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Post by trikesrule on May 20, 2007 11:02:19 GMT
Click on pics to enlarge. This is me at Baskerville Raceway awaiting the start of the 5 man g/f which I duly won first time out. Whats with my helmet I hear u ask. Here in Australia we had a lot of people raising the red flag to wearing heavy m/c helmets because of the weight adding to slow speed impacts. So after having no reply from the international body u guys are affiliated with we the Southern Tasmania Billycart Group www.southerntasbillycart.com did a heap of research with Standards International thru Stds Aust. The short of it is we have to wear full face helmets also but lighter versions like Bmx Speed Ski Street Luge Hang Glider lids even the lighter versions of mc lids fair better in a slow speed impact that we would probably have on a G-Bike. A slow speed impact is regarded as below 50-60 mph. Subsequently I can't use that aero Lazer helmet anymore on my g-bike. Saw John Richards iron bike the other day on GBA and I've seen the pics of Wills alloy flipped frame. I tried flipping the frame. Wasn't happy with the way it went so I changed it back to right way up. Don't be surprised if that frame of yours Will flexs around a fair bit. If it's not 6061T6 it's not really stiff enough to do the job. Keep an eye on the frame for cracking for in time to come as Alloy work hardens it becomes brittle and drops in strength. I don't use disc brakes as I don't need them. There are other good calipers and pads that work well + discs are very un-aero but a lot people in the USA and Spain use them. Anyway pop in from time to time on the www.southerntasbillycart.com website and say gidday. I'm doing a promo run at Baskerville 06 Tas Titles. The one behind me with big hairy bollocks and the camera is Steve Daddo from Queensland Australia. Steve races regularly overseas and his only complaint doing the filming was 'man I came round the corner and you were gone just gone'. We've got the State Titles in about four weeks and the ol girl is going a fair bit harder now.......trikes
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Post by John Richards on May 21, 2007 19:00:26 GMT
hello scott. my name is john richards, i built the bike pictured on the gba site and it is made from plain old mild steel! but i have never "flipped" a frame,all of our bikes have been purpose made. the helmet regulation we at the ukgsa run to is the same as igsa regs. i come from a motorcycle racing background and personally feel that these regulations are right and proper. ukgsa officials also do not allow their competitors to compete without full leathers. these safety systems have saved lives from crashes in excess of 150mph so speeds less than half of that shouldnt mean less than half the protection, cheers john
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Post by trikesrule on May 21, 2007 21:26:30 GMT
Hi John My mistake I thought I saw a pic of a flipped alloy framed bike. Nice to see you guys have a whole series of race meetings planned. We have an insurance / Police / Council issues here. If we can't get Police permission the event just dosen't go ahead. Bit of a downer that but we have found a way around it by conducting meetings at a local race track - Baskerville Raceway. But that costs in track rental. Theres a big Gravity Race Meet planned and approved for Bathurst early next year. Bit of a downer that as I have to travel for two days to get there. Hopefully I will have my new composite bike up and running by then. I like the lok of your mild steel bike it looks great. Had it on a set of scales yet? Do you have a wheel bearing brand you can recommend? I was using SKF but lately I've found the un-named japanese bearings that come std in the Velocity Hubs that I like are a little faster (I've heard Japanese steel is pretty good). The only class of gravity racing we can use ceramics here is in G-Bikes. Thats because it's an international class.........trikes
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Post by trikesrule on Jul 5, 2007 10:19:04 GMT
I thought it about time I posted some pics of where I'm at with my steel Gravity Bike development mule. Click on the pics to enlarge. You can see the Kneelers the most comfy I've made so far. The pad / supports are the elbow rests from Transx Aero Bars (2nd hand) that I won on Ebay. Presently they are only zipped tied into place but they will be welded on soon. Up top I've installed a belly lower chest support (thanks for the idea FastOne). This is made from Harley Davidson windscreen (polycarbonate) that I got for free from one of the local bike shops. Had a few scratches on it when some dude dropped his Harley. These two items installed in the right spots have transformed the comfort and controllability of this bike. Next we have the work of art (read frustrating/fiddly) handle bar set up These are a combination of many pieces and are adjustable in many directions. The adjusters are from the Transx Aero bars while the curvy handle bars are simply from 22mm drop down bars (racing bars). The excess on the horizontal bar ends will be trimmed along with the kneeler bar. This set up could be tidied a little by replacing the levers with Aero Levers which plug in the bar ends thus reducing the bar mass a little and concealing the cables inside the bars So basically nearly one years development (including crash repairs) has yielded over 13 kmh at my local test track and the bike is actually pleasant to ride. No longer do I have to run the gauntlet with the family jewels cause I've also got a new seat which was fabricated from a curved Mazda B1600 chassis cross support. This is covered with 20mm Closed Cell Foam. It turned out to be just the right shape for my nether regions. With a bit more fiddling I'll get my elbows back till they nearly touch my knees. A big gap in this area definitely is not the way to go. I found better flow in this area by closing this gap and this translated to good speed increases and time decreases at the test track. The aim with my back is to get a flat back or have the air bend less than nine degrees. This is the best I've done so far. Next thing is to get the bike back on the scales then build a small front and rear fairing to hold the race #. More later.......
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Post by John Richards on Jul 5, 2007 16:59:11 GMT
hey scott! looks like your development bike is coming along well. your tuck is not unlike the one that steve lambie (chops) and myself have come to. one difference you might like to try is re-positioning your foot pegs in order to allow the top side of your foot to become the resting point thus further reducing drag. it feels a little weird at first but soon becomes normal, some might say a bit like drinking with me and chops!! cheers john
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Post by trikesrule on Jul 5, 2007 21:35:28 GMT
Hi ya John I'll take another look in my 'tunnel' at feet position. Last time I looked at the foot area there wasn't much of a gain cause I didn't have kneelers and my knees were placing my feet in 'shadow' so as to speak. The composite bike I'm building will encompass most of the development stuff from the steel bike (eventually) it dosen't have a feet area problem at all as the feet and lower leg area is not in the air stream.
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Post by trikesrule on Jul 7, 2007 22:40:12 GMT
JR I just had had another look at your scammo pics and I see what you mean. C the blue plates on my front forks well they have reduced the trail to Zero. Because I run zero trail I need to 'press' the bars hence my toes being on the front of the pegs. I also understand why you've chosen the your current 'tuck' and it looks pretty functional. If I may add something I've found thats it's more important from an aero perspective to aim at a flat back. I'm not there yet with my steel bike but pics taken by my wife show me I've achieved that with my composite bike. Finding a flat back pozy is dictated by seat height but then if one changes the seat height everything else like kneeler's / pegs / handle bar / brake levers / visor open angle / weight bias changes also. She's a real Catch 22 for sure. BUT in short I will be looking at improving the feet / peg shape area (need to do something about those darn laces too). I reckon some aero pegs (or aero foot rests?) would be the go here. Fun isn't it.........trikes
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Post by trikesrule on Jul 23, 2007 12:54:01 GMT
Hey John I went for a ride on the weekend and my body dosen't want to get 'down' into the position shown in the pics. Basicly it's dam uncomfortable and I feel unbalanced. I can't get my head / helmet far enough back to look far enough down the road. I thought about lowering the kneelers a little and repositioning the footpegs so the torso twists / rotates downwards. But if I do this it tilts my chest / tummy more vertically and catchs more of the airstream. Any ideas?.........trikes
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Post by John Richards on Jul 23, 2007 21:03:24 GMT
Hey Trikes, i was going to mention that you looked to be making a mistake that me and steve made a while back in taking a fitting on your bike without your leathers and helmet on. we did that two frames ago and never really fitted on the thing. there is some speed to be had from your position by maybe moving your hands up and back slightly so your knees touch your elbows and getting your bum down to touch your calves. at first this doesnt look to be reducing frontal mass but we think it reduces the drag caused by the air hitting your chest, kind of like a body fairing. in making the last of our frames we started by sitting on the bench in the most aero tuck possible then made the frames to fit. hope this helps some, john. p.s. did you find out what the un-faired speed record was?
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Post by trikesrule on Jul 24, 2007 8:19:55 GMT
Hi John Yeh Snarlin (GBA) set the record for stock bikes back in 99. He went 64 mph from a dead start and thats the speed he achieved over 1/4 mile. I've had some talks with Guiness people and they don't recognize that procedure any longer which is probably why Snarlin is a bit miffed that it's been removed from the Record Books. I understand what you say about not having my gear on whilst setting the pozy but I only had it off for the photos so people could put a (handsome ha!) face to the name. Taking what you said into consideration though for sure. At work today I had a brain break from detailing cars (while the boss was hanging around) and I believe I should not have set position on a flat surface. As in perhaps I should have set it with the bike on a "hill' and also with the bike set on scales as well to get my weight bias correct. Doing it on the scales and on a hill is how I set my Trikes. After all I originally discovered the 'true' weight bias when I set my machines at the test track which is one of the race tracks I have been so dominant at over the last ten years. It's nice to leave work when I'm at work occasionally.........trikes
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Post by trikesrule on Jul 29, 2007 6:28:12 GMT
JR your a wizz. I modded my pozy like you suggested. Rode the bike about an hour ago (Sunday 3.00 pm here) and it's the first time I've actually not been in pain or any discomfort at all. And suffered no loss of speed. Setting the bike up on a 'hill' on my bench seemed to be the most important key. One thing that has arisen is the steering has gone 'light' like it was when I first built the bike up. Not real keen with the way it quickly steers but it's not disconcerting all that much but I will look to altering the bias a little. Getting close now thank goodness. It's taken some stuffing around to it get better. So we worked it out and I'm very very happy (and so are the family jewels). Thanks John...........trikes PS I've positioned my feet like yours and while there was no speed difference at my usual low speed test track there may well be an improvement at the other tracks which are all faster. To me this suggests that perhaps there is something up stream of the feet which is dictating the flow. Anyway it's all good
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Post by John Richards on Jul 29, 2007 16:44:15 GMT
thats great news trikes! glad to have been of some help ;D john.
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Post by trikesrule on Aug 10, 2007 22:20:45 GMT
Hi John and Chops. I notice you guys have your hands close together in your 'tuck' especially you John. I have my hands close together too as you can see in the above photos. I have a problem with controlling the bike when I kick. In my early days I had wider bars and the control was there but now with the narrow bars control isn't there. Oh it's reasonable if I only kick once but in the racing when I get the big kick going I'm all over the place. So I've started making a set of 'aerobars' for a wider stance yet retain the narrow bars for in my tuck just like the Tour Le France Time Trial riders use. At present they are made from syntactic foam and ready for f/glass. My question is this - under IGSA Rules do u reckon aerobars would be legal? (posting pics soon and testing this weekend)......trikes
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Post by trikesrule on Aug 18, 2007 7:28:04 GMT
Hey JR today I had a look at the tuck of a couple of speed skiers and gee their position looks remarkably similar to yours? ? Is that where you got your tuck idea from? If it is good on you. I've had to learn the long way by using the suck it and see method. Finished my aerobars last weekend but it rained all day - something you've probably seen enough off for a while from what I see in the news. We've had a few floods lately too......trikes
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Post by John Richards on Aug 18, 2007 19:45:03 GMT
hi trikes. your push off bar design is one we have considered and i see no reason why it would not be legal? ian round would probably be the best guy to ask. my tuck is all my own and chops' doing , as i said before all we did was to assume the tightest possible tuck without the bike then design a frame to accomodate that position. how is your composite frame coming along? some pictures would be great? iv been busy lately getting my bike ready for the world cup round.
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Post by trikesrule on Aug 19, 2007 7:12:16 GMT
Ala Aerobars. Tested these today and there are + and -. Negative is now the tuck bars are partially hidden and when I change from aero to tuck I have to sort of feel for the tuck bars resulting in a couple of wobbly rides but this became less of a problem the more runs I had (6 in total). + is it's given me almost unlimited control back over the bike and I've never kicked so hard yielding a 3.7kmh increase in top end and when I tested with just the one kick test method that I use just for testing there hasn't been any speed loss at all. Two positive weekends of testing - I'm on a roll. Who is Ian Round and what does he do? R u getting ready for MH in the US or something else?...........trikes
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Post by John and Chops on Aug 19, 2007 18:53:28 GMT
we are getting ready for the go-fast sponsored uk round of the world cup to be held in eastbourne on the first and second of september. Ian Round is the ukgsa secretary and also a very good gravity bike rider, and main competition to scotlands dominance!!! a few years ago he built and raced a faired bike in a few world cups (winning one!) and is pretty clued up on igsa rules.
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Post by trikesrule on Sept 10, 2007 21:34:52 GMT
Ian those aero bars I made do they look legal to you? Bars are well under width dimensions. What I'm wondering is why no one else is running anything like these in gravity bike. So I must assume either they are illegal or others have put them in the too hard basket or they haven't thought of them - yet...........trikes
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Post by trikesrule on Oct 9, 2007 8:31:52 GMT
This is the first pic of what I believe is the first of this type of fairing that complys with the latest rule changes laid down by the IGSA. Click on pic to enlarge. The Fairing must fit within a box 31cm x 23. Much better punchy shape that flows a heck of a lot better than whats currently favoured by most of the competitors (in the US) (I've tested their design and thrown it in the binbut I've not tested your design JR / Chops). You can also see the aero guard that prevents the air flow from hitting / interfering and causing extra drag on the top front part of the front tyre. This was something I learn't quite a few years back with racing my trike billycarts here in Tasmania Australia and there was some discussion about a similar thing on the GBA site. Hence what happens is the air flow can only hit the tyre on the lower side and makes the wheel want to turn faster. In front of a fan in my 'tunnel' the uncovered the wheel wouldn't turn at all. When the Aeroguard was installed the wheel turned by itself and maxed out at 13kmh. At the track this equated to 1.3 kmh. Almost something for nothing!!!!!!! Thats my 13 y/o son on the bike wearing a now very crappy AGV helmet. My new full face helmet has recently turned up from Israel and no you can't see it but I can tell you it's faster again than my yellow dimpled bicycle helmet. See that wool tuft(s) going downward. With bits of cardboard fences (not shown) (come on! I've got to keep somethings to myself!) stuck on here and there I was able to 'clean' the airflow even more and get that piece of wool running cleanly along side it's mates. I'll post more pics later as time permits. And the speeds have crept up a bit more.........trikes
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Post by trikesrule on Oct 28, 2007 6:15:00 GMT
Read em and weep. All the fiddling is starting to pay off. You know that air stream that crashes into the chest area. Well none of that happens at all because of the new fairing with the little fences I added. And I had my first try of my new helmet - very quiet. The only little problem I have is the bikes a bit quick in the steering when the road gets a bit rough for these sort of speeds ........trikes
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