Street legal 670 trike

[vegasboy]

Just wanted to show you guys my newly-completed 670 project. This is version 2.0 of an existing trike I had they had a 250 Ninja motor in it. I only have a few miles on the trike right now but so far I am pleased with the 670 power so far. I am not new to Predator Motors but I have never owned a 670 before this project.

 

[Kartorbust]

Looks like you are using 2 axles in the rear with only 1 brake rotor and caliper, how well does it stop with that?

 

[vegasboy]

I haven't got the rear caliper hooked up to the master cylinder yet. However the front brake does a pretty decent job of stopping the whole thing. We'll see how decent it works after the rear gets put together.

 

[Budget GoKart]

I plan on building a big wheel type thing with a old motorcycle front end and a live axle because they are cool i like your trike a lot it's interesting

 

[vegasboy]

Thanks budget. However if you drive your trike on the street and it is a live axle, you will likely have problems trying to turn the trike without the rear wheels pushing you straight forward. That is why I have a split axle. The reason the old three wheelers would work with a live axle is because the tires would slide across the top of the ground making it easier to turn with a one piece axle. If you're building a drift trike, the plastic pipe on the outside of the wheels create the same effect allowing you to have a one piece and still be able to turn with ease.

 

[Budget GoKart]

Thanks budget. However if you drive your trike on the street and it is a live axle, you will likely have problems trying to turn the trike without the rear wheels pushing you straight forward. That is why I have a split axle. The reason the old three wheelers would work with a live axle is because the tires would slide across the top of the ground making it easier to turn with a one piece axle. If you're building a drift trike, the plastic pipe on the outside of the wheels create the same effect allowing you to have a one piece and still be able to turn with ease.

My current axle is from a Montgomery ward and it has a differential I have to take some pictures

 

[vegasboy]

Please do take pics, I want to see what one of those differentials look like especially something that was vintage. I'm curious to know if it would hold up to a more modern higher horsepower motor?

 

[Budget GoKart]

Oh I forgot I'll go get some really quickly I just got a pit bike so who knows what I will build

 

[vegasboy]

The current top GPS speed is 61 miles per hour and that's with a 10 tooth clutch 48 tooth sprocket and 20 inch wheels. I think I'm going to look into getting 22 or 23 in tall tires on a slightly bigger rim. That way I know it'll go down the freeway without the motor being wound out.

 

[Kartorbust]

Fortunately you can buy a lot of performance parts for the 670. So you could keep your current tire and wheel size (unless you want to get a more common size) and just modify the engine. Could do it for more mid to high end for better highway travel, or low to mid for more cruising around town.

 

[vegasboy]

It's not a power problem it's a gearing problem, I could buy a smaller sprocket and achieve the same goal. This motor has more than enough power to do what I needed to do. However I have the sprocket welded to the hub and the axle, so changing it would require a little more work then just bolting on a smaller sprocket. That's why I was looking into taller tires with slightly bigger rims then what I currently have on there. And most of the time when we've ever heavily modified the 420cc engines they usually didn't last nearly as long as a unmodified motor. However I did bypass the governor on the 670 to give me more RPMs.

 

[Kartorbust]

Well that is the cost of modifying industrial engines. So what's the story of the Ninja 250 being replaced by the 670? A bike engine is generally a better option if it's not too cost prohibitive.

 

[vegasboy]

The 250 engine was maxed out for the weight of the trike and I, plus the radiator was behind the seat and it wouldn't get proper airflow I had to add a second fan. And the motor plus wiring and the general positioning was just not very clean. Here's what it used to look like

 

[Kartorbust]

That makes sense. Deeper gearing might have helped, but would have made the top end be a lot slower. Air ducts might have helped for cooling, but it would not have helped with the lack of power.

 

[vegasboy]

I thought about air ducts but eventually went with an extra fan. But even on the hottest Las Vegas days it just wasn't enough and the temperature readout would go up pretty high. The motor was enough to power the trike 70 miles per hour. That's why I love equipment Motors on motorcycles because I could sit in traffic all day and not overheat and I do not need to worry about air flow going down the road getting to the motor properly.

 

[Budget GoKart]

Please do take pics, I want to see what one of those differentials look like especially something that was vintage. I'm curious to know if it would hold up to a more modern higher horsepower motor?

Oops forgot again here's pics

 

[vegasboy]

How is that a differential? It just looks like it would be one wheel drive? Very odd-looking I've never seen this before

 

[Budget GoKart]

How is that a differential? It just looks like it would be one wheel drive? Very odd-looking I've never seen this before

It drives both wheels when going strait but i know that because it was used to do wheelies but it's meant for a lawn mower to take turns but not get stuck also it's a simple design that works well it's a very simple one I need to change the sprocket probably but it's gonna be geared for high speeds

 

[landuse]

Love the trike!! Welcome back to the forum. I have always liked your projects, especially because they are considered road legal

 

[vegasboy]

Thanks landuse, it took forever to rebuild it do to saving up funds to get parts and just take my time to fix all of the issues I had with the first version so I did not have them with this version. Taking my time with this one paid off. It's a much simpler and much more Bulletproof then the last design.