per mile), including every stop.
Raw pace25:10/km
PressureLower pressure
Cutoff pressure compares the published time limit with distance, ascent and verified course demands. Lower pressure does not mean the race is easy. Raw pace includes checkpoints, food stops, navigation errors and any sleep; it is not a pacing plan.
Who this suits
First ultra?
There is not enough verified information to assess first-ultra suitability yet.
Navigation
fully marked
The route is described as marked, but runners should still read the final race instructions.
Exposure & kit
unknown kit
Significant overnight running is likely for many entrants. Lighting, temperature management and sleep strategy can materially affect the outcome.
Personal race predictor
Will you make the cutoff?
Use a previous result to estimate a realistic range for Grim Reaper 40, your potential buffer and the biggest change in demand.
Practical detail
Support & logistics
StartGrimsthorpe Castle PE10 0LY
FinishGrimsthorpe Castle PE10 0LY
Support levelsemi-supported
Logistics are only shown where currently recorded. Confirm parking, transport, crew access and final aid-station plans with the organiser.
Latest verification
Trust the source, see the gaps.
Data PartialStarts 08:00 at Grimsthorpe Castle PE10 0LY. Official ascent is 550ft per lap; four official laps give 2,200ft × 0.3048 = 670.56m, stored as approximately 671m. Official date 22-23 May wins over partner copy that sometimes says 29 May.
- Successful source check
- 3 Sept 2026
- Catalogue record updated
- 3 Sept 2026
- Official source
- Available
Elevation is approximate or awaiting final confirmation.
Event details can change after a successful source check. Confirm the final route, kit, cutoff, price and entry terms directly with the organiser before entering or travelling.
Found something wrong?
Help keep this race accurate.
Wrong cutoff? Date changed? New course? Tell us what moved and include the official source if you have it.
Report an updateKeep exploring
Browse the race catalogue
Use explicit distance, place, date, terrain and format filters to compare current races.