V2 Trike




This trike was built for economy and home workshop constructability. It evolved from our first (V1) trike, designed and built in 3 weeks using almost totally recycled bike tube and parts. V1 used ideas from several commercial trikes, had nice handling, was fun to ride, comfortable, efficient and reliable. But after a year of abuse including BMX track jumps and hacking the frame for some crude suspension, the limitations of V1 became apparent (see images). V2 has evolved as a lower, narrower and more robust version, still using mostly recycled parts but with a high tensile tube frame.

V1 was built using basic handyman tools and welded totally using a fixed current (i.e. no adjustments) arc welder. We don't recommend this. Arc welding thin tube also isn't something we'd recommend but it was possible. Avoiding burn-through too often was tricky but made easier by:
- using short (10-20mm) inner sleeves of tight fitting tube at welds (where possible).
- using 2.5mm and sometimes 3.2mm electrodes.
- using a high speed tapping action when welding.
- keeping the rod moving.
V1 took about 25 hours labour and cost A$250 to build and after buying new tyres, mudguards, computer, rear derailleur. More resourceful builders could have done it cheaper. V2 added A$20 in tube cost and the advantage of a MIG welder. The joins in the main frame tube are still sleeved (also assists in alignment).

Since V2 wasn't built from scratch, there isn't a full sequence of construction pictures. The attached info includes images from V1, V2 and cross-member construction method from another project to represent the way it would be best to build it from scratch now. Some of the original jigs were very complex - the info shows the most reliable and simplest ways to jig the construction that we have found. Trike construction without some basic jigs can be a very courageous move (courageous as per the British comedy "Yes Minister"). The trike needs to be square and true to have reasonable handling.

We've tried to make the build info as complete and correct as we could make it but we can't guarantee it is either. If you use it, check it, we take no responsibility. Having said that hopefully there’s something useful in it for you.

Other random info:
- SHS (square hollow section) steel tube should be grade C350 (350Mpa yield strength). Locally this is common, comes painted blue and 35x35x1.6 is about A$5/metre. Mild steel (ERW) tube isn't as strong (about 200Mpa).
- For short lengths and jigs check the offcuts at your steel supplier - usually much cheaper.
- 31.8x31.8x1.6 ERW tube is good for sleeving joins in the main tube.
- The images show an extra tube on the left rear chain-stay. This was a low mount for a Bionx battery pack but grit and water could get into a drain hole because the battery pack was mounted upside down.
- The images show clipless pedals recently added. (They keep your feet up if taking bumps at speed!)
- Sealed bearing front wheels would be a better if you have that choice (see axle mount page).
- Small chain pulley came from MR Components (Trisled pulley looks very similar). Three prior were home made from inline skate wheels but weren't that reliable for us.
- Rod Ends came from bearing suppliers (note they vary from about A$11 to A$20+)
- Seat Fabric, Eyelets came from Greenspeed.
- We sourced parts to recycle from (in rough order from least cost to easiest selection): our own garage, friends who know we are building, hard rubbish (we ask the owner!), some rubbish tips that recycle bikes, Trash & Treasure Markets, Ceres bicycle group, garage sales, commercial bike recycling shops. The cost of building depends on how resourceful you are and how much time you have.
The seat was made for a rider approx 1.8m (6ft) tall (seated shoulder height 65cm, x-seam 110cm) but seems to suit shorter riders also.
- Personal measurement definitions, see http://www.greenspeed.com.au/newgsweb/web-content/usa/measure.html

- V2 has been made as narrow and low as possible while retaining under-seat steering. The seat is only 30cm wide but with the seat fabric stretched fairly tight this is quite comfortable. The handlebars as dimensioned are a comfortable fit for someone 40cm hip width. If in doubt, start with the central handlebar section wider (currently half-width shown as 160) and trim to suit. Too wide and you will conflict with the front tyres. If you make it much wider you will need to increase the track or dispense with under-seat steering.
- If dispensing with the under-seat steering or modifying anything in the steering geometry take care to check it on Peter Eland's Ackermann Steering spreadsheet(s). http://www.eland.org.uk/steering.html
- Since the small 60mm ground clearance occurs just behind the front wheels it has been adequate for all but the more severe spoon drains and speed humps that need to be taken on an angle.
- The 19mm bender was made from an alloy pulley from a scrap dealer, cost <A$20 to make, and seems to work well. The 16mm bender worked fine for the original V1 seat but 16mm tube without support under the middle of the seat didn't hold on jumps. Possibly 19mm with mid seat support may be overkill but that's what V2 has.
- Take care to cover any threads when welding to avoid spatter damage – it can be nasty. Easiest for us was to screw in a cheap expendable bolt into inner threads and for outer threads put a bit of tube over.
- The handle and light mount above the chainwheel is a piece of handlebar welded to a piece of seat tube, then held in with a small screw in the front.
- The 25mm Diameter fornt fork head-stem tubes need to be approx 190mm long.
- If using the Sealed bearing front wheels and High Tensile bolts for axles, you may not be able to remove the axle jig after welding the bolts on, so on one side just tack weld the axle tube to the jig and grind off after, or make it demountable.
- The images show several trial locations for the chain pulley. the drawings show the final location.

- Refer also to members pages, builders info and links on the ozhpv and vichpv web pages and join their email lists for more useful construction stuff. We can be contacted via the vichpv email list.

Alan and Eric

Recycled parts:
2- front wheels 20in BMX 1/2inch axle, or sealed bearing wheel, 1/2inch hi-tensile bolt and nyloc nut.
1- rear wheel 20in
1- rear cluster 14-28 ok (11-34 better), derailleur, cable, shifter
1- front derailleur, cable, shifter
1- triple chain-wheel, cranks (alloy better), pedals.
3- bottom brackets with crank axle, including one with frame seat tube from frame still attached.
2- crank arms, steel for welding to.
1- pair of rear axle dropouts, preferably with derailleur mount.
1- seat post, steel (for main frame to rear chain-stay tube).
2- bar ends (simple type that clamp can be cut from).
2- handlebars – steel racing type with maximum straight section.
1- frame head-stem tube and bearing set (for steering pivot)
1- fork head-stem tube for the above.
2- 25mm Diameter fork head-stem tubes approx 190mm long (or join two)
1- forks, strong "D" cross-section 26in-28in for making rear chain-stays.
2- forks, round cross-section, approx 29mm diameter just below v-brake mounts.
2- V-Brake sets including brake levers, cable and calipers.

1- Chain Pulley 8mm shaft, approx 42mm Dia outside. (or make one from a skate wheel)
2- Rod Ends 5/16in UNF male – Left Hand Thread
2- Rod Ends 5/16in UNF male – Right Hand Thread
7- 8mm Rod couplers (2=boom, 2=steering arms, 2=seat, 1=chain pulley)
1- Seat fabric, Breezeway 1200mm x 660mm
40- Eyelets 10mm
6 -metres approx 6mm shock cord.
various - bolts, nuts, washers.

0.2m - 40x40x2.5mm Square Hollow Section (blue painted grade C350-C450)
2.0m - 35x35x1.6mm Square Hollow Section (blue painted grade C350-C450)
0.4m - 30x30x1.6mm Square Hollow Section (blue painted grade C350-C450)
0.4m – 22x1.6mm ERW circular (or handlebar sections)
4.0m – 19x1.6mm ERW circular (mostly for seat)
0.5m – 12.7x1.6mm ERW steel circular or 10x1.6 Alum 6061 tube (see drawing)
1.0m - 16x16x1.6mm ERW square tube (or recycle something similar)
0.1m - 20x5 flat bar ( or recycle something!)

Trike Specifications:
Length: 1850mm
Width: 840mm
Height: 680mm
Weight: 22kg as built.

Track: 716 mm
Wheelbase: 1000mm
Seat Angle: 39 degrees
Road Clearance: 60mm
Wheels: 20 inch : Front= ½ inch BMX axle.
Turning Radius (inner wheel): 2.1 m ( measured)
Chain-wheel: 48:38:28 ( two mountain bike rings fitted to road bike alloy 48 chainwheel and cranks )
Rear Cluster: 6 speed 28:14 (adequate but a 34:12 would be nicer!)

Final Tyres: Front= Maxxis Miracle pumped 100psi, Rear=Maxxis Hookworm, pumped 40psi.