Test riding a true racing recumbent

[Balor]

Admittedly, if you hands block your view, they also somewhat block your head from incoming wind.
Of course, it depends on a lot of variables including side winds, and whether this is worth it depends on whether you:
a. Ride nothing but track.
b. Don't value your life .

 

[ed72]

Hand and arm position on bars like in this thread is pretty subtle in that small position changes can have significant changes in CdA. I am not so sure hands in front of the head is faster than lower.....more at shoulder level. It would also depend on the helmet, clothing, and bike setup. All very individual. I have done some aero field testing and a position that I would have sworn was faster surprisingly wasn't.

Edit: the one limitation that is hard to work around at least for me is trying to get the elbows out of the wind. It is all a set of tradeoffs.

 

[Balor]

This setup does exactly that - maybe not as much as gunners, but nearly so and without penalty of vision. I really liked despite non-tilting limitations.
Alternatively, you can try something like 'reverse cruzbike cockpit' I've did, but rotated 90 deg at you.

 

[bladderhead]

On an M1 the handlebar design is important because of aero and ability to steer. On a FWD MBB there is the added complication of using arm-strength. Some arm-positions are stronger than others.

 

[ed72]

On a FWD MBB it seems to me that one advantage is the ease with which the elbows can be brought into profile of the legs whereas this is not so easy on a tiller setup.

Does anyone have CdA data for this M1? RChung field testing? How fast is it?

Maria and Larry both seem to be down in the 0.145-0.160 range on the Cruz V20. Slippery for sure and certainly very practical. I try to study photos to learn better positioning. It would seem to me that a faster racing setup to try on a V20 would be narrow aero TT bars with etap buttons (not the big levers) and carbon TT brake levers. Aero profile bars. No gloves. Arm coverings. Might cut a lot of drag down.

For me, getting my elbows in has been a positioning challenge. When I get my railgun, there might be more room.

 

[Osiris]

So on the subject of handlebar design, this is the most recent computer model of a design I came up with. I've discussed it with Thom Ohlinger, who builds and races recumbents, and the resulting geometry reflects some of his own thinking with respect to grip angles and sound aerodynamics. Shifting gears is done with the the Di2 TT style buttons on the top of each grip. Due to the hyper-sensitivity of gunner bars, mechanical shifters were avoided; I want to be able to perform rapid gear shifts without the slightest change in hand position, and without creating any unintentional steering inputs.

On a FWD MBB it seems to me that one advantage is the ease with which the elbows can be brought into profile of the legs whereas this is not so easy on a tiller setup.

Does anyone have CdA data for this M1? RChung field testing? How fast is it?

Maria and Larry both seem to be down in the 0.145-0.160 range on the Cruz V20. Slippery for sure and certainly very practical. I try to study photos to learn better positioning. It would seem to me that a faster racing setup to try on a V20 would be narrow aero TT bars with etap buttons (not the big levers) and carbon TT brake levers. Aero profile bars. No gloves. Arm coverings. Might cut a lot of drag down.

For me, getting my elbows in has been a positioning challenge. When I get my railgun, there might be more room.

 

[Osiris]

On a FWD MBB it seems to me that one advantage is the ease with which the elbows can be brought into profile of the legs whereas this is not so easy on a tiller setup.

Does anyone have CdA data for this M1? RChung field testing? How fast is it?

No CdA data that I'm aware of, but if you do a search on Bentrider, you'll find some speed tests done by Sean Costin, showing that his M1 has a top speed approximately 2 mph faster than his M5 at the same power output. If I recall correctly, he also mentioned that he and some other M1 riders were able to cruise at around 30 mph for extended periods. I was very skeptical of that claim when I first read it, but having now ridden an M1, it seems entirely plausible. My M5 will blow the doors off my V20 when it comes to outright speed, so if the M1 is 2 mph faster than even the M5...

One thing I did notice is that it took me longer than expected to reach high speeds (25 mph+). It's uphill capabilities also failed to impress me. It seemed as if I was working much harder than I should be, and the resulting speed wasn't sufficient to capitalize on the M1's superb aerodynamics. My perception is that it's a phenomenally fast bent, but not a "quick" bent. It's just a theory for now, but the reason that it feels sluggish could be because of the difference in geometry, I'm simply not able to produce the high power numbers on it that I can on my V20.

Yesterday I rode a new trail that goes from Osteen all the way out to Titusville. It's newly paved, flat, and straight as an arrow, with almost no road crossings for 20 miles. That will be an ideal place to do some speed/power testing.

 

[ed72]

No CdA data that I'm aware of, but if you do a search on Bentrider, you'll find some speed tests done by Sean Costin, showing that his M1 has a top speed approximately 2 mph faster than his M5 at the same power output. If I recall correctly, he also mentioned that he and some other M1 riders were able to cruise at around 30 mph for extended periods. I was very skeptical of that claim when I first read it, but now ridden an M1, it seems entirely plausible. My M5 will blow the doors off my V20 when it comes to outright speed, so if the M1 is 2 mph faster than even the M5...

One thing I did notice is that it took me longer than expected to reach high speeds (25 mph+). It's uphill capabilities also failed to impress me. It seemed as if I was working much harder than I should be, and the resulting speed wasn't sufficient to capitalize on the M1's superb aerodynamics. My perception is that it's a phenomenally fast bent, but not a "quick" bent. It's just a theory for now, but the reason it feels sluggish could be because of the difference in geometry, I'm simply not able to produce the high power numbers on it that I can on my V20.

Yesterday I rode a new trail that goes from Osteen all the way out to Titusville. It's newly paved, flat, and straight as an arrow, with almost no road crossings for 20 miles. That will be an ideal place to do some speed/power testing.

Wow.

Let's say it takes me 250 watts to hold 29 mph and let's assume my CdA is 0.159 m2, an additional 2 mph would is about 7% more speed and therefore approximately 20% more power or alternatively one could lower the CdA down to 0.127 m2 to get the same 2mph (for free, sort of). Or, one could say I would only need about 215 watts to hold 29 mph on the M1. So, a respectable 235 watts would get me 30 mph on that hot rod. Wow. This would approximately represent a pretty serious advantage the M1 has over the M5 if the 2 mph estimate is accurate. My guess is that the advantage is closer to 2 km/h but down in such low numbers, the rider factor can't be forgotten

 

[ed72]

So on the subject of handlebar design, this is the most recent computer model of a design I came up with. I've discussed it with Thom Ohlinger, who builds and races recumbents, and the resulting geometry reflects some of his own thinking with respect to grip angles and sound aerodynamics. Shifting gears is done with the the Di2 TT style buttons on the top of each grip. Due to the hyper-sensitivity of gunner bars, mechanical shifters were avoided; I want to be able to perform rapid gear shifts without the slightest change in hand position, and without creating any unintentional steering inputs.

I was going to steal my wife's stoker stem, cut down some old TT bars, and put some old mountain bike grips on. It would look similar to yours but even uglier. I have etap and several pairs of TT brake levers. I planned to rotate the other direction to free up space for the legs. Alas. I just can't afford the divorce.

 

[ed72]

I think I found the comparison, it wasn't on BROL. Three "problems" with the comparison. Different tires, wheels, and especially two different powetaps. My two powertap wheels differ by 4%. A front disk is certainly faster than a trispoke. I am not familiar with the tires used. Nonetheless, 0.155 for the M5 CHR and 0.120 for the NoCom sound about right although it is unclear whether the estimates were temperature, dewpoint, altitude, and atmospheric pressure corrected. What is also interesting is Sean's humbleness about his power output.

Blistering nonetheless.

One of my goals this year is cracking 20 minutes for 10 miles, it is going to be hard. I think my best so far is 20:40 ish but there are two hills and if I just lose the 40 pounds of blubber, I'm surely going to do it. If I had one of those really fast bikes I might crack 19 minutes.

http://www.wisil.recumbents.com/forums/topic.asp?TOPIC_ID=3986

 

[Osiris]

I think I found the comparison, it wasn't on BROL. Three "problems" with the comparison. Different tires, wheels, and especially two different powetaps. My two powertap wheels differ by 4%. A front disk is certainly faster than a trispoke. I am not familiar with the tires used. Nonetheless, 0.155 for the M5 CHR and 0.120 for the NoCom sound about right although it is unclear whether the estimates were temperature, dewpoint, altitude, and atmospheric pressure corrected. What is also interesting is Sean's humbleness about his power output.

Blistering nonetheless.

One of my goals this year is cracking 20 minutes for 10 miles, it is going to be hard. I think my best so far is 20:40 ish but there are two hills and if I just lose the 40 pounds of blubber, I'm surely going to do it. If I had one of those really fast bikes I might crack 19 minutes.

http://www.wisil.recumbents.com/forums/topic.asp?TOPIC_ID=3986

That's the article I was thinking of. Strange, because I could have sworn that Sean rides an M1, not a NoCom. I noticed that his speed/power numbers at 27 mph are considerably better than mine. That may be due to differences in our power meters, or he's done a lot of tweaking to go so fast. I'm using a Gatorskin rear tire, which is supposed to be one of the slowest rolling tires out there. Definitely not something I'd choose for racing.

My ultimate goal is to beat the local 10 mile TT record, which stands at 29 mph. Nobody has been able to touch it, even when drafting. Because my endurance is so poor, records like that should be out of my reach, but with the M1, who knows...

 

[Osiris]

I was going to steal my wife's stoker stem, cut down some old TT bars, and put some old mountain bike grips on. It would look similar to yours but even uglier. I have etap and several pairs of TT brake levers. I planned to rotate the other direction to free up space for the legs. Alas. I just can't afford the divorce.

I've been tinkering with the design, and made a few changes to the stem. My objective is to be able to route all the wiring through it, so I increased the diameter, cut two slots into the bottom, and modified the clamp. It was inspired by the design of my V20, which has two narrow slots underneath the handlebar clamp. I don't know what it's intended purpose is, but I passed the Di2 wires through it. Maybe that's what it was meant for.

 

[ed72]

That's the article I was thinking of. Strange, because I could have sworn that Sean rides an M1, not a NoCom. I noticed that his speed/power numbers at 27 mph are considerably better than mine. That may be due to differences in our power meters, or he's done a lot of tweaking to go so fast. I'm using a Gatorskin rear tire, which is supposed to be one of the slowest rolling tires out there. Definitely not something I'd choose for racing.

My ultimate goal is to beat the local 10 mile TT record, which stands at 29 mph. Nobody has been able to touch it, even when drafting. Because my endurance is so poor, records like that should be out of my reach, but with the M1, who knows...

Get a full sleeved skinsuit. Shave or put compression legs on. Mount GP5000 with latex tubes or GP TT. (I don't trust the Vittoria on a bent plus they wear out so fast). Helmets are another big area of improvement. No gloves.

 

[Osiris]

Get a full sleeved skinsuit. Shave or put compression legs on. Mount GP5000 with latex tubes or GP TT. (I don't trust the Vittoria on a bent plus they wear out so fast). Helmets are another big area of improvement. No gloves.

Is there a particular brand of skin suit you'd recommend? I've heard that some are "slipperier" than others.

Phil gave me several of his Schwalbe Ultremo racing tires. How do they compare to the GP5000?

As for the helmet, I've got the one Phil wore when setting his world records. At 30+ mph, you can really feel the lack of drag compared to a conventional helmet.

 

[Balor]

s for the helmet, I've got the one Phil wore when setting his world records.

Paraglider helmets seem slippery. Good protection too

 

[ed72]

Is there a particular brand of skin suit you'd recommend? I've heard that some are "slipperier" than others.

Phil gave me several of his Schwalbe Ultremo racing tires. How do they compare to the GP5000?

As for the helmet, I've got the one Phil wore when setting his world records. At 30+ mph, you can really feel the lack of drag compared to a conventional helmet.

Here is a comparison test. I have a Velotec and also an Assos. The Assos is much more comfortable but a little slower on me than the velotec. I expected the velotec to be a lot faster but I suspect the fabric is optimized for DF and might not be ideal for the bent....not sure. I also have a short sleeved Castelli San Remo (it is too tight right now) and a winter weight long sleeve and long legged Castelli. The Castelli's zip in front to the waist and make access easier if say used on a long race. The Castelli's generally test pretty well on all riders from my wind tunnel test readings and also various TT forums, BUT, there really aren't many recumbent riders that I know who have done extensive wind tunnel tests. I use RChung protocol. There is a huge difference at racing recumbent speed to wearing a normal loose jersey and bibs to a skinsuit...more of an effect than a good set of wheels. It isn't that noticeable at 20-23 mph but up around 28+ mph, it is very, very obvious. It also shows up in CdA VE testing (Chung).

No idea which one would work best for you...sorry

https://www.cyclingweekly.com/group-tests/best-skinsuits-for-cycling-360975

 

[ed72]

I forget your front wheel....it is a 406, right? I was thinking you had the bike like Larry with the larger wheel in the front.

I had a 406 front wheeled bent and tried the Ultremo and also Schwalbe Pro one tubeless. Those are probably your best choices although there is an unobtainum Michelin tire that is fast. I never did comparison testing because dismounting was such a pain. I suspected the Ultremo was faster but that would go against logic because famous people say it is the fastest. At the speeds you are going, the tire/rim interface is more important than a tiny bit of Crr. A 23 mm vs 25 mm can save you 10-25 watts on some rims at 30 mph whereas at 20 mph, the lower rolling resistence of a 25 mm wins for sure and of course a 28 is even better on real roads at the right pressure.

 

[3bs]

on my tica i have a bar set up very similar. best way to describe is a hampster bar with a slight flat at the tip of the V. then i have thumb shifters and small brake levers. it allows me to hold my elbows in tight to my sides so most everything is in behind my thighs. quite comfortable. i also thing it helps me psycologicly on fast down hills to create a stable position as speeds climb. schwab ones for tires schwab light tube

 

[Osiris]

I forget your front wheel....it is a 406, right? I was thinking you had the bike like Larry with the larger wheel in the front.

Yes, Larry traded his M1 for an Arrowhead, which has a 650 in front, as opposed to the 406 on the M1:

I had a 406 front wheeled bent and tried the Ultremo and also Schwalbe Pro one tubeless. Those are probably your best choices although there is an unobtainum Michelin tire that is fast. I never did comparison testing because dismounting was such a pain. I suspected the Ultremo was faster but that would go against logic because famous people say it is the fastest. At the speeds you are going, the tire/rim interface is more important than a tiny bit of Crr. A 23 mm vs 25 mm can save you 10-25 watts on some rims at 30 mph whereas at 20 mph, the lower rolling resistence of a 25 mm wins for sure and of course a 28 is even better on real roads at the right pressure.

I've got the Ultremo, so I might as well go with that for now. I wonder if they're going to make a GP5000 in size 406.

 

[Osiris]

Here is a comparison test. I have a Velotec and also an Assos. The Assos is much more comfortable but a little slower on me than the velotec. I expected the velotec to be a lot faster but I suspect the fabric is optimized for DF and might not be ideal for the bent....not sure. I also have a short sleeved Castelli San Remo (it is too tight right now) and a winter weight long sleeve and long legged Castelli. The Castelli's zip in front to the waist and make access easier if say used on a long race. The Castelli's generally test pretty well on all riders from my wind tunnel test readings and also various TT forums, BUT, there really aren't many recumbent riders that I know who have done extensive wind tunnel tests. I use RChung protocol. There is a huge difference at racing recumbent speed to wearing a normal loose jersey and bibs to a skinsuit...more of an effect than a good set of wheels. It isn't that noticeable at 20-23 mph but up around 28+ mph, it is very, very obvious. It also shows up in CdA VE testing (Chung).

No idea which one would work best for you...sorry

https://www.cyclingweekly.com/group-tests/best-skinsuits-for-cycling-360975

Very interesting read. My biggest potential problem with fit is the ripples running across my abdomen. It happens no matter which bent I'm on. Even my tightest race fit jerseys can't get rid of them. :-(