The Best Gravel Challenge Near London: "GRVL Nychthemeron Chilterns” is a culmination of the very best gravel routes across the Chilterns and the Ridegeway.
Starting from Church Farm Café in Aldbury, this is a proper gravel adventure through some of the best riding country in the Chilterns. And despite feeling remote once you’re out on the trails, you’re only around 30 minutes by train from London to the Chilterns, making this one of the most accessible long-distance gravel challenges for London-based riders.
There are two versions to choose from:
12-hour challenge – 138km / approximately 1,880m climbing
24-hour challenge – 284km / approximately 3,340m climbing
Both routes have been designed as proper endurance gravel rides, taking you through the Chilterns and linking together gravel roads, tracks, trails and quieter roads. The 24-hour route is a serious undertaking, while the 12-hour version gives you a shorter but still demanding way into the NYCHTHEMERON.
And the best bit? You don’t have to race anyone. You just need to beat the clock.
Start Your Nychthemeron at Church Farm Café
The natural starting point for the Chilterns NYCHTHEMERON is Church Farm Café in Aldbury.
Situated in the heart of the Chiltern Hills, Church Farm has become a destination for cyclists, walkers and runners, making it the perfect place to meet your mates, grab a coffee and prepare for the challenge.
The café is located at Church Farm, Station Road, Aldbury, HP23 5RS, and is open seven days a week from 8:30am to 4pm. It's also the home to GRVL.
For London riders, the Chilterns are surprisingly accessible. You can get out of London by train and be riding through countryside, woodland and gravel trails surprisingly quickly. That makes this a genuine gravel challenge near London rather than an adventure that requires a full weekend away.
Choose Your Gravel Challenge: 12 or 24 Hours?
The beauty of the NYCHTHEMERON is that you get to choose how far you want to push yourself.
The 12-Hour Chilterns Gravel Challenge
The 12-hour gravel route is approximately 138km with 1,880m of climbing.
It’s a big day on the bike, but achievable for experienced gravel riders who are comfortable spending many hours in the saddle.
It gives you a taste of long-distance gravel without committing to riding through the entire night.
If you’re new to endurance riding, this is probably the place to start.
Plan your route, get a few mates together and see whether you can complete the Chilterns loop inside the 12-hour window.
The 24-Hour Chilterns Gravel Challenge
Then there is the big one.
The 24-hour Chilterns Gravel NYCHTHEMERON is approximately 284km with 3,340m of climbing.
This isn’t simply a longer bike ride. It’s an endurance adventure.
The route takes you deep into the Chilterns and beyond, with more than 280km of gravel riding and enough climbing to make the final stages very different from the first few hours.
You’ll ride through daylight. Then, if you’ve timed it that way, into darkness.
The temperature will change. The trails will change. Your legs will change.
And somewhere along the way you’ll discover that the hardest part isn’t necessarily the climbing. It’s keeping moving when you’re tired, hungry and still have plenty of kilometres ahead.
The 24-hour route is classified as a hard gravel ride on Komoot, with some sections where riders may need to push their bikes. That’s exactly what makes it a NYCHTHEMERON.
The Best Gravel Route Along the Ridgeway and Through the Chilterns
If you’re searching for the best gravel route near London, the Chilterns are an obvious place to start.
The area has everything you want from a proper gravel adventure: woodland tracks, farm lanes, bridleways, open countryside, steep climbs, fast descents and quiet sections where you can disappear from the traffic.
The Ridgeway is another major attraction for gravel riders.
Running across the Chiltern landscape, the Ridgeway and surrounding network of trails provide some of the UK’s best opportunities for linking together longer gravel adventures.
But this isn’t about simply following one famous trail from A to B.
The NYCHTHEMERON route is about connecting the best sections together into one continuous challenge.
If you’ve never explored the gravel trails in the Chilterns, this is a great excuse to do it.
This Isn’t a Gravel Race
NYCHTHEMERON means a complete day and night.
The GRVL challenge is designed around endurance rather than racing.
You choose the route. You choose when to ride. You choose who you ride with.
Then you have a continuous 12 or 24-hour window to complete it.
The idea is simple: take on the route, manage yourself, manage your kit and manage your time.
You can ride alone, but we’d recommend getting a few mates together.
Long-distance gravel is better when you’ve got someone beside you when the going gets tough.
The person who keeps you moving up the climb. The mate who finds the next café. And the one who convinces everyone that the next section is definitely easier.
Plan Your gravel Kit Carefully
A long gravel ride through the Chilterns needs more thought than your normal Sunday morning ride, especially if you’re taking on the 24-hour challenge.
Weather can change quickly and temperatures can drop significantly once the sun disappears. Staying warm and dry becomes increasingly important as the hours pass.
Your kit should include:
· Suitable gravel cycling clothing for the forecast
· A gilet or additional insulating layer
· Front and rear lights
· Spare batteries or reliable rechargeable lights
· Battery packs for your phone and GPS
· Food and energy supplies
· Plenty of hydration
· Basic bike tools and puncture repairs kit
· Pump or Co2 inflation system
· Phone and GPS navigation
· Emergency essentials
Don’t underestimate the importance of battery management.
A GPS computer is only useful if it still has power.
Your phone is only useful if it still has power.
And your lights are essential once darkness arrives.
For the 24-hour route, think about what you might need 12, 18 or even 22 hours into the ride, rather than what you’ll need when you leave Church Farm.
The GRVL 2L Hydration Pack
One of the easiest ways to carry the extra kit you’ll need for a NYCHTHEMERON is a small hydration pack.
The GRVL 2L Hydration Pack is designed specifically for gravel riding, with a lightweight design, adjustable four-point harness and 2-litre hydration bladder. It also has a large zipped compartment for the bladder and additional contents.
For a NYCHTHEMERON, it gives you a practical place to carry the things you don’t want stuffed into your jersey pockets.
The pack is small enough to ride comfortably with, but gives you space for a GRVL 3-season jacket, gilet, food and essential tools, while the 2-litre bladder provides enough water to keep you going for hours before you need to think about your next refill.
And that next refill could be at a café.
Because one of the best things about gravel riding is that stopping for coffee isn’t necessarily a bad thing. It’s part of the adventure.
What Do You Get for Completing the Challenge?
There is more than just bragging rights.
Complete a 24-hour NYCHTHEMERON route and you can claim:
· 50% off the GRVL NYCHTHEMERON Jersey
· 30% off a future GRVL order
· A unique NYCHTHEMERON woven patch
· A prize bundle featuring discounts and offers from GRVL partners including Tailfin, VANGO, Veloforte and Sportive.com.
Complete a 12-hour route and you can claim:
· 25% off the GRVL NYCHTHEMERON Jersey
· 20% off a future GRVL order
· A partner prize bundle featuring offers from Tailfin, VANGO, Veloforte and Sportive.com.
There’s something satisfying about finishing a 12 or 24-hour gravel challenge and having a physical badge to prove you’ve done it.
How to Enter the Chilterns NYCHTHEMERON
It’s simple.
1. Choose your challenge.
Pick the 12-hour or 24-hour Chilterns route.
2. Get your mates involved.
Share the challenge with at least two friends using #NYCHTHEMERON.
3. Plan your ride.
Check the weather, prepare your bike and work out your food, hydration, clothing and battery strategy.
4. Ride the route.
Complete the entire route within the continuous 12 or 24-hour window.
5. Submit your ride.
Send your Strava or Komoot activity to GRVL for verification.
Then claim your rewards.
The full NYCHTHEMERON challenge rules and all available routes can be found on the GRVL NYCHTHEMERON page.
