Wednesday, 27 May 2015


Took the bank holiday weekend off from dragbike building, and instead went to Santa Pod to watch the main event, and guests of Bob Brooks - Yellow metal racing team. It was a great weekend even though the bike wasn't on form. Some upgrades are due and the bike should make it into the 6's sooner rather than later. Thanks to Bob for inviting us.

Back in the cellar and it's been wheely bar construction time. The bars are of a similar but improved version of my current ones, just in larger diameter tube. And this time i was able to use the lathe to thread the tubes and ends rather than a tap and die, as the headstock tube on the lathe has a much bigger diameter than the old one.

Another mission is currently underway too. The V&H head uses valves with 6mm stems, but the retainers and collets i have are for 7mm stems. To buy them new off V&H is quite expensive, so i'm attempting to make retainers out of titanium, and i'm using collets/locks from a Toyota Supra.

This one is a test piece, i have enough bar to make a full set and a couple of spares.

Tuesday, 12 May 2015

A late update

The review of the springspeed nationals is a bit late coming but here it goes anyway....
 Going into this event we still hadn't made it down the track this year, so there was still a few new bits on the bike to test, mostly the new experimental nitrous system with dual fuel solenoids and extra massive nitrous solenoid. 
Picture courtesy of Callum Pudge

The first run then and the huge nitrous solenoid sucked all the electricity out of the battery and it hardly made it down the track, backfiring and spluttering most of the way. This wasn't helped by the fact that the battery charger had been playing up and maybe hadn't charged it fully or at all.
On the next run it didn't do any of those things, it 'calmly' went down the track without incident. Dead slow though. turns out the new solenoid had blown the fuse in the nitrous system so it didn't come on, and it blew the next few fuses i tried too until it finally stopped with a 30amp. Greedy.
The data logger was key to diagnosing this problem, without it we could have been guessing and changing everything for months and at great expense. But the graph shows battery voltage dropping with each solenoid pulse, turning the ignition and O2 sensor off at the same time. video 

With no easy way to resolve this issue, i changed back to the little baby solenoid and managed a 7.8 on the next run - but that was with our usual shakey issue of tyre shake and bouncing for the first 200ft or so. On the next run the bouncing was so bad it turned the nitrous activation switch off less than a second into the run, so that was that run over as well. 
The 7.8 was good enough to put us 4th and I'd be up against fellow comp bike deserter Allan Davies, i decided to make a few totally random changes hoping to reduce the launch issues and maybe get through that first round, but it completely didn't work, buckarooing around so bad i wasn't actually in the seat at one point. Crazy thing.
Needless to say, we didn't get through that round. 

The good news is that the rest of the changes to the nitrous system seemed to have worked pretty well, reducing the lean spike that we always had, to the point where it's hardly visible on the logger graph. And the huge solenoid is now for sale on eBay, it's 33amp draw is just too much for a total loss 12.8v system. I'll be looking to buy the next size down, which draws a mere 13amp. 
If we can find a softer clutch setup that works i'm hoping it'll run really well at the next round in june, we have more power in it and it could be it's last chance to go faster if we are to run the new bike at the following round. 

New bike is still coming along steadily. I now have some MTC pistons for it, and valves are now with Roger Upperton - being modified to fit the head. I'm currently making a set of wheelie bars for it, and as soon as they are done and the lathe is free I'm going to make some titanium valve retainers as it's nearly impossible to find any that will fit 6mm valves. Loads of other stuff piling up too, wiring stuff is sat there, cans of paint sat there, steering damper partly done, fuel tap splitters partly done, coil mounts to make etc etc. Plus i need to service the race bike, check it thoroughly for broken stuff and decide on a setup for the next round. Busy busy. 

Thursday, 30 April 2015

2015 Springspeed Nationals

It's nearly time to head off to Shakespeare County Raceway in Warwickshire for the Springspeed Nationals - the second race of the season.  Only 6 bikes on the last entry list for Funnybike but hopefully a couple more will turn up to make it a full field.
8 in Comp bike which is better than last year, and also sees the return of Phil Leamon after missing a few rounds.
We will be traveling down tomorrow, qualifying starts on Saturday and continues Sunday with eliminations on Monday. will be covering the event as usual, with live reports, live audio and webcam. Links to all of which can be found HERE

Sunday, 26 April 2015

A few steps closer

Next weekend we should be at Shakespeare county raceway for the second race of the year. I've fitted a new head gasket and a fresh set of power rings to the engine so we shouldn't have head gasket problems again.
Getting that sorted and the bike ready hasn't taken too much time and i've been busy making bits for the new bike. I'm hoping - quietly, that it will be finished by the end of august in time for the 2nd shakey round. But thers still a lot to do so i'll just chill out and go with the flow a bit.
Battery box and nitrous bottle bracket are now done, and the rear mudguard is mounted properly. Made a start on wheelie bars too, which are similar to the last ones i made. just a bit more complicated and longer!

Monday, 20 April 2015

Blazing brazing

Some nice weather at the weekend meant i got chance to work through my backlog of 'waiting to be brazed on' bits and pieces. Front subframe is now done, battery mounts, footpeg mounts, mudguard brackets, allsorts.
Decided the mudguard i bought wasn't really wide enough so i tackled widening it, added 40mm and it seems to have worked, i used carbon fiber/aramid weave to make the modifications, so it's pretty strong still despite being chopped in half.

Used some of the carbon stuff to reinforce the bodyshell mounting points too. Should help prevent them cracking. Cutting the stuff requires quite some effort too .... amazingly tuff.

Thursday, 16 April 2015


Easter then ...... umm, new gazebo was ace. Came home with 2 trophys, but it was a bit of a disappointment really.
Friday it rained all day and nothing went down the track. Saturday it was slow going and we didn't get called till mid afternoon. Took the bike down, did a burnout and started pushing the bike towards the stage beams, halted to select 1st gear and i could hear an odd noise from the engine. Took another listen and sure enough an odd tapping noise - then i remembered the last time it sounded funny and i ran it anyway and it destroyed itself. So i turned it off and pushed it away.
Back in the pits i checked the tappets, lashcaps, camchain, clutch but found nothing. Ran it again and i spotted smoke coming from one of the unused 6mm cylinder head bolts. the head gasket was leaking! there was no time to pull the head off as we were due out again, so i loosened all the head bolts and re torqued em hoping it might do the job but no, still the same, and the tappety noise was still there. And so i didn't run and didn't qualify. We headed off home teh next day. I've since investigated further and can't find anything else wrong, the noise must've just been produced by gas leaking past the gasket. The power rings i got last time were rubbish so i wasn't too surprised they leaked when reused. New set on the way.
Lots of work on new bike recently, many things have come together making it feel that bit closer to getting finished. The bodywork is mostly sanded and ready for paint, and more importantly i have a final paint scheme i'm now happy with .... on the computer least. I've also made a start on a set of wheelie bars for it, battery box, nitrous bottle bracket are under construction too, oh and pistons are on the way as well.

Tuesday, 31 March 2015

Festival Essentials

A quick link update before we leave for the Festival of Power. The event will be covered as usual by and you can find the live reports, commentary and webcam links here on the event coverage page

With the bike now very nearly ready (i have 2 fuel pumps to replace after both the brand new ones i bought were found to be faulty, one ran for a few minutes then stopped, the other never worked at all), I've had a bit of time to work again on the new bike. I've made a fuel tank out of stainless steel - it's thin so ain't too heavy, although a lighter replacement will probably be on the agenda at some point in the future. It's been the first real job for my new welder and i found it pretty easy to do with it set on pulse. It holds just 1.4L of fuel, and it'll be rubber mounted and fastens to the frame with 2 rubber battery straps that go right under it and i thought were ideal for the job.