Mambo"esque" trike, the resurrection

[pegasus]

Or maybe I should have named it "the transformation"
Popshot kindly donated his leftover frame from his Mambo"esque" trike
https://atomiczombie.com/forum/threads/mambo-esque-trike.260/
Thank you very much.
My plan is to make some minor changes to make the tadpole ridable again.
Popshot project used massive fat tyres, mine doesn't,
So first task was to make the rear frame narrow again to handle a normal wheel , so some brut force was needed,

And the frame was narrow again, but needs some readjustment. The top part of the rear frame to be altered later.
The frame was also to long so I cut off the front of the frame.

And It also only 500mm between the headtubes which is to narrow for me and I don't think the headtubes angle will suit my wheel, so

ops....

 

[Popshot]

Good luck with it. Looks like you're effectively starting from scratch there though.

 

[pegasus]

I have after a long delay started the resurrection.

I bought a second hand seat a long time ago

It going to be mounted high, front end about 45cm from ground, and the tadpole is narrow so it might be to wide and interfere with the steering.
But for now it's the mounting points I'm concern about.

I have a 30x15x1.6 tube which fits neatly in the front fork.
I will have a movable seat by drilling holes in the tube every 25mm to give me a 150mm adjustment. This will be fitted 80mm over the main tube.
For the rear support, only tube I have which fits is a, very thin, old piece of curtain rail, I might only use a minimal length welded into a thicker tube and then fitted somehow.
My concern is that the side forces on the seat are to strong. I would prefer to have 2 wide fixing points up front.
Should I be concern?

 

[Popshot]

Given that having 2 wider points will still ultimately be attached to the same frame there is no point in making them. Almost all tadpoles use a single tube chassis with the same limitations on seat mounting. You should be fine.

 

[pegasus]

I'm using steel bushes as bearings, a method copied from Popshot.

Using a 18mm tube with 2mm wall. The steel bushes I'm using has a 1mm wall so I can use a 12mm stainless bult.

This is the under steering setup using 3 short bushes, the longer ones are for the kingpins.

And in the frame. First spot, no gas. Open the gas, second spot, NO GAS.

I had left the gas bottle open and have wasted a 1/4 of a bottle.

 

[Popshot]

I too have that T shirt in my collection. I now have two bottles as supplies were hard to find at one time local to me.

 

[stormbird]

I'm using steel bushes as bearings, a method copied from Popshot.

Using a 18mm tube with 2mm wall. The steel bushes I'm using has a 1mm wall so I can use a 12mm stainless bult.

Pray tell more ?

Where from , will they last in kingpins etc etc etc

Paul

 

[pegasus]

Where from , will they last in kingpins etc etc etc

The tube from Ebay, bought 1m last year.
The bushes from onlinebearings, mine measures 12 x 14 x 7 @ 78p and 12 x 14 x 12 @ 88p.
Will they last, can they handle rain, dust? I don't know.
But they are easy to replace.

 

[Popshot]

These are called split flanged bearings and are 1mm thick steel with a PTFE or teflon coating. They do work though I have never done a lot of miles on them so can not attest to durability. Knock out and knock another in to replace is simple enough. If you intend to use a bolt and sleeve system as any type of pivot these should assist in keeping a smooth operation. Just use sleeve 2mm over the bolt to allow for the bearing. Plenty on ebay or any large bearing supplier. Cheap too.

 

[stormbird]

These are called split flanged bearings and are 1mm thick steel with a PTFE or teflon coating. They do work though I have never done a lot of miles on them so can not attest to durability. Knock out and knock another in to replace is simple enough. If you intend to use a bolt and sleeve system as any type of pivot these should assist in keeping a smooth operation. Just use sleeve 2mm over the bolt to allow for the bearing. Plenty on ebay or any large bearing supplier. Cheap too.

is there a reason for selecting those over these ?

Flanged Oilube Bearing Bushes

• Can be used in industrial, automotive and agricultural applications
• Operate efficiently under heavy loads at moderate speeds or light loads at high speeds.

Which seem more traditional ?

Do the bolts have to be SS ? thinking I may have to weld to them ?

Paul

 

[Popshot]

Oil-lite type bearings are usually phosphor bronze and I can't see any reason not to try them. No reason the bolt needs to be stainless though I've welded loads of stainless to itself and mild without any problems.

 

[pegasus]

is there a reason for selecting those over these ?

Flanged Oilube Bearing Bushes
Do the bolts have to be SS ? thinking I may have to weld to them ?

Smaller, cheaper.
I had some ss bults laying about, so I'm using them.
If this work, I probably buy some chromed round bar rail slide material for the next project.
I cut the head of the bults and inserted the bult into a small piece of tube with a old bush in one end,
to centralize the bult, and a new short one in the other.

And then welded it all together with the mig.

It weld as easy as mild steel

 

[pegasus]

So this is it, 2 wheels, 12 deg castor and 12 deg kingpin inclination, I rather build a python any day, tadpoles are to complex.

Anyway it's tacked.

I checked some measurement and something is not wright, but I'm ignoring it for now.

 

[stormbird]

So this is it, 2 wheels, 12 deg castor and 12 deg kingpin inclination, I rather build a python any day, tadpoles are to complex.

yes you are right , another reason for me NOT to build a quad .......
and you haven't tackled the steering yet !

I checked some measurement and something is not wright, but I'm ignoring it for now.

I suspect the pictures has distorted it somewhat and your wheels are slightly turned from the pallet planks adding to effect of it looking crooked ?

Paul

 

[pegasus]

I bought a meter of 12mm bar so I could hold the wheel bushes steady and in line during welding.
But when I come to use the bar, I realised I had design the frame so the main frame tube was in the way.

 

[Popshot]

You aren't the first and won't be the last on that one. Done it myself and then ended up tacking them on by eye.

 

[pegasus]

I double checked some of the measurement again. What was wrong in post #13, was that the under steering was not straight. measured about 3deg out, was perfect when i fitted it, turned out the weld was broken, so all is well.

 

[pegasus]

I'm considering using a old 5 gear cassette as a middle cassette and run 2 chains.
If I look on a 26" mountain bike a common setup is 48/36/26t front and 11-32t cassette,
which gives min 0.8 and max 4.4 ratio.
My setup is front fix 42t, mid 14-28t 5 speed, rear 11-30t 8 speed on a 26" wheel.
I presume that the 2 higher gears are interchangeably and the same with the 2 middle and the lower is the nut on the cassette.
If I link the front with a 24t middle ring and uses the 28t on the middle to go to the rear cassette gives a max ratio 4.45.
and if I use the 17t on the middle, that gives a min ratio of 1 which is acceptable.
Is above concept doable, front chain fixed 42-24 rear chain 28/17 to 11-30?
I understand that the 17 and 28 should preferable be the other way around,
but because the rear chain is probably closer to 1.5 times longer than a normal setup, would it matter?

 

[Popshot]

Why run a double chain system? Can you find room under the middle for a derailleur?

 

[pegasus]

Why run a double chain system? Can you find room under the middle for a derailleur?

First, I bought a single speed chain by mistake and only have 2 suitable 8 speed chains in stock.
I only fit new chains, have had to many chain brakes.
Secondly, to gain a more preferable gear ratio.
The front 42t is on a central motor and I don't want to change it.
The seat position is high so there may be room for a derailleur.
But it might not be possible, I haven't checked the chain line yet.