New project. Trike, customer wants it to go fast

[docnjoj]

Not relevent to KMX but to going downhill fast. Check out the video of a team Steintrike going down a luge chute in the summer. Supposedly 100km/hr speeds. Yes it is full suspension and is is about 4500 USD but it comes fully developed. Frames are a lot less, like mine.

http://www.steintrikes.com/gallery/movie_gallery/movie_gallery.php

otherDoc

 

[rborger73]

And we're off to the races! Project is now underway. More pics coming in a week or two.

 

[mlb2109]

I have HUGE experience with powered tadpole trikes. 40 mph is fine on a KMX. Above that I recommend a steering damper. With the damper, the sky is the limit on stability. I have run 72 mph on my KMX and Outrider went 86mph. Dampers cure any stability issues.

Matt

40 MPH on a KMX is like 200 MPH in a Yugo. With enough power it can be done. Just seems like a waste of power to me.

40mph doesn't seem all that extreme.

Said the guy that hasn't done it! "Seem" You say 36. Hit 40. Report back if there's a difference. (report back on the difference)
Oh, and don't forget to turn in that run. No straight line bs.

 

[mlb2109]

Not relevent to KMX but to going downhill fast. Check out the video of a team Steintrike going down a luge chute in the summer. Supposedly 100km/hr speeds. Yes it is full suspension and is is about 4500 USD but it comes fully developed. Frames are a lot less, like mine.

http://www.steintrikes.com/gallery/movie_gallery/movie_gallery.php

otherDoc

You do understand that a luge chute isn't really like the real world?

Physics DOES apply!

 

[rborger73]

Said the guy that hasn't done it! "Seem" You say 36. Hit 40. Report back if there's a difference. (report back on the difference)
Oh, and don't forget to turn in that run. No straight line bs.

I hit 40 yesterday on my main ride. lol Not sure exactly who you were replying to here... I hit 36 to 40 everyday man. lol

 

[docnjoj]

Not relevent to KMX but to going downhill fast. Check out the video of a team Steintrike going down a luge chute in the summer. Supposedly 100km/hr speeds. Yes it is full suspension and is is about 4500 USD but it comes fully developed. Frames are a lot less, like mine.

http://www.steintrikes.com/gallery/movie_gallery/movie_gallery.php

otherDoc

You do understand that a luge chute isn't really like the real world?

Physics DOES apply!

Not sure what U mean. It is on Earth. The sleds go even faster on the snow in winter.
otherDoc

 

[MadRhino]

Speed is highly subjective.
One does find 40 Mph to be scary fast, while another does find it boring.
Then, speed comes with a responsibility, to build and ride safely at high speed is not given to everyone.
Although I never built a trike, I guess it is more challenging to build properly for speed, than it is for a bike.

We are not talking fun, but handling and braking distance that are adequate for the performance of the build, making it safe and comfortable to ride that speed.

 

[rborger73]

Speed is highly subjective.
One does find 40 Mph to be scary fast, while another does find it boring.
Then, speed comes with a responsibility, to build and ride safely at high speed is not given to everyone.
Although I never built a trike, I guess it is more challenging to build properly for speed, than it is for a bike.

We are not talking fun, but handling and braking distance that are adequate for the performance of the build, making it safe and comfortable to ride that speed.

Safe is subjective too I suppose. We hung out where I work till 10pm or so tonight, and had a thunderstorm go through around 6pm or so. Well weather is warming up and of course had crazy fog. Fog so bad I had to take my glasses off as they were getting wet within 30 seconds of cleaning them. So in the fog, at 30mph give or take with no glasses on, and then my headlight switch starts flashing indicating it could go dead at anytime. Now if this wasn't the exact route I ride twice a day for the better part of nearly 10,000 miles over the last year, I probably would have made other travel arrangements, and if the roads I were on weren't very rarely traveled, I'd have not rode the 17+ miles home on the bike. I forgot to look and see what my top speed was on my gps tonight, I'm sure I hit at least 33 though. I know every pothole, but still of course was dangerous. I would have slowed my pace much more if not for the headlight that might leave me in the dark with just my rear tail light leds. lol I have to find a dc/dc converter that can handle higher amperage so I can use it as an option instead of the 4s pack that goes with the headlight so that isn't an issue again. lol The good thing here is that I can still see cars from a better distance at night and be ready for them earlier. Heart beating faster lets you know you are alive.

I expect by the end of June I'll have hit 50mph on a trike, so I'll let everyone know how scary it is.

 

[MadRhino]

Safe is subjective too I suppose.

Well, feeling safe sure is subjective. Building safe is only meeting performance data: Stopping distance and cornering adherence are (or not) adequate for the speed that it rides. When it does brake shorter than average and corners predictably, it may be considered as being built safe for its speed.

After that, the rider is responsible to trust it or not, to abuse it or not. This is subjective.

 

[mlb2109]

Not relevent to KMX but to going downhill fast. Check out the video of a team Steintrike going down a luge chute in the summer. Supposedly 100km/hr speeds. Yes it is full suspension and is is about 4500 USD but it comes fully developed. Frames are a lot less, like mine.

http://www.steintrikes.com/gallery/movie_gallery/movie_gallery.php

otherDoc

You do understand that a luge chute isn't really like the real world?

Physics DOES apply!

Not sure what U mean. It is on Earth. The sleds go even faster on the snow in winter.
otherDoc

I had a feeling you didn't and I doubt I could explain it to you.

 

[docnjoj]

Well waste a bit of time and try to explain what you mean. If you don't, I'll just figure you don't know what you are talking about and go about my business! With only 20 posts I'll bet you know it all!
otherDoc

 

[www.recumbents.com]

Note that Matt did widen his KMX trike a bit, which may have helped the high speed handling.

http://www.recumbents.com/wisil/shumaker/e-typhoon/default.htm

 

[docnjoj]

Note that Matt did widen his KMX trike a bit, which may have helped the high speed handling.

http://www.recumbents.com/wisil/shumaker/e-typhoon/default.htm

Wow! His attention to detail is astounding! I wish I had the desire (and the money) to afford one of his creations. It would have to have a suspension, of course. 8)
otherDoc

 

[macribs]

Note that Matt did widen his KMX trike a bit, which may have helped the high speed handling.

http://www.recumbents.com/wisil/shumaker/e-typhoon/default.htm

The creations done by Matt are top notch. Who in their right mind would complain about too much power in any vehicle? :lol:
Look at his trike smoking tires and doing donuts. Sure seems like a great ol' time to me. And he got plenty of stopping power too.

[youtube]WKAMus3oSdw[/youtube]

 

[rborger73]

Note that Matt did widen his KMX trike a bit, which may have helped the high speed handling.

http://www.recumbents.com/wisil/shumaker/e-typhoon/default.htm

Lot of ideas there I like. I've already had a steering damper in mind for the fast play toy one I'm doing now. I've seen a few different ways people have implemented it. Thanks much for that link. The guys I'm doing this build and weld race car frames. We'll try it at first just stock and see if we need to adjust it a bit. I'm not super keen on widening things. I like the idea of at least only a little wider than the average set of mountain bike handle bars. Lot of potholes around this time of year still. I know on two wheels I can't miss them all. So having 3 wheels avoiding them may be a touch trickier, but we'll make due. I have another customer wanting a lot of range, and he is going to use it to cold call homes with paved driveways to see if they are in need of sealing or repairs, and I think they stop to see if people wanted paved driveways put in as well. He is pretty spry, so getting in and out while using no gas, and not having to leave the car run, or turn it on and off should be nice. He'll go with the guys with the trike loaded in the back of the truck, then canvas the area around where they are working, and be able to stop back in to check on progress. He also has his license suspended, so allows him transportation for whatever. Aiming at a 100 mile range and welding in light boxes on to the frame to support mondo battery capacity. I'm looking forward to both projects.

I already know I'll have to build my own before fall as well. It will be in between the other two. I want a good 70 to 80 mile range if I need it with the throttle full out the whole time. I get a good 60 mile range without being nervous on my ebike now, so shouldn't be a problem. I like the 40mph mark. Seems like a good even number. I live out in a rural area and I'll drive 6 miles without seeing another car at times. So I like to keep it as far above 30mph as I can with no traffic around. There really should be areas where ebikes have no speed limit other than the posted for normal traffic. In town I see the concern, but on backroads, I honestly feel much more safe being able to keep up with traffic. My average rolling speed on my bike is around 27mph over a 17 mile trip. We have pretty good hills around here and I even have a few spots I can barely keep it above 15, but rarely drop that low. Most hills I'm 17 to 22mph for a low. With the new controller I'm adding I'm hoping to keep it 20mph as the slowest since I can push some more amps. Adaptto mini E is going on both of these trikes and my ebike. I wish they would get a better payment system setup...

 

[Willow]

Couple of things about this design that are worrying...

The biggest one is that you're using cable pull brakes on the front wheels... which may be deadly, not because they won't stop you but because when one front wheel gets more braking pressure than the other the trike will pull dramatically to one side - at speed in the wrong situation this will kill you. You MUST use hydraulic front brakes that branch left and right from one brake lever - braking forces will be equal then.

No suspension is also a big mistake for such a high powered vehicle...

Hope no-one gets hurt, or worse.

S.

 

[recumpence]

The most important component in making a KMX trike stables at high spec is a steering damper. Outrider ran 86mph on a totally stock KMX chassis with a steering damper.

Matt

 

[Triketech]

Note that Matt did widen his KMX trike a bit, which may have helped the high speed handling.

http://www.recumbents.com/wisil/shumaker/e-typhoon/default.htm

The creations done by Matt are top notch. Who in their right mind would complain about too much power in any vehicle? :lol:
Look at his trike smoking tires and doing donuts. Sure seems like a great ol' time to me. And he got plenty of stopping power too.

[youtube]WKAMus3oSdw[/youtube]

Kind of reminds me of the Austin America fitted with an Allison V12 WWII aircraft motor I saw at a dragstrip many moons ago.....

Spreading the stance X & Y makes a huge difference on stability. Very nice build.

 

[rborger73]

The most important component in making a KMX trike stables at high spec is a steering damper. Outrider ran 86mph on a totally stock KMX chassis with a steering damper.

Matt

Steering damper is a must I can tell. Just from my non powered ride this morning on it. Did about 23mph coming down a hill and the thing dives left or right just barely moving the front wheels at that speed.

I'm not concerned with the suspension too much yet. The steering I do have concern with, and it will get a damper of some sort no doubt.

 

[rborger73]

Couple of things about this design that are worrying...

The biggest one is that you're using cable pull brakes on the front wheels... which may be deadly, not because they won't stop you but because when one front wheel gets more braking pressure than the other the trike will pull dramatically to one side - at speed in the wrong situation this will kill you. You MUST use hydraulic front brakes that branch left and right from one brake lever - braking forces will be equal then.

No suspension is also a big mistake for such a high powered vehicle...

Hope no-one gets hurt, or worse.

S.

One brake lever works both left and right. I have a few plans to counteract that.

My bike has no rear suspension and I have 10,000 miles on it just about. There are higher power trikes with no suspension that go much faster than this will.

This trike will be tried and tested, and modified as needs come up. No worries.

 

[docnjoj]

I have separate left and right brakes on my Steintrikes and due to the suspension settings (camber, caster, toe etc.) it stops from 22 MPH perfectly straight. I have never gone faster, but the race luge video I posted speaks for itself. I also learned brake/ steering going around tight corners, and it is a big asset. Bike spins a bit on it's axis and corners quite fast and well. I have had the 2-in-one system on other trikes, and it can be made to stop very straight with some adjustment.
otherDoc

 

[rborger73]

I almost feel like I should put 29er front rims and tires on this. I run a 29er front rim on my ebike, and a 26" rear with the hub in the rear. At speeds over 30mph there is a very strong gyroscopic effect with the steering. Since the 29er is spinning faster than the rear wheel. It noticebly helps control over steering, yet makes the bike handle much better. I don't know I'll have to think this over since I'm going to lose a lil on the overall profit. The 20" rim and tires just seem so dinky. 16" would have seemed like skateboard wheels. lol.

If I could do a light steering damper for slower speeds, plus 29er rims and tires up front, with the 17" moped rim out back, it should steer rather nice at speed. Is my thinking wrong on this? I know with my ebike the faster I go, the more controlled the steering feels and I can feel the urge for the bike to try and maintain it's balance thanks to the gyroscopic effect.

I suppose the weak part would be the hub setup and the extra torsion on the larger front wheels could be a problem?

 

[docnjoj]

If you made a tilter, then there would be no worries about overall C/G and big wheels!! 8)
otherDoc

 

[rborger73]

If you made a tilter, then there would be no worries about overall C/G and big wheels!! 8)
otherDoc

Well not for this one for sure. lol But I do think the 29er front setup might work nicely.

 

[John in CR]

Customer has race cars, but somehow 40mph is the goal for a trike. I'd build it with the idea that easy changes can make it go to 60 or 70mph. It's essentially a 3 wheel gokart with far less ability in the turns...Would he be happy with a 40mph gokart? I doubt it.

With no suspension the roads need to be pristine for high speed, because there's no easy weaving to avoid potholes like a bike. That's why riding bikes is often called "single track".