Wednesday, 18 July 2012

Tour des Muverans

Leaping Julia
Tour des Muverans

I have just spent a very pleasant week with my wife June and daughter Julia walking in the mountains of Switzerland.
Julia has been working at a Swiss boarding school being an assistant house parent and taking the children on various expeditions, walking, skiing, canoeing and all things outdoor.
Julia organised a walking tour for us, over four days, staying in huts for the three nights. 

The Tour des Muverans follows a high level route around the impressive peaks of the Muveran Massif (which Julia can see from her balcony at the school).  It is apparently one of the wilder parts of the Swiss Alps, and we’ll be walking through a couple of nature reserves en route.

June and I left a very soggy UK on Sunday and were told to bring Clothes for all weather conditions. Things were looking up as we flew south across a sunny France but the clouds thickened as we started our decent into Geneva. A very pleasant train journey around Lac Leman to Aigle, followed by a bus ride up the mountain to Villars sur Ollon at 1300m, we were met by daughter Julia. It was raining but we were prepared.

We were staying with George and Carol Logie, who are the parents of Julia's fiancé Mark. They are house parents at the same school as well as teachers. Normal school life had finished for the academic year the week before and Summer school was about to start.

On Monday the weather was even worse but we decided to go on an acclimatisation walk up in the mountains. We walked into town to the telecabine station where nothing was moving due to lack of customers but it was started just for us. The telecabine took us from the town up to Roc d’Orsay for a lovely walk up Grand Chamossaire (2000m), along the ridge to Petit Chamossaire and down to the restaurant at Lac des Chavonnes. The decent took us via the ski resort baby slope to Bretaye, where we caught a train back to Villars. Full waterproofs were required most of the day but it was still a very pleasant walk.
It was funny seeing the baby slope again, where George had tried valiantly and very patiently, to teach me to ski 18 months previously. I did eventually sort of master this slope after a week but I am not a natural to say the least and did not progress to anything more technical. I think my main problem is lack of confidence caused by a fear of heights. Is walking in the Alps really a good idea?
On Tuesday, Carol kindly gave us a lift to the start of the walking tour at Pont de Nant (1253m). It wasn't raining but cloudy, which was a bit of an improvement on Monday.
Day one of the walk took us from Pont de Nant, up a lovely valley, through forests, open pastures and crossing snow patches up to the Col des Essets (2029m) then dropping down into Anzeindaz (1876m) for a coffee stop.  From here a gentle climb up over the Pas de Cheville (2038m) and finally a fairly steep descent to Derborence (1450m) where we were to spend the first night. We got there in the evening sunshine, dropped off our bags and went to test the water with the idea of having a swim. It was very cold and there were some large snakes near the water, so we decided on a paddle and wash rather than a swim.
The Hut at Derborence
The first hut was an interesting mix, with a fantastic menu, great wines but no showers and one shared dormitory which was basically split into one large lower and one large upper bunk. Fortunately, the dormitory was not full and there were no loud snorers, so we got a good night’s sleep.
Ascent: 940m              Descent: 750m           Distance: 13.5km
Giant Swiss Flowers
The second day started sunny and warm but ended with a violent thunderstorm chasing us up a glacier to the Rambert Hut at a height of 2580m. We met our first serious amounts of snow during the day.  Now, I don't mind horizontal lying snow but when it is at an angle, I start to panic. Julia and June went ahead of me and made deep footsteps for me to follow and as long as I didn’t look up or down the slopes, I was just about OK.
On the final scramble up to the hut, with the thunderstorm chasing, we thought that June was hallucinating when she reported seeing three monks in their habits running up above us. However, her sighting was confirmed later that evening by a couple that saw them climbing the Grand Muveran earlier.
The delicious evening meal was soup, stew with rice and fruit salad for pudding, with a bottle of red wine to wash it down. We ate our meal together as a group that included a German / Mexican couple, two Dutch lads and eight Swiss. The Swiss parties’ age range must have been from about 20 to 70 and they kept us entertained during the evening with their singing. They were walking in the opposite direction to us around the tour and I was amazed to find that their following day was to take them well beyond where we started that morning.
The facilities were even more basic with a drop toilet and no running water but the dormitories were a little more private.

Ascent: 1240m            Descent: 150m           Distance: 9.5km
The third day started downhill, all the way to Petit Pres (1598m), and then a climb up to the Col de Fenestral (2453m) with a picturesque view down to the Lac de Fully.  We headed down to this lake (2135m) and then finished the day with another climb up to the Col du Demecre (2361m) for the last night on the Tour.
This hut was run more like a youth hostel where we cooked our own meals with supplied ingredients (spaghetti Bolognese) and did our own washing up. The warden made his own bread and jam which we had for breakfast. Julia asked how they got their provisions up from civilisation and the answer was by helicopter.
Continuing the toilet talk, this hut had a very modern but distant composting one, with solar powered lighting and we were given a bowl of warm water for washing, which was very welcome.Ascent: 1120m            Descent: 1400m         Distance: 13.5km
Hut at Col du Demecre
Outside Hut
Day four started and ended wet, with a cloudy middle. We were advised not to take the high route that Julia had planned because of the amount of rain and the likelihood that the narrow and precarious path would have been washed away. This meant a long detour down 500m and then back up 500m to a hut for lunch. This was a fantastic newly built hut, with an amazing view over the valley and it had flushing toilets and a shower! However we weren't staying and after a steep climb and the crossing of the scariest snow slopes so far, the rest of the day was a 1200m decent back down to Pont de Nant, where George was waiting to pick us up.
Scariest Snow Slope of the Tour
The only other problem on the way down was crossing the stream in the valley, which normally would be possible with a couple of stepping stones but because of amount of rain we had to go quite a way up-stream to find a crossing point.
Ascent: 900m              Descent: 2100m         Distance: 15.5km
Back at the school and having had an enormous feast and a shower for the first time in four days we all felt re-vitalised and ready for a trip to Montreux the following day.
We were fortunate with our timing, as the Montreux Jazz Festival happened to be on all week, so we spent a very sunny and warm Saturday being entertained by free music, entertainers, exotic food, a swim in the lake and an all-day paraglider demonstration. The paragliders were leaping off a distant mountain, doing loops and tricks above us and then trying to land on a floating pontoon in the lake.
A Successful Landing
All in all a wonderful trip, slightly beyond my comfort zone in a few places but that’s probably not a bad thing. The weather was a nice temperature for walking, it’s only a shame that some of the views were hidden in the clouds; we should have been able to see much more including Mont Blanc.
Oh well, next time.

Tuesday, 19 June 2012

No Camber Tests

From the Sunday Times 17th June 2012

We had a nice bit of publicity from the World Championships at Fowlmead in the Sunday times last weekend, although not totally complimentary about Quattro. “a four-wheeled recumbent of such comical appearance that you’d think it belonged to a low-budget 1950 ski-fi film". But there is no such thing as bad publicity and a two page spread in a national newspaper can only help our cause.
Kingpin Bent to Eliminate Camber (Do not try his at home)

New Fatter UJ Ring

UJ with Eight Bearings Fitted
I made some new double depth UJ rings that can now take eight bearings rather than four and a new slightly shorter and hollow drive shaft. I was still running the same 19mm diameter solid steel one that was made for me half way across America.
So Steve and I set off to Reading Velodrome again to test the new setup.

No Camber and 145mm Ground Clearance
Interestingly I have ended up with about 145mm ground clearance, any less, and the wheels would rub on the fairing.
The initial conclusion from the testing was that there was little change; I was able to maintain 30mph (48kph) reasonably comfortably with a number of laps at 32mph (51kph). We did try taping up the nose vent and that did seem to help the speed a little. I left Reading feeling disappointed that there wasn’t a dramatic increase in speed but when we got back to work, I noticed that yet again, one of the tyres was completely flat and just like at Fowlmead, it was caused by a piece of metal and I have no idea what effect it had on the testing. This means that a return trip is needed to repeat the tests.

Lee Wakefield sent me a link to an interesting looking device that wirelessly monitors tyre pressures; it is designed for trucks but would work just as well on Quattro.

Tyre Presure Monotor
The trouble is that at the moment, our tests on Quattro are not very scientific; it may be possible to see a large improvement but any small changes in performance could go un-noticed. I do have a very old pair of SRM Cranks that are in Germany, being updated and calibrated. I am not sure they will be of much use for my Quattro because of the very narrow custom chainset. Graham Sparey-Taylor’s Quattro may be easier to adapt as he has a more standard bottom bracket arrangement and he has also made provision for an electric motor, which could also be used to give a constant power input.
Following his recent success, newly crowned World Champion Steve Slade has been offered a lucrative sponsorship deal with Raleigh Cycles and is seen here modelling his new team strip.

Friday, 15 June 2012


Laser Alignment of Wheels Showing Camber
Having noticed the grease exiting my UJ bearings after the Worlds, I dismantled the front axle and found that half of the bearings were already quite rough. This is after only about 150 miles at the most. Dr Graham suggested that this could be caused by cornering forces. I probably did more, high load cornering over that weekend than the whole crossing of the USA during ROAM.
I ordered and now have received some sealed rather than shielded replacements but I am not sure that the problem is only caused by the loss of grease, I am sure they are overloaded as well. The bearings I am using at the moment are 696ZZ which are 6x15x5mm and have a static load rating of 655N. Unfortunately, I can’t increase the bearing size easily without a re-design, so I am stuck with them for the time being. The only interim solution could be to double up the same bearings within a modified housing.
UJ Assembly
While Quattro was in bits yet again, I decided on some more drastic action. For testing purposes, by adjusting (bending) my kingpins and modifying the lower wishbones, I am going to eliminate the camber on all four wheels. This will result in a narrower track of 600mm rather than 650mm but with the four wheels and low centre of gravity, Quattro will still be very stable.
From the excellent “The World’s Most Fuel Efficient Vehicle” (PACII) book.
The original idea for cambered wheels was to give maximum stability within the narrowest body. The 650mm track was chosen as it is one of the regulations required for pedal car racing in the UK. I was also influenced by the authors of “The World’s Most Fuel Efficient Vehicle” (PACII) book. In the section on tyres, they show a graph of rolling resistance versus camber angles. The curve is more or less flat between 4deg and 8deg, so I decided to go for 8deg. What I should have noticed was that this flat section of the curve indicated a 15-20% increase in rolling resistance. In fact, when I measured the camber on Quattro, it was closer to 9deg.
The other advantage of eliminating the camber will be that the UJs are running concentrically when Quattro is going straight, which should reduce friction losses considerably.
Camber Eliminated
Thinking positive, this could save me up to 20W in my tyre rolling resistance power at 35mph as well as reducing the side loads and therefore the friction in the wheel bearings. The power saving in the UJs is difficult to quantify but the angular speed variation I mentioned in an earlier blog should be minimised.
A couple of people mentioned the lack of shelter behind Quattro compared with other vehicles while racing at the weekend. Mike Burrows tried drafting me during the two hour event and said that there was no noticeable shelter. This is hopefully a sign of good aerodynamics and leads me to think and hope that any big gains in speed may well come from improved mechanical efficiency.
I should be able to get the modifications done over the weekend, so off to Reading for a testing session on the velodrome which is free Tuesday morning next week.

Monday, 11 June 2012

World Championships Fowlmead

Firstly, a big thanks to all the organisers, helpers, marshals, timekeepers, first aiders etc who made this a very smooth running and thoroughly enjoyable weekend.

Steve and I arrived at a very windy Fowlmead circuit early afternoon on Friday 8th June. With assistance from the Reltons, lee and other helpers, we attempted to erect Steve’s large dome tent. Although we eventually managed this, there was no way the pegs were going to hold it down for more than a few minutes. Fortunately, Mike Burrows had a spare, smaller tent that he loaned us for the weekend.
Lower Campsite
Quite a few people set up their tents in amongst the trees and bushes up nearer the circuit to try and find some shelter from the relentless wind.
Fowlmead is a excellent venue for cycle racing; there are two loops that can be joined together by a testing hairpin bend to make a 3.5km circuit. The first race was held on Friday evening, and was one lap standing start, anticlockwise around the smaller, Lydden Wood Loop. There was a second chance, for late arrivals and anyone else who was keen to have another go on Saturday evening as well.
Although Quattro was wonderfully stable in the ferocious Friday night wind, I probably should have had a go on Saturday as well, when the conditions were a little calmer. Steve went four seconds faster on Saturday but the event was eventually won by Lee Wakefield in his Beany with an average speed of 36.0mph (61.7kph) on his fourth attempt. I came 21st with an average speed of 29.5mph (47.5kph).
Start of One Lap Flying Start

Saturday morning’s race was a one lap flying start, clockwise, using the whole circuit. The wind was still very strong but because it was coming from the Southwest, it gave a welcome push along the main uphill straight. I was very pleased to get 9th place with an average speed of 32.7mph (57.9kph). Steve won with an average speed of 38.3mph (61.7kph).

Eddie Robbins in his Rome

We were all very impressed when Eddie Robbins in his untested Rome took 7th place. Rome is based on a tiny pre-Beano, K-Drive moulding that I was doing nothing with. Eddie has added a spacer along the length of the faring so that he can use standard length cranks. With a few refinements, still to come, it should turn out to be a very swift machine.
Faired Ice Monster

Tim Parker at Speed

Another new machine and a very talented junior rider is Tim Parker in his very elegant Faired Ice Monster, 12th place with an average speed of 32.1mph (50.4kph).

Saturday afternoon was still very windy and the one hour time trial on the full circuit was started with the slower riders going off first, at 30second intervals. This worked very well from a safety point of view, as there were never any riders with vast speed differences on the track at the same time.  I went off about 75 minutes after the start and was pleasantly surprised not to be overtaken by another machine until I was nearly ¾ of the way through my hour. Quattro was running smoothly and my legs were feeling good, I was delighted with 7th place and an average speed of 31.1mph (55.2kph). Surprise, surprise, this was also won on by Steve with an average speed of 37.8mph (60.8kph).
Quattro, Wayward Cousin Wobbly Bob & Spiderman
The two hour mass start race was held on the Sunday, with the faster riders going off first. I started off well and got to a similar running position as the one hour time trial. Unfortunately for me, the un-faired and part-faired bikes were running as a large group, doing bit and bit, which gives them a higher average speed. Being faster up the less wind assisted hill, they caught and passed me. I put my loss of speed down to lack of training and old age but towards the end of the race, I realised I was running with a puncture. Having four wheels means that a puncture is unlikely to cause any danger but the downside is that a slow puncture can go un-noticed. The first sign I had was that the steering was starting to pull to one side with about 20minutes to go and then a couple of laps later, it was completely flat. I had two spare wheels at the side of the track and could have stopped and changed one in a couple of minutes but I decided limp on to the finish. I ended up 18th with an average speed of 29mph (46.7kph), which seems a little optimistic. Guess what, Steve won with an average speed of 37.7mph (60.8kph).
Overall, I am delighted how well Quattro performed. The only mechanical issue other than the puncture that needs looking at is that some of the grease has already come out of my new UJ bearings. I think that part of the problem may be that they are only shielded bearings and they are spinning at 90deg to their normal rotation, so the centrifugal force is pushing the grease out.
UJ Bearing Leaking Grease
Champion, Steve Slade, Second Howard Yeomans and Third Lee Wakefield

Oh I nearly forgot, Steve is World Champion again!

Wednesday, 6 June 2012


Quattro Reeling in Free Wheelie
So it was back to Reading last Monday with the new UJ bearings fitted to Quattro. This time, I left off the spats and locked the rear steering.
Keith and Chris from Wycombe Abbey School met Jim and I there as we were planning to do some tests on the Greenpower car (Free Wheelie) at the same time. We were also met by Graham Sparey-Taylor who was hoping to have his Quattro there but unfortunately ran out of time to complete the latest modifications.
The tests we can do at present are still not very scientific but the bottom line is “how fast does it go mister?” Well the answer is a bit faster than last time. The weather conditions were much better with a temperature of about 24deg and very little wind. I was able to maintain 30mph (48kph) reasonably comfortably with a number of laps at 32mph (51kph) and after a pep talk from Dr Graham a sprint lap at 35mph (56kph)!
At the very beginning of my Quattro development, 35mph was the magic number that I was trying to achieve as a racing speed. This is generally about the average speed of the winner (Steve in the Beano) of most BHPC races. Unfortunately one fast lap around Reading Velodrome is not the same as a 40 minute race on a twisty cycle racing circuit but at least it is a step in the right direction.
Forgive me for the next bit, as it is largely a repeat of my original Quattro article for our club magazine but with some of the numbers updated.
The power required to maintain 35mph is made up of two main elements.
Air Resistance Power = CdxA x½ρV³
Where Cd is the drag coefficient, A is the frontal area in m², ρ is air density (1.2kg/m³ at 20°C) and V is the speed in m/s.
Rolling Resistance Power =CrxVxN
Where Cr is the rolling resistance coefficient, V is the speed in m/s and N is the normal force in Newtons (kgx9.81) on the tyre.
There are other mechanical losses such as bearings and chain friction but these are small and I will ignore them in the following examples.
35mph Beano Power
The Cd for the Beano is probably about 0.12 taking into account gaps, wheels etc. The frontal area is 0.35m².
 Air Resistance Power = CdxA x½ρV³      gives 0.12x0.35x0.5x1.2x15.5³      =94W
The Cr is about 0.006 for good cycle tyres, Steve weighs about 65kg and the Beano about 17kg giving a total weight of 82kg.
Rolling Resistance Power =CrxVxN        gives 0.006x15.5x82x9.81              =75W
Therefore Steve needs to put out about 169W to maintain 35mph in the Beano.
35mph Quattro Power
The frontal area of Quattro is about 0.6m². Let us assume the drag coefficient is the same value of the Beano at 0.12.
Air Resistance Power = CdxA x½ρV³       gives 0.12x0.6x0.5x1.2x15.5³        =160W
If I was to use my Solidworks CFD drag figures of 6N at 15m/s this would give only 90W which I don’t believe, as there is no account for gaps, rotating wheels etc. More on this another time.
Again assuming a Cr of 0.006, I weigh about 76kg and Quattro weighs 34kg giving a total weight of 110kg.
Rolling Resistance Power =CrxVxN        gives 0.006x15.5x110x9.81           =100W
This makes a total of 260W which is the high end of an attainable figure for me and gives an idea of what I am up against!
35mph “Upright” Racing Bike
Putting things in to perspective, a racing cyclist in a crouch position has a frontal area of about 0.3m² and a Cd of 0.9.
Rolling Resistance Power =CrxVxN        gives 0.006x15.5x82x9.81              =75W
Air Resistance Power = CdxA x½ρV³       gives 0.9x0.3x0.5x1.2x15.5³           =603W
This makes a whopping 678W!

Greenpower Car Tests
Free Wheelie at Reading
The Greenpower events are aimed at secondary school children, are all four hour endurance races and are generally held at motorsport venues around the UK. All teams have the same motor and six 12 volt batteries to be used in pairs. During the race at least five team members must drive the car, and up to six further members can act as pit crew. Other than the motor and batteries, teams are free to design a car from scratch, or build one of the kit cars. All cars must follow a set of strict safety regulations but there is quite a variety of designs sitting on the grid before a race.

Free Wheelie's First Race at a Soggy Silverstone
The same equations can also be applied to Greenpower Electric Cars but at the moment the target speed is 25mph (40kph) for the Wycombe Abbey School car.

25mph Free Wheelie Power
Again there is a bit of guesswork for the Cd of Free Wheelie but it is probably about 0.25 taking into account gaps, wheels etc. The frontal area is about 0.35m² and the speed is 11m/s.
 Air Resistance Power = CdxA x½ρV³      gives 0.25x0.35x0.5x1.2x11³         =70W
At the moment, the car is fitted with 16” (349) Schwalbe Marathon tyres. These were one of the tyres tested by John Lafford. He found they had a Cr of 0.01, Keith weighs 80kg and the car about 95kg giving a total weight of 175kg.

Rolling Resistance Power =CrxVxN        gives 0.01x11x175x9.81                 =189W
This makes a total of 259W.
So it seems that at 25mph the rolling resistance is dominant.
If the tyres were changed for ones with a Cr of 0.006, and the weight reduced with a 20kg lighter driver, the rolling resistance power could be reduced to 0.006x11x155x9.81=100W.

As can be seen from the Reading picture, teacher Keith is a little large for the car as it is designed for smaller and lighter young ladies. His shoulders are causing extra air drag and a pupil would probably weigh 20kg less.
The aim of the trip to reading with Free Wheelie was to find the optimum gear to use at the next race. Greenpower cars have the opposite problem to human powered vehicles in that, the motor spins at about 1850rpm rather than the 90rpm of leg power.  To get the correct wheel speed, the car has a 14t freewheel on the motor and a 5 speed block on the axle with 47t, 50t, 53t, 57t and 62t sprockets which are selectable with a standard rear mech. At the moment, the gear ratio is selected before the race, based on battery capacity, race conditions and duration; it is not touched during the event. Most of the circuits are flat and the motor becomes horribly inefficient if it is run too slowly, which would flatten the batteries before the end of the race.
The two 12V batteries can provide about 17Amps to the 24Volt motor for the 80minutes before they are changed. This gives a motor input power of 24x17=408W, taking off a bit for controller, contactor and wiring losses probably leaves 400W.
Motor Performance Graph
At 17Amps, the motor is running at about 73% efficiency, which is near its peak. This means there should be 292Watts at the output shaft.
Working backwards from this power, using the same equations, with a lighter driver and better tyres (0.006), gives a theoretical speed of 14.5m/s or 32.4mph (52kph) with the rolling power at 132W and air power at 160W.
Splashing About at Silverstone
The next Greenpower event is on Sunday 10th June at Goodwood Motor Circuit and the aim is to complete the four hour race without any major breakdowns or flat batteries. The team will be using the Schwalbe Marathon Tyres and starting on a low gear. The gear could be increased at the first battery change, depending on the battery condition.

I'll not be there, as I am going to be splashing about at Fowlmead in the World Championships. The weather forecast is not very good, which is a shame but in Quattro, it may give me an advantage over some of the bikes.

Tuesday, 22 May 2012

Quibell Park Velodrome

Quest, Quattro & Wobbly Bob
Firstly a big thanks to Jeff (blogwat) for all the photographs, I have not used any of the ones I took, as his are so good.
We arrived at a cold and overcast Quibell Park Velodrome at about 10am on Sunday morning after a three hour drive from High Wycombe. Having said our hellos and signed on for the race, I did a few test laps. The handling was still horrible, just like it was at Reading and my low slung spats were catching the timing loop wires that were taped across the track. I stopped to check the wires and they seemed OK, so I carried on for a while.
We then all lined up for a three lap standing start time trial, which is not my favorite event, in a hefty Quattro but I gave it my best. The first bend on the track feels horrible from a standing start because the speed is low and you feel like you are going to tip up on the relatively steep banking. By the time the second bend comes along, the speed is high enough to make it more comfortable. I rode the whole event in my middle chainring to give me better acceleration, but it did mean that I was spinning rather fast on the final lap.
Main Race
After the time trial, Martin the race organizer asked me if I could do anything with my spats to stop them hitting the timing wires. The wires are probably only about 5mm diameter, which shows how little ground clearance I was running. He was quite reasonably worried that I could un-stick the wires and drag them down the track, potentially damaging them and causing an accident. As my time trial performance was not very good and the handling was poor, I was quite happy to take them off completely. This also gave me a chance to look at the steering to see if there was anything obviously loose causing the bad handling, which there wasn’t.
Lee Wakefield's High Speed Crash
The main race was due to be a 40 minutes mass start but was stopped after 10 minutes because of the 42mph (67kph) puncture and crash of Lee Wakefield’s Beano. The Beano lost a lot of paint but Lee was fine and the race was re-started with him in his Quest.

Although it was my fastest race yet (about 28mph-no official results yet), I found it a little depressing as the handling was rubbish and Lee and Ian Fardoe both beat me easily in their Quests. Ian Perry was the fastest multi-track with his exposed knee Wobbly Bob. The bad handling of Quattro seems to have appeared since I locked the suspension. Ian Perry had a go after the racing and was amazed at the way Quattro kept changing direction and didn’t dare try and go fast.

Watching Ian Fardoe’s video of the event clearly shows me struggling to hold a line around the velodrome.
Ian Perry Flashing His Knees
I was talking to Jim at work the other evening about the efficiency of the drive chain in Quattro and it occurred to me that what I had assumed about the Sprags being locked is not actually the case. Because of the slight speed variation in my UJs, unless they are lined up, the drive shaft will drive one wheel and then the other, depending on the relative position of the UJs. I think the speed variation is only about 1.2% but it could create quite a bit of drag as each Sprag locks and unlocks under torsional and side loads. A cure would be to have the aligned UJs fixed to the drive shaft and the Sprags on the outside. Having said all that, on a velodrome, I am probably driving the inside wheel for 80% of the lap.
After the 30min race I did stop quickly and turn Quattro over to see if there was any heat in the bearings etc. The only thing I could detect was a warm disk but that was probably from stopping quickly.
Steve in his Beano
I suppose I should mention that (subject to publication of the race results) Steve won the time trial and the main two races despite his chain falling off in the 30 minute race. He had to stop to put it back on but still managed to beat a newly spatted Howard Yeomans in his Great White.
Howard Yeomans in his Great White
I am beginning to think these spats are over-rated....!
I had a useful chat with Geoff Bird after the weekend and he mentioned my long connecting rods from front to back maybe vibrating on the rough track. I think he is probably right about the rods. When I looked at them yesterday, the rear ones which are thin and kinked seemed to be working in compression, which is not good. He also reminded me that I had similar problems on bumpy roads around High Wycombe. Hillingdon and Castle Combe circuits are smooth enough not to be a problem. Back to two wheel steering for a while I think.
UJ Outer & Bearings
While putting Quattro back into two wheel steering mode, I decided to check all the front bearings as well. I stripped down the front axle and found that my UJ bearings were knackered, one side slightly rough and the other side very bad. I know one of the bearings failed completely on the last day of ROAM but I can't remember how many bearings I changed when I got back to the UK. I have got 8 new ones here so I am going to change the whole lot. Definitely need to go up a size on the re-design, at the moment they only seem to manage about 1500miles.
After getting back from the frozen North on Sunday evening feeling a little depressed about Quattro and my performance, I have again got reasons to be optimistic. I will replace the bearings, sort out the steering and then it’s off to Reading again for another testing session........

Tuesday, 15 May 2012

Wheel Spats Part II

Having lowered the front wheels and replaced all the suspension springs with nylon spacers, I trimmed the spats to give 10mm ground clearance. This may prove to be insufficient even for testing at Reading Velodrome, but I thought it was a good starting point.
Underside of Quattro
Wheel Spats Trimmed
Once the spats were trimmed, I turned Quattro over to check the tracking. It was way out. The front was very toe in and the rear was slightly toe out. This would suggest that my new Ackermann compensating rods are not doing a very good job at controlling bump steer. Hopefully this will not be a problem for the spat tests, now that the suspension is locked out.
Foam Strip
I used some adhesive foam strip to locate the spats before I taped them in place.

Ground Clearance
All four spats are taped into position and have very little ground clearance.
Spatted Beano
Testing at Reading Velodrome was a bit tricky as the weather conditions were very blustery. Steve quickly got going in the newly spatted Beano before the rain started. He managed ten or so laps at about 38mph (60kph) but was having trouble with the wind and stopped when the rain came down.
I got going just as it started raining and was being blown about quite badly by the gusts. The spats were hitting the ground on a few of the bumps and the handling seemed horrible. I did about 20 laps, including three roll down tests from 28mph to a stop which took more or less two laps (950m). Graham Sparey-Taylor asked me to try and gather some data from my Garmin that he could analyze to verify the rolling and air resistance of my Quattro. We then took the spats off Quattro and I taped up the wheel cut-outs to reduce the gaps. I then repeated the 20 laps with roll downs.
The conditions were not good enough to draw any real conclusions from the testing we did. My gut feeling was that the spats made me a little faster. Also, I was expecting the handling to be better without them but in fact it was still horrible. So I will give them a try at the next race. Steve didn’t like them and felt they didn’t help his speed and will race without them. The banking at Reading is also a bit flat for Beano speeds and he was grounding the spats on the bends. Our next race is at Quibell Park Stadium, which is a large outdoor velodrome with a good smooth surface and steeper banking than Reading.