DIY low cost " Locust" tadpole trike

Hi Folks
With the workshop too cold to spray and another couple of projects stalled at present .
I was starting to get rid of some old bits of frames , when I had an Idea ( oops sorry ) .
A low cost trike built from a few bits of left over tubing that could be swapped for pieces from a scrap bike frame and using the rear triangle from a MTB and BMX 14 mm spindles front wheels .
I have a rear 24" wheel and rear MTB triangle spare and a pair of BMX front wheels that came from our local tip
The "new " parts for the build will be :- the rear freewheel , 3 x 112 link 3/32 chains , a 80mm Ball raced nylon pulley as I don't believe in using second hand parts for the transmission I will also use NEW brake and gear cables for safety reasons .

The locust is a basic tadpole trike that can be built from anyone with some welding experience from a few scrap bike frame but still look like a professional Build . the use of round and oval tube will give it that shop built look ,

So here is the "concept " and the start of the project in photos .

The basic parts , the piece in front is a piece of oval tube cut at an angle of 75 degrees ( 15 degrees on the chop saw ) that is a sliding fit in the main piece of the MTB frame this gives the caster angle for the front boom and allows the front to rear section of the boom to line up perfectly . the cross boom made from a piece off a scrap childs gate has the camber angles ( 75 degrees ) cut into the ends of the tube and the centre tube is drilled to clear the 29mm seat tube which will form the stub to hold the adjustable pedal /BB boom . This fabrication "joint " will make assembly easier to jig up and weld .
The pedal/bb boom was cut from a standard DF frame and uses the down tube and part of the seat tube .
The seatpin will be used as a sleeve to strengthen the join where the sliding BB boom is clamped onto the stub of the nose that sticks through the cross boom .

The trike will have an approx track of 30" and a wheel base of 41 inches and Direct Knuckle steering for simplicity with caliper front brakes .

The frame with its main pieces slotted together as a test run for the welding once the cross boom has be welded up and the front axle lugs welded on the fork tubes

Well that is it for now and I hope to continue the build after the new year and I hope I may have whet your appetite in building your own DIY tadpole trike .

Happy Christmas all

regards emma


Do you ever stop, emma ? :laugh:

What do you do with all your trike builds ? :laugh: :ohmy: :scratch:

Take a break over the 'festive season' - please ! :wahhey:
Do you ever stop, emma ? :laugh:

What do you do with all your trike builds ? :laugh: :ohmy: :scratch:

Take a break over the 'festive season' - please ! :wahhey:
Hi Scoosh

I stop when I am either cold or ill unfortunately with old age comes not so good health and cycling is my way of fighting type 2 diabetes , now having reversed it for over 2 years :boxing: it was a hard fight but I have got there and I don't want to return there again :ohmy:

I still have most of my trike builds but I will need to dispose of a couple this year as l have run out of space . :laugh: :ohmy: :scratch:
I have a hi-power 20/26 e-trike and a hi spec 20/26 tadpole that I am forced to sell this year .
If anyone is interested please PM me for details ( trikes are located just outside of Brighton )

We took a break over Christmas and whist the Christmas Dinner was happily cooking in the oven and the sun :sun: came out , we triked down to Shoreham beach for a couple of hours


Voyager e-trike and the red 20/20 basking in the sun !!!!! with the South Downs in the distance.

Christmas Day at midday looking from Shoreham Beach (the Fort Car park ) across to the harbour mouth and the Lighthouse with the new Lifeboat Station , Air Temperatures are about 7 degrees C

What a brilliant project. Let's see all the progress pics. Don't work too hard and have a great Christmas.
Thanks Cycleops we had a quiet Christmas with lots of festive cheer .

Today :ohmy:
After the early morning activity of Jack Frost who painted everything in view white , the air temperatures rose to about 4 degrees C :sun: and thus armed with a hot cup of tea :cheers: and thermals :wub: I braved the 5 metres between the house and garage to do an hours work before dinner

I set up and welded on the head tubes ( the position is dictated by the accurate drilling of the holes on the top and bottom of the cross beam and the
distance between the lower part of the head tube and the underside of the boom . Then after rechecking the angles the wheel tabs were welded on using an "ambidextrous" jig to ensure the tab were the correct distance and square from the reference line along the top of the cross boom . A bit crude single use jig but after welding both sides the jig destroys itself as it is made from wood .:cry: but they are easy to make ^_^.
Now the axles tabs are in the correct position I only need to find a pair of brake calipers and weld on the brake arms to suit the " drop "


So that is it until next week :stop: as I hope to have another couple of days doing very little over the New Year ( In reality I have the Kitchen ceiling to paint and the wall to emulsion as we had a flat roof leak just before Christmas , Having fixed the roof it only leaves the room to redecorate :sad: )
It also gives me some time to find :hello: the brake calipers which I think :rolleyes: are at the bottom of the bike bits dustbin :cursing:

( :bicycle: Ken is now using the e-shopper as a commute to work bike and has put several miles on it so far this week :bicycle:)

regards emma
Hi Folks

Thought that I would keep a running total for the build this time so
The front wheels from the Street -E-fox (1)
disc upgrade ( value ) £40
Bike bits and gate from the tip about £30 ,
3 chains and Pulley £30
brake cables £ 8
spherical rod ends ( track rod ends ) £10
and Decals . £ 4
Paint ( primer 2x colour 1 laquer) £20
and upholstery
(the new wood for the seat
foam and fabric with
new bolts and tee nuts and staples ) £20
2 bottles of disposable gas £30
wire £10
cutting discs and grinding discs £10
total to date just over £200
hours to date lots

(1) these are almost new and will look better than the ones from the tip

Building a trike at home is not a cheap alternative, even using low cost parts and the hours mount up, even valuing an hour at £10 , several hundred pounds of value would be put into a trike if included with the parts ,

(But and there is always a but )

but as I said it is 110% hobby (Just like building model boats or model aircraft ).

you know how it is built and the satisfaction of saying I built it myself makes it worth while .

Regards emma
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Today I did a test assemble on the cross member to check all will be fine on the assembly day , also I found to my delight in the bike bin that as well as the pair of brakes I have a seat pin collar that fits the front boom perfectly , That has spurred me on and forward into 2015 . this should make the fitting a lot more professional and easier for me . The front brake were a "from the top pull "( front brake style ) and they need to become "under pull" ( ladies rear style ) so a little adjustment and a new pair of adjusters ( £3) ordered from ebay they will fit without a problem .

The final Photo of 2014 - the trial fit of the cross boom with the head tubes and wheel tabs in place .
The initial measurement indicate that a wheel base of 40" and track of 31 " and the BB should be about 15" minimum off the ground so eliminating heel strike . The seat mounts will be about 13" approx from the ground .

with headtubes.jpg

Happy new year to you all.

regards emma
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Hi Folks

Today I started to weld up the frame and spent 3 hours in the front of the garage with air temperatures about 7 degrees C . I have welded the main parts together , the drive pulley mount, 3 seat mounts and the rear suspension mount .That leaves the brake arms to trim and mount , to complete the "frame " leaving only a couple of bits to weld once the frame in on its wheels ( Ackerman steering arms and tie rod ) , The return chain tube mount can only be welded once the trike is on its wheels with cranks and gears fitted . I hope to take a photo tomorrow if we are blessed again with fine weather .
I had to change the gas bottle (CO2 Argon mix with a larger disposable bottle) this morning as I used the smaller one up .The problem with a build of this type using ex MTB bike frames means more welding than normal to do as the tube is more complicated to prepare and weld as the compound shapes have longer and more complicated shapes to weld around . Still l am over 50% done and that feels good .
The new brake adjusters arrived today and the brakes have been reassemble and will work , leaving me to strip and paint them once the trike has had some test riding .
The seat back and squab is ready to mark and drill for the tee nut and then I can cover it .

regards emma
Hi Folks

After the rain early this morning , I got a few hours out in the workshop today , The time flew by but at the end of a morning I had plenty to show for it.
I cut and welded the brake arms to the front wheel lugs and fitted the front brakes and fitted the tie rod arms and made the tie rod .
This made it possible to test fit the seat and mark the position for the tee nuts then drill and fit them .
Here are a few photos to see how far I have got ,

The wheel fitted was a spare 26" wheel not the 24" that will be fitted . It was just to give an idea of the finished trike . The afternoon saw me doing a few other chores but I have sprayed the back/bottom of the seat with underbody shield to keep the moisture out . Hopefully I should have the rear wheel over here and the seat covered before the end of the wheel and start to assemble it for a test ride .

regards emma


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Hi Folks

Yesterday I collected the 6 speed 24" rear wheel and the other bits from my garage
The seat back and bottom have been finished using 1" foam and upholstered with cream vinyl fabric .
The trike was then reassembled with the 20"/24" wheels and shorter D.K.S steering arms ,

Today after I fitted the triple chain set and pedals I fitted the spacer on the top pulley , assembled the 3 chains and welded on the return chain guide .
Finishing off by welding 4 support gussets to reinforce the seat arms (as they are welded to the top of oval and round tubing )
All the welding is now finished ( another bottle of gas ran out ) after i cleaned and touched up some of the welds I could not get to before .

Finally fitted the new seat onto the trike .

This only leaves me to find a front changer and weld on a cable guide . Find and fit a pair of brake and gear levers and finally to cable up the trike
then its ready for a road test.

More photos tomorrow if the weather is good to me

regards emma
Hi Folks

With the sun trying to come out I took the trike along to the corner of the road today

Here is the only photo as I am waiting to sort out the gear and brake levers so I can cable up the trike
Protective Seat covering removed ( poly bag ) to show the cream seat swab and back .


regards emma
Hi Folks

As it was a wet ( really wet and COLD day today
) I was not going to get much done, so I decided to concentrate on the bars . These were the original bars off the street fox ( pre USS ) and as they were looking lost in the box I decided to use them . Handlebars are best painted before fitting the furniture , ( having tested them last week without brakes :hyper:) so as it was so wet I cleaned them up in the garage ( after half an hour with a flap wheel about the time my cup of tea ran out :cheers: I knew it was the right decision ^_^ ) and brought them inside to repaint together with the brake callipers to refurbish in the warm.
Hopefully the postman will bring my brake levers tomorrow :bicycle: and I can refit the handlebars complete . and road test it with brakes . :wahhey:
pic host
regards emma
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