Power Kite Forum

Lowering a Libre VMax-II

MeatÐriver - 25-4-2013 at 04:34 PM

Well before I jump into it I should introduce myself.... Hello, I'm Aaron. I've been lurking PKF daily going on half a year now, as my love for kiting has grown exponentially. It all started with a Prism delta, which grew into a quiver. Then an impulsive purchase of a Snapshot 2.5, "I can just throw that thing into my backpack...be ready for anything!" Fast forward>> quad handles and brake lines? why not>> scudding across the beach, this is fun>> face plant into sand, less fun>> bought a cheap Yak, holy !&$#, this is power>> convince wife that I need a buggy>> CL a fair deal on the VMax>> now here we are today. Sorry for the long intro, but I must say the wealth of knowledge-community and stories have been invaluable...thank you. P.S. I'm on my mobile, so I cannot put this in proper paragraph form. So at the moment I am still waiting for some cash for some proper engines (the Yak shall remain for static fun for a good while yet.) In the mean time I want to get the bug up to snuff. The VMax2 came my way in very clean condition with a set of barrows as well as BFL's with proper fork. Given most my time will be spent at Sunset beach and the surrounding coastline, the BFL's will be the primary rollers, which leave the bug up higher than I care for. Being no stranger to some minor fab work, I will be building a kinked downtube. Upon mocking up my desired ride height I felt this left the seat back too vertical, wouldn't mind something slightly more "reclined." Which leads me to my question...It appears to me that the rear axle could be flipped 180 so that the siderails meet the axle with the flange on bottom, tipping the seat back several crucial degrees. In regards to keeping ideal steering geometry, I'm holding off building the downtube until I'm certain that I can run the flange down without issue. So, if anyone with any experience with such matters could tell me...might the durability/reliability of the axle be compromised by running it flange down? Thank you and sorry for the wall of text.

martinipro - 25-4-2013 at 04:41 PM

People run Libres with the inverted axle all the time in the UK.

I run my TruckII with inverted axle and it lowers it by maybe a couple of inches. Not sure if it will fix the angle though, the truckII comes with a kinked down tube.

bigkid - 25-4-2013 at 05:18 PM

you can lower the seat also.

John Holgate - 25-4-2013 at 11:17 PM

I bought the 'knicked' down tube from my local shop after confirming which part I needed via the Libre site (don't blame me for the spelling!!) and it certainly did lower the Vmax - a bit too low with the midi's on but ok with the bigfoots. I have not seen the need to flip the axle over - which I still could. It does make the seat more vertical which is not quite as comfy but still ok with the backrest. It also has steepened the 'rake' ? angle making the steering a bit quicker...but not overly twitchy. Extending the axle back by about 4 inches also makes it a little less likely to slide out at the back.





edit: if you're going to make one, here's the dimensions of the Libre downtube...




MeatÐriver - 26-4-2013 at 06:56 PM

Right on. I appreciate all the info. Dropped the seat a bit and inverted the axle, just need top hit the metal yard to get the tubing for the downtube. Also, thanks for the pics with measurements John, will definitely help. Seen a lot of vids and reviews of yours across the web, eventually inspiring me to build a pretty accurate diy turbo bar from an Ozone control bar that came with the Yak. Now if I could just get my hands on the engines....all in due time I guess.

van - 27-4-2013 at 09:02 AM

When you convert from a straight downtube to a swan neck, the second angle its always smaller than the firstto keep your rake the same

DAKITEZ - 27-4-2013 at 11:23 AM

Maybe you can find the info here on the forum somewhere but I seem to remember that Jon (Jellis pkf name) use to make extenders for the back of the libre to lower them even more in addition to flipping the axle.

John Holgate - 27-4-2013 at 04:11 PM

The standard 8" Libre extenders are a little too long for the Vmax. I ended up with some 4 x 2" RHS steel (5mm wall thickness). I had the metal shop cut me two pieces the right length (cos it takes me forever with the hacksaw to cut) and drilled the appropriate holes to go inbetween the side rails and axle. Buggy is more balanced now and as a bonus I have a little extra room to put my bag on the back.

Axle extender.jpg - 208kB

jeepersjoey - 27-4-2013 at 07:52 PM

Ok...now I need to know where to get the cool Libre backrest.

I actually snapped my backrest in half during SBBB. I was wondering why my back hurt...then I checked the metal plate that I had in the seat. Yikes! I'd love to know how I did that!

Any leads or specs that you can share for your backrest?

MeatÐriver - 27-4-2013 at 08:15 PM

Good question Joey, I'm sure it makes it quite nice for long play days. As for the extensions John, does the rear end step out often enough that I would want to add them sooner than later?

John Holgate - 27-4-2013 at 08:53 PM

Some backrest info here: http://www.extremekites.com.au/forums/viewtopic.php?f=17&...

As you can see, there was some debate over comfort v safety with a backrest of this type. Personally, I'm comfortable with the safety aspect - considering my driving style. I've only flipped the buggy once and the backrest was not a problem. Having said that, anything is possible and we have to make our own risk assessment. It is very, very comfortable.

The back end was not a problem as such, but whenever I started getting overpowered, the back end would slide out first - I just wanted to try and get it so that all three wheels would begin to slide at the same time to give the best grip and balance. 4" extensions have just about nailed it. The 8" caused the front to start to let go first - you can see it in your tracks on the beach. Depending where you have the seat and downtube length set, it could be quite different for you.