Flat grade share
- Thames Meander Marathon (London)
- 82.8% Favoured
Thames Meander Marathon (London) vs Two Tunnels Railway Races Marathon
A data-led head-to-head using sourced race facts and available derived figures under one published methodology.
Data current as ofThames Meander Marathon (London) or Two Tunnels Railway Races Marathon — which comes out ahead?
Thames Meander Marathon (London) has the stronger available profile on flat grade share, course flatness and value score.
Route comparison snapshot
Thames Meander Marathon (London)
- Mapped route
- Held
- Elevation profile
- Held
- course flatness
- 0.4% Favoured
- flat grade share
- 82.8% Favoured
- lower ascent
- 274 m
- climbing density
- 6.5 m/km
- net elevation
- 0 m
- maximum grade
- 6.1%
Two Tunnels Railway Races Marathon
- Mapped route
- Held
- Elevation profile
- Held
- course flatness
- 2.0%
- flat grade share
- 71.5%
- lower ascent
- 415 m
- climbing density
- 9.8 m/km
- net elevation
- 2 m
- maximum grade
- 21.0%
| Metric | Thames Meander Marathon (London) | Two Tunnels Railway Races Marathon |
|---|---|---|
| Flat grade share | 82.8% ✓ | 71.5% |
| GAP factor (% slower than flat) | 0.4% ✓ | 2.0% |
| Uphill share | 9.4% | 16.6% |
| Steep-up share | 0.1% | 5.7% |
| Downhill share | 7.8% | 11.9% |
| Total ascent (m) | 274 m | 415 m |
| Climbing density (m/km) | 6.5 m/km | 9.8 m/km |
| Longest climb length (m) | 160 m | 1,920 m |
| Longest climb gain (m) | 7 m | 99 m |
| Longest climb average grade | 4.1% | 5.1% |
| Total descent (m) | 274 m | 413 m |
| Net elevation (m) | 0 m | 2 m |
| Max absolute grade | 6.1% | 21.0% |
| Start elevation (m) | 11 m | 41 m |
| Finish elevation (m) | 12 m | 43 m |
| Value | 80/100 ✓ | 79/100 |
| Scenic score | 89/100 ✓ | 77/100 |
| Conditions | 36/100 | 62/100 ✓ |
| Entry fee (GBP) | £55 ✓ | £60 |
| Lowest modelled true cost (GBP) | £185 ✓ | £190 |
GAP factor (% slower than flat)
- Thames Meander Marathon (London)
- 0.4% Favoured
Uphill share
Steep-up share
Downhill share
Total ascent (m)
Climbing density (m/km)
- Thames Meander Marathon (London)
- 6.5 m/km
Longest climb length (m)
Longest climb gain (m)
Longest climb average grade
Total descent (m)
Net elevation (m)
Max absolute grade
Start elevation (m)
Finish elevation (m)
Value
- Thames Meander Marathon (London)
- 80/100 Favoured
Scenic score
- Thames Meander Marathon (London)
- 89/100 Favoured
Conditions
- Two Tunnels Railway Races Marathon
- 62/100 Favoured
Entry fee (GBP)
- Thames Meander Marathon (London)
- £55 Favoured
Lowest modelled true cost (GBP)
- Thames Meander Marathon (London)
- £185 Favoured
Only metrics available for at least one side are shown. A ✓ marks the better value for each metric (higher-is-better aware). Scores are out of 100 when available. Ascent, climbing density, max absolute grade and median finish describe course or field context and are not marked as better or worse.
Race facts that change the decision
| Fact | Thames Meander Marathon (London) | Two Tunnels Railway Races Marathon |
|---|---|---|
| Schedule | Exact race date not confirmed. Event weekend starts 2026-08-09 (legacy event-level date). | Exact race date not confirmed. Event weekend starts 2026-08-16 (legacy event-level date). |
| Location | Barnes, London | Bath, South West |
| Actual distance | 42.2 km | 42.2 km |
| raceindex.org mapped route held | Held | Held |
| raceindex.org elevation profile held | Held | Held |
| Course type | Out And Back | Unavailable |
| Surface | Thames Path towpath, described as a runnable riverside route. | Unavailable |
| Laps | Unavailable | 2 |
| Elevation character | Flat | Gently Rolling |
| Terrain | Trail, Towpath, Mixed, Road | Mixed, Towpath, Trail |
| Scenery | Coastal, Waterfront, Parkland, Riverside, City | Parkland, Countryside, Riverside, City, Historic, Forest |
| Atmosphere | Scenic Tour, Community | Scenic Tour, Community |
| Technicality | Non Technical | Non Technical |
| Total ascent | 274 m | 415 m |
| Climbing density | 6.5 m/km | 9.8 m/km |
| Total descent | 274 m | 413 m |
| Net elevation | 0 m | 2 m |
| Max absolute grade | 6.1% | 21.0% |
| Flat grade share | 82.8% | 71.5% |
| GAP factor | 0.4% | 2.0% |
| Cutoff | 6:30:00 | Unavailable |
| Entry model | Open | Open |
| Entry fee | £55 | £60 |
| Lowest modelled true cost | £185 | £190 |
| Cost model origin | National Average | National Average |
| Measured course | Yes | Unavailable |
Schedule
- Thames Meander Marathon (London)
Exact race date not confirmed. Event weekend starts 2026-08-09 (legacy event-level date).
- Two Tunnels Railway Races Marathon
Exact race date not confirmed. Event weekend starts 2026-08-16 (legacy event-level date).
Location
- Thames Meander Marathon (London)
- Barnes, London
- Two Tunnels Railway Races Marathon
- Bath, South West
Actual distance
- Thames Meander Marathon (London)
- 42.2 km
- Two Tunnels Railway Races Marathon
- 42.2 km
raceindex.org mapped route held
- Thames Meander Marathon (London)
- Held
- Two Tunnels Railway Races Marathon
- Held
raceindex.org elevation profile held
- Thames Meander Marathon (London)
- Held
- Two Tunnels Railway Races Marathon
- Held
Course type
- Thames Meander Marathon (London)
- Out And Back
- Two Tunnels Railway Races Marathon
- Unavailable
Surface
- Thames Meander Marathon (London)
- Thames Path towpath, described as a runnable riverside route.
- Two Tunnels Railway Races Marathon
- Unavailable
Laps
- Thames Meander Marathon (London)
- Unavailable
- Two Tunnels Railway Races Marathon
- 2
Elevation character
- Thames Meander Marathon (London)
- Flat
- Two Tunnels Railway Races Marathon
- Gently Rolling
Terrain
- Thames Meander Marathon (London)
- Trail, Towpath, Mixed, Road
- Two Tunnels Railway Races Marathon
- Mixed, Towpath, Trail
Scenery
- Thames Meander Marathon (London)
- Coastal, Waterfront, Parkland, Riverside, City
- Two Tunnels Railway Races Marathon
- Parkland, Countryside, Riverside, City, Historic, Forest
Atmosphere
- Thames Meander Marathon (London)
- Scenic Tour, Community
- Two Tunnels Railway Races Marathon
- Scenic Tour, Community
Technicality
- Thames Meander Marathon (London)
- Non Technical
- Two Tunnels Railway Races Marathon
- Non Technical
Total ascent
- Thames Meander Marathon (London)
- 274 m
- Two Tunnels Railway Races Marathon
- 415 m
Climbing density
- Thames Meander Marathon (London)
- 6.5 m/km
- Two Tunnels Railway Races Marathon
- 9.8 m/km
Total descent
- Thames Meander Marathon (London)
- 274 m
- Two Tunnels Railway Races Marathon
- 413 m
Net elevation
- Thames Meander Marathon (London)
- 0 m
- Two Tunnels Railway Races Marathon
- 2 m
Max absolute grade
- Thames Meander Marathon (London)
- 6.1%
- Two Tunnels Railway Races Marathon
- 21.0%
Flat grade share
- Thames Meander Marathon (London)
- 82.8%
- Two Tunnels Railway Races Marathon
- 71.5%
GAP factor
- Thames Meander Marathon (London)
- 0.4%
- Two Tunnels Railway Races Marathon
- 2.0%
Cutoff
- Thames Meander Marathon (London)
- 6:30:00
- Two Tunnels Railway Races Marathon
- Unavailable
Entry model
- Thames Meander Marathon (London)
- Open
- Two Tunnels Railway Races Marathon
- Open
Entry fee
- Thames Meander Marathon (London)
- £55
- Two Tunnels Railway Races Marathon
- £60
Lowest modelled true cost
- Thames Meander Marathon (London)
- £185
- Two Tunnels Railway Races Marathon
- £190
Cost model origin
- Thames Meander Marathon (London)
- National Average
- Two Tunnels Railway Races Marathon
- National Average
Measured course
- Thames Meander Marathon (London)
- Yes
- Two Tunnels Railway Races Marathon
- Unavailable
Facts are shown only when they exist in the sourced race record; Not held means no sourced value is held for that race.
Common questions
Which is flatter, Thames Meander Marathon (London) or Two Tunnels Railway Races Marathon?
Thames Meander Marathon (London) has the lower GAP factor, making it the flatter course on our route model and more favourable on gradient alone.