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Rolling Resistance Rig

 

I have borrowed the idea for a RR test rig from the authors of The World's Most Fuel Efficient Vehicle.

Theirs looks a bit swisher than mine but the principle is the same.

The whole rig weighs about 60kg which is approximately half the weight of a loaded Quattro. The wheels are bolted directly to the axle with no bearings.

To do a test, I pull the pole down to touch the ground and then let it go.

I time it until it stops and average over four runs. Two tests in one direction and two in the opposite direction.

 

 

Description: Quattro 002.JPGDescription: Quattro 003.JPG

The Rig is being modelled by Steve whose interests include, fashion, foreign travel and fast bikes.

 

The tests I have done so far are not that scientific, as I need a more accurate means of measuring a stop point for each test.

I may try and fit a mercury switch or some other kind of level switch.

The tests have also been done on the smooth factory floor at Portaprompt and should be verified on a number of road surfaces.

 

All tyres are 16" ETRTO 349mm

                                                            Pressure              Width                    Time to Stop

New Greenspeed Scorcher                            100                         39                           71.9s        

Part worn Old Yellow Brompton                     100                         34.5                        61.3s

Part Worn Kojak                                                140                         30.5                        55.7

Part Worn Kojak                                                120                         30.5                        51.9

New Marathon                                                   100                         33                           46.9s

Near new Kojak                                                 100                         30.5                        46.8s

Near new Marathon Plus                                 100                         33                           45.8s

New Stelvio                                                         100                         28                           43s         Estimate based on only having one.

New Brompton Green Kevlar                          100                         35                           38.1s

  

I have ordered some more Greenspeed Scorchers for the BHPC races this season, on the strength of these initial results.

There are a couple of drawbacks with the Scorchers, as their greater width may cause extra aero drag and less lock.

 

Latex tubes do seem to help but unfortunately, I only had some very old Moulton ones that only survived a couple of runs.

My next trick is to try and go tubeless. I watched Stan's Video over the weekend and will try and have a go later this week.

 

It has always been suggested that Kevlar does horrible things to tyre RR and my initial tests seem to support this.

We used the original Brompton tyres on our first Greenpower car to great effect. It is a shame they are no longer available.

 

Another interesting thing is that the Marathon Plus tyres don't seem to be that bad compared with the Kojaks.

I mentioned this in my Quattro part III write-up. When I switched from Kojaks to MPs on the ROAM trip, I didn't notice a huge difference in performance.

 

I must emphasise that these tests need doing again on a more realistic surface and with more accurate timing, which I will try and do soon.

 

 

The year started with very mild weather and no icy roads, so I managed to cycle to work most days and even did a couple of longer rides, one with son Jonathan on his new 64cm Trek road bike. He is a tall lad (206cm) and it was the biggest production frame I could find.

It wasn't exactly a new year's resolution, but I decided to take training a little more seriously for the coming racing season. To help with this, I went onto Amazon to see what books on training were available. The one that caught my eye was The Time Crunched Cyclist by Chris Carmichael, which suggests I can get Fit Fast and Powerful in 6 Hours a Week. I haven't started reading it yet, as I bought another couple of books to further boost my newfound enthusiasm.

One of these books is a large and colourful hard back called Mountain High which is a subtitled Europe's greatest cycle climbs and includes 50 legendary ascents. The other book I downloaded onto my new excellent (Xmas present) Kindle. The Hour by Michael Hutchinson, which I have now read. It is a very well written account of his bid for the Athlete's Hour and the history of the hour record. There is a very funny section where he describes coming to see us at Kingcycle to have a look at the Mango, with a view to having a go at the HPV hour record. When he sees Mango for the first time, he assumes we are showing him a scale model of what he is to ride. When we take off the lid, and he gets inside, he likens it to "sitting inside a suitcase full of cycle components"!

I know training is frowned upon in certain sections of the BHPC but having a fully working machine ready at the beginning of the racing season is a bit of a novelty for me and I intend to make best use of it. I have loads of improvements that I want to make to Quattro but they will be on a new machine.

Having received my book on training, I planned to modify my Kingcycle by shortening the cranks to something closer to Quattro's 140mm and attaching it to a Kingcycle trainer. Graham Sparey-Taylor was planning on meeting me at Reading Velodrome with his Quattro so that we could run some real-world tests, rather than CFD. He needed to know my current power output so that we could try and work out true, air and rolling resistance figures for my Quattro. His Quattro is fitted with an electric motor that he can monitor to give the equivalent figures. 

Then on Tuesday 10th January, I got a phone call from Wycombe Hospital regarding my Pennsylvanian Hernia. They had a cancellation on Thursday two days hence and would I like to go in and have it sorted? After an initial panic, I decided to take the appointment.

The operation went well and I was back home by 8pm the same day with only a small plaster dressing and another bald patch! I stocked up with pain killers before I went in but have only taken a couple of precautionary Ibuprofen. I have also been taking anti-histamines to stop me sneezing, which is painful.

It has been quite nice sitting at home and letting my brain freewheel for a few days. Not sure anything useful will come of it though.

Many thanks to June, who has been very busy building this website for me, it was only started three days ago!

I imagine I will be back to work more or less as normal next week. There are a couple of pressing Portaprompt projects that need my attention but I will try and get the Kingcycle test setup going by next weekend. Jim tells me that our new CFD computer also needs some attention as it is falling over at the same point as the old laptop, so we may need to buy some more RAM for it.

 

 

2011 summary.

My spare time in the early part of 2011 was largely devoted to getting Quattro going.

That Cyril Northcote Parkinson was a smart chap and must have known some early bike builders when he formulated his well known law that: Work expands so as to fill the time available for its completion.

I demonstrated this perfectly in my attempt to get Quattro going before the Monza World Championships in June. A couple of laps of the car park at work and we were off to Italy! Not surprisingly, Quattro's debut was not a total success but at least it was running.

Slash had more success and won the 1 lap, 1 hour and 3 hour races but did not pick up enough points in the 50m drags, 200m sprint and 1000m races to retain his World Champion status for the fourth year. He had to be content with being relegated to over 50 World Champ. His Beano is being updated over the winter to give him a wider range of gears for these shorter sprint races, so I wouldn't rule out a return to the top step in 2012. Congratulations to Aurélien Bonneteau for a great all-round performance and for showing the potential of multi-track machines.

The rest of June and most of July was again spent in a state of panic as I tried to get Quattro ready for ROAM. This time, I managed a 20mile test ride the day before flying to Portland! Quattro performed remarkably well during ROAM and although the engine was showing its age, it was a fantastic experience and well worth all the long days and sleepless nights of preparation.

The remainder of 2011 was not my most productive; it took me about six weeks to recover from the exertions of the trip. I had to have a course of antibiotics to clear up a bite on my elbow caused by an unknown critter and investigations into a lump that had appeared in my trouser region while climbing the ferocious hills of Pennsylvania. This turned out to be an inguinal hernia and would be sorted out in the New Year.  

 

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