Flat grade share
- Thames Meander Marathon (London)
- 82.8% Favoured
Two Tunnels Railway Races Marathon vs Thames Meander Marathon (London)
A data-led head-to-head using sourced race facts and available derived figures under one published methodology.
Data current as ofTwo Tunnels Railway Races Marathon or Thames Meander Marathon (London) — 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
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%
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%
| Metric | Two Tunnels Railway Races Marathon | Thames Meander Marathon (London) |
|---|---|---|
| Flat grade share | 71.5% | 82.8% ✓ |
| GAP factor (% slower than flat) | 2.0% | 0.4% ✓ |
| Uphill share | 16.6% | 9.4% |
| Steep-up share | 5.7% | 0.1% |
| Downhill share | 11.9% | 7.8% |
| Total ascent (m) | 415 m | 274 m |
| Climbing density (m/km) | 9.8 m/km | 6.5 m/km |
| Longest climb length (m) | 1,920 m | 160 m |
| Longest climb gain (m) | 99 m | 7 m |
| Longest climb average grade | 5.1% | 4.1% |
| Total descent (m) | 413 m | 274 m |
| Net elevation (m) | 2 m | 0 m |
| Max absolute grade | 21.0% | 6.1% |
| Start elevation (m) | 41 m | 11 m |
| Finish elevation (m) | 43 m | 12 m |
| Value | 79/100 | 80/100 ✓ |
| Scenic score | 77/100 | 89/100 ✓ |
| Conditions | 62/100 ✓ | 36/100 |
| Entry fee (GBP) | £60 | £55 ✓ |
| Lowest modelled true cost (GBP) | £190 | £185 ✓ |
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 | Two Tunnels Railway Races Marathon | Thames Meander Marathon (London) |
|---|---|---|
| Schedule | Exact race date not confirmed. Event weekend starts 2026-08-16 (legacy event-level date). | Exact race date not confirmed. Event weekend starts 2026-08-09 (legacy event-level date). |
| Location | Bath, South West | Barnes, London |
| Actual distance | 42.2 km | 42.2 km |
| raceindex.org mapped route held | Held | Held |
| raceindex.org elevation profile held | Held | Held |
| Course type | Unavailable | Out And Back |
| Surface | Unavailable | Thames Path towpath, described as a runnable riverside route. |
| Laps | 2 | Unavailable |
| Elevation character | Gently Rolling | Flat |
| Terrain | Mixed, Towpath, Trail | Trail, Towpath, Mixed, Road |
| Scenery | Parkland, Countryside, Riverside, City, Historic, Forest | Coastal, Waterfront, Parkland, Riverside, City |
| Atmosphere | Scenic Tour, Community | Scenic Tour, Community |
| Technicality | Non Technical | Non Technical |
| Total ascent | 415 m | 274 m |
| Climbing density | 9.8 m/km | 6.5 m/km |
| Total descent | 413 m | 274 m |
| Net elevation | 2 m | 0 m |
| Max absolute grade | 21.0% | 6.1% |
| Flat grade share | 71.5% | 82.8% |
| GAP factor | 2.0% | 0.4% |
| Cutoff | Unavailable | 6:30:00 |
| Entry model | Open | Open |
| Entry fee | £60 | £55 |
| Lowest modelled true cost | £190 | £185 |
| Cost model origin | National Average | National Average |
| Measured course | Unavailable | Yes |
Schedule
- Two Tunnels Railway Races Marathon
Exact race date not confirmed. Event weekend starts 2026-08-16 (legacy event-level date).
- Thames Meander Marathon (London)
Exact race date not confirmed. Event weekend starts 2026-08-09 (legacy event-level date).
Location
- Two Tunnels Railway Races Marathon
- Bath, South West
- Thames Meander Marathon (London)
- Barnes, London
Actual distance
- Two Tunnels Railway Races Marathon
- 42.2 km
- Thames Meander Marathon (London)
- 42.2 km
raceindex.org mapped route held
- Two Tunnels Railway Races Marathon
- Held
- Thames Meander Marathon (London)
- Held
raceindex.org elevation profile held
- Two Tunnels Railway Races Marathon
- Held
- Thames Meander Marathon (London)
- Held
Course type
- Two Tunnels Railway Races Marathon
- Unavailable
- Thames Meander Marathon (London)
- Out And Back
Surface
- Two Tunnels Railway Races Marathon
- Unavailable
- Thames Meander Marathon (London)
- Thames Path towpath, described as a runnable riverside route.
Laps
- Two Tunnels Railway Races Marathon
- 2
- Thames Meander Marathon (London)
- Unavailable
Elevation character
- Two Tunnels Railway Races Marathon
- Gently Rolling
- Thames Meander Marathon (London)
- Flat
Terrain
- Two Tunnels Railway Races Marathon
- Mixed, Towpath, Trail
- Thames Meander Marathon (London)
- Trail, Towpath, Mixed, Road
Scenery
- Two Tunnels Railway Races Marathon
- Parkland, Countryside, Riverside, City, Historic, Forest
- Thames Meander Marathon (London)
- Coastal, Waterfront, Parkland, Riverside, City
Atmosphere
- Two Tunnels Railway Races Marathon
- Scenic Tour, Community
- Thames Meander Marathon (London)
- Scenic Tour, Community
Technicality
- Two Tunnels Railway Races Marathon
- Non Technical
- Thames Meander Marathon (London)
- Non Technical
Total ascent
- Two Tunnels Railway Races Marathon
- 415 m
- Thames Meander Marathon (London)
- 274 m
Climbing density
- Two Tunnels Railway Races Marathon
- 9.8 m/km
- Thames Meander Marathon (London)
- 6.5 m/km
Total descent
- Two Tunnels Railway Races Marathon
- 413 m
- Thames Meander Marathon (London)
- 274 m
Net elevation
- Two Tunnels Railway Races Marathon
- 2 m
- Thames Meander Marathon (London)
- 0 m
Max absolute grade
- Two Tunnels Railway Races Marathon
- 21.0%
- Thames Meander Marathon (London)
- 6.1%
Flat grade share
- Two Tunnels Railway Races Marathon
- 71.5%
- Thames Meander Marathon (London)
- 82.8%
GAP factor
- Two Tunnels Railway Races Marathon
- 2.0%
- Thames Meander Marathon (London)
- 0.4%
Cutoff
- Two Tunnels Railway Races Marathon
- Unavailable
- Thames Meander Marathon (London)
- 6:30:00
Entry model
- Two Tunnels Railway Races Marathon
- Open
- Thames Meander Marathon (London)
- Open
Entry fee
- Two Tunnels Railway Races Marathon
- £60
- Thames Meander Marathon (London)
- £55
Lowest modelled true cost
- Two Tunnels Railway Races Marathon
- £190
- Thames Meander Marathon (London)
- £185
Cost model origin
- Two Tunnels Railway Races Marathon
- National Average
- Thames Meander Marathon (London)
- National Average
Measured course
- Two Tunnels Railway Races Marathon
- Unavailable
- Thames Meander Marathon (London)
- Yes
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, Two Tunnels Railway Races Marathon or Thames Meander Marathon (London)?
Thames Meander Marathon (London) has the lower GAP factor, making it the flatter course on our route model and more favourable on gradient alone.