Sunday, August 30, 2015

 Did some fibreglass work on the tail section.  Fabbed this piece in order to have somewhere to mount the tail light/ licence plate/ turn signal assembly.  If not that, to simply clean up the rear somewhat... a streetbike will no doubt kick up a bit of rain!
New exhaust mount location.  Its another Hindle titanium muffler, but a quieter one (allegedly) made for a snowmobile.  Otherwise identical to a streetbike exhaust.

August Trackday Fun

Made sure I got out of the garage and had some fun on the big kwacker!

Sunday, August 23, 2015

Here's the working concept for my exhaust version 2.0 plan, courtesy of XTR Pepo -- the guy behing Radical Ducati.  Another thumping single, so it makes sense to keep the muffler away from your butt...

Thursday, August 20, 2015

So some changes since the last post.  I did get the bike up and running, and took it for a few quick spins around the block.  A few things have become apparent:
1.  I've decided to make this a streetbike.  The zx7r is a perfect trackday hack, with improved suspension, lighter wheels, and enough power to keep me with the faster guys on the track... this supermono would be a rolling chicane, as well as an uncompetitive race machine in Canadian Thunder, even if I did throw a visa card at the engine.
2.  The bent fork I talked about in the video are disappointing.  It means another front end build (bearings, anyway), and re-fabbing the spacers for the wheel and the caliper.
3.  The old R1 16mm master started to weep at the bleed nipple.  I swapped it for an 18mm zx7r one I had lying around.  Bad move, brakes are wooden!  I've found another used R1 master in 16mm, and have ordered some replacement pads (the ones that came with the calipers are long overdue for replacement).  Hopefully this results in better braking performance.  The bike this caliper orignally came on, an Aprilia SXV, had a 17.5mm master, but those in the know all suggested swapping it out for a 16mm master.
4.  The Baja street kit is inbound.  I already have the headlight and horn, and have found some DOT tail lights and have a line on some turn signals.

The biggest issue is the vibration.  I suppose attaching a muffler to what is basically your arse, and then fitting that to a single cylinder bike is going to lead to some potential harmonic issues with the backside.  I need to conduct a bit of an experiment to see if the hindle exhaust mount location is the root of the problem... I'm gonna run the bike with it not attached, to see if the vibes are the issue.  If this is the source of the shaking, I've got a couple of solutions rolling around in my head.  One is a complete re-route of exhaust system to create an under-engine arrangement, and the other is to use a different muffler, and mount the can to the mainframe itself, and not the rear subframe.  I'll have to do some thinnin' on that one.

The under-engine arrangement would cost more in time and tubing to fab, but it would eliminate the vibration problem as well as the kickstart rubber melting on the link pipe.  My fab guy might want to hit me, considering all the hard work he did to create the exhaust.

Thursday, August 6, 2015

 Got the painting done.  After years of getting "decent" results with spraybomb primer, color, and a inexpensive 2-part clear, I struggled a bit with this one.  I think part of the problem was I was using a fast-hardening activator, and with the temps on the warm side, I got crazy orange peel with the first coat.  Knocked it down with some wet 600, and switched product for the 2nd coat.  Came out much better, but with a thinner final consistency, actually got some runs (minor) in the clear on the tank.  That's a first.  Anyway, the finish is nothing if not durable, and that's the main thing for a racebike.
 Still details to sort... waiting still for the carbs, and need some seat foam and a rear brake line.  Am also going to run a small cafe race fairing, a 250 BMW rennsport one from Boxer Cafe.  Should look pretty cool, I think.  The numberplate is all right, but some wind protection might help with top speed a bit.
 Been learning a lot about these XT engines.  There is an oil pump upgrade -- I bought a NOS one from an ebay seller from Canada, and just need the gear to go with.  David Lambeth from the UK has also been helpful with his suggestions.  He does offer a complete bullet-proof rebuild but the cost is staggering, and I'd need to factor in shipping a very heavy engine to the UK and back.  Not sure if I can justify this expense.  2000 thousand pounds (choke).  There are other options as well.  Part of me would like to do this work myself as the engine is simple enough.