Monday, March 31, 2008

It is becoming real!

In order to complete the evolution of my speed bike, I am looking for a financial help to buy a powermeter like ERGOMO or SRM.
They are very useful to measure how much power you need to reach a given speed. This tool tells you immediately if the a wheel or a modification is better than before.
i am open to any proposition, even a long term rental.

More pictures added.

My DAD and me at the CERAM track.

My father and I left home at 2:00am to Paris. After 6H drive we arrived at the CERAM High speed track where we met everybody.
It took all morning to get ready, Damjan was ready first and set off for a couple of high speed tests and video shooting for his sponsorship AKRAPOVIC. He was cruising at 80Km/h+ and his maximum top speed recorded on his GPS was 96Km/h (!). The tarmac friction is acceptable but 3Km/h slower than the Nissan track for the same power output.(Sorry I don't have the exact numbers)
Then Francesco Russo went for his attempt. After a few minutes, he was obviously not confortable and stopped due to internal hear balance problem.
Good balance is very important when you lean a lot in a closed fairing.
Then it was my turn.
I only completed a small distance arround my house so it was the very first Open test. I had no problem to start without the canopy. Julius and Barbara lent me a Polar to record my speed, cadence and heart beats so we can analyse that later on. I could cruise at 46/48Km/h without the canopy and there was nothing wrong with the gears ( I will post a detailed picture later.). The chain was only noisy on the very small 11 tooth because chain side deformation. The chain is perfectely aligned only with the middle of the cassette and I could clearly feel (and hear) when the chain was not happy. After some recommendation from Francesco, we de-bent a few teeth of the intermediate cassette(14/22) to avoid any deraillement.
My father finished to taped the front window (home made):

Then I went for my first test with the canopy. After some last minute adjustements (my crash helmet was a bit too big so I borrowed Francesco's), I was taped in and ready to leave. Simone Russo assisted my launch with his rollers (very easy) and I went for the first time. Whouahhhhh! 250m later I crashed! The front visibility was very bad and I could only follow the yellow line but in the corners, the track is inclined and I was not ready for that. As my side visibility was inexitante, I could not see an other reference to keep my visual balance.
Back to the starting line. I was ready to make some major modifications to the bike to complete one hour on the track. To impove the front visibility, we decided to cut the front window to get a clear visibility (and more ventilation)and side windows. I managed to complete 2 laps like that but it the lack of visibility was scary for a beginner. In the last turn and in the straights, I could not see any thing over 200m. My speed and the shape of the fairing kept me vertical but it is a very bad experience when you loose the reference line. It is like pedaling blind. I decided to further open the side window.
Finaly, I was ready for my first real attempt.
Damjan launched me but I crashed after 10m(I will place my stickers elsewhere next time...)
My second launch was missed but I did not crash.
My thrird launch was a success but I crashed after 2 laps. (Hard to learn)
The side window was open even more. (I will ask for double glazing next time!)
Then I decided to make one more attempt.
Damjan launched me again and I managed not to fall. I started the first lap as a warming lap (47Km/h) then I decided to accelerate. I was was cruising between 48 and 58Km/h (the track is not perfectly flat)at 160/170 hart bits/min but the visiblity was a real problem. My head rest was shacking my head so much that it reminded me the movy about Appoplo 13. I also add a problem with my eyes, I could only see in front when my knees were down and by the side with only one eye this resulted in a crossing eye vision (loucher/squint)After 30minutes, it was worse and worse, I got some dust in my eyes, I was scarred to hit the Timing guy (Christian Dague) on the side of the track. I could see my friends on the side of the track but I could not hear a single information on the radio because the noise was too important.
After 34minutes,10 laps, 30Km at 52.64Km/h average I crashed once again, it was a dispointement but also a relief.
It took me about 1H to get a normal balance, I felt like being at sea for 4 days.

I did not achieve my goal but I learned a lot:

1- outside visibility is the most important aspect. If you don't feel that you are in control of the direction then you can't use all your power.
2- Cross wind can make your bike very instable. Above 15m/s you need some experience to drive. You can never relax.
3- Experience is valuable, the more you ride in the fairing, the more you learn.
4- You must be ready to make major modification to your concept.
5- You must have good friends!
6- A suspension is good idea on that track.

The bike is complete and ready to go.

Christian Dague (FFC Official time keeper) during Damjan's attempt. He stopped after a few laps because he felt that he was not fit enough to break his record. I must say that it was very windy (20m/s)and gusty during his attempt but he did a good job to stay up-right. He started too fast and could not keep-up the speed.

Result of a single side crash. I made the right decision to build a polyester shell to practice. Only the gelcoat was scratched. It will be easy to repair. I need a white paintjob anyway to reduce inside heat.

More pictures from Jean-Lou Desbarbieux:

This is the fairing without any scratch:

The breathing pipe is instaled in the bike. Julius thinks it is funny because it is a garden pipe:

I am taped in! Well a dark blue color is not a good idea when it is hot outside. It only took a few minutes to tape the two halves together but it was already too hot inside:

Perfect launch by Simone Russo. Thanks mate for your help.

Picture of the middle gear. My Dad machine an aluminum cassette support, the two bearing are placed side by side and the outside nut is coming form an old bottom bracket:

The middle gear ratio is assembled. The axle will be threaded then it will go diretely into the carbon frame with a little bit of epoxy glue (Araldite):

The axle is made of aluminium. The 22 chainring will be change for a small cranck chainring to avoid any deraillement:

As planned, I tried the bike and it clearly not finished but the chain path is far from perfect but it should work fine.
The steering angle is good at low speed, I will try the bike at higher speed tomorrow once the front brake is fitted.
We changed the derailleur lugg position twice and is now 50mm below the font wheel axle so my heels don't touch is anymore. When room is limited and you want to solve a problem then you create a new problem: we have very limited access for the cable.
I tried to fix an old polyester seat that I had in the garage but it is too high with the ribbs so changed for a natural fiber panel (plywood :) )
The very bad new is that I don't lean back enough and my head is touching the top fairing. I will need to change the rear wheel. Bummer!

Bike is complete à 90%.
I still need to fix the seat, build a small handle bar and build the canopy.
I will try the bike for the fist time tonight!
The first speed attempt is booked for Sunday on the CERAM track, North of Paris.
Francesco Russo and Damjan are joining me.
We have organised two IHPV observers, an official FFC time keeper.
The weather forecast is not perfect but good enough (no rain, no wind and mild temperature)

All the parts are now ready to be assembled tomorrow.
The lower part of the fairing (tub) weights a mere 10.5Kg without any bulhead. The top part weights 7.5Kg. Remember this is only a training fairing so there no plan to exceed 80Km/h with it (if I can!).

My Dad is machining the cassette support on his lathe for the intermediate gear ratio (14 x 22 teeth). We always start from an existing part that we machine. Machining a thread requires some experience.

The carbon frame is now complete but the bottom bracket appears to be to far away.
The fork is complete.
The fairing is complete but still need a couple of bulheads.
I still have about 20H of work.

I would like to say thank you to David of DistriCycle Vannes for the old bicyle parts needed to complete the bike.
I have done some preliminary calculations for the gear ratio and I believe I can reach 62 to 67Km/h at 85/90rev/min if I don't have any mechanical problem. I have no experience about what top speed I can reach in sprint(85Km/h?) and what gear ratio I will need. Calculation is one thing, reality is sometime different. If I don't feel confortable then I will not be able to deliver my maximum power. (well very small anyway due to the lack of training :( )

The female mould is finished and the fairing will be laminated today. I will demould tomorrow evening and start the assembly.
The bottom bracket support has been started and will be finished tonight.

I am late, late, very late.
A friend of mine is building the female mould today.
I tried to bend the 5mm cross linked PVC (HEREX C70.75) sheet to make the sandwich but it is very difficult so I will need to change to Linear PVC (AIREX R63.80) which is heat formable.
As time is running out quickly, I have decided to build a single skin polyester fairing with local coremat (SORIC core) reinforcement.
My carbon front wheel will not be ready so I will be using a normal 451 wheel for the time being.
The fork is finished, Thanks to my grumbling father in charge of the welding. :)
The frame is done at 70%, I only need to add the bottom bracket (tonight). I have just applyed a layer of Polyester resin to seal the surface. I will now wet sand it and spray a varnish.

The fairing should be demoulded on thrusday 1st of May and I will start final assembly during that bank holiday. (Hope I won't need anything from the DIY shop.)
I have two rear wheels and a spare tire for the front wheel. (Thanks to my racing mates)
My digital camera is working again so I will post more picture later.

The first layer of polyester filler has been applied with a brush. I tried with a gravity spray gun (2.5mm nozzle) but it did not work and there was many pin hole left behind. The weather is really good in Britanny at the moment so I need to rush to finish what needs to be done outside. (the polyester smell is not appreaciated by the rest of the familly!)

The plug is now covered with a layer of E-glass cloth 300g/m2 and I can start fairing it with a polyester filler. One side is already done and I need to do the second half tomorrow.
As time is running out, I changed my mind once again on the drive train and because the gap between my knees is limited. To keep it simple, I will only use a single iddler and a big chain ring. The chain will return diretely from the derailleur to the chain ring thus saving a diverting pulley. I tried a similar arrangement on Ali's blue bike during the KIDAM's races and it is pretty efficient at steady speed.

Down below, you can see the size of the fairing. It should be about 20mm wider and 40mm taller than Francesco's bike but I need more room to feel confortable.

The foam former of my streamliner is finished thanks to Steph Vallet ( ) for the 3D modeling and to Cedric Demaine (M-C-N) for the CNC machining.
The fairing is made of polyurethane foam 80Kg/m3.
I also received the carbon from SICOMIN and the PVC sheets to make the sandwich structure ( AIREX C70.75 - 5mm)

More pictures down below.

Sunday, March 09, 2008

Carbon low racer

The bike still needs a bit of work and cleaning.
The double idler works well.

The aluminium handle bar will need changing soon.

I am back from the French FFC championship held in Chatellerault and I got my worse result ever. (15th over 18 starters) My little training proved that a good and light bike is clearly not enough to follow the pack. I completed the 79Km (600m alt) in 2H29min and I felt naked.
I am now sure that the bottom bracket is too far down and the riding position is not good for racing. (Seat is to high by about 80mm and the angle between the leg and the chest must be smaller to produce more power)
I will need to build a new carbon frame soon and sell this one.

I changed the top bearing angle and there is less movement in the steering.
The frame had be trimmed localy to fit the front brake.
The front fork is now complete and it took me some time to figure out how to fit the wireless speedo.

The fork has been faired with an Epoxy filler (Resin + microsphere) and covered with a final layer of carbon to look nice. This is a 12K 'flat' woven fabric and it is very nice to use on simple and flat shapes. I will probably try it on my next frame.
As you can see, the final layer is the peel ply. It is used to remove the excess of resin and create a uniform surface.

The first track session is now finished and I have some mixed feelings about my bike.
The frame is stiff enough, the steering angle is wrong but it does not matter too much on the track, the tektro 725 capiler is a piece of Sh.t, my seat angle is too up-right and my leg/body angle is too open resulting in a loss of maximum power. My iddler needs adjusting but most of all: I need to train properly if I want to stay in the first group.


At last! My carbon low racer is near completion (see Carbon low racer construction page). I need to stiffen the forward part of the frame and hammer it down to see it is good for the 2008 championship.
The complete bike weighs 7.8Kg and need a few up-grades to be under 7Kg.