Drag Racing Drag Race your bike?

Aky might as well go to WSID. It's probably the same distance.

 

Hey Murdo,

I ran my ZXR250 "drag bike" at Ballarat Drags a couple of weeks ago. It's 1/8 mile and I'm still trying to sort out my 16,000rpm restriction problem. Quickest bike was an A/MB Suzuki (ex-Pro Stock bike) that was running 5.7sec. I ran a 9.82 @ 70.53 on my last run. I had a 4 second head start on the Suzuki when I ran him...he got me right on the line (better R/T). Missed out on getting into the final, but had a good day (Bloody cold in Ballarat!). I've now stripped the bike and am rebuilding it with bits I got from Kiffsta. Should run the 1/8 in low 9's when it runs right.

Hopefully will test this weekend (weather permitting) on 1/4 mile track.

Cheers

Frank

 

That's about the only thing that bike does well at the moment!

 

Aky,

That's actually a very quick time (14.07) your mate ran. I've been building up a list of 250cc drag times from the interweb and the best I've found anywhere is 14.26 @ 150.54kph from a guy on a MC19. Most CBR250RR bikes I've come across run mid-14's (see 2nd attached pic).

My bike is off the road while I try to fix the 16,000rpm cutout issue. I'm keen to break your mate's 14.07 time.

Cheers

 

Aky, I wasn't questioning the time, I was commending your mate. I found an obscure post on another website where someone claimed a guy ran 13.8 on a ZXR250 at WSID a few years back...no proof, but the 60-foot time he mentioned (2.30sec) is about right for these bikes. My goal from the beginning has been to run quicker than 13.8 for the quarter on a ZXR250. Your mate's 14.07 is the 2fiftycc record and that's my immediate target. Cheers Frank

 

Hi All,

Finally back in Oz & happy to be home. Will start pulling the engine out of the green ZXR this weekend (to change the gearbox bearing that came apart) and eventually get back to trying to get my drag bike running (still no spark).

Found this photo the other day. As you can tell from the date it's over 8 years old. Apparently, Heathcote Park Dragway used to run a 250cc class for kids aged 15-17 (basically like Junior Dragster, but for bikes). From what I was told, they used to run 12's which. if you weigh 45kg and have wheelie bars and a hard tune is probably what a 250cc bike should run.

The other photos are from a few years ago when I went to buy a drag bike from a guy here in Melbourne. The sale fell through because the bike wouldn't start, the wheeler bars were bent and the "seller" couldn't put me in touch with the previous owner or tell me anything about the bike's history (bit sus really). I expect the bike I was trying to buy was the same if not similar to the one in the drag photo. Hopefully, I can get my bike running soon. Now that my arm is better I really want to get out there.

If anyone has any information about the 250cc class they used to run at HPR I'd be happy to hear from you.

Cheers

 

Ballarat Drag Racing Club: Sunday 15th FEB 2015 meeting – Part 1

Hi All,

Just updating this thread with my recent activities.

Before I do, I just wanted to say thank you to everyone on this forum who has helped me get my bike to this stage. A very special shout out to Kiffsta for his assistance with knowledge, parts and his commitment to all things 250cc…thank Chris.

Update: Sunday 15th Feb 2015 – Ballarat Drag Racing Club Round 3 of 4 (2014/2015 season).

Background: My 1990 ZXR250 drag bike has been off the track for 11 months while I rectified some of the damage done to the bike by an ex-friend of mine who decided to help me out by modify the bike for better performance, but only succeeded in (mechanically) wrecking it. “Modifications” that required removal/reversal included welding the back part of the frame back on; Putting a standard loom back in the bike; putting a full instrument cluster back in the bike; reinstalling a stator and associated wiring; putting a standard ignition system back on the bike (including a new triple clamp) and putting the engine back to standard spec (it’s a C engine in an A frame).

The biggest issue I had was that the bike refused to rev past 16,000rpm. After consulting the forums on this website and doing some research, I discovered that the speedo in the ZXR has a built in restrictor that stops the engine revving over 16,000 in top gear. If you remove the speedo (as my “friend” did) then the bike’s CDI thinks it is in top gear all the time and every-time the gearbox is out of neutral and your engine hits 16,000rpm the bike’s engine shuts down like it has a rev limiter. Unfortunately, I couldn't just put a speedo back on the bike because my “friend” decided to remove it using a grinder and since I apparently didn't need all of this extra weight from the loom, he threw it away and then rigged the bike to start by turning the kill switch on and pressing the start button. Since I didn't need a key for this to work, he cut the ignition and key off the bike with a, you guessed it, grinder! Needless to say, these modifications were bad enough, but when the bike refused to rev past 16,000 in any gear and my “friend” decided the problem was fuel related, well lets just say this was the straw that broke the camel’s back!

Most of the fixes weren't too hard to do, but one modification really held me up. After installing a standard loom on the bike I was unable to get spark. Long story short (it took 5 months to sort out); a second loom fixed the issue and we’re ready to go testing. Unfortunately, I was unable to do any testing before the race, so I broke my own rule and tried to sort the bike out during qualifying. Part 2 of this story covers Qualifying.

 

Ballarat Drag Racing Club: Sunday 15th FEB 2015 meeting – Part 2

Sunday morning: Well, I knew I was in for one of those days when I couldn’t find the key to the bike and spent 45 minutes running around the house like an idiot looking for it…

Got to the circuit in time to unpack the bike, put on my leathers and head to the staging lanes for first round of qualifying.

The first run was a feeler as during the “rebuild” I had lowered the front end 15mm, changed the air pressure in the tyres, changed the engine dramatically (see part 1) etc. The run went okay, but I didn’t rev the bike too hard or kamikaze the start. Brakes worked fine and steering was also fine.

The second run wasn’t great. I moved into my lane and waited for the other bike to finish it’s burnout and as he started to move into the staging beams I inched forward with my feet; I noticed he’d already pre-staged (top light); I normally give the throttle a twist just before I role in to put my top light out. When I revved it, the bike moved forward into pre-stage (damn, clutch dragging me). He then put the second light out (fully staged); I revved it again and it moved into full stage. This basically meant I couldn’t use any revs on the hit, because if you roll through the beams before the tree is activated, your lanes timing is turned off and you get no data. So, I could have stood on the brakes and tried holding the bike, but in the 2 seconds that all this happened I wasn’t thinking clearly. The tree was activated and I launched from idle…not happy (I’m shaking my head as I leave the line). I missed a gear going from 1 to 2 and that was that.

My third run was a shocker. Having fixed the clutch drag issue I was hoping to see if the 16,000rpm issue was still there. It was 30+ degrees and humid (very un-Ballarat weather), so I started the bike and checked the temp (it was okay). I launch and (I’m using the clutch this run) somehow I’ve unbalanced the bike and I’m heading for the centre line. I steer it straight but I figure this run is ruined so I might as well test the 16,000rpm issue (see part 1). I’m nearing the magic number and I’m getting ready to pull second (if it starts cutting out)…15, 16, 17, 18 halleluiah…I change into second and let it rev out in that gear. Normally, on an eighth mile track I’m in third by the time I get to the finish line, but my start line stupidity and cautious first gear revving meant I was near the speed trap and still in second (nearing 19,000rpm)… and this is where the run goes from bad to awful. I pull in the clutch and let the throttle shut and …nothing happens! In fact, the bike is on the rev limiter and heading into the braking area at speed. I could have hit the kill switch, but my mind wasn’t working properly. I went for the front brake and did a 80mph stoppie. Thankfully, my brain decided to let go of the front brake and then, strangely, apply the rear brake (?). A small broadside later and my brain now decides to stop using the rear brake and try something else…turn off the bike! After pulling off the track I looked down and notice that while dicking around with the clutch I had not secured the loom properly and it had dropped down onto the throttle mechanism. I pulled the loom out of the way and started the bike again and rode it back to the pits under its own power.

My pit area was popular with a few spectators coming over and asking about the “incident”. One guy, who had his 2 young sons with him, said “It must have been an optical illusion, but I swear your back wheel came off the ground!” Yes, mate it certainly did. One guy had taken some video, but had stopped taping as I went through the lights; you can just hear the bike on the limiter before the video stops. I might YouTube it when I get hold of it. I think the little 2fifty is popular because all the other competitors are on full race machinery of 900cc to 1425cc capacity. Go to Part 3 for racing results.

 

Ballarat Drag Racing Club: Sunday 15th FEB 2015 meeting – Part 3

Well after 4 qualifying runs ranging from completely useless to life threatening, I headed into racing with no idea what was going to happen. The 16,000rpm issue was solved, but I had no real data to work with. I sent a text to the wife saying I could home much earlier than normal! We had 8 bikes show up, but one dropped out during qualifying, so the organisers decided to run us in a three round Chicago Shootout. I was the only SB (Street Bike) class bike as the other SB (CB900) dropped out. The other racers all run MB (Modified Bike) class and they run the 1/8 anywhere from 5.4secs to 7.8secs. I somehow managed to win my first 2 rounds and crossed the finish line first in my third but lost due to going faster than my nominated dial-in; probably best I didn't make the final anyway as I was not a happy camper and just wanted to pack up and go home.

Basically, a frustrating day with a few positives thrown in for good measure. The heat, direct sun and humidity didn't help either. I was happy to get home. I might post pics/vids at some stage. I will check the bike when I get a chance (it was on the rev limiter for such a long time); do a comp test and maybe do the valve clearances and put my carbs on it for a test&tune in the near future. I need to get 60ft times down to 2sec flat in order to run good numbers. My racing stats for the day (1/8 mile track) are as follows.

Best run: 9.74sec
Best speed: 71.77mph
Best reaction time: .450 (.400 is perfect)
Best 60 foot: 2.21

 

Some pics from the 15th of February 2015 Ballarat Drag Racing Club meet (Round 3 of 4 2014/2015 season).