[trikes] testing suspension trike on rough trail

[Julian Edgar]

The springs are Firestone rolling lip airbags. The choice of this springing
medium is covered in detail at
http://www.autospeed.com/cms/A_108591/article.html . I think that airbags
are superior to any other springs for an HPV. The dampers are separate and
use oil. They are based on Yamaha R1 motorcycle steering dampers. 
 
With carrier, three bidons and pedals, weight is 24kg. (Trike also has
all-wheel brakes and 81 gears.)  
 
Maximum all-up test weight has been 159kg (ie trike at 24kg,  rider at 90kg
and test load at 45kg). This pic shows two wheel testing at full load -
http://us1.webpublications.com.au/static/images/articles/i1112/111232_2mg.jp
g
 
 
 
Regards,
 
Julian Edgar
 
 
From: Philip Donahue [mailto:granpita at gmail.com] 
Sent: Monday, 14 December 2009 12:29 AM
To: editor at autospeed.com
Subject: Re: [trikes] testing suspension trike on rough trail
 
You do some remarkable work. What is the empty weight of the trike at this
point?
 
Also, did you consider using an elastomer suspension instead of the oil
shocks? I ask because I have the last ICE Explorer made. I had it done with
the rear suspension which was a Cane Creek shock but all of Trice's new
models use elastomers. 
 
Thanks,
Phil Donahue
Kennersley Point Marina
410.490.0810 Cell
 
 
 
On Dec 13, 2009, at 3:13 AM, Julian Edgar wrote:



Hi Folks,

After about a 9 months' hiatus I am again back on my self-built suspension
trike. (Hiatus due to moving interstate, changing jobs, etc.)

Details on my trike at www.autospeed.com - search under 'Chalky' - there's a
7 part series that covers its full development. Since that series I have
added front dampers to go with the Firestone airbags (I've always used a
rear damper). 

Today I went on a very rough dirt trail that follows the railway line out of
Bungendore (New South Wales, Australia). You can see a pic of the trike on
the trail at
http://i638.photobucket.com/albums/uu102/JulianEdgar/Chalkyontrail.jpg
(with other photos of the trike development at
http://s638.photobucket.com/albums/uu102/JulianEdgar/ )

The photo doesn't really do the trail justice - estimated 15 per cent
ascents, washaways (where creeks have crossed the trail and removed much
dirt, leaving behind rocks), steep descents, one very quick black snake,
some beautiful birds, lots of large rocks as big as a man's fist (fallen
from the railway's ballast), etc.

I rode with about 10-12kg of extra load - 3 litres water, RT40 Arkel
panniers with lunch and Arkel Tailrider with tools.

I was mightily pleased with the trike's performance: no failures, no
punctures (I think the suspension massively protects the tyres), excellent
handling on really treacherous surfaces, excellent ride, appropriate
physical effort. 

My front Watts Link scraped perhaps 5 times (need to look at this) and the
rear derailleur scraped perhaps 10 times (not much I can do with 16 inch
wheels and the required gear range - except use an internal gear hub with
more than the current 3 speeds). One front damper also has a glisten of  oil
on its shaft - perhaps a weep past the seal caused by overly high
instantaneous internal pressures on the really big bumps. 

Did about 10km on really rough dirt and then the return 10km on the (nice
and smooth!) bitumen road. Tomorrow I'll inspect the (prototype) frame for
cracks and abrasions.

Regards,

Julian Edgar


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