Help me build a mono wheel trailer for my MTB

[greenaero]

Nice work!!

[choneofakind]

Why not mount the forks ahead of the givi case instead of behind it to reduce the moment a little bit?

[rojoracing53]

So I just took it for a test ride after securing straps from the handlebars down to the passenger pegs area to reduce the bouncing and pull the wieght forward. As soon as I tried to leave the parking lot I noticed the front wheel of the ninja wants to shimmy(head shake) at speeds less then 10-15mph especially while turning. Once I get up pass 20mph the ninjas totally stable and the bike on the back looks solid, moving with the tailpiece and no extra bouncing.

I've never ridden this bike or any bike with a passenger so I have no idea if I'm just feeling the extra weight screwing with the bikes geometry or something else. My bike has a stock rear shock with all the preload cranked in but my front forks are at the stock ride height but much stiffer springs so its sag is a lot less.

I could try softening the front forks to see if it helps but that'll be a PITA. Any of you guys have another idea of what could be causing this?

[rojoracing53]

Well I just filled the givi top box with 100lbs of metal chips and removed the bicycle to similar the wait. I figured 100lbs over the seat has to be more then a 20lb bike off the rear. First of all props to anyone who rides with a passenger because that extra 100lbs of top weight made the bike feel so heavy. So with the metal in the box it makes the bike squat in the rear and the front wheel feels really light, it get that deceleration headshake that's common on these bike really bad but it ok in the u-turns.

I'm thinking I've got two things going on here.

First the extra weight over the rear just isn't helping with my current stiff front and soft rear suspension and now the ballance of my geometry is past what will work.

Second is harmonics. Because the bicycle is 5 feet off the rear even its small amount of side to side flex has a large leverage on the subframe. Also because of harmonics it's always flexing out of rhythm with the ninja so it only gets worse and worse at low speeds when the ninja wheels aren't turning fast enough to create enough stabilizing gyroscopic effect. Once I get the bike up to speed the gyro of the ninjas wheels and change in the harmonics makes everything run in tune.

For now I guess I better master the U-turn at over 20mph

I guess I'm probably always going to deal with harmonics at slow speeds but I think if I can get a stiffer rear shock into the bike the balance will be better and I may not start the tail wag harmonics as easily or at all.

[choneofakind]

Can you just add more preload to the rear to at least make it ride a little higher?

And yeah, riding with a passenger can be a little unnerving and is best left for larger bikes. It's totally doable on the ninjette but meh.



I'm still voting for making a trailer. Make your own hub to run with automotive bearings, lace it to a bicycle wheel, and make a super lightweight trailer. You'll just have to keep it under 60-ish.

[rojoracing53]

Originally Posted by choneofakind

Can you just add more preload to the rear to at least make it ride a little higher?

And yeah, riding with a passenger can be a little unnerving and is best left for larger bikes. It's totally doable on the ninjette but meh.



I'm still voting for making a trailer. Make your own hub to run with automotive bearings, lace it to a bicycle wheel, and make a super lightweight trailer. You'll just have to keep it under 60-ish.

I'm still going to make a trailer later on to pull under the bike for camping trips so I need this thing to work up top. My preload on the rear has been maxed out since the first week I got the Ninjette so it's got no more adjustment left. I guess I need that GSXR rear shock mod that the racers are doing. Who knows where the shock swap thread was so I can start looking into that.

[csmith12]

http://www.ninjette.org/forums/showthread.php?t=59486

Great, cheap easy mod yo.

[choneofakind]

Geez dude, get a Vstrom already.

There's some info on this thread:
http://www.ninjette.org/forums/showthread.php?t=126734

and this thread:
http://www.ninjette.org/forums/showthread.php?t=59486


EDIT: ninja'd by @csmith12, yo! Wascally wabbit!

[csmith12]

[choneofakind]

Sorry Jason

[dcj13]

Originally Posted by rojoracing53

So I just took it for a test ride after securing straps from the handlebars down to the passenger pegs area to reduce the bouncing and pull the wieght forward. As soon as I tried to leave the parking lot I noticed the front wheel of the ninja wants to shimmy(head shake) at speeds less then 10-15mph especially while turning. Once I get up pass 20mph the ninjas totally stable and the bike on the back looks solid, moving with the tailpiece and no extra bouncing...

...I could try softening the front forks to see if it helps but that'll be a PITA. Any of you guys have another idea of what could be causing this?

The huge moment arm hanging off the bike might have something to do with it.

As it bounces up, down, and side to side, it's causing your front end rake and trail to continually change. Screwing around with the front and rear suspension ain't gonna do anything to help appreciably.

Your "plan B" (or was it really "plan A"?) to make a trailer for the bike is a much better (safer) idea. Heck, you might even be able to market the idea.

[choneofakind]

Thinking out loud here.

What's happening to cause excess bouncy feeling is resonance between the suspension and the bouncing bike rack. Even a small input from the road at just the right frequency makes the whole system move a huge distance.

Technically he could fiddle with the damping (or spring rate) on one end and change the frequency that resonance of the system occurs at. Or throw metal at the bike carrier so it is less springy. Or make the carrier shorter so there's less moment arm. Or use a different material for the carrier. Etc etc etc. If you can make changes to move the resonance to the correct frequency range, the issue goes away completely for during 'normal use'.

The trick is, if you mess with the suspension, you're messing with how the motorcycle handles, not just the resonant frequency. Ah the joys of 'tuning' a chassis and suspension...

[rojoracing53]

Well GSXR shock is in the mail and even if it doesn't solve the problem it will finally be that last excuse out of the way off me not racing the ninja.

I just rode it home 25 miles with 10-15mph winds and 30mph gusts and it worked wonderfully. I had my dad follow me in his truck to give me the play by play over the Blutooth. Aside from him giving my a ton of **** about just buying a cheap ass economy car, he said it all looked good, ridiculous but solid. I got it up to 85mph with no sign of issues and as long as there is not much wind you can't even tell its on the back.

Stability doesn't feel as bad as earlier but it's still want to wobble coming to a complete stop and cruising the neighborhood but I can deal with that. I'll take it on a easy canyon ride to see how well in corners but I suspect as long as I'm over 20mph I probably won't even feel it. Lane splitting past trucks feels a bit weird because the handle bars are only an inch more narrow then my mirrors but I can see them behind me and any evasive swerving will make the bike up top tip a lot side to side. I guess limited splitting is in order but I don't plan on doing much anyways.

[choneofakind]

I like the rims on your Tundra.

Seriously though, why not just trade it for something small and fun and hatchy? Get a roof rack for bikes and a small trailer for gear/ninja and you're good to go

Older hatch Civic Si? Hatchback WRX? VW GTI? I don't like driving big trucks. Bleh.

[tfkrocks]

I want to see people's reactions to seeing this on the road

[Alex]

Clearly the next step is for someone to be sitting on the bike seat while you're riding the motorcycle. Think about the wheelie potential.

[rojoracing53]

Originally Posted by tfkrocks

I want to see people's reactions to seeing this on the road

People rubber necking as I go by has been epic. I'm currently watching my neighbors drive down my street and do full on double takes as they pass by. Maybe ill mount a gopro facing sideways to capture the action

I've been wanting to get that GSXR sock into the bike forever so this will be the perfect motivation to do so. I'm considering remaking the beam out of a very think walled aluminum to save weight and stiffen up the setup. Honestly though with the straps from the bike to the foot pegs this thing doesn't bounce out of time from the rear end. If I remake it the whole setup out of aluminum who want this one

[Klondike1020]

Originally Posted by Motofool

Link to original page on YouTube.

I think if you made a long tubular carrier that attached at the spindle mounts or passenger peg mounts and used a small scooter wheel and tire on the back such as a ruckus or zuma you could make something similar to the above video.

But it would take a bit of experimentation to find an appropriate length and pivot point.

But it would have the benefits of being able to carry the weight mostly off your suspension as well as have more varied uses!

That seems like such a cool Idea for a project
1

[allanoue]

Need a video, plese. Are you still going to let Cam ride it?

[rojoracing53]

Originally Posted by allanoue

Need a video, plese. Are you still going to let Cam ride it?

Maybe but his ****ing work schedule sucks ass and we can never find time to ride these days.

[CycleCam303]

Lol I just got home from work...hooray... I'm free the next two days so let me know. Plus I need to clean up the ninja and throw it up on Craigs and here so I'll be local.

Thread jack... For serious if you're looking for a super clean stock ninja 250 pm me. I has title and I'm willing to let it go for a good price.

[ai4px]

Originally Posted by rojoracing53

So as a cheap ass(gas is expensive) and an avid MTBer(at least I have been for about a month) I want to figure out how to tow the Mtb behind the Ninjette. I've seen the rack system that mounts the bike to a beam off the rear seat of the motorcycle and the bike is way up in the air but then I'd have to remove my top box and it would be a quick on and off deal.

My idea is to use a normal Yakima roof mounted bike rack and mount it to a custom fabbed mono wheel trailer and then tow that behind the Ninjette. I plan on using a Mtb rear shock for the trailer wheel to help keep the thing planted through the corners. I'm a little unsure how it's going to handle mid corner during lean though. I've scoured the web for pics and ideas but there's been little related to my exact Idea that's been helpful.

So here's where I'm stuck.

1.How do I get this trailer mounted to the Ninjette so its stable, strong and can corner?

2. What kind of small wheel would handle several thousand miles at hwy speeds. Trailers only going to weigh 70lbs max fully loaded

3. What are the hoops I need to jump through to get this thing approved by CA DOT. It probably needs a full trailer license plate with brake lights and turn signals but that easy enough for me to get signed off.

Please chime in with any helpful ideas or pics that could help me get this project jump started. Thanks

Here's what the Yakima bike rack I'm thinking of using looks like.

Are you really sure you wanna do this???? lol. Back when I was in college, I rode bikes and had a rack on my VW bug. My g/f at the time used to pick at me like hell about having a spare vehicle for when the veedub broke down. you wouldn't want anyone to think your bike needed a spare would ya????

[rojoracing53]

[allanoue]

video please

[rojoracing53]

Tested rode the bike on bike setup today for the first time with new tapered steering bearings and it mad a huge difference. Now I'm not saying that tapered are that much better then roller, it more like Properly torqued tapers are way better then loose old ball bearings. Now the bike only shakes when I make very abrupt weight transfers from left to right and back, but the good news is it will stabilize rather quick now once I straiten out. Unfortunately lane splitting still feels hairball with that must product hanging off the back but that didn't stop me from carefully splitting half the way home.

[choneofakind]

Watch out Jason, you're becoming old3!!! The transformation has begun. Better buy a ktm.

[rojoracing53]

Maybe someone with a camera like @Jiggles, @Alex or @lolibater has the day off tomorrow and want to head over Hamilton with me after my MTB race and get a little footage of the bike in action.

[choneofakind]

Don't you have a camera? Ahem.

[rojoracing53]

Originally Posted by choneofakind

Don't you have a camera? Ahem.

Well yeah but how the **** am I supposed to film myself

[choneofakind]

Pull a Kevin2109 and put the camera on a pole.

Or. You could use a handlebar clamp. Put the gopro on the MTB. Film you from eagle eye perspective. I put my gopro on my bike rack to film my car sometimes. Works great. Be creative.

[Klondike1020]

here is a guy with a bike carrier and he even goes off road lol

https://www.youtube.com/watch?v=5UVd3pvSqZ4#t=472

Link to original page on YouTube.

[choneofakind]

Jason, watch the video Hernan posted in another thread. It goes more into how those Third Wheel trailers attach. Looks like they use a set of spools on your swingarm, not the axle of your rear wheel. Looks like it articulates up and down, as well as side to side.

Originally Posted by Motofool

[

Link to original page on YouTube.

Winter project so you don't have to worry about the crosswind effect with your current setup.

[allanoue]

crack kills

[tfkrocks]

Originally Posted by choneofakind

Jason, watch the video Hernan posted in another thread. It goes more into how those Third Wheel trailers attach. Looks like they use a set of spools on your swingarm, not the axle of your rear wheel. Looks like it articulates up and down, as well as side to side.



Winter project so you don't have to worry about the crosswind effect with your current setup.

But then he'd probably be subject to the trailer speed limit. I don't think jason can handle a 55mph speed limit on the highway

[Sirref]

Originally Posted by tfkrocks

But then he'd probably be subject to the trailer speed limit. I don't think jason can handle a 55mph speed limit on the highway

I think jason would just fall asleep and wake up at his destination after the car w/trailer drove itself there because it was going so slow

[choneofakind]

Trailer speed limit?! You're kidding right? That's silly

[rojoracing53]

Originally Posted by choneofakind

Trailer speed limit?! You're kidding right? That's silly

Sammy Hagar said it best plus I really doubt a trail could follow me through the corners as well as my current setup which would worry me. Then there the chance of someone cutting in behind me after I pass them and not seeing such a low profile setup.

Link to original page on YouTube.

[rojoracing53]

I had a Hwy Patrol Moto pull up alongside me in my own lane on Friday while I was going 30mph in traffic. I kinda surprised me because I had my mirrors folded in to make lane splitting easier so I first noticed him when his shadow passed me with the sun to our backs. While still riding down the hwy he asked me half a dozen questions about the setup with both of us yelling over the tire and wind noise then continued on his way down the emergency lane which apperantly is a rule they don't have to follow.

[choneofakind]

I bet the trailer would be fine on corners, but I understand the low profile and traffic issue.



And yeah, officers have a nasty habit of doing **** like that. Sucks, huh?

[tfkrocks]

Oh yeah forgot about the turning part too. Imagine a trailer trying to follow you on Mt. Hamiliton at your normal riding pace lol.