Thor Dolphin Tail Box

TransAm

Well-Known Member
only because of his front wheel choice. The disc wheel and the tail box will have 10% of the effect you would imagine.
Maybe 1%. People have wild imaginations.

On my TT bike, I always rode with the disc (it was an Al clincher, so it worked as an everyday wheel). I can't tell you how many "experts" thought the rear disc made the bike un-ridable in the wind. Actually I preferred a windy day, especially when the wind was a quartering tailwind! I really enjoyed sailing the bike in the wind. You can't change the angle of attack directly since the wind and road direction are fixed. But you can vary the speed to find the sweet spot.
 

benphyr

Guru-me-not
I really enjoyed sailing the bike in the wind. You can't change the angle of attack directly since the wind and road direction are fixed. But you can vary the speed to find the sweet spot.
Please, if you can explain it simply in a way that a non-sailor can apply it that would be really cool. Would it work with a rear wheel skirt too? I have a half skirt on the top half of the rear of my QX100 and I feel the wind but I don't know how to use it to my benefit.

Cheers.
 

TransAm

Well-Known Member
Please, if you can explain it simply in a way that a non-sailor can apply it that would be really cool.

It's not going to be easy to explain how to sail a bike to someone who has not sailed before.

The basic art of sailing is to trim your sails so they deflect the wind optimally for the direction you want to go. On a sailboat, you can swing the boom at the bottom of the sail, relative to the keel at the bottom of the boat. Same thing for an ice boat, only you have runners (like long ice skates) rather than a keel to work against. For a bike, the sail (disc) is attached to the runner (tire), so they are locked at 0 degrees relative angle. You can't change that. Also you need to go where the road goes, so you can't change your heading (unless you take a different road).

The only thing you can adjust is your speed, which changes the angle of the relative (apparent) wind. So to trim your sail, you can only speed up or slow down. No sense slowing down. But if the wind angle is just right (crosswind from behind, which becomes a cross-headwind at speed), you can put in just a little extra effort, and get a lot of extra speed. Normally it's the other way around....
 

jond

Zen MBB Master
Please, if you can explain it simply in a way that a non-sailor can apply it that would be really cool. Would it work with a rear wheel skirt too? I have a half skirt on the top half of the rear of my QX100 and I feel the wind but I don't know how to use it to my benefit.

Cheers.

bake beans charging system with directional u tube as exhaust. Optional ignition system.
 

jond

Zen MBB Master
Trust me, only in tailwinds though. The engineer in me got it wrong 1 time and THAT was enough. This is the 1 area DF bikes are superior.

My my.......cricket and tennis are games in which to follow through. Never cycling.

I might well ask for more information.......
......................
however mentioning the superiority of a df bike to a cruzbike fanboy is giving me the shits.

Wearing a nappy pad on a df with ass hatchet is an acquired time honoured wipe of passage for the uninitiated ignoramus. ;). Lol

I love my df bikes too.....sometimes.

plumber/electrician what can you expect. Apologies to the faint of heart.
 

jond

Zen MBB Master
Please, if you can explain it simply in a way that a non-sailor can apply it that would be really cool. Would it work with a rear wheel skirt too? I have a half skirt on the top half of the rear of my QX100 and I feel the wind but I don't know how to use it to my benefit.

Cheers.

wearing skirts or half skirts on your cruzbike....... are you sure about being a non sailor.?
Perhaps a repressed Scotsman lurks within. Get thee a warm sporran laddie
 

ed72

Zen MBB Master
It's not going to be easy to explain how to sail a bike to someone who has not sailed before.

The basic art of sailing is to trim your sails so they deflect the wind optimally for the direction you want to go. On a sailboat, you can swing the boom at the bottom of the sail, relative to the keel at the bottom of the boat. Same thing for an ice boat, only you have runners (like long ice skates) rather than a keel to work against. For a bike, the sail (disc) is attached to the runner (tire), so they are locked at 0 degrees relative angle. You can't change that. Also you need to go where the road goes, so you can't change your heading (unless you take a different road).

The only thing you can adjust is your speed, which changes the angle of the relative (apparent) wind. So to trim your sail, you can only speed up or slow down. No sense slowing down. But if the wind angle is just right (crosswind from behind, which becomes a cross-headwind at speed), you can put in just a little extra effort, and get a lot of extra speed. Normally it's the other way around....
Very true

You get the sail effect on the rear disc but you can also reduce the apparent wind angle sufficiently that a deep front rimmed wheel won't be stalling anymore. Sometimes, just riding a little harder in certain cross winds can make you go a lot faster. I notice this effect especially with my 2 Spoke wheel. I tried to quantify the effect, the results I got were almost unbelievable. I first saw it on my Dupont Tri Spokes circa 1994. I wasn't the greatest racer but I understood the math well enough that an attack just before a corner where a cross wind would be coming, a small group could gutter the field and ride away.
 
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