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Ex race bike purchase?

Discussion in 'Bike Reviews, Questions and Suggestions' started by removed-6, May 24, 2006.

  1. Would you buy a late model ex race bike for use on the road, that has been well maintained? I know it's a very open ended question, but why or why not?

  2. Most ex-race bikes have had all of their wiring for the headlights, indicators, and tail-lights stripped, as well as having no working speedo, nor likely to even have the stock instrument panel. The front fairing brackets typically get replaced with light-weight items not designed to hold the headlights or mirrors. Also, the original fairings that allow you to mount the headlights, indicators, and so forth may not even be available.

    The exhaust system will typically be a race-only muffler, and too loud for street use and unlikely to pass a road-worthy test.

    I guess the upshot of the answer is: It depends. Can the bike be easily and cheaply put back into a road-worthy format? Remember, it will have to pass a road-worthy before you can register it again for road use, and if it's missing all the bits required to do that, you could be looking at up to $3000 to get it back into a road-worthy condition if it's a late-model bike and all the required parts aren't available.
  3. not to mention its spent its life being flogged to high hell.
  4. Yeah but what second hand road bike hasn't?

    It is already in RW condition, as new.
  5. yeah most road bikes get flogged, but not held at high revs EVERYWHERE, track bikes are on the limit all the time.
    Thats the difference.

    It may be in great condition mechanically, its up to you ultimately.
    I just know i would be inventing noises and problems in my head knowing its past.
  6. Race bikes, however, are nearly always correctly warmed up, recieved very frequent fluid changes and very regular servicing. Not doing those things will do alot more damage to an engine then keeping the revs high on a meticulously maintained race bike.
  7. Thanks guys, now I'm even more unsure what to do :?

    more info- from owner
    It's an '05 model 600 with less than 5000k's at a reasonably low price.

    What's a 'valve lash'???
  8. Has had a new clutch within 4000kms? Sounds like the result of many hard starts and clutch-up wheelies. I'd be concerned with the steering head bearing too as a result. People replacing clutches within 4000kms spells extreme abuse, or maybe, just maybe, the guy was just maintaining the bike well after its race use alone. Still, been riding my R1 at the track for maybe 2000 track kms, and the bike has 24000kms on it, and the clutch on it is just fine. 4000kms seems very early to be changing clutches.
  9. Taken from here.

    What Is "Valve Lash"?

    Valve lash is the mechanical clearance between the cam lobe and valve stem or transfer rocker when the valve is fully closed. It's usually checked with a feeler gauge and is some non-zero value on with "mechanical" non-self adjusting valve lifter mechanisms.

    Differential expansion characteristics cause the cold clearance to be different than the running clearance and margin is built in to make sure their is always some clearance, especially on exhaust valves. An exhaust valve that doesn't close completely doesn't transfer enough heat back to the head and can "burn".

    Cam lobes have entry and exit profiles (called ramps) which are designed to limit the opening and closing acceleration of the valve to limit mechanical stress and also noise. Still, the tighter you set the valve lash (less clearance) the more open valve duration you get which tends to boost top end performance slightly. The looser you set the valve lash the more bottom end is boosted and the more valve train noise you get.

    If you have all the valves adjusted too tight idle quality and low end performance may suffer slightly with an attendant small gain in top end horsepower. Looser valve lash does the opposite and results in a noisier valve train.

    If you have some tight and some loose that might also effect smoothness since different cyclinders will have different power contributions at different RPMs. Some of the above is a little simplified but you get the drift.
  10. Thanks Cathar, also, what difference will a close ratio gearbox make on the road?
  11. i thought it was the yanks that called it 'valve lash' as i have seen it in US sites and the referneces to that here i've only heard 'valve clearance' check.

    anyways i say check it over extra good, can you get a mechanic to do a detailed check also as mentioned can all the fairing, lights etc be put back easily for road use again.
  12. One point worth mentioning is that racebike cooling systems are filled with distilled water, not coolant, it's too slippery on the track after an 'off'. This can shorten the life of the pump considerably as water has none of the lubricant capability of coolant. I've known lazy buggers who used tap water, not many but they do exist, and that can mean a new radiator real soon.
  13. Typically close-ratio gear-boxes feature a slightly taller 1st gear than stock, a lower top-gear than stock, and the gears in between are usually fairly evenly spaced. So by bringing up the 1st gear, and down the 6th gear, all the other gears are much closer together as well, hence "close-ratio". Race-bikes don't have the luxury of 4km straights to hit peak speed. They're geared to hit peak speed with the power that they have in the space available, so that's why top-gear is lower.

    A 600cc race bike that hasn't had a lot of engine work would likely be geared for around 120kph (actual) in 1st at red-line, around 240-250kph (actual) in 6th, with the gears 2-5 fairly evenly spaced in-between. This allows for tractable controllable power in 1st around hair-pins, and allows the bike to peak at red-line in 6th at the end of the straight. Of course different tracks may favor different ratios, but that's what I'd roughly expect.

    What that means for road use is that the bike because of its smallish 600cc capacity without much low-end grunt will be a little harder to launch off at traffic lights (perhaps the reason for the clutch wearing out early - rider has to slip the clutch heavily for take-offs at the track, and even on the road). For general road use you'll probably just be sitting a gear lower than stock gearing unless you often find yourself doing 160+ on the road, in which case you'll be typically sitting a gear higher than stock. Overall, aside from the launches off lights your riding style will generally adapt fairly quickly to the demands of the gearbox ratios without it bothering you.