I went with Frankster to pick this and some other bits up from Newcastle. Frankster took the engine home with him to Melbourne to fix the head and check it over while I worked on the frame. After making sure the forks, bearings and frame were ok, I set about modifying it for a drag bike. This required making a solid rear shock/strut to lower the bike 60mm. I slipped the forks up 60mm to level the frame and keep the geometry right. With that sorted I bought some 16mm tube and made the 'wheelie' bars. Used 6mm alloy plates welded to bottom of swingarm and two more bolted to the original rear footpeg mounts for the top. Also made an alloy chain guard.
The bars I made the same length as the wheelbase and width of the bike (to fit with the rules) and fitted two 65mm plastic wheels to the end. I mounted the front up on a 70mm block and sat the wheels on the ground while I welded the bracing in. Ready for paint.
The fairings needed a lot of rewelding and filling after the bike had been layed down on both sides. I was able to save the black bits with the stickers on them and did some black touch-ups around the rest. The pattern on the sides was too complicated to be bothered repainting so I just went with a two colour scheme with a 10mm wide silver pinstripe to match the wording.
I made a basic wiring harness for it to run with just tacho and temp gauges and did the resistor in the pink wire mod too (to bypass the speed limiter). A couple of chair leg caps from Bunnings to hide the ugly tank holes. Filled the headlight holes with some aluminium sheet glued into place. And why the Wasp? Well future plans are to get the bike running straight and true with stock engine and to then put a 'sting in it's tail'.
Just a question in interest, why have you made the drag bars so long? surely if they go back so far the leverage power would actually lift the rear wheel of the ground not the front wheel, you need to keep all the power on the rear wheel, if you shortened the length, the front wheel would come higher forcing the center of gravity back onto the rear wheel, have a look at all the successful drag cars, their (wheely bars) are very short for this very reason, the only reason for using these drag bars is so that you can use all of the engines power without flipping the machine over backwards.
Maybe Iv'e got it wrong murdo, in fact placing the point of contact further back would require more horse power to lift the machine from contact with the track surface, any way I may have started an interesting discussion, all the best with your project, I can't believe how many you manage to work on.
Nice job as usual from the Doc ... I sat on the Wasp yesterday and the rigid rear sure felt 'weird' ( no movement! ) to begin with but u felt 'planted' and low so I would think a great position to go straight and fast nice work lads
Yeah & the bike without its sting on sure looks like a pretty little savage Wasp, I love those wasp colours. Very well done job.
Loving it so far.. the ONLY mod I would consider having watched multitudes of episodes of STREET OUTLAWS on Foxtel is to have some adjustment built into the Wheelie Bars for height adjustment.. especially for when the Sting is inserted because with more power you may well want to alter the angles etc.. @GreyImport you need to get to work on the Flyer... Wheelie Bars... Wheelie Bars, repeat after me.. Wheelie Bars
Thanks fellas. Mike, this is my first go at building the wheelie bars so some experimenting may be needed. ANDRA rules say the bars can be no longer than 3.2me overall length (bike and bars) but I choose to go with what I've seen most other bikes run, ie equal to wheelbase. If the bars were shorter like a heavy front engine car then from what I've seen over the years involved in drag racing that the bike would be very hard to control when 'on the bars'. Think of it like trying to reverse a trailer with a very short towbar (compared to a long towbar) in that a small movement of the steering wheels makes a big difference to the angle of the trailer, so by having the W/Bars longer gives the rider better control to keep it going straight. Yes, I have built adjustment into the top mounts. Should give between 1" to 3" above ground level, may need more or less when Frankster gets it on the track. Bike is now back in Melbourne, but Frankster left another frame and engine cases here for me to have a think about how to mount 'the sting'. Yes, Grey needs to get on with his bike as the March meeting will be here sooner than you think it will and we want to have ALL the 250's ready to run.
All good @Murdo, I was working late and didn’t look closely at the pics. As I said my experience is limited to many many episodes of Street Outlaws Are you able play around with rear wheel size? Depending on what appropriate size drag slicks are available and the ability to get the rear hot enough to get to the right temp for diameter etc Once you start getting into these sorts of areas you will find different settings for different tracks, times of year etc. I will be watching eagerly as the set-up side I find fascinating. Good work so far Sent from my iPhone using Tapatalk Pro
The Wasp is back in Melbourne now, so I will post an update as the engine gremlins get looked at and we start track testing. Unfortunately, I'm interstate for the next couple of weeks, so don't hold your breathe. Congrats to Murdo for his hard work and the bike he has built. A quick spurt up and down the street checked out okay and the bike felt "right". Unfortunately, the Chief popped over after we'd given it a run, but he did try it on for size. Hopefully, the flyer will be the next Tamworth-based drag bike to debut.
The Wasp - background As Murdo has gone over most of the fabrication of the bike, I thought I'd put a bit of background up for anyone who's interested. The idea behind the bike was to build a 2fiftycc drag bike that we could really push on the line. This meant wheelie bars, and wheelie bars are best on solid rear ends, so both those features needed to be built in to the frame. Lowering the bike was also discussed. The original mock up was lower... But, we went with 60mm drop front and back to start with and Murdo has built some adjustment into both the rear height and the wheelie bar angle. @Mike Fulcher - the wheelie bars aren't as long as they might look. I'll try to get a pic with them on and post it. My first time with wheelie bars, so learning curve for me too. I've never ridden a solid rear bike before and the initial run up the street wasn't fabulous. After a few adjustments, the second lap was much better and bike launches straight and seems to get the power down as hoped. We won't be running the wheelie bars until the engine is fully sorted. Thanks again @Murdo for a great job.