why do bikes run better after a thrashing?

[Ginge09]

Agree with Drew. No comparison between the human body and a mechanical device in this context.

Giving a bike a good hard run may or may not improve it. Depends on the bike.

A highly tuned 2 stroke used in commuter mode will foul and clog. A good hard run should clear that. It's not designed to run in stop/start low rev mode.

A mild 4 stroke is designed to tug all day across a wide range of riding conditions. It won't complain too much, but a good thrashing occasionally will clear its lungs.

The cobwebs are a whole bunch of stuff like the engine mapping in your electronic gubbins if you have them ( coz some of them "learn" your riding style ), the carbon build up in your head and plugs, the various mechanical tolerances of 250 hot whizzy bits of metal, your own mental state on a a Sunday morning when you head out for a thrape with the lads.

It's a piece of machinery. Learn to get to know how it responds to external influences and keep it maintained. It'll let you know when it's unhappy.

...and that's why these guys talk about thrashing Jags to improve the state of tune. They were an expensive high performance car used as cruisers. A 20 minute squirt up the motor way gets them back in the comfort zone they were built for.

[Grumph]

A highly tuned 2 stroke used in commuter mode will foul and clog. A good hard run should clear that. It's not designed to run in stop/start low rev mode.

...and that's why these guys talk about thrashing Jags to improve the state of tune. They were an expensive high performance car used as cruisers. A 20 minute squirt up the motor way gets them back in the comfort zone they were built for.

Mmmh, not only Jags - and some of the 2 stroke comments hold...

A shop in ChCh was well known for the "5 minute tune up" on commuter 2 strokes.
It consisted of the foreman taking the bike out into the alley and revving the tits off it for the 5 minutes...
What this did was break off the carbon deposits that had built up on port edges - most noticeably the exhaust port top edge....
Full timing resumed, you had full power back again.

The same foreman - who is still around - was noted in the trade for his ability to charge out 16 hours in an 8 hour day....

[Daffyd]

I had a P76 back in the day. I had to take it for a thrash about once a month. For the first 10-15 km you couldn't see anything but smoke and crap in the mirror. It was a different car after that.

[Cosmik de Bris]

No. Just no.

That fails as an analogy. Since biological things are tuned through use and repetition, and mechanical components wear with the same treatment.

A motor that goes best after a thrashing is likely tired. Once things get proper hot they seal better perhaps. Though one would think as soon as it cools down it all needs to be done again.

I don't think tired is the answer, both my bikes are pretty new. Hot though maybe the answer because yes, once it cools down it does seem to go back to unzingy, except for those days when the temp and humidity are ideal.

Cheers

[old slider]

I had a P76 back in the day. I had to take it for a thrash about once a month. For the first 10-15 km you couldn't see anything but smoke and crap in the mirror. It was a different car after that.

They made great little jet boat engines.

My old girl has an awesome 3 litre v6 from the late 60s early 70s even though it is a blue coloured motor it has been an amazing power plant for many years.

[caspernz]

No. Just no.

That fails as an analogy. Since biological things are tuned through use and repetition, and mechanical components wear with the same treatment.

A motor that goes best after a thrashing is likely tired. Once things get proper hot they seal better perhaps. Though one would think as soon as it cools down it all needs to be done again.

You're overthinking it.

Take a high performance 2 stroke, potter it around town for a week and it'll be asleep. Give it a decent run, remove the built up carbon or soot and it comes alive.

Take a couch potato, send him to boot camp for a couple of months and he'll come back more lively.

But yeah take it to the long term and mechanical stuff wears out, look at it in terms of well within normal service life, and I stand by my analogy.

Since you like mechanical comparisons, take a high horsepower truck that's never been held wide open on a decent climb at max payload, then compare it to the same version that's been "worked" hard and a blind man can tell the difference. One is "asleep" and the other one is well and truly "awake"

[rastuscat]

A guy I knew in the navy in 1983 was away overseas and had left his RD350LC sitting idle.

He contacted me when they were on the way back, and asked me to get it running for when he was back.

Basically it was seized. No electric start, it just would not kick over.

Took out the spark plugs, sprayed in some CRC, left it to sit for a couple of days. Charged the battery during that time too.

When it started first pop next time, the smoke was incredible, as it burnt 6 months of oil and CRC sitting above the pistons.

Took it for a blat (a colloquial term for a vigorous ride) down the Southern Motorway. Bingo, sorted.

When he got back it was running like a charm.

[rastuscat]

My mechanic gave me a lecture a while back about being too polite to my bike. I rode it generally in the lower rev ranges.

Since my tune up (by my mechanic) I'm giving it more stick.

Mechanic said it was something to do with our low quality fuel. Needs to be flogged from time to time to clear out the gunk.