tag:blogger.com,1999:blog-3052588339740303416.post8643589112952420283..comments2023-05-31T11:18:01.609-04:00Comments on The Velomobile Observer: EfficiencyLuc On The Gohttp://www.blogger.com/profile/06270789105989269682noreply@blogger.comBlogger15125tag:blogger.com,1999:blog-3052588339740303416.post-36938240822934892042017-05-25T07:59:54.872-04:002017-05-25T07:59:54.872-04:00Thanks Robert, I did not mention wheel spoke cover...Thanks Robert, I did not mention wheel spoke covers that are especially important for open wheel velomobiles. I don't know how much of a gain is made when the velomobile has covered wheels wells like the Quest or even for the rear wheel. There must be one but I have not seen any report on the subject. As you mentioned, having covers makes it much more difficult to put air in the tires. I actually remove the front wheels of the DF to put air in my tires instead of trying to find the valve and put the pump head on the hidden valve. Luc On The Gohttps://www.blogger.com/profile/06270789105989269682noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-29988403469106524652017-05-25T04:48:28.512-04:002017-05-25T04:48:28.512-04:00I use canvas covers on the rear wheel of my WAW wh...I use canvas covers on the rear wheel of my WAW when wanting to be - or feel - faster. The idea is of course that the many round spokes move around in the rear wheel well with enough speed to cause drag. Wheel covers should to some extent prevent some of that "internal" drag. In every day use, I have however removed one of the covers in order to have better access to the valve. I also have canvas covers on the inside of the front wheels (for the same reason). A couple of years ago I also got wheel house covers - or "wheel pants" - for the WAW. Haven't done any measurable tests in order to see improvements - but there should theoretically be some effect I suppose.Robert Backhttps://www.blogger.com/profile/09079564438623143554noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-80672761272027107972017-04-28T23:21:32.536-04:002017-04-28T23:21:32.536-04:00I was riding my EVOX semi-recumbent today downtown...I was riding my EVOX semi-recumbent today downtown and into South Keys - and I must say that the pot holes are terrible - I want to ride my velo in the city - but the roads are terrible this year. I am scared that I will hit a pot hole and destroy the velo. I will have to stay on bike paths. demetriushttps://www.blogger.com/profile/06616879523176780543noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-90516293960891682332017-04-28T10:41:56.255-04:002017-04-28T10:41:56.255-04:00I'm not an expert in repairing fiber and would...I'm not an expert in repairing fiber and would let someone else take this. There have been numerous threads on BROL regarding fixing cracks and gelcoat and probably on recumbents.com.<br /><br />If you are in Ottawa there was a high performance carbon fiber shop in the west end near Carp. <br /><br />Regarding police stops if you live in Ottawa and eastern Ontario, the police is pretty cool about my velomobile, I was never stopped in about 6 years of riding. I don't ride downtown Ottawa very often. Across the river is another story but not too bad. The use of a motor is usually the first question and I have none so it isn't an issue but in your case they may want to probe further (see motor and see that you are restricted to the 30km/h or so that is permitted.<br /><br />Luc On The Gohttps://www.blogger.com/profile/06270789105989269682noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-15181891895561239232017-04-28T10:27:59.665-04:002017-04-28T10:27:59.665-04:00This is off-topic Luc but maybe you or one of your...This is off-topic Luc but maybe you or one of your readers can discuss the cleaning and waxing of velomobiles. And also the repair of small damage - like flaking fiberglass repair. I almost have my new velo on the road but I would like to give is a clean and high shine. I have looked over your archive briefly - but could not find any discussion of this topic. I was thinking of going to a boat shop - but would like your advice.<br /><br />I will be riding around downtown Ottawa soon. <br /><br />I also have a BionX 350 watt system I want to put into my Quest. This is a legal ebike system but will I have trouble with police stops anyway?<br /><br /><br />demetriushttps://www.blogger.com/profile/06616879523176780543noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-8184026695802055942017-04-24T19:35:21.280-04:002017-04-24T19:35:21.280-04:00Swordfish also use oil from glands in their sword ...Swordfish also use oil from glands in their sword snout to further reduce friction in water. Burst speeds up to 100 km/u through water are very impressive. <br /><br />Oil won't make us faster in air though...probably a very smooth wax coating might :-))Quezzzthttps://www.blogger.com/profile/13340009785237362388noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-16257613819129720152017-04-24T14:03:42.801-04:002017-04-24T14:03:42.801-04:00The velomobile is the rarest vehicle on the planet...The velomobile is the rarest vehicle on the planet. As you know - we are the 1 percent of the 1 percent of the 1 percent of the 1 percent of cyclists. <br /><br />There are 100 times more Rolls Royces than velomobiles!<br /><br />So it is a very small club - and I am very happy to have joined it.<br /><br />As for danger in cycling - I believe that if you do something for 2 hours a day - for 40 years - whether riding a bike or watching TV - you will probably die doing it. demetriushttps://www.blogger.com/profile/06616879523176780543noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-27876353724460627792017-04-24T13:13:33.761-04:002017-04-24T13:13:33.761-04:00Thank you for your contribution, you mention some ...Thank you for your contribution, you mention some good points and I did gloss over many details. I did not want to provide a thesis on velomobile aerodynamics, just an account of the best ways people have used to make their everyday velomobile faster.<br /><br />Again, I would not recommend removing mirrors for daily use because it would remove an important safety equipment but if people are racing they could consider removing one or two for an event. <br /><br />There are some riders who are exploring the use of cameras as a replacement with very small screens but there are several issues including the reverse display so the items appear on the correct side when looked at from the rider's seat and dealing with dirt.Luc On The Gohttps://www.blogger.com/profile/06270789105989269682noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-87160391192585654072017-04-24T13:01:00.108-04:002017-04-24T13:01:00.108-04:00Good to know that you will not take a hammer or dr...Good to know that you will not take a hammer or drill to your shell. Be careful in your experiments as elongated nose and tail not to mention any type of sail have major impact on your ability to ride a straight line except in the most favorable wind conditions. You would not want to end up in the ditch if a tractor-trailer passes next to you on the road. From experience it is a real danger with a regular velomobile under gusty conditions. Good luck!<br />Luc On The Gohttps://www.blogger.com/profile/06270789105989269682noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-17565219026084112642017-04-24T11:40:59.421-04:002017-04-24T11:40:59.421-04:00I always wondered if an aerospoke on rear wheels w...I always wondered if an aerospoke on rear wheels would bring anything as turbulences occurs also inside the wheel arch.<br />Also the mirros with aero cones can benefit the drag as a study showed that at last velomobil seminar ( i will try to find the link back).<br />Last, another point is stiffness. Without pants, the DF plays equals to the Milan thanks to his improved stiffness I think (also, smaller size).<br />One more think I have in mind: Air intakes are ok if you canalize the flux, and also let it out! See Milans and their multiple rear holes or the DF hood.<br />I will be at Spezi and share pictures and info on the fb group.<br />Nice work as usual Luc, thanks!Anonymoushttps://www.blogger.com/profile/14967202725051555143noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-7880351074260932582017-04-24T11:29:47.218-04:002017-04-24T11:29:47.218-04:00I would never touch my velomobile skin either - I ...I would never touch my velomobile skin either - I would rather carve out a piece of my own skin! <br /><br />My idea would be to introduce a foam dimpled skin onto the front of the velo - minimal weight and easy to remove. <br /><br />I have read enough about aerodynamics and fluid dynamics to know that I know nothing! But I am intrigued by the shape of marlins and sword fish - which have bodies radically elongated and with very pointy noses - but otherwise they are shaped close to velomobile dimentions. They can travel through the water at 80 kPH or more - in water! This shape makes me think that my velo should have a beak or nose shape. And a much more pronounced tail. <br /> This is another possible experiment that could be done non-destructively. Coroplast is cheap and light. <br /><br />My last thought is very radical but I know I will implement it - a tail propeller! Please google DWFTTW (down wind faster that tail wind) to see this real effect. Basically, a tail propeller - linked directly to a back wheel (wheel spins the propeller and the propeller spins the wheel) - will push against the wind in a way to multiply the effect of a tail wind by 3 times.<br /><br />Enjoy your spring cycling.<br />demetriushttps://www.blogger.com/profile/06616879523176780543noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-47826306631125563562017-04-24T11:04:33.702-04:002017-04-24T11:04:33.702-04:00There is pressure drag and friction drag. It looks...There is pressure drag and friction drag. It looks like faster velomobile models improved on pressure drag and record attempting "velomobiles" even more so. Mostly by means of reduced width and frontal surface. There is probably nothing to be gained on existing models without changing the model as you probably cannot make it smaller. ( lower or less width ) <br /><br />Then there is friction drag. Not necessary holes, seams and objects sticking out the streamline as mentioned are part of that. That is simply a matter of making the streamline surface as smooth as possible. Reducing hole size or preventing them ( hood over man hole ) as mentioned. Still a foam cover - without use of a plump cycle helmet (!) - will be hard to improve on (by much) with a hood. <br /><br />Such things are on par with everyday usability however. You either own a practical velomobile or a racer....not having anything sticking out of the streamline will prove to be rather hardcore...( mirrors must become camera's and a lightwight screen such as a mobile phone ) <br /><br />Interesting is dimple holes are "slow" (air)speed effective, and velomobiles are certainly within that speed range but i guess it is rather impractical to use on an existing velomobile model. Another thing is where to place them, research on that subject didn't use velomobiles yet. So i guess :-))<br /><br />Another more proven method is placing vortex generators to prevent the air layer to let go of the velomobile too early but (air)speed may be to low for a real difference. Where to place them exactly is another thing, i guess they should be on the broadest with part of the velomobile. Easy to find for a "fat" Quest...but in a DF ? <br /><br /><br /><br /><br /><br />Quezzzthttps://www.blogger.com/profile/13340009785237362388noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-37883385336763022282017-04-24T06:00:47.804-04:002017-04-24T06:00:47.804-04:00For dimples you would need to drill holes in your ...For dimples you would need to drill holes in your expensive velomobile and considered many are already built as a very light monocoque designs they would lose structural integrity doing that. Or apply a thick layer of material ( as the mythbusters did ) you can impress with dimple holes. Adding weight. <br /><br />Both a no go unless you can produce streamline hulls yourself to experiment with. It may be more reachable with experimenting with self made hoods, not touching the (expensive) velomobile itself. <br /><br />Still the Battle mountain teams could be locked into a certain direction of thinking ( improving things, but not too radical different from their predecessors ) to even consider such things. I know that in aircraft wings air pockets or micro turbulence designs are being used to get increased fuel efficiency. But those are incomparable (air)speeds, velomobiles operate at speeds where air resistance only begins to come into play while being hampered with very limited (human)power. <br /><br />Quezzzthttps://www.blogger.com/profile/13340009785237362388noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-56566153954420648972017-04-24T01:49:58.748-04:002017-04-24T01:49:58.748-04:00Well I will not be the one trying golf ball dimple...Well I will not be the one trying golf ball dimples on my velomobile. I don't know that they make a difference, I do know that Mythbuster tried them and may have seen improvements on a not so aerodynamically efficient car to begin with. If you look at the Battle Mountain streamliners, you will see that they are extremely smooth, no dimple there. The level of detail to make it to the record speed of 89mph is incredible including very advanced flow simulations. I would expect that they would have used dimples if they thought these would help. It is so precise that last year ETA scrubbed a run because they encountered an insect that disturbed the airflow and as a result of that splat they realized that they would be unable to reach the record setting speed. After a cleanup, the streamliner broke the speed record. There are so many things that could be improved on most velomobile that IMO would give a better bang for the buck than dimples.Luc On The Gohttps://www.blogger.com/profile/06270789105989269682noreply@blogger.comtag:blogger.com,1999:blog-3052588339740303416.post-56201548773816401542017-04-23T23:57:12.177-04:002017-04-23T23:57:12.177-04:00Have you ever thought of introducing dimples into ...Have you ever thought of introducing dimples into the front of a velo - to imitate a golf ball effect that introduces turbulence to cause a layer of air to cling to the shell - with the effect to reduce drag. I will have to try this on my velo. demetriushttps://www.blogger.com/profile/06616879523176780543noreply@blogger.com