Shock Horror

Suspension - motosickle development has come a long way since rigid-frame, sprung-seat two wheelers were the norm. Suspending as much of the mass as possible of any vehicle by spring has the effect of cushioning the occupants from the harsh vagaries of the road surface. Springs alone will provide cushioning and a degree of comfort but left to their own devices they will absorb the energy and reciprocate with an equal amount of rebound offering a very "bouncy" ride and failing in the all important task of keeping the tyres in contact with the road. In vehicle suspension we really need this springing to be controlled by damping.

When the GT50 first appeared on the scene last year it was apparent that the ancient Paioli suspension (both back and front) had long since given up damping and was content with doing just the bouncing. Fellow Shit-Bike Club member and enthusiast Rupe Paul will have no truck with iffy suspension and is something of an expert - so I listen to him. Initial response, in the usual Diplo 'shop manner, was to strip the offending shocker (only one on the very advanced mono-shock GT50) and fettle/bodge some sort of recovery. The constituent parts can be seen laid out in the picture - piston, damper rod, seals and pressure bladder are all shot to pieces. Time for a Yorkshire Gold brew and a Turkish smoke to consider the options. First port of call was the very accommodating suspension guru Darren Wnukowski at MCT in Suffolk - he suggested I shipped the offending item to him for a re-build quote. Next day a very brief 'phone call - "beyond salvage". That said, Darren immediately furnished a quote to get a new bespoke shock built by Falcon Shock Absorbers - the beauty of these guys doing their job properly is that they absorb all the shock of the quote - suffice to say very reasonable.

How refreshing to keep bumping into friendly, helpful, practical people in the world of the motosickle - people actually manufacturing top quality products on this little island of ours - marvellous.
I include a shot of the new unit by way of demonstrating just how wonderful life can be - doesn't get any better than this ......
Front forks and other issues to follow.
MORE DAMPING  !!

Fine Tuning

CB engine rebuilt, new cam chain, valve timing set, clearances at 2 thou, ignition timing spot on. Fuel on, tad of choke, ignition on, kick - fires first swing, marvelous. After initial warm up run of five minutes we cut the ignition and went over the engine looking for leaks and loose bits. Satisfied all's well I took the bike for a blast up the road - at 1/2 throttle it all went horribly wrong - EXACTLY the same misfire as before !?&@?!!$£?@%!. Back to the carbs then. These are 18mm round slide Kehins. Basically at tick over you've got a pilot jet and mixture control to adjust, from tick over to 1/4 throttle the mixture is determined by the shape/size of the cut-away at the bottom of the slide, from 1/4 up to 3/4 throttle the tapered jet needle and the needle jet it slides in control the mixture, from 3/4 to full throttle you're running on the main jet. All these stages are adjustable, plus float height adjustment is critical. Add to this you've more than one of these instruments to synch and you have a rough idea of what's required - PATIENCE. Lets forget about atmospheric humidity, temperature, altitude, pressure etc. The carb parts on the bench are: throttle stop screw, pilot mixture screw, float valve seat, float valve needle, pilot jet, assorted main jets #88,85 & 83, jet needle, needle jet, emulsion tube/jet holder. The mini pocket microscope (50 X mag) is handy for reading jet numbers and identifying wear. Unfortunately ALL of the above parts are subject to wear and, in the science of fuel/air mixing, this wear is ruinous. Off to stock up Yorkshire Gold supplies and try and find some decent Turkish cigarettes. MORE VARIABLES !

Honda Project Part 3

Rebuild's on the way - the Series bonnet is open as the battery's being used as a slave for CB electrical testing. The only failing revealed to date is a weak/intermittent starter solenoid. I was pleased to see at Old Bike Hack that my mucker has been playing with OPE (other people's electrics) - this one's also been a challenge as we have a mixture of 175 and 200 looms, alternator, switch gear etc plus yards of soggy insulting tape to unravel. Allowing myself to drift into Zen mode, isolating myself from the outside world, and taking much Yorkshire Gold - ooh yes, and a couple of imported Izmir Turkish smokes - I seem to have become at one with the problem and started a process of self-healing which has lead to a clean bill of health for the CB electrical system - "...first take the log out of your own eye....".
This rather unattractive nondescript bike has entered my life in a list from D7, Greeves 250 Scottish, C15, G80 S, GPZ 600R, GSXR 1100, G3 L, DR 650, Speed Triple ,GS 1150 and now CB 175/200. It seems remarkably at home. As yet unridden, I think it may have become my favourite so far. I have mentioned earlier in these pages that I have reached the point where any bike will do, having got there it is, of course, obvious that the machine becomes no longer "ANY bike" but "THE bike". I have noticed myself taking great care and effort over reviving failed switches, poor electrical connections and putting right horrible ills inflicted on mechanical objects by many, less sympathetic, past owners. I am not a fan of polished, over-restored renovation but am more concerned with getting things to work smoothly, efficiently - as intended even. At strip-down I really thought a lot of parts would need replacing and had started to make a worrying list for e-bay hunting and a call to David Silver Spares. What I have discovered, with the help of some wise words, much tea and Turkish and a bit of peace and quiet, is that many individual bits can become perfectly serviceable by taking them to one side, stripping them to their smallest constituent parts, cleaning, lubricating and re-assembling without 37 years of accumulated grit, grime, road salt and abuse. Taking up far too much space rambling here. More to follow. MORE IZMIR TOBACCO !