Tuesday, 14 October 2014

All to play for

Coming up is last race on the 2014 ACU calendar - the Extreme bike weekend at Santa Pod.
Two championships will be decided at this meeting, both the ACU and Santa Pod racers club championships. Alan Davies has the points lead in both, but i'm not too far behind and it is possible for us to take it. The SPRC championship being the most desirable as the prize is free entry to the Santa Pod rounds next year.
A summary of all the possible bike class outcomes has been posted on eurodragster.com and can be seen HERE
There are 6 entries in comp bike including one newcomer (to comp bike at least).
4     Phil Crossley         Suzuki GSX     1500cc
5     Tony Clark         GSX1100     1500cc
8     Kevin Osman         Hayabusa     1300cc
15     Paul Hambidge         ZX12R         1200cc
16     Dave Smart         GSX 1300R     1300cc
42     Allan Davies         Suzuki GSX     1428cc

The bike is ready, it hasn't required much attention, clutch servicing and valve clearances, and  a general going over looking for loose bits. I decided to further modify the progressive graph on the controller as the recent experiments to eliminate the lean spot have been quite successful, and so i've taken out even more nitrous, dropping it down to just 20% at one point. If that still isn't enough then i can work on the fuel graph and have that increase momentarily before resuming the progressive build. Tyre pressure will be hopefully be the other area of experimentation at the weekend, finding out how high we can go before it stops working, and seeing if we can get the 60ft times down a bit further. 1.15 is the best so far.

I did some more Bronze welding at the weekend and got the last of the engine mounts welded on, plus front subframe mounts. Fork shortening has also been on the menu, travel has been reduced by nearly 50mm, and i chopped up some FZ750 springs which will be added to the rather soft 125cc ones to make them a bit stiffer. They can also be preloaded should they not be firm enough.

Tuesday, 7 October 2014

On it's wheels

Made some significant progress recently on the new build. Firstly, i got the wheel fully assembled and sealed with silicone, and made all the spacers for the back axle. Before bolting the rims on i fitted the tyre to save having to fit it later - although it was still a pain to get the bead to seat and took some lighter gas and a lighter to get it on in the end.
One of the main frame parts still to weld on properly was the headstock. The idea is that you weld the rest of the frame, then cut the tacks holding the headstock in, make sure the headstock is 100% true, then weld it in permanently. So, with the aid of a self leveling laser level i now have it all aligned perfectly and welded up. Time to stick the forks in it, axle blocks g-clamped into place, and suddenly it's on it's wheels and ready for a spin around the cellar!

Only problem is it's actually too long to fit properly. I'm going to need a bigger bench!

Sunday, 28 September 2014

Build your own back wheel kit

Some things have had to be put on hold the last two weeks when my new Mercury milling machine conked out completely. Luckily, Chester machine tools were very good and were able to sort it out pretty quickly, it was the main board which was at fault, and replaced under warranty. Excellent service overall however!
Despite this setback i managed a fair bit of progress recently with the back wheel for the new bike. It's 90% complete, just the rims to bolt on, back brake hanger to invent and spacers to make. It all fitted together nicely ..... the DRO and mill have paid for themselves already in my opinion, everything aligned perfectly, and bolted up snug and when i gave it a spin there was no visible runout whatsoever. Makes it all worthwhile!

Engine mounts have been on the agenda too. Bit tricky to get right but they are almost there, the next stage it to braze them on properly. The back mounts are recessed and fit snugly over 2 large diameter lugs on the frame, the idea being to support the engine as well as possible, and as it is with most of the bolts missing it's not possible to move the engine.

Monday, 22 September 2014

Close encounters

We really struggled at this weekends national Finals, yes we ran some pretty consistent and fast runs but struggling with tyre shake and wheelspin, and a mixed bag of great 60ft's followed by some of the worst in a long time. We tried something different every run too but it always did the same thing.
We qualified 2nd in the end, out qualified by Allan Davies who ran a 7.604 to our 7.608, so we knew it was going to be close. Race day we woke up to sunshine and a good forecast for the day, this meant we might actually finish an event for a change. In the first round i faced Tony Clark, and in the past Tony has a history of beating me in eliminations, but not this time, he did have a good run however - back into the 7's with a 7.91, and so ended a troubled weekend on a positive note.
In the semi final it was a race against Paul Hambridge, who has run into the 7's before, and he improved on his qualifying times making a 8.06 run against my winning 7.64.
Into the final then, and it was shaping up to be a close race, we had both run a string of 7.6's over the weekend and the outcome was anybodys guess. Before the race we took a gamble to increase the tyre pressure, something we had been delaying trying as we just wanted to go through rounds, but this was the end of the line, and we had nothing to lose so we upped the pressure by nearly a whole psi. Now that may not seem like a lot, but in drag racing changes are usually made in quarter or half psi increments the tyres have so little air in them anyway.
The result was a releif, we didn't win but we did have a really close race, and importantly hardly any of the tyre shake, wheelspin and bouncing. It just went nice and straight and we were side by side the whole length of the track, i was slightly ahead till three quarter track but Allan had 2mph on me and krept past to take the win by .009 seconds. Allan ran a personal best time and i ran a personal best mph. A great Race.
1st slow mo clip shows the tyre shake we were struggling with.

And the 2nd it's much better, just a small amount of spin but the tyre doesn't unload badly.

Tuesday, 16 September 2014

National finals 14

It seems like only a few days ago that we got back from Santa Pod, but a couple of days from now we are heading back for the next meeting, the National Finals. Which isn't the finals at all - well, not for bikes anyway - for us it's round 5 of 6.
Last week i made some new axle blocks for the bike, they are only a bit so longer than the current ones, but with the addition of a few links to the chain it's allowed the wheel to move a clear 2 inches further back from it's current location. It won't be radical that's for sure but it should help stop the bike hitting the wheely bars quite so hard off the line, and reduce the bouncing that then happens - or at least that's what I'm hoping for.

Only 6 entries again in comp bike, funnybike is faring a lot better this year, with 13 entries once again. The points tables are interesting so far, mainly because almost none of the events so far have actually gone to eliminations so there's only qualifying points in it. As a result pretty much anyone stands a good chance of winning this year.

We will head down to the pod on Friday, with qualifying on Saturday and (fingers crossed) eliminations on Sunday. Eurodragster.com will be covering the event as usual with all the usual links on the event page here: http://www.eurodragster.com/santapod/live/2014uknationalfinals/default.asp

Thursday, 4 September 2014

Production goes fulltime

Got a week off work next week so dragbike production goes full time for a few days!
Recent good weather meant i've pretty much finished bronze welding the frame
It's also been decided - after watching some videos of the runs at shakey that it would improve traction off the line if we could make the wheelbase a bit longer, so i have some new, slightly longer axle adjuster blocks to make for the bopchop. Only 1 inch longer, but with 3 links added to the chain it will allow the back wheel to go back 2 inches. i can't go any longer without crude modifications to the bodywork, and as it stands i'm having to make an extended chain guard.

The second half of the wheel 'hub' is done now too. Only polishing left to do!
I had some parts water cut this week too. Mk2 axle blocks for the new bike and the back wheel, which also incorporated the front and back engine mounting brackets.
It marks an end to having thicker parts water cut.  It takes a disproportionately long time to cut thicker bits of ally and therefore gets expensive. A jigsaw, and then onto the milling machine for the big things in future, or maybe it's time for a bandsaw?
The wheel is a 6 spoke curved design to match the front. I started machining it this evening. I started by boring the center hole by mounting it on a faceplate in the lathe, then skimmed the outside edge too. This allowed me to transfer it over to mill and center it accurately on the rotary table, where i;ve made a start on drilling the bolt holes.

Taking a short break before any more progress however. We are off to Santa Pod to watch the last 2 days of the European finals. Tomorrows qualifying includes an evening session .... Top fuel in the dark!

Wednesday, 27 August 2014

Here comes the rain again

With 3 out of 4 events rained off this year it's not been the most successful year for drag racing, and it seems unbelievable that the day it rains has always been eliminations day rather than a qualifying day. Surely it's some kind of conspiracy!?
The Open sport nationals was not exception then, 2 days of pretty good qualifying weather followed by a day of non stop rain and no racing whatsoever. We were in a good position too, no1 qualifier for the second event in a row, and we ran a new best time and speed in the opening round, with a 7.53 at 172mph.
We had a few problems getting the bike to leave the line properly to, much like we did at the last event at shakey. It leaves ok then quickly starts to get tyre shake and wheel spin, then it starts bouncing until finally away it goes. I think the bike is too short really, I'm going to put a couple of links in the chain so the wheel can be pulled right back towards the end of the axle blocks. The extra 1.5inches should help calm it down a little and maybe stop it hitting the wheelie bars so hard.

As mentioned in previous posts, i'd created a nitrous graph to help cancel out a lean spike on the O2 trace of the racepak. It was just an experiment really but it has worked to reduce it and a little more tweaking should see it disappear completely. It's not a fix for the problem but it's a pretty good band aid for it.

There are now 2 races left in the ACU championship, and mathematically anyone could still win. However we are currently placed in joint 1st with Allan Davies. Because of the rain off, and with no more rounds at Shakespeare county raceway Allan has now secured the shakey club championship and we are runner up. The Santa pod championship is still to play for.