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. will be covering the event as usual with all the usual links on the event page here:

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.

Thursday, 21 August 2014

2014 open sport nationals

Tomorrow we head off to Shakespeare county raceway for round 4 (of 6) of the ACU championship - the Open Sport Nationals. Qualifying is on Saturday and Sunday and eliminations on Monday.
The bike is ready but will likely need a new tyre fitting at some point over the weekend - a new Mickey Thompson will be collected at the track.

Coverage of the event can be found on, with live reports and end of day galleries.
The link to the page is here:

Sunday, 17 August 2014

Wider, stronger, lighter.

Frame is half brazed - awaiting a dry and less windy day so i can finish it. In the meantime some aluminum nuggets arrived so i made a start on making the back wheel. It'll be just like the current one but lighter, stronger and wider basically.