Sunday, 25 January 2015

Body work

The bodyshell i bought has gone through a slight - cut it into pieces stage, mostly because it didn't fit right good! The seat rails on the frame are so low the seat of the shell was miles off, it was also too long by a few inches oh and my ass was too fat to actually fit in the gap where the seat was.
So, the seat hump had been chopped out and the tank separated to allow things to sit better.
The front fairing is not a drag race item, i just liked the look of it and now trying to make it fit. Today i made the front subframe to hold it and added the mounts for the electronics which will live up there too. Small side panels are yet to be added to the front fairing and lots of the body shell is still to be cut round the engine and frame rails.

Sunday, 11 January 2015

Problem solved

Quick recap.....
The last race of 2014 - the extreme bike weekend, we qualified first but after the last round of qualifying i found a problem with the clutch and decided not to run it in eliminations in case it got worse and damaged something.
3 months later and after a lot of head scratching, it seems i have found the problem. At first it seemed the clutch primary gear was bent, I'd measured the runout of the gear by setting it up on an input shaft in a set of cases and using a dial gauge, and by laying it on a flat surface, and it did seem to be simply bent.
Then i decided, to be more accurate i'd put a bit of large diameter bar in the lathe and machine a shoulder into it and butt the gear up against that and bolt it to it, guaranteeing a true surface. This corroborated the theory that it was bent as it had nearly 0.5mm of runout. 
However, in my attempt to mark it up with a view to straightening it i turned the gear around and bolted it down again. Suddenly, the gear isn't bent anymore - no wobble!
I'd never even imagined the thrust surface of the gear wouldn't be straight... after all why wouldn't it? I still don't know. But anyway it was miles off, as you can see in one of the pictures where I've started to cut it flat again.
The surface was tough but with a carbide cutter and light cuts it turned up just great, and i finished it by lapping on a flat plate till it looked consistent.
Total runout now is less than 0.1mm. So i made up some new rivets to hold the basket and gear back together and used a large glamp to hold it all whilst i welded the ends of the rivets to the backing plate.

Tuesday, 6 January 2015

What's 2015 got in store?

Lots of small things happening in the background at the minute. I've been tidying and rearranging things in the cellar, making new shelves to store some of the rubbish i keep collecting, and generally trying to make it a nicer place to work. Plus i've been freeing up some space by selling quite a few surplus GSX bits on eBay, Barrels and pistons, and a few smaller bits. Cylinder heads might be next. I have 9 of them!

With the proceeds of the eBay purge I've managed to save up enough to upgrade my DC arc welder with scratch tig torch to a proper TIG set with High frequency start gas flow control and Pulse welding mode. Disappointingly it hasn't improved my TIG skills, i still need some practice.
Also managed to find a 30 ton hydraulic ram at a good price on that site, it arrived today. It's massive,  and a decent frame to mount it on is on the agenda now too. It'll also need a hand pump and some significant steel slabs to finish it off, but it's a useful thing to have is a small press - steering stems, gearbox parts, cranks etc.
Bodywork is due to arrive via courier tomorrow. The courier is bound to have something to say about the size, but at least it won't be heavy. Once i have it i can make a start on mounting it, getting the seat position right, and related parts like footpegs. Plus I'll have my first job for the new welder - making a stainless fuel tank.

Sunday, 21 December 2014

Sprocket support

I've not been able to make much progress with the bike recently, largely because i'm waiting on a few parts before i can move on.
Bodywork is next on the agenda, and i've long since abandoned making my own, it's just too much work. Instead I've had one made from a mould, it's ready and just needs collecting.

One of the parts i have done is a sprocket support plate, it's been designed, waterjet cut, test fitted and machined for the bearing holder and crank seal.
The design was too 'curvy' to do on the mill, so it went to K-cut, where John was as helpful as ever, firstly fixing my troublesome CAD file, then cutting me a wooden one to test fit first, and finally cutting ally one.

Found time to do some footpegs too!

Tuesday, 2 December 2014

Aluminium cake

I've had numerous cake shaped pieces of aluminium delivered before, most get turned largely into swarf  and this one was no exception. This one was destined to become offset sprocket bearing holder. It took a lot of hacksawing to cut it in half partway through.

This was preceded by top yoke manufacture.....

Sunday, 30 November 2014

The blog without a subject

A little over 7 years ago i started this blog when i bought my first dragbike which i named the bopchop. With work now well underway on the 3rd dragbike I'd started to run out of space, and so i decided that i needed to rehome the original bopchop.
I didn't even get chance to post on here that i was looking for a buyer. I mentioned it on our facebook page on Wednesday and by Thursday it was sold. Only the rolling chassis, no engine or electrics. And today, it was collected by it's new owner.
Hopefully it will be out again before too long, which is something that was unlikely to happen if i kept it anyway.

And so, here is a concise recap of the bopchop!
As it was when purchased in 2007
One full rebuild later and ready to race 2008
Open Sport Nationals at Shakey 2008
At the extreme bike weekend 2008 the bopchop did what i never imagined it would when i was rebuilding it. It ran the into the 8 second zone with an 8.87 at 150mph
By the middle of 2009 it was running fairly consistent mid 8's and the best time it recorded was an 8.33 at the National finals, and a best terminal speed of 158.36mph

And finally - here it is today, ready for a new home and an engine transplant!

Saturday, 22 November 2014

On the bottle
Team Bopchop are pleased to announce that 'On the bottle' will be supporting us next year. Providing discounted nitrous refills, nitrous parts and VP race fuel. On the bottle will be at most rounds at Shakey next year as well as selected Santa Pod events. More details of the events they will be attending, and their full product range including full nitrous kits for cars and bikes, as well as bottles and parts can be found online at
Or take a look at their face book page - Mark Onthebottle, and tell them you heard about them here.