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Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 05/21/2011 :  20:30:56  Show Profile  Reply with Quote
Hello World

This forum is for students competing in the ASME HPVC. Please introduce yourselves and your team, feel free to ask advice, post pictures, brag and discuss away!
(of course, if you want to stay anonymous, thats cool)

Victor Ragusila

Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 05/21/2011 :  20:36:03  Show Profile  Reply with Quote
Hi All

My name is Victor Ragusila, from the University of Toronto Human Powered Vehicle Design Team. (UofT HPVDT)
Our not-really-up-to-date-website http://hpvdt.skule.ca/
One of our past projects (Todd and Cam's baby) http://www.youtube.com/watch?v=0E77j1imdhQ

Victor Ragusila
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Jonathan Sanders
Starting Member

USA
11 Posts

Posted - 05/21/2011 :  21:42:37  Show Profile  Reply with Quote
Hello As Well World,

My name is Jonathan Sanders from the Missouri University of Science and Technology (Missouri S&T). Our website that also needs to be updated: http://humanpowered.mst.edu/
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W Hilgenberg
recumbent enthusiast

USA
283 Posts

Posted - 05/22/2011 :  00:47:17  Show Profile  Reply with Quote
Hey there,

My name is Will Hilgenberg and I am with the Cal Poly HPV team. Unfortunately we have a very out of date website http://hpv.calpoly.edu/ with a little bit better of a job done on facebook page: http://www.facebook.com/pages/Human-Powered-Vehicle-Cal-Poly-SLO/169181253111061
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Moorhead17
Starting Member

USA
36 Posts

Posted - 05/23/2011 :  05:08:05  Show Profile  Visit Moorhead17's Homepage  Reply with Quote
Hello all,

Most of you on here already know me, but I am the faculty advisor of the Rose-Hulman HPVT.

The team's website is http://hpvt.rose-hulman.edu/ (will receive an update in the near future)

AND

The Facebook page is http://www.facebook.com/RoseHulmanHPVT/ (up to date)

Our building plans are on haitus until next year, but we do hope to send some people to Waterford, Northbrook, and Xenia for HPRA racing.

Also, we have a standing offer to host HPVC design reports on our website. You may forward those to me (moorhead@rose-hulman.edu) or any of the team officers if you wish to partake in the spirit of information sharing and innovation. I personally look forward to the day when there are 40 teams just like Missouri, Toronto, Cal Poly, and Rose-Hulman at the ASME HPVC events. This forum is a great way to make that happen.

Good luck,

Prof. Moorhead
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Jonathan Sanders
Starting Member

USA
11 Posts

Posted - 05/23/2011 :  10:35:52  Show Profile  Reply with Quote
Our facebook page for those who are interested.

http://www.facebook.com/pages/Missouri-ST-Human-Powered-Vehicle-Team/297064810050
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Travis Schuh
Starting Member

USA
4 Posts

Posted - 05/24/2011 :  12:02:32  Show Profile  Visit Travis Schuh's Homepage  Reply with Quote
I figure I should introduce myself as well. I am with the Olin College team. You can find our website at http://hpv.olin.edu/ As seems to be the trend, it is in the process of being updated.

-Travis
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Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 05/24/2011 :  12:55:11  Show Profile  Reply with Quote
Hi Travis

Wanted to say congrats on sweeping the Speed Class! Your vehicle was awesome this year. I was wondering, did you machine the spindle for the custom BB? How did the custom bottom bracket feel, was it successful? I was considering doing a similar design next year, and wanted to learn from your approach. Did you machine your cranks or got them CNCed?

also, are you guys considering entering the utility class next year? You should join the utility party, speed bumps and landing gears are fun! :D

Victor
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Travis Schuh
Starting Member

USA
4 Posts

Posted - 05/24/2011 :  14:10:57  Show Profile  Visit Travis Schuh's Homepage  Reply with Quote
Victor,

Thanks! Congrats to you guys also on your impressive showing in the Unrestricted Class, you guys had an amazing bike! We did machine the cranks and spindle ourselves. Because we were using the new external cup bottom bracket style, we were able to machine a strong enough axle ourself without having to heat treat it. We did all of the machining ourself, although we started with a BB from Nova so we only had to thread one side. For the cranks, we used a 2 axis CNC mill. I find the reduced tread to be a more natural pedalling stance and prefer the custom cranks over the standard cranks on our previous bikes. I think the final number was that we dropped something like 2 inches from a standard crank set width and it allowed us to make them 160mm instead of the standard 170/175mm length. While this didn't directly reduce our frontal area because we had more room around the shoulders and elsewhere than necessary, it did allow us to have a more graceful taper on the front profile. The one thing to watch is that reducing the tread does reduce the amount of room that you have for the mechanisms between the rider's knees, like the steering column and drive train.

And we are definitely considering joining the utility class next year. We have not officially discussed it as a team, but I think the general consensus is that the added challenges would be fun and that we missed racing with all of you guys.

-Travis
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Jonathan Sanders
Starting Member

USA
11 Posts

Posted - 05/24/2011 :  20:40:16  Show Profile  Reply with Quote
quote:
Originally posted by Victor Ragusila

Hi Travis



also, are you guys considering entering the utility class next year? You should join the utility party, speed bumps and landing gears are fun! :D

Victor



I beg to differ. Speed bumps and landing gear are bastards. Our fried electrical systems (and maybe one of our broken forks) can attest to that.

I agree, Congrats to you and the rest Olin college for sweeping speed class.

Custom cranks or commercial reduced cranks for reduced length is a becoming an increasingly popular trend amongst the faired bikes since it helps reduce the frontal profile so much. We do it (and are considering going even shorter), you guys do it, as well as Victor and the rest of Toronto. the only real down side is the spinning at a higher RPM for the same power. I'll be running some power studies with a few of my riders for this coming year to see if there is any significant change in power output when changing the crank length.

I was talking to Todd and watching the rest of Toronto's riders and the reduced length didn't really seem to bother them or slow them down. Of course, from what I understand, your transmission was limited, so that may not be a fair statement.
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Dreamer
recumbent guru

USA
589 Posts

Posted - 05/24/2011 :  21:18:19  Show Profile  Reply with Quote
Jonathan,
quote:
I'll be running some power studies with a few of my riders for this coming year to see if there is any significant change in power output when changing the crank length.

James C. Martin published an excellent article titled "Muscle Power: The Interaction of Cycle Frequency and Shortening Velocity" that discussed, among other things, his findings on several crank lengths and power outputs based on his research copyrighted in 2007 by the American College of Sports Medicine that may be of interest as a good starting point.

Wishing success to all the teams on their projects!

Don
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W Hilgenberg
recumbent enthusiast

USA
283 Posts

Posted - 05/25/2011 :  18:34:46  Show Profile  Reply with Quote
Reducing the length of the cranks to what? 155mm?
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Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 05/25/2011 :  18:55:06  Show Profile  Reply with Quote
Vortex was calculated for cranks of 130mm...going any lower and you start to loose power. We were able to fit 140mm cranks however because we reduced our Q-factor from the designed one of 110mm to 98mm in the final part.

For BM we hope to get to 150mm by modifying the bike floor and lowering the Q-factor to 90mm. That would hopefully make the bike even more natural to ride.

It sometimes feels odd to ride with such low crank length, but after a number of laps I didnt notice it anymore. My legs are rather short tho, i usually fit 155-160mm cranks on my bikes, so some of the taller people might have issue with that.

Victor
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Jonathan Sanders
Starting Member

USA
11 Posts

Posted - 05/25/2011 :  18:58:23  Show Profile  Reply with Quote
Thanks Dreamer. I'll be sure to check it out.

I'm actually looking to reduce them to about 150mm. The past two years we have machined our cranks to be 165mm.
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Jonathan Sanders
Starting Member

USA
11 Posts

Posted - 05/25/2011 :  19:00:30  Show Profile  Reply with Quote
quote:
Originally posted by Victor Ragusila



It sometimes feels odd to ride with such low crank length, but after a number of laps I didnt notice it anymore. My legs are rather short tho, i usually fit 155-160mm cranks on my bikes, so some of the taller people might have issue with that.

Victor



Does it feel harder or does it just feel strange because of the reduced range of motion when pedaling with a smaller crank size?
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Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 05/25/2011 :  19:23:11  Show Profile  Reply with Quote
We only had 1 gear available, and that was pretty high, so it felt like we were pushing hard. We were definitely not in the correct RPM range for 140mm cranks. I will tell you more after the Michigan rally on June 12 as we will have all gears and more time to try out the bike on hills, corners etc

The 140mm cranks felt actually much better than 130s for me personally. None of our riders complained, but it might be that with so little time to ride, and mostly during the race, nobody really had time to concentrate and understand if the cranks felt good or not.

Victor
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Larry Lem
human power expert

South Sandwich Islands
2179 Posts

Posted - 05/25/2011 :  20:04:17  Show Profile  Reply with Quote
Short crankarms - it helps to live with them for awhile, stepping down in length by 5 mm / month so you acclimate and can make a fair judgment. Sinz BMX are fairly inexpensive for such testing (but flare out a lot). Switch to more-expensive straight crankarms after you decide on the final length.

Only you can decide the compromise you'll make in toebox area vs. power.

Larry Lem

Edited by - Larry Lem on 05/25/2011 20:04:36
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W Hilgenberg
recumbent enthusiast

USA
283 Posts

Posted - 05/26/2011 :  09:38:26  Show Profile  Reply with Quote
I think (and that is pure thought, because I haven't actually tested anything) that the benefit would depend largely on the background you come from. Most of the people on our team come from Mountain Bike racing backgrounds and ride singlespeeds more often than geared bikes. I know personally I have found it hard to adjust my fairly high gear lower cadence style to a little more of a spinning style even for road riding on 165mm cranks. It just feels foreign to me. That being said, while narrower cranks will get the front of the bike to be smaller, and therefore more likely to promote laminar flow (I know, it is a massive generalization) you still have to get the fairing around the riders shoulders so you won't be making that much of a change in the fairing shape.

Also, to Victor and Jon, how do you fit the number of different rider sizes in your bike? we typically utilize a moving seat to get the riders to a proper position but I don't see that happening too much with a tub bike as with Victor's design or in the seats with Jons design. What are you doing to alleviate that issue?
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Jonathan Sanders
Starting Member

USA
11 Posts

Posted - 05/26/2011 :  15:17:45  Show Profile  Reply with Quote
quote:
Originally posted by W Hilgenberg



Also, to Victor and Jon, how do you fit the number of different rider sizes in your bike? we typically utilize a moving seat to get the riders to a proper position but I don't see that happening too much with a tub bike as with Victor's design or in the seats with Jons design. What are you doing to alleviate that issue?



We actually measure all of the riders and base the fairing off of the largest parts of each rider. We also taking rider pictures with the riders on a bike with the same geometry as the one we are planning to build. We then take a picture with a slow shutter speed to see their total range of motion so that we know exactly how far each body part of each rider will move and how small we can make the fairing. There are limitations however. We try to allow as many to ride as possible, but some people we just can't. My main example is our 6' 6" member Ross. If we built the the fairing around him, it would just simply be too big and not very aerodynamic. As for our shorter members, what we have always done is had a "booster seat" made of foam so that it is easier for them to reach the pedals and see out the windshield. We have always want to incorporate items like an adjustable boom and/or an adjustable seat since they earn a fair amount of design points, but have always abandoned the idea in order to shave as much weight as possible. I'm really hoping to incorporate them this year with minimal weight gain. It shouldn't be too hard. I've got a design in mind but it's still in the works.
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Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 06/02/2011 :  08:06:49  Show Profile  Reply with Quote
We have two ways of fitting people. First we have a solidworks model of a human that is fairly accurate and can predict correct pedal movement. We use this to brainstorm ideas about the rider configuration.

second, when we have a rider position mostly figured out, we use a jig in which people can sit and pedal, and we measure the clearances required for pedaling, and we come up with a 3d envelope that cannot be touched, for the aero people to play with (shoulders are considered "squishable", so we have movable wooden sides to our jig, to see how much we can squish the shoulders)

To allow different size people, our first bike, ACE, had a movable BB and we would raise the seat height.
Vortex has a fixed BB, so we raise the hips of the shorter riders. This puts them in a relatively more layed back position, so they can reach further. We also move their shoulders forward to have them reach the steering (which is pretty much like varna's, with little tiller and narrow).

Our shortest riders are slightly shorter than 5ft and the tallest is 6.3 i think. The tallest rider barely fits, and his knees are currently interacting with his wrists, so we will have to play around with the steering to get another inch of clearance. The shortest needs a rather thick seat to move her hips up and shoulders forward.

During the race we have a system of modular foam seat pads that each rider throws in before their stint. This year we had a normal recumbent seat pad to to put on top of these modular pieces for comfort.

A moving carbon seat sounds like a good idea if i can figure out a very light and bulletproof way of building it. We are still looking to drop a lot of weight off the bike, and the foam pads are simple and light, so we might keep the same idea, we are still debating.

Victor
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Larry Lem
human power expert

South Sandwich Islands
2179 Posts

Posted - 06/02/2011 :  12:19:18  Show Profile  Reply with Quote
Note that the pedaling motion and required clearances are different under no-load versus full-load. And it can change even more as cadence increases (at the high pedaling speeds typically associated with relatively short crankarms).

Guess how I learned these things.

Larry Lem
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Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 06/02/2011 :  14:10:04  Show Profile  Reply with Quote
Indeed Larry, you are correct. Our jig has a training stand connected to it so one can put in power at the correct RPM (around 60-100). It did make a big difference, and Vortex is harder to pedal at low power, our heels tend to rub more.

Victor
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Larry Lem
human power expert

South Sandwich Islands
2179 Posts

Posted - 06/02/2011 :  14:40:16  Show Profile  Reply with Quote
If you're going to use 130 mm crankarms, you'd better be spinning to 120 rpm.
100 rpm max is for 170's.

Pedaling motion can also go to hell when you're in the middle of passing out between the 1000 m and 200 m signs. Whoops, I'm talking about Battle Mountain and you're probably talking about ASME racing.

Larry Lem

Edited by - Larry Lem on 06/02/2011 14:43:22
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Dreamer
recumbent guru

USA
589 Posts

Posted - 06/03/2011 :  22:36:08  Show Profile  Reply with Quote
quote:
A moving carbon seat sounds like a good idea if i can figure out a very light and bulletproof way of building it.


We made a mold, using a quick set concrete and sand mix, of each rider while they were in their pedaling position and bagged shell seats. After lining the cockpit with plastic We then used foam blocks taped under the seat to block the riders into position and then poured expanding 2 lb foam under the seat to fill the void and make a solid block that locked the seat into position inside the hull. Rider's heights varied from 6'2" to 5'5" but all were locked in at the correct knee clearance and crank distances for their riding style.

This likely works best with a monocoque hull but swapping seats is as easy as just pulling one seat out and dropping the next one in.
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Victor Ragusila
recumbent enthusiast

Canada
347 Posts

Posted - 06/08/2011 :  20:38:22  Show Profile  Reply with Quote
We did the same chair idea for some of our shorter riders. It seems to work ok, but we havent perfected it yet.

Larry, we designed Vortex mainly for Battle Mountain top speed, while being able to win ASME. We are not very experienced with streamliners, and i find our cadence is quite low, which makes it easier to control. Also my gearing is very high, so it makes cadences very low (Waterford hill should be interesting...). Right now it doesnt take a lot of mental effort to keep the pedal stroke correct, so i hope we can keep it decent in the last 1000m at BM, hopefully spinning at 120ish.

Right now our gear range is 13t-32t so about 250%. It is my goal next year to get it up to 500% so the same bike, unchanged, can win ASME and have enough top speed to run at BM. That should keep everyone happy, no matter their cadence.

Victor
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RossDaGigatornator
Starting Member

USA
2 Posts

Posted - 06/12/2011 :  20:10:06  Show Profile  Reply with Quote
Ross J. here from MS&T. I am that 6'6 rider whom i just need a hack saw to fit correctly on about any bike :)
No but really the foam idea is pretty good cause if you do it really really well you can keep correct geometry for each rider. Although... you are changing the position of the biggest part of the body, so my vote would be for an adjustable boom.

Too big? Bullsh!t. Just give me some Astrolube and I'll get in that bike!
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