Warrior front end/Streetfox rear end combination - where to start?

[Kiezel]

Dear members of my knowledgebase,
Earlier this year I have completed my warrior trike (and using it). Now it is time to build another tadpole, this time a warrior/streetfox combo, with the warrior frontend. During the first build I discovered that the plans are not totally in sync with my body dimensions. Since I am of 1.90m height with rather long arms, I am thinking about ways to change dimensions without compromising the setup of the trike. The parts that are concerning me are the seat-placement in relation to the underseat stearing in relation to the location of the front wheels (no knuckle shaving please). What is in your opinion the best way to start and what are possible implications? Thanks for your help!
Best, Gertjan

 

[Radical Brad]

You could probably do most of the stretch by just making the front boom somewhat longer. Maybe leave extra, mock up the basic frame then trim after you have the cranks set where the feel good.

 

[Popshot]

Long arms would suggest handlebars further forward which will in turn require the front wheels further forward. This can then impact heel clearance but long legs will probably require the bottom bracket well forward curing that. This puts slightly more weight over the rear but not enough to worry over.

 

[Kiezel]

You could probably do most of the stretch by just making the front boom somewhat longer. Maybe leave extra, mock up the basic frame then trim after you have the cranks set where the feel good.

Thanks Brad, building a mock-up is probably necessary to get the right distance on the key points where my warrior is sub-optimal.

 

[Kiezel]

Long arms would suggest handlebars further forward which will in turn require the front wheels further forward. This can then impact heel clearance but long legs will probably require the bottom bracket well forward curing that. This puts slightly more weight over the rear but not enough to worry over.

This is indeed my line of thinking, with the build of a mock-up as an added bonus, as Brad replied.
One question, only the handlebars should be place further forward or the USS fork as well? I would expect the latter. Not only because of weight (more material) but also the 'swing' of the steering will be blocked by my upper legs.

 

[Popshot]

Yes, the USS pivot forward too. If you move everything forward (USS pivot, and wheels / cross boom chassis members) by the same amount you'll keep all the angles and measurements of the chassis parts intact. Measure your elbow to knuckles against a regular sized person and use the difference as the amount to move everything.

Having the front wheels further forward will add slightly to the comfort as more of your weight will be over the suspended rear. It may be too little to have a noticeable effect. Another effect will be a slightly larger turning circle, again not by much though.

 

[Popshot]

You'll need to decide right at the start if you intend to build a Warrior chassis and modify the rear to accept a std sprung triangle at the back or if you are going to build a Streetfox chassis and add Warrior Style cross booms to it or even just use discs on a full Streetfox chassis. The Warrior sits a lot lower than the Streetfox and the crossboom angles and measurements are designed around that. Those same angles and measurements won't translate to the higher main chassis of the streetfox. It's nothing that can't be sorted, it will just mean you have to measure the angles yourself. The Warrior chassis will place the rear triangle pivot lower though it will still work there but that lower starting point for the rear suspension means a bigger risk of grounding the middle bits on full droop. A stiff spring will go some way to sorting that. Which route you take will depend on if you want to keep a low centre of gravity for cornering stability and just have a bit of rear suspension or if you are looking for a softer ride and will trade some cornering ability for it.

 

[Kiezel]

You'll need to decide right at the start if you intend to build a Warrior chassis and modify the rear to accept a std sprung triangle at the back or if you are going to build a Streetfox chassis and add Warrior Style cross booms to it or even just use discs on a full Streetfox chassis. The Warrior sits a lot lower than the Streetfox and the crossboom angles and measurements are designed around that. Those same angles and measurements won't translate to the higher main chassis of the streetfox. It's nothing that can't be sorted, it will just mean you have to measure the angles yourself. The Warrior chassis will place the rear triangle pivot lower though it will still work there but that lower starting point for the rear suspension means a bigger risk of grounding the middle bits on full droop. A stiff spring will go some way to sorting that. Which route you take will depend on if you want to keep a low centre of gravity for cornering stability and just have a bit of rear suspension or if you are looking for a softer ride and will trade some cornering ability for it.

Thanks, I was hoping to get away with some minor tinkering and adding the two frameparts. It seems like I have to do some more serious thinking and drawing to get the angles right. As the projected result I have the warrior front, low but not to low (no bottoming out on bad French roads, even with the suspension) and married with the streetfox rear. The cornering stability is definitely a must! The donor bikes just came in, I am waiting for the steel for the main boom. Enough time to do some more drawing and calculations.

 

[Popshot]

Even a little bit of suspension feels great after zero so long as you get the right spring rate. I tend to use air springs so the best rate can be found by adding or removing air. More expensive but easy to tune. A basic cad program is useful. Fusion 360 is great but a long learning curve. Librecad is much more basic but a doddle to pick up in minutes and perfectly adequate to design a chassis, especially as you have plans to start from.