The longest you've ever ridden underground

[ufkacbln]

I have done the Standedge tunnel.... by canal boat

 

[Edwardoka]

You could ride the 27km LHC tunnel at CERN if you were a particle physicist. Too high a price to pay IMO.

"They're waiting for you Gordon... in the test... chamber"
"Ok, be there soon, just need to get my Strava KOM back"

 

[andrew_s]

I've done the Bielsa tunnel in the Pyrenees. 3070 m long, with a 5% gradient (downhill the way I did it, France to Spain).
Unlit at the time, but a nice man in a car took station behind and lit the way for us.

The most entertaining tunnel I've been through was the tunnel du Parpaillon.
Entrance at 2637 m, 520 m long, no lighting, so sunny outside that the bike lights were very nearly useless, unsurfaced and rough, with 6" deep puddles of icy water, and the odd remnant patch of ice from the previous winter.

 

[ianrauk]

I think the longest I've done is the Rotherhithe tunnel on a night ride. The exhaust fumes were pretty horrible but it was fun.

Indeed, highly enjoyable to ride through... but can do without the taste of petrol.

 

[ianrauk]

I used to commute through this one, sadly cyclists are now banned from it:

Where is that? And why banned if there is (what looks like) a cycle lane?

 

[NorthernDave]

I've ridden through the unlit haunted tunnel in Parlington Woods on NCN R66 - that's about 50yds, but it is curved and you can't see one end from the other...

 

[david k]

I've done the Mersey tunnel on a sportive twice, think it's at least a few miles long

 

[Edwardoka]

The most entertaining tunnel I've been through was the tunnel du Parpaillon.

That looks incredible. I guess I have to go back to France then

 

[slowmotion]

Indeed, highly enjoyable to ride through... but can do without the taste of petrol.

It's pretty humid down there too.

 

[subaqua]

I can't tell you as I would likely get sacked. It was good fun and done late one Saturday

 

[DaveReading]

Where is that? And why banned if there is (what looks like) a cycle lane?

Heathrow.

The small side tunnel is intended for taxis. For a time, bikes were allowed through as well, under sufferance (provided you didn't mind an impatient black cab up your backside) but cycling into the centre was banned last year when work started on the tunnels and is not expected to be reinstated.

 

[Tigerbiten]

Héðinsfjarðargöng, 7,100 m and 3,900 m, Route 76 on Iceland.

 

[slowmotion]

Has any stealth cyclist attempted the St Gotthard Base Tunnel? I would imagine that it's got an escape tunnel to sprint down. Pretty boring though.

https://en.wikipedia.org/wiki/Gotthard_Base_Tunnel

 

[Accy cyclist]

I have done the Standedge tunnel.... by canal boat

I watched that all the way through. When you think how many man hours it took to dig it,and then the brickwork as well!

Amazing.

 

[ufkacbln]

You could ride the 27km LHC tunnel at CERN if you were a particle physicist. Too high a price to pay IMO.

...... What difference do cycle helmets make?

If te two particles colliding were wearing helmets, would this make a difference?