XTreme Tadpole Trike Build

[Pure]

I've been thinking about this build every since my accident made me lose the use of my left arm. It's going to be a wile (if ever) before I can ride a normal bike. This left me looking/shopping for a trike of some sort. Obviously I gravitated toward the tad pole recumbents. Their design just makes the most sense. But there are a few things I dislike about most of commercially available tadpoles. So this build will be my attempt to fix those problems, either my solutions be right or wrong.

For starters IMO they are too low to the ground to be used as an every day commuter. This bike will be my primary source of transportation, the risk of getting squished is just too high in the average tadpole. So I intend to make this trike with a seat height that will put my head at least mid window on average car. Raising my center of gravity has it's down sides. Obviously the risk of tipping being number one. So to combat that this is another things I've thought long and hard about.

The width of the front wheels. From reading I gather that most trikes don't ever go wider than 32inches. This is to keep them so that they will fit on most bike paths and through most doors. My bike, well is going to be big. It's never going to see the inside of my house. I have a large shop/shed in my back yard with concrete floors to store and charge it in. Also, well there really are not any trails/paths in Jacksonville for me to go on. In fact I can drive west of here and find more 4 wheeler trails than I can shake a stick at. Bottom line, I want the width to be at 42 inches. I would like to go wider, but 42 inches is what I consider at the edge of what's reasonable for a car to go around in the same lane. No I will never ride it on the sidewalk, not that Jacksonville has loads of those either. I do still realize I'm going to have to be careful in high speed turns. But again I don't foresee me ever trying to do a slalom in this thing.

Suspension is going to be tricky. I'm looking at a dual a arm setup and instead of bike shocks, I'll be using MotoX shocks meant for a 150CC motorcycles. I'm aiming for 8 inches of travel. I'm not stuck on what exact shocks I'm going to use but something like this is where I'm going. http://www.ebay.com/itm/16-NTC-Air-shock-absorbers-Quad-Go-Kart-ATV-Motorcycle-pair-yellow-/180767996727?pt=Motorcycles_Parts_Accessories&hash=item2a169cbb37&vxp=mtr#ht_3928wt_1366

For the frame, I'm working with one of my brothers for this. Well he is the certified welder in the family so he'll be handling the welding part of assembly. What I'm envisioning (sorry no fancy cad renderings) is a terrace frame design, but like most trikes Using the mono tube design but instead have one terrace rail mocked up then cut and rewelded to the rough shape most other tadpole frames are shaped. This also isn't set in stone so, I am open to suggestions. If you are having a hard time seeing what I'm thinking, I can slap something together on MS paint.

I'll be using my X5 for the power plant, and as soon as this project is completed (paid for) I'll be taking either the LiPo or A123 plunge.

Steel is being ordered on Monday. Spindles, brakes, BB, and rims will be ordered this weekend when I take the X5 into my LBS to be relaced into a new 26" rim.

Because of suspension geometry and what I want,(Basically I don't want the front A arms to be fully extended downward to give better clearance. When it sits with rider the front A arms should be almost level with the frame.) I want to get a good portion of my ground clearance from the wheels. So 24s on the front and a 26 in the rear. The track should be wide enough that the larger rims should have no clearance issues in turns.

That about sums it up, Basically I want a full suspension trike with at least double the travel and ride height of what's currently available. Wile this build will not be the lightest, I think it's whats needed to support my 250 pound frame dropping 4 feet from what ever I run over.

I'll be updating this thread as I go and will be sure to get plenty of pics.

I'm open to all comments and suggestions so lets hear it.

Oh before anyone says it. Yeah Leaning would be really nice but, I'll save that for version 2.0.

 

[MattyCiii]

If I understand you correctly regarding A-Arms - I have a couple sites to suggest & hopefully inspire you.
http://fn-trike.de/
http://tripendo.com/EDEFAULT.htm
Both use dual A-Arms, if I understand correctly.

Both are also tilting trikes. If you're doing the A-Arm thing you're 90% there anyway, so why not consider building a tilter? Complexity goes up, but risk of tipping goes down. Your wheels don't need to be as strong either because force is always in the plane of the radius.

I've never owned/ridden either of these trikes - all I have are my dreams...

 

[Pure]

The fn trike is actually very close to what I'm doing for the frame. Mine is just going to be + sized.

It at least shows me that my frame design can be used in a simple leaning solution. I might give the leaner idea a revisit.

edit: looking at the fn trike further, it doesn't appear to have brakes on the front. Having your wheels lean left to right seems like it may play hell on trying to mount brakes.

 

[MattyCiii]

I have always been a fan of this home built (leaning) trike: http://www.recumbents.com/wisil/wianecki/leaning_trike.htm

Not only does he have a good solution for disc brakes, the "hub centered" wheels solve some steering geometry problem I barely understand. :?

 

[Pure]

That is a very cool build, thanks for linking it. He definitely went a different way with how his works. All good research material, again thanks.

The more I think about it though, the more I'm sticking with my original decision to forgo leaning. One of the problems with leaners and one reason I believe it' not common place and all trikes use it, is what to do when you stop or are going slow. Wile the fix is simple, constantly having to hit a 3rd brake leaver any time you don't want the trike to flop around would get old quick. Lets not forget this trike is going to be heavy. I'm going to be hard pressed to keep it under 100 pounds. Also with a front track width of 42 inches should help enough in turns for leaning to not be necessary. Even then, should it prove to be unstable, I can always make it wider. My care for the convince of other drivers (cars going around me) is fleeting at best, besides I don't intend to be passed often.

 

[Pure]

OK For everyone's approval my MS paint version of the frame. I gave myself some room behind the seat for storage/batteries. So to make up for the lengthened rear I had to p ush the front wheels out about a foot from where they usually are. Also I'm still working on the front suspension layout, but it will be similar to how the fn trike is done with an upper and lower A arm coming off of the lower frame.

Again, this is all preliminary so I'm definitely open to suggestion.

Actually a little help with the rear swing arm geometry would be appreciated. Having the swig arm at such an angle to provide the needed ground clearance makes for mounting the shock at the appropriate functioning angle a little tricky.

 

[Pure]

Rear swing arm/suspension take 2

 

[Pure]

No opinions? bump

I only have a couple of days to decide. Metal is being bought on Monday.

 

[MattyCiii]

Well I wish I had the brains or experience to contribute meaningfully. One day I'd like to build a trike myself. So mostly I'll be watching this thread from the side lines.

Are you going with a mesh seat, or a hard shell? Years ago I was going to build myself a recumbent bike. I got as far as a few parts, including a hard shell seat. It just sits there like sculpture in the basement. If you have any interest at all I can take pix/send dimensions, and maybe find the info on the place I bought it. That would be one less custom piece for you to fab.

~Matt

 

[MattyCiii]

There's a lot of great build threads here http://www.recumbents.com/wisil/whatsup.htm that will give you ideas and hopefully inspiration. After mentioning the hard shell seat above I recalled there's at least a few mesh seat installations at the above site - if you're comfortable bending and welding tube it looks pretty easy.

 

[Pure]

Well I wish I had the brains or experience to contribute meaningfully. One day I'd like to build a trike myself. So mostly I'll be watching this thread from the side lines.

Are you going with a mesh seat, or a hard shell? Years ago I was going to build myself a recumbent bike. I got as far as a few parts, including a hard shell seat. It just sits there like sculpture in the basement. If you have any interest at all I can take pix/send dimensions, and maybe find the info on the place I bought it. That would be one less custom piece for you to fab.

~Matt

That would definitely be a big help. Any thing you can send me will be appreciated. My seat is going to be pretty simple but should be very comfy. With my *cough* robust stature, I'm making it a few inches wider then say what the standard KMX seat would be. Coming off of the main frame you can see in my drawing, the tubing for the bottom/buttox and back seat support will have seat supports welded in place goinig from left to right, off of the mainframe/bar. On those bars I plan to bolt fitted, cut plywood. I intend to make these supports strong enough tho mount a 5 point harness to.

Now I'm lucky that I also have another brother who owns a custom car audio shop that also does appolstry. So I'm going to take the trike to him to have the plywood seat fitted and upholstered, with high density foam molded to my back and bum, then covered/appolsterd in a very thick black leather. The stuff is so thick that it's going to have to be naild, as to using common appolster stables that are too short. The job should be about free as I'm going to let them embroider the Shop's name in the leather.

 

[docnjoj]

Our trikes were purchased with one of the parameters being that they can go through the 36" front door, so both have fairly narrow tracks. My Steintrike is only 30" wide at the widest part, but the front wheels have a slight negative camber (bottom of the wheel tilted out) of about 5 degrees. This makes it pretty stable even with the larger 20" front wheels i put on and the raised seat. You may not need all that extra width at the front axle to corner well, but only testing will tell. Yours is definitely a cool design!
otherDoc

 

[Pure]

You're right doc, it may not need the extra width, but I figure better safe than sorry. My ars is going to be about 3 feet off the ground, so not insane high, but high enough too allow for longer suspension travel, and of course safer riding height. Also with properly tuned front suspension cornering at speeds can be fun. The trike should be able to drift the rear tire wile the suspension absorbs the frame wanting to roll or at least dampens it.

Steel has been ordered. I had to buy a 24ft piece of 1/2 square tubing for the rear swing arm, so I'll use the rest for the larger diameter tubing in my sketch. Waist not want not.

 

[MattyCiii]

...Are you going with a mesh seat, or a hard shell? Years ago I was going to build myself a recumbent bike. I got as far as a few parts, including a hard shell seat. It just sits there like sculpture in the basement. If you have any interest at all I can take pix/send dimensions, and maybe find the info on the place I bought it. That would be one less custom piece for you to fab.

~Matt

That would definitely be a big help...

Well since someone went ahead and started a thread on recumbent seats I posted what I have (so far) there: http://endless-sphere.com/forums/viewtopic.php?f=2&t=38648
No dimensions, I was running out the door and almost forgot to grab pics. Measurements to follow.

 

[hekdude]

The fn trike is actually very close to what I'm doing for the frame. Mine is just going to be + sized.

It at least shows me that my frame design can be used in a simple leaning solution. I might give the leaner idea a revisit.

edit: looking at the fn trike further, it doesn't appear to have brakes on the front. Having your wheels lean left to right seems like it may play hell on trying to mount brakes.

the cover photo angle hides them. Here is another photo on the site showing that it does have front disk brakes