News and Events

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

Monday, March 25, 2019

Helmet Finished

Old front light mount bolt could be forehead-impaling

New front light mount using cloth covered elastic bands might be a bit safer.
Similar elastic used to hold the lid of my tailbox down.

Mirror in action

Side View.  The original visor has been removed from this Scott helmet, and the blind holes used to secure it drilled through for the cable ties at the side. 

View from below

Wearing it.



Hi

As mentioned last time, I’ve been working on a helmet visor project.  I’ve made 3 different 3d printed samples and have come up with something I’m happy with.  Coincidentally, my friend and neighbour, Stu has been recovering from a bad bike crash which forced him to be helicoptered to hospital from north-western Victoria.  Quite a few people advocate helmet-free-cycling in Australia, but Stu would vote for wearing helmets always, as it’s quite probable that his has saved his life.

Anyway, Stu’s crash and injuries made me think about the safety aspects of my own helmet design, and forced me to make a few changes.  Helmets are …….”protective head coverings especially made of a hard material to resist impact” (Penguin Pocket English Dictionary 1986), and this defines their primary purpose as preventing head injuries during accidents.  But on bikes they can have a range of secondary purposes, and these can include

* preventing accidents themselves by improving cyclist visibility by being brightly coloured, and including front and rear lights and reflectors.
* improving rider comfort by preventing sun glare and sun burn through use of a visor
* improving rider awareness of traffic and comfort by providing a rear view mirror.

These secondary purposes of the helmet are often used, but the primary purpose of the helmet is rarely used. However, as Stu’s accident showed, when used for the primary purpose, the design of the helmet is really important, and the secondary bits on the helmet shouldn’t compromise the original purpose of the design.

So advertently and inadvertently, my new printed-side helmet design takes a few positive steps in this direction. The flutes in the corflute part of the visor now run in the fold direction of instead of perpendicular to the folds as in the earlier version.  This means that on impact the corflute should crush more easily avoiding injury.

The corflute is only held in the side plates by the tight fit of the corflute, and there is no glue, and no pins or other fasteners. (At one stage I was contemplating adding map pins to the design to hold it together, but sofar it hasn’t needed them) So on impact the corflute should slip out of the side plates and not cause injury.

The front light is held on to the visor by this sort  of elastic band which I discovered on a shopping trip with my wife Christine.  This makes for a sort of resilient mount which should break apart on impact. Previously I had drilled the base of the blinky light and the centre of the mirror to hold it in place.  This needed work but also left a large bolt-end protrusion ready to pierce the forehead!
So that’s it for now.  I will put the design on thingiverse soon.  Hardest to obtain might be the 3mm x 20mm x 180mm plastic mirror sheet.

Steps to make helmet mirror thing:

Find a suitable helmet, my conversion is of a Scott Supra-Pak 10 from Anaconda.
You will need 6 cable ties approx 200 x 2.5mm wide,
3mm coreflute,
3 x 180 x 20 plastic mirror.

Navigate your way to Thingiverse.

Print the coreflute plan, cut out and fold the coreflute.
3d print the parts for the sides of the visor.
Remove the original visor from the helmet.
Drill approx 2.8mm through the holes used to hold the visor.  This small diameter means the black visor hole surrounds are not disturbed.
Assemble and test.

Good Luck!


Regards

Steve Nurse

Sunday, March 24, 2019

More bike progress

Seatpost base from 3d printed parts

Seatpost base
After a blockie

During a blockie

Ceres bike shed in full swing

Disused bikes and scrap tyre pile at Ceres
Stopped for a chat with ....

this couple from Kooweerup who had ridden down on their Rewaco trike for the day.


Hi

After a bit of time working on the trike, it was on the road yesterday complete with brakes and gears hooked up.  Yesterday I went round the block a few times and it went ok, but its pretty laid back and it was slightly hard to see over the handlebars.  As well, I'm thinking of the weight distribution, and the laid back position probably makes the load on the front wheel a bit light for hillclimbing.

So today I organized the backyard studio, and took a few photos of the new bike and my daily driver for comparison.  From the pictures, my daily driver places my head about 75mm higher than the new trike.  The new trike is slightly lighter at 17kgs, compared to about 20 for the daily driver.

I plan to do a rework of the seatpost, propping the seat up a bit higher and making sure it stays in compression.  Will keep you posted.

A few pics from later in the day are included.  I dropped some worn-out bike tyres at Ceres for recycling and chatted to a couple on a BIG trike just near a bike path in Reservoir.  Later I went to the Reservoir tip shop and did some food shopping on the way home.

Regards

Steve Nurse

Monday, March 18, 2019

Bike progress

Seatpost showing printed crushbar inside the left hand side.

Seat mount padding from an old tyre.

Progress sofar.
Hi

Over the weekend, I managed to put in some work on the new bike I talked about here.  Its fairly well together now and all I need to do is check the seat position and fit brakes, gearchanger and bell.  The steerer needs a bit of modding so the gear and brake cables can run through it too. Will report more soon. Next Post Here

Regards

Steve Nurse

Saturday, March 16, 2019

New trike project

Fibreglass seat and 3d printed parts from Emona

Disused Trike

New Mambo stunt scooter to turn into a steerer as per my previous entry.

The weigh-in: new steerer is.....

about half a kg heavier than the previous model but I am not too concerned by this.
Hi

For a while, I have been working on a new bike project and in the last few days it has started to come together.  Last Monday was a public holiday and I cruised in to the city and bought a Mambo scooter from Big-W.  A few weeks ago, I'd altered a scooter to use on my bike and it worked quite well, so have some confidence in being able to work with a new part.  Weight of the parts is a bit of an issue but the scooter parts are upgradeable with options in decreasing order of weight going from steel to aluminium to (woohoo) titanium.

Anyway, I am hopeful of reasonably quick progress on this, will keep you posted. 

Regards

Steve Nurse

Saturday, March 9, 2019

Helmet Makeover



Old....
New....
Old.....
New....
New....
New....

Old...
Old...
Sketch for helmet mirror made after I lost my old helmet coming back from Darwin by plane.

Side Plates sketch for new helmet.
Corflute sketch for new helmet.





Hi

For about 7 years I have been riding using rear-view-mirror helmets of my own design and have found them to be quite good.  Having a mirror on the helmet I use means I always have mirrors on the bikes I ride, and don't have to equip them with mirrors of their own.  Recently I added blinky lights front and back to my helmet as well, meaning I always have visibility lights as well.

But the helmet is a bit rough, and 2 things have prompted improvement.  Firstly, when traveling back from Darwin on an overnight flight, I managed to lose my helmet at the airport, so set about making a slightly modified replacement when I got back. And secondly, during the recent Cobram ride, I had 130 unaccompanied km in which to contemplate the design, and by the end of it, I was able to sketch out something which might both work and make the helmet mirror look neater.  Oh, and having a 3d printer helps!

Anyway, photos show the progress on the makeover sofar.  I have made 2 versions of the orange sideplates, and a third, final version is coming up soon.

The helmet I have is now updated, and I've bought a new helmet to make the final version with.  A few sketches are included, and I've interspersed photos of old and new helmets above. 

Improvements with latest version are fewer cable ties, and most corflute edging is hidden away, either inside the orange plastic or as a folded edge.  

When I do the final version it won't need fibreglass rods at the side, and I will use thinner, longer cable ties. I'll work on the light mount at the front and make that look neater as well.

Regards

Steve Nurse

Sunday, March 3, 2019

Some recent Publications



Hi

Just wanted to let you know about a couple of on-line articles I've written which have become available in the last few months.  When I was at uni studying for a Master's a few years ago, part of the culture was writing papers for conferences, and I attended and wrote papers 2 years in a row for the Australasian Transport Research Forum or ATRF . When a call came out for papers for ATRF 2018 early last year, I thought I had something in me to write, and so started on a paper.

Initially I approached one of my ex-work colleagues Mehran Ektasabi to help co-write, and he introduced me to Saman Gorji who had just finished a phd.  When it came down to writing though, Saman and Mehran were not in a position to help much so I plugged on alone.  In the end I wrote 2 articles, 1 accepted by ATRF and now published online here, and the second, initially rejected online by ATRF but now published online at Hupi.

The second article published should really be read first!  It (Hupi Article) deals almost exclusively with mechanical devices while the other (ATRF) deals with electrical and mechanical.

The background to the articles started a long time ago.  Although I'm not sure that I got the first issue when it first came out, I collected all of Bike Culture magazine which ran from December 1993 to August 2000, and then subscribed to Velovision, getting the first edition and staying a subscriber until its recent extended leave. And Bike Culture has the nucleus or prehistory of the articles in issues 15 on the predecessors of Series Hybrids and 18 on the front drive hub gear bicycle.

Stefan Daniel's 2004 folding recumbent.


I've had reminders of the front hub technology ever since.  In 2004 my family travelled to Germany and I took part in the Spezi Folding Recumbent Competition (English Translation via google) there.  Stefan Daniel had a folding front hub recumbent at the competition and I mentioned this in a 2010 interview with Jim Wilson, along with the possibility of using a Pinion Gearbox as a front hub gearbox.  More recently I have ridden Aki Kubota's front drive hub bike built by Robert Warszak, and Alexander Vittouris researched front drive velomobiles and preceded  me as a master's degree student at Monash University design school.

The appendix of the ATRF article is a bit of a design provocation, a mashup of series hybrid and front hub drive technology. It probably won't be in bikes in 20 years time but who knows?

Regards

Steve Nurse

Saturday, March 2, 2019

Scooter Steerer

Donor vehicle
How it ended up
Scooter fork mod started with..
Cutting some tube to 
be brazed on to close the fork
Weight of the old unit which has been documented here , its a bit lighter but more complex than....
The new one.
Star nut from previous mod, and new modded star nut.

Top caps, old and new.
1st step in top cap mod.  Here's one I stuffed up earlier by drilling in the wrong spot.
Assembled Headset
Modified Stem
The whole trike...
showing riding position in this photo.


Hi

My most up to date trike has been working quite well but the handlebars I'd made weren't that great, they were from a bit of a mashup of parts.  When I found a Razor scooter on hard rubbish about a month ago, I gradually started gathering parts and working on it to make a steerer relacement.  Most of the story is shown above.  Although the new steerer is slightly heavier than the old one, its very neat, hides the brake and gear cables nicely and does not compromise the actions of the  star nut or top cap too much.  I plan to use this design again shortly. My first ride was to a preview of a Mirka Mora auction, it went well.

Regards

Steve Nurse