News and Events

Keep up to date with the latest news and events of Modular Bikes.

Saturday, January 13, 2018

Around The Bay 2018

Lineup at the start, tea & coffee & biscuits provided.
My trike, second from right

Rick Harker's Cattrike Musahi

On the 12 O'clock Ferry which

most of the riders I saw on the route caught.

A selfie.

The end of the year came round quite quickly last year, and when I checked the weather for the upcoming Buckley's Ride date (6th of Jan ) it promised to be neither hot, nor horribly wet or windy, so I signed up for the ride, which is a 217k jaunt (ok, tough ride, but moderately flat) around Melbourne's Port Phillip Bay.  Buckley's is Audax Oz's cheap and cheerful ($6 plus food plus ferry fair) version of The Bicycle Network's Around the Bay in a Day ride (Up to $205!)

For a few days prior to the ride I did 2 25k loops of a hilly circuit near to where we live, and I used the wireless speedo on the bike to ensure I kept a steady pace (usually 10k minimum) up the hills.  This training stood me in good stead, and the speedo was useful on the actual ride too.

Saturday, the day before the ride was hot, 41 degrees I think and my wife and I spent most of it inside.  I was fettling the bike and watching television, I checked tyre pressures, bought in supplies of bananas and biscuits and filled the water bottle.

Next morning I was off early and rode to the start at Albert Park.  There were a few familiar faces there from previous years and events like Ian Knoz and Rick Harker.

The ride to Queenscliff went quite well.  There were a wind-protecting bunches to ride in and for most of the way to Geelong did about 27 kph and made the 12 o'clock ferry.  Across the heads in Sorrento I rode with Rick and Ian for a while, but hared off with a fast bunch of Bendigo riders soon after. Haring doesn't do much good though, Ian and Rick caught and overtook me near Frankston.

In the end I was in by 5pm, a good result in my book.  I was happy with the way the trike went.


Steve Nurse

Monday, January 8, 2018

Disc Wheel Tests Part 2

Problems with Roll Down Tests: Cars parked near the gutter means its hard to mark the stopping position of the bike accurately.

More problems: For accurate results comparing aerodynamic setups (in this case wheels with covered spokes), conditions like tyre pressure, temperature and wind condition all need to be the same between runs.
This is a composite of several screen grabs from this ride with gps post .  It includes the on-screen square popups showing slope and height at different locations.

For the last few days I've been doing roll down tests on trikes with different style wheels fitted.  The aim was to see which wheels are the more aerodynamic or wind-resistance decreasing.  I'm forced to admit I didn't really come up with worthwhile results in terms of the aerodynamics, but thinking about it and jotting down a few formulas has come up with some methods which might be useful.  So here we go.  I'm going to ask a few questions, see if I can answer them mathematically, then work out if measurements I've made make any sense.


The answer depends on lots of factors, but its not hard to work out the fastest speed.

At the top of the hill when the cycle is at rest, the potential energy is MgH where M is the combined weight of cycle and rider, g is the gravitational constant of 9.8 m/(s^2) and H is the height of the hill.  Without pesky wind and rolling resistance, all that potential energy is converted to kinetic energy
 (  (  0.5*M*(V^2))  where V is the velocity at the base of the hill.

We want to end up with V expressed in km/h, and not some other silly units like m/s or miles/h.

First lets simplify the equation MgH = 0.5*M*V^2

to get g*H = 0.5 * V^2

or V(m/s) = (9.8 * 2 * H(m^2/s^2))^0.5

or V(km h/3.6) =  (9.8 * 2 * H(m^2/s^2))^0.5 or

or V(km/h) = ((9.8 *2)^0.5) * 3.6 * H^0.5

or V(km/h) = 15.9 * H(m)^0.5

With my own trials and speedo with maximum speed function, I got up to 54 kph going down the slope shown in the third pic.  Does this make sense?

Well it seems to! The calculated maximum top speed is 15.9 * 29m ^ 0.5 or 85.6 km/h, and I reached 54km/h, so it seems plausible the rest of the speed was lost to air and rolling resistance.

Before adding to this bit of maths, I thought I'd clarify what I'm trying to do here and made the diagram shown below.

Cycle Performance Improvement Map

The whole thing can be labelled Cycle Performance Improvement Map. It doesn't take everything into account, for example adding mudguards will  add weight and may worsen aerodynamic drag but still improve performance.  The tests I'm doing here are seeking some justification for cycle mods in the C5 cell of the diagram, that is showing that improving aerodynamics while increasing weight slightly is sensible.


The method I propose is to perform an energy balance by quantifying:

A: The energy expended by lifting an aerodynamic cycle accessory up a hill. This is actually the difference in potential energy between "bike plus rider plus accessory"  and "bike plus rider".

This works out at mgH where m is the weight of the accessory, g is acelleration due to gravity and H is the height of the hill.

B: The gain in energy achieved by the accessory giving extra speed during coast-down on the same hill. 

This works out at Mgh where M is the weight of the "bike plus rider plus accessory", h is the difference in height achieved during roll down tests and g is acceleration due to gravity.

To reckon that we have improved things we want an energy gain from the process, that is

mgH < Mgh.  "g" can be taken out to get

mH < Mh.

Now h is the height difference at the end of a downhill run, with and without the accessory installed and is in fact H1 - H2 (H1 with accessory, H2 without).  This is the same as (X1-X2)sin S where X1-X2 (call it X) is the distance apart in metres of the stopping points with and without the accessory and S is the angle in degrees of the slope.  With these new variables plugged in we get

mH < MXsin(S) or

We can divide everything by mH to get an Energy Gain Ratio figure

Energy Gain Ratio = (MXsin(S)) / mH and

For Energy Gain Ratio > 1, the accessory is demonstrably "worth it" in gross energy terms when ascending and descending the hill, but there are some provisos.  For example, your peak energy output of the entire course could be when climbing the hill, and adding to that burden might not be helpful even if there are overall energy gains.


Meanwhile here is a link to an article (p16) about a Lightning Recumbent that seems relevant.


Steve Nurse 

Thursday, January 4, 2018

Disc Wheel Tests Part 1

Standard Wheel Weight 1.22kg

These are part of the wheel covers, I used them to make the "fast trike"

Final Weight of wheels is 1.41 kg, making the whole set of wheel covers weigh about (1.41-1.22)*2kg or 0.38kg

Made from foam mat and gaffer tape, both available from Bunnings, total cost is about $24.

The trike with the 2 sets of wheels, black taped wheels should be more aerodynamic. 

After a roll down test with visible-spoke-wheels. The small stick marks the "first spot", how far I got back up a hill after a controlled" roll down with the exposed spoke wheels.....

and this is the "second spot" result with the covered spoke wheels.

This was photographed from the first spot toward the second spot, distance is about 40m.

Room for Improvement 1, by learning how to operate my wireless speedo properly, I can capture the max. speed.

Room for Improvement 2, by using this gizmo the angle of the road can be calculated and a bit of stuff worked out.
Screen grab from this ride with gps file . Start point is circled right (50m elevation), and approximate stop points are circled at left.


For better or worse I've signed up to do the (200k or so) Round the Bay in a Day or Audax Buckley's ride on Sunday.  Temps are forecast to go up to 41 on Saturday but return to a more handleable 22 degrees on Sunday.  And I've trained for it a bit, doing about 50 hilly k's on each of Sunday, Monday and Tuesday.  The ride is mostly flat, so an aero bike will help.

So today I've been building some wheels with aero covers for my trike and at the end of the day did some testing. 

The covers are designed to be robust, and whereas previous wheel covers used gaffer tape or camping foam mat, the new designs use both.  Basically I want the design to be reliable and strong first, then light, and looking good comes somewhere down the bottom of the criteria.  I already had all the bits needed including some cut foam.  Cost is $24.00.

Anyway, results were quite good, and I will report more later.

Tuesday, January 2, 2018

OzHPV Challenge 2017

One Tree Hill After Hill Climb

Overall Winner Graham Signiorini (right) with Struan Little 

Spring Gully rail trail with with Kevin Crockett

Lineup of Bents at the Koolamurt Scout Camp

Paddy O'Sullivan, oversized Unicycle

Dome Deli winning the Miss and Out.

Simon Watt's front wheel drive "Albatros" tourer.

Rail Trail near Axedale

Me in the off road

Graham Signiorini, Off road.
This year’s OzHpv Challenge was held in Bendigo and the early arrivers at the scout camp were treated to a ride in to Bendigo and out to Axedale along bike paths and led by Kevin Crockett.  The paths are pleasant, meandering and shady and we stopped at Kennington Reservoir for a short time. 

In Axedale itself we had a great afternoon tea at the Axedale pub, (3 OzHpv’ers and 4 Bendigo locals) before riding back to town along the main highway.  Kevin is building his own velomobile complete with electric assist and radio gear, and is planning to help his mate Graeme build a trike next year. We had a mutual friend in Lloyd Charter from Albury and even discussed using the Barec clubrooms for accommodation at a later challenge. 

Later at the Spring Gully pub, we caught up with Simon Watt and his friend Dave who had toured from Bendigo to Geelong over 3 days, Simon on his Albatros bike, and Dave on an electric assist tourer.  Simon is getting keen on the electric assist idea, as Dave’s return journey of 180 heavily laden kilometres was knocked off in 8 hours or so. 

Next day, races were held at the Tom Flood Velodrome in town.  We had 2 unicyclists among the recumbents. Racing with them was fine and everyone participated enthusiastically in the come and try sessions.  Low racer recumbent?  Check. Front wheel drive moving bottom bracket tourer? Check. Front wheel drive, fixed bottom bracket leaning trike? Check.  Rear wheel drive recumbents with Pete Heal carbon seats & tailboxes? Check.  Racing trike chassis from carbon fibre? Check. Fat tyre and large wheel unicycles? Check.  Dome Deli paid for 3 race entries and used the most appropriate of his bikes for each race, knowing full well he wouldn’t accumulate points when he switched bikes.

Graham Signiorini won the event overall as well as winning the Master’s trophy.  Dome Deli came second after winning every event but on a variety of bikes, and our newly elected treasurer Richard Ferris was third.

Overall Bendigo proved to be a good place to hold the challenge.  Should the Challenge be held next year at Bendigo? It needs more input from more groups to get crowd and participant numbers up.  There are many Bendigo local Pedal Prix trikers and keen Albury and Adelaide triking groups who could be involved in the social and racing aspects of the challenge. 

(This is an abbreviated version of the Challenge article from the OzHPV magazine, "Huff".

Here is a link to Several videos.

3d Videos by Dome Deli
Offroad Circuit Race - with Stephen Nures Richard Ferris Graham S & Unicyclist Peter F -
My 2D Videos

Steve Nurse

Thursday, December 7, 2017

Preparing for Ozhpv Challenge

Plastic Pot plants from recycle centre (right) will do the job of extra traffic cones, and they are very cheap at 5 - 10c each.  I am an old hand at this, having sourced cones for the Corryong event several years ago.

Newly created arrows for road race guidance.  Timber from a dumpster, laminated A4 paper, paper clamps.

Mr. T., the Miscellaneous Rolling Thing as detailed in the last post.

Shopping Race Items, the race will have 2 riders racing against each other, they will have to pick up and deposit the shopping, otherwise receive a time penalty.

Left to right, Junior, Women's, Men's and Senior trophies.

Hi, for the last few days I have been preparing for the OzHpv Challenge in Bendigo, and some of the results can be seen above.  The trike I will take is on sale through ebay, here is the link, and there is a photo of the trike below with one side cover removed . Off to Bendigo tommorrow.


Steve Nurse

Rolling Thing

A few months ago, I pulled my son's Unicycle down off the storage rack because I thought that I could make something new out of it.  My son is married and has left home, and I asked him if I could destroy his unicycle, and he said ok...... I took apart the unicycle and removed the tyre and tube, then added 2 wheels from my initial "Vicycle" tilting trike.... 

And hey presto, this is the result.  It is a 2 wheel unicycle / rolling thing with the dummy middle wheel still in place.  You could sit on the seat, kick the top of the wheels with your feet and move along, or stand on the wheels and walk along while holding on to the seat.  Now it was easy to make but I am not a unicyclist or daredevil, so it just sat around unused for a while until.......

it got to a day or so before the ozhpv challenge in bendigo which I am organising.  Although keeping the "middle" wheel in the creation still made a rolling thing, it mostly limited its configuration to a "cranks opposite / 180 degrees" configuration, because otherwise the middle wheel would touch ground.  So I took out the middle wheel by undoing and removing the spokes, and ....

......this is the result.  Note that the cranks are at 90 degrees, and the machine does not bottom out, and this.....

is the same configuration machine with the wheels flipped to a high position.  The other position for the cranks is cranks next to each other. 
Hi, taking this new creation to the OzHpv Challenge in Bendigo this weekend to liven up the Come'n'Try event.  Peter, who I met a few weeks ago is competing with his unicycle, and hopefully a few other unicyclists will also rock up, so this should keep them amused or bemused or both.


Steve Nurse

Wednesday, November 22, 2017

Tweaking the separating frame

A few bolts I made for my bike, the one on the right is the production model, made from.......

these bits.  The thin nut works better
My current trike with rectangular aluminium frame. The seat cantilevers off the fframe and doesn't need extra support.

Bolts that keep the trike together shown at right and in front of the chain, centre.

To split the trike, take the wingbolts off, and separate the frame halves can be slightly.  In that position, the custom bolt screws into the frame and then the plain bolt screws into that.   

From there, the 2 frame halves slide apart.

Bolts are kept on the frame and out of the waywhile the trike is transported.  A new bit of bling, a Speedo mount is in the foreground.
Hi, I have been working on my bike switcheroo for a while, and in the process have been upgrading whatever I can on the bikes.  This includes fixing small problems with the trike.  On country trains, I separate the trike like this and when I do, the bolts which hold it together have to go somewhere, and previously there was no good spot for that and it got a bit awkward trying to wrangle the bike halves.  And the bolts. 

And then Ta Dah! I had an idea and slowly set about turning it into a thing made from an idea.  The photos show the results.  I brazed a nut onto one of the wing bolts with holds the trike together, and hey presto, that makes a spot for the extra wing bolt somewhere out of the way on the frame.

Even though these trikes are a long way from being in production, I did my best to make the tapped wing bolt as best I could.  At first I made it using a standard wing bolt and a tapped plate, then progressed to an m8 nut and a standard wing bolt before finally settling on a narrow m8 nut brazed nut and a standard wingbolt.  (Despite having enough parts in the shed to make a rocket to the moon,  I didn't have any of the narrow nuts in my shed and my friends at Metro Bolts gave me a few samples when I bought some other fasteners there).

And I'll get to test it out next week, I will be getting up early on Tuesday to take the train to Bendigo to promote the ozhpv challenge which will be held up there in December.  Will report, all for now.


Steve Nurse

 30 Nov 2017 update.

This is not the first tricky design I have had for a removable front wheel assembly on an HPV.  Several years ago, I made a bike and called it the X15 (after its paint colour) , and while riffling through my old SD cards came across some photos of it.  I sold it to Brett in the ACT, and as far as I know he still has it. Details of frame split on that bike are shown below.

X15 has a round tube as a frame, this means the seat assembly can't cantilever off it and be secure and not rotate around the frame. There is a small amount of seat adjustment though, a couple of bolts sticking out of the back of the seat clamp into a seat post and the clamping length is adjustable.

Front tube clamp mech.  The Cool Tool was made at home from an allen key and chromoly steel.  It has 2 uses, to tighten the clamp screw as shown here...... 

And to act as a pin securing the bike halves as shown here.