Archive for the ‘SR500’ Category

XS650: Habits

English is an odd language … a mongrel … a lexic melting-pot … context rules … it’s quite easy to gain a basic working knowledge of English – average daily vocab uses around 700-1500 common words (depending on the person and their circumstances … 20-40k passive vocab) … but you have to listen carefully (grammar, pronunciation, intonation, colloquialism and proficiency aside) … words in english language take on a life of their own depending how they’re used

Habit:

/ (ˈhæbɪt) /


noun

  • a tendency or disposition to act in a particular way
  • established custom, usual practice, etc
  • psychology: a learned behavioural response that has become associated with a particular situation, esp one frequently repeated
  • mental disposition or attitude a good working habit of mind
  • addiction
  1. a practice or substance to which a person is addicted
  2. the state of being dependent on something, esp a drug
  • botany zoology: the method of growth, type of existence, behaviour, or general appearance of a plant or animal, a climbing habit; a burrowing habit
  • the customary apparel of a particular occupation, rank, etc, now esp the costume of a nun or monk
  • riding habit a woman’s riding dress
  • crystallography: short for crystal habit

verb (tr)

  • to clothe
  • an archaic word for inhabit, habituate

Usable in fields such as Tradition, Psychology, Botany, Zoology, Crystallography to describe custom, state, disposition, growth, dependence, clothing, residence …

I have many habits. Depending on who you’re talking to, some good, some bad. Being not so “woke” I don’t give a flying-flick how people react – grow a set of balls – have a good look at yourselves, get a life.

One of these habits (customary practice) is to treat my favourite bike (addiction) to a birthday present. Another (behavioral response) is to listen to my angels (whether i act or not is up to me). This year, the local version of fleabay presented an opportunity to acquire a paired set of XS1 wheels. At a reasonable price, no-less. In Nelson – the ‘other’ island. No postal option. Surprised – the last few years I haven’t been able to look at a bike.

Weighing freight options I shat buckets of blood – checking local flights and booking in advance, it proved cheaper to drive (from my habitat) to Auckland, fly down to Nelson, stay the night, shuttle back to the airport and fly back to Auckland (<$100 each way) – my elderly mates widow also winning a couple of hard days gardening and newly built external stairs down to the garden … all in all 6 rather long days … gotta be getting old-this trip hurt.

Kool post-sunrise, mid-autumn flight down the west coast, Mts Ruapehu and Ngauruhoe snowy head and shoulders shrouded in mist, then over Mt Egmont/Taranaki, across Cook Strait, Nelson. 1.5 hours … the coffee was even drinkable.

Ruapehu from Taranaki … late sunrise … some Mordor scenes were shot here for Lord of the Rings
Mt Egmont/Taranaki showing Farthams Peak on southern flank

Sun was shining. A small miracle (although Nelson is renown for sun). Many major storms-rain-wind- damage in NZ so far this year (odd how in our region jet vapour trails only seem to occur just before stormy rain – or is the jet called Daniel and the trail is crack laden hot and sweaty bad breath). This weather is a real bonus. Worth a walk. Airport to city, via the waterfront – bit over an hour

nelson waterfront

for these …

XS1 wheel pair

Very clean, all there, excellent drum lining, rims appear fine, spokes are fine, even have good tyres. These wheels have had little use.

SR500 and XS1 Front Wheels

Easy set-up for later 35mm XS and SR generic forks. The SR500 model 48T and SR400 introduced into Europe and Japan in the late 80’s and 90’s had the ‘Trommel’ or Drum Brake option – basically a reconstituted XS1 drum brake, with 5 black rubber inserts instead of 6 and no chrome cover for the air-vent which itself is not open anymore, cast offset is a bit different and the 19″ chrome steel rim became 18″ aluminium. This mated to the generic forks, set up for disc brakes, using Yamaha Part Nr. 1JN-25192-01-00

SR500 Drum Brake adapter

You can find these on German fleabay (kleinanzeigen), for an arm and a leg. Also from Motolanna.

SR500T front brake lever provides Yamaha generic brake light switch and brake cable operation.

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XS650: Viton® Valve Seals   Leave a comment

Had in mind to tart up one of the XS1 heads I have lying around. Picked up a set of Viton® valve seals for it. Reputed to outperform the originals. Got sidetracked and they sat on the shelf a while.

Viton® valve seal … metal jacketed

 

These are available with or without a metal jacket.

unjacketed valve seal

 

I am now sorting out a head for an extra SR500 motor. To go in the sidecar. Emphasis torque. Early 78/79 crankshaft and cases (larger crankshaft counter-weights), specially ground cam, larger valves, lighter valve springs, thinner spring plates, modified ports, carillo rod, O/S piston, modified/heavier flywheel etc. The XS650 and the SR500 use the same valve seals. No point leaving these sitting. Collecting dust.

Wonder how they will work.

Viton®. Flouroelastomer (FKM/FPM). A fluorocarbon based synthetic rubber. These contain 5% Teflon for reduced friction and wear.

Advantages:

  • have a wide and stable Temperature Range -30°C to 225°C (-10°F to 400°F)
  • resist hydrocarbons (fuel/oil)
  • excellent oxygen, ozone and weather resistance
  • incombustible
  • have excellent dynamic properties (coeff. of friction, tensile strength, range of hardness and resistance to compression set etc) – good abrasion resistance
  • have low permeation rates (esp. relevant to alcohols, hydrocarbons and biofuels (biodiesel, ethanol)
  • be solvent, mineral acid resistant (don’t really like ketones, amines or low mw esters,)
  • show low compression set

Disadvantages:

  • low alkali resistance
  • relatively poor mechanical properties
  • limited elasticity at low temperatures
  • the tensile strength decreases substantially at elevated temperatures
  • high price

The fluorocarbon rubbers are used for special applications that require good heat, oxygen or corrosion resistance and hot solvent and oil resistance.

Applications:

  • car and airplane seals and hoses
  • fire-resistant coverings
  • heat-resistant insulators
  • o-rings, shaft seals
  • gaskets, fuel hoses, valve-stem seals

Note: Viton® is a registered trademark of DuPont. It is often misleadingly used as a generic term for FKM/FPM flouroelastomers.

For the chemically-minded FKM’s thermal and fluid resistance are a function of 3 main features

  • Extremely strong bonding between the polymer backbone carbon atoms and the pendant (attached) fluorine atoms
  • High ratio of fluorine to hydrogen atoms bonding to the carbons (high fluorination levels tend to create stable compounds)
  • Full saturation of the carbon backbone .. no covalent double bonds between carbons minimizes attackable sites

Structures of fluorocarbon rubbers

Monomers Structural unit Type designation Commercial types
VF 2 + HFP

FKM

Viton A, AHV, A-35, E-60,
Fluorel 2140, 2141, 2143, 2146
SFF-26
VF 2 + HPFP

FKM

Tecnoflon SL, SH
VF 2 + HFP + TFE

FKM

Viton B, B-50
VF 2 + HPFP + TFE

FKM

Tecnoflon T
VF 2 + TFCIE

CFM

KEL-F 3700, 5500, SKF-32
PFMVE + TFE + X

FKM

ECD 006

 

Typical FKM structure … flourocarbon rubber

 

An example of a structure of the fluorocarbon rubbers, VF2 / HPTFP / TFE -copolymer.

 

Posted March 23, 2014 by xscafe in Motor - Head, SR500

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