My DIY Trike

[cooke86]

Hello,

Im totaly new here and i hope this is interesting to some of you. I would like to know your opinions my current DIY trike design. The idea is that it is built completely from commmonly available Aluminum profiles and is bolted and Braized together.

My ultimate goal is to create a Velomobile that I can use for my commute to work all year round. I plan on making a complete video build log and making the design open source in the future.

I would love to get some feedback and new ideas!!

PS. The design isnt complete and there are a few parts missing, Its a work in progress.

 

[Tigerbiten]

The bottom bracket looks very high in relation to the seat.
If your building it in cad then I'd put a stick figure on it and see where the highest point of the knee is.
This point wants to be below your eye level otherwise you'll not see over the body shell.
I use a Streamer Fairing on an ICE Sprint FS and at the maximum recline angle I use then I only just see over it, so I know the problem.
Swop the cranks to ~150mm, decide if you'll have heel holes in the floor then drop your bottom bracket as low as possible.
This will let you drop the front as low as possible so you can more easily see potholes close in.

Luck ..........

 

[Scoosh]

Calling @voyager !

 

[cooke86]

Hey Tigerbiten,

Thanks for taking the time to look at my design!!!

The bottom bracket is actually one of the things which Im still very unsure of, I think before I call the design finished and start building I will have to mock something up and see what the positions are like. But its something that im pretty sure is going to be changed!

... As for the potholes. Here in germany the bike roads are really well maintained so that shouldnt be too much of a problem.

I plan on building this as a comunity, if there is enough interest?? I will make a Youtube channel based around it and log the build process.

 

[irw]

Make sure you know how your bottom bracket is going to be held ultra-securely! I went through a number of revisions of bottom-bracketry when building my quad!

 

[voyager]

Hi and welcome to the forum .

@Scoosh - it was noted earlier but we have been on 3 wheels for the past few days .

Having built a few trikes ( about 20 I think ) over the last 5 years , several builds being documented on this forum I tend to agree with tigerbitten that the BB seems too high about 100mm seems to be the maximum difference between the seat and bb assembly and there are a few "problems " that can rear their ugly head with brazed and bolt together trikes ,
There is a lot of sideways force acting on the pedal boom and these can bend , even our 40mm square section 16g boom do flex .

The N5 bolt together trike has poor steering geometry . This makes a lot of difference to the "running " of a trike .
Still there are a lot of home builds going on including a "wooden trike " I noticed in Germany earlier being built ( az website ). main problems I can see are getting the angles correct and stopping movement of parts -

We weld our trikes together and don't have these types of problems . Currently time and weather have slowed down our building as Old bones and cold weather don't mix .

The last couple of my build threads that were popular on this forum was Project X The folding e-trike and the 20/20 e-trikes .

Enjoy yourself and good luck from the UK

regards emma

 

[Tigerbiten]

Any reason for the front suspension ??

I think unless your planning on a lot off road/cobble stones then there's not a lot of point due to the extra weight/complexity to get right.
I've only seen but never sat on a couple of trikes with front suspension like you're planning.
The ones I've seen used double wishbone setup.
Fattish front tyres (40-406 or 50-406) at around 60 psi will absorb a lot of the road buzz.
Also a mesh seat/thick pad helps.
I've the front sus on my ICE Sprint not so much due to potholes but mainly because I found it helps a lot with bump steer when going fast over speed pillows.

Luck .............

 

[Tigerbiten]

Re:- Bottom bracket height.
Just measured mine and it's around 15.5"/390mm, the ground wasn't 100% flat.
That gives me a couple of inches clearance with 170mm cranks and size 8/42 with the cleats set as far back as possible.
My bottom bracket is an inch or so higher than the non front sus model.
That still worked ok, but my heels where just starting to touch the ground on single track road with a very high crown.

Luck .........