flatshift5
Allentown, PA
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Joined: 11/24/2003
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ummm......no i must have missed that one.....
let's see......cow......strawberry...... yeah, i can see the resemblence there!!!
PA......gotta love it!!
* This post was
edited 01/04/04 12:36pm by flatshift5 *
"Life's a journey, not a destination..."-Aerosmith
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motorhead
Newnan ,GA
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If your not worried about getting every last HP to the wheel(which a chain does most efficient) then go for a shaft or belt drive. Much less maint., no hassle & the bike stays cleaner.
Keep the rubber side down!
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sidekick
los angelas
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Joined: 11/25/2003
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thanks for all the reply guys, it cleared up alot of minor questions i had. I think i'll most likely go with a shaft drive.
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springtown
springfield, mo, usa
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Joined: 07/18/2003
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Quote:If your not worried about getting every last HP to the wheel(which a chain does most efficient) then go for a shaft or belt drive.
Are you saying you loose HP in a belt drive? Why is that, it looks like it does the same thing as a chain to me.
Don't sweat the petty things and don't pet the sweaty things
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recycl8
Charleston South Carolina
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Joined: 12/10/2003
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you would lose horsepower if the belt were not wide enough,(belt would snap?)A belt has to be wider than a chain to handle the same amount. yet other than that they are the same identical concept and work the same.
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BlackZZR
California
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Joined: 01/02/2004
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wow I don't think you lose HP to a belt. Harley was the big company to go to belts in the early 80s. Others experimented but went back and forth, Harley stuck with it, THey use belts for 2 main reasons. THe lope of harleys is smoothed out by the belt and you do not have to use a chain oiler.
But if they loose HP? I don't think Harleys can afford a loss of HP. the stock HP of harleys just got close to 60 with the Twin cam engine. it was 52 with the evo and thats at the crank. With numbers like that you can't afford to loose HP.
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recycl8
Charleston South Carolina
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nah you don't lose horsepower with a belt, if that were true, if there were horsepower handling issues with the belt, they would not use a belt on the Boss Hoss motorcycle (EngineCycle) that's for damn sure, lol, it's just that for the same amount of horsepower, a belt needs to be wider.
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motorhead
Newnan ,GA
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When I mentioned getting every last HP to the wheel ,I kinda had sportbikes or high HP bikes in mind. So belt drive is really not meant for long life under those conditions.
I think a belt is very close to a chain as far as efficiency goes (if not the same), but although a belt will last longer & run quieter, it won't handle high HP like a chain will. Even the guys that race Buell's on the track usually change over to chain drive due to strenght & ability to change gearing easily.
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beltdriveman
Chelmsford. UK.
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Chains are a very efficient means of power transmission. Testing at the National Physical Labs in the 30s showedfor example that a Renold 1 inch pitch chain carrying 25 HP at slow industrial chain speed with CORRECT lubrication(Sump and pump) was 98.4 to 98.8% efficient
People often quote 98% as the efficiency for a chain. THAT is, to be polite about it a LOAD OF BOLLOCKS. Even Jack Williams in his 1949/50 design note book for the 7R AJS states that a drip fed primary chain is no more than 90% efficient and lower at high chain speeds.
People do not Qualify the statement about chain efficiency. It should state as Mr R Coulson of The Renold and Coventry Chain Co stated in his paper to the Institute of Mech Eng published in their 1937 vol 2 book 'General Discussion On Lubrication' headed 'The Lubrication Of Chains'with Particular Ref4erence to Transmission Chains of the roller Type'and I quote....
'Chain transmission correctly proportioned, erected with reasonable care and lubricated on the lines laid down in the forgoing, can berelied uponto transmit the power d4elivered to them with an efficiencyof not less than 98 per cent'
So when was the last time you ran a primary or secondary chain correctly??? Where is the 2000 ft per min max chain speed? Where is your sump and pump oil lubrication system? When did it last carry the max power the chain company specify in their specs?
Ever read the 'Book Speed and How to Obtain it'???? I sometimes wonder why the Staff of The Motor Cycle bothered to write it all those years ago becauseeven if they state that over 110,000 copies were sold few seem to of bothered to open and read it......A Quote. Page 47.
'It is not always realised what a hard working component the primary chain is. It runs at very high linear speedand, though it comprises a series of plain bearings, it is given nothing like enough oil either to lubricate or cool them.Under the best conditions a chain is a most efficient form of transmission, but even so it absorbes about 2%of the power input in internal friction. This lost power converts to heat . The wastage with an inadequately lubricated chain is consigerably higher, so that several horse power may well be used simply in heating up the chain.'
The chain was an improvement over the flat or wedge belt used pre 1914 but in those days chain speed and power outputs were low.
Th MAjor problem is all diown to getting lubrication into the chain and at high chain speeds the rediculously high MASS of the chain which then does not want to bend round the sprockets but carry on going straight on. As the chain is forced around the sprocket all those incorrectly lubricated plain bearings heat up and if one is really brain dead you can confirm this for yourself by burning your finger on them.
It was in 1977 that Supercycle Mag did a Harley dyno belt /chain shoot out and the results showed that for primary drive speeds up yo say 80mph the belt system was up to 1 HP better BUT at a drive speed equating to 90mph the belt was FIVE POINT FIVE H.P. better off the artical stating,'The chain, at 6000 ft per min is virtually stiff as a broomstick and not only eats bunches of horsepower at high speed, it wears almost fast enough to see , and self destructs.' Supercycle Magazine Sept 1977.A LONG TIME AGO.
It is to keep chain speed and power losses down that your modern motorcycle has such rediculously small sprockets, especially the gearbox ones. Race bikes use the lightest chain they can get away with that will last the race..to keep chain weight down.
Personally although I have wasted a bit of time picking the brains of chain industry people, both present and retired, both in the UK and USA I can find no complete test results done to determine the power losses in motorcycle chains and I suspect the chain industry doesnt want us to know!!I understand that when Harley and Gates did their testing for the all belt driven motorcycle decades ago (SAE paper No 800972)they did no testing to determine the power loss difference between the std chain and their belt systems....personally i dont know an Engineer who could not do such testing just to satisfy engineering curiosity...pahaps the test prog was run by what we know as ac****ants over here in the UK and no money out of their own pockets was available for such testing?????????????/
Shaft drives are all very nice but its a bit of a bastard changing gear ratios and its more expensive FOR THE BIKE MANUFACTURE who doesnt give a toss that your incorrectly lubricated etc rear chain only lasts a couple of thousand miles and costs you a fortune to change.... and you probably hae to change the shagged gearbox sprocket as well.
A 5/8 x 1/4 o ring rear chain on a road going BSA B25 running at 1000 ft per min chain speed carrying 10 HP may well be 98% efficient but it sure as hell aint carrying 50 HP at 3000 ft per min after a couple of laps of the ISLE OF MAN!!
Please remember to ask the correct question Example to my friendly retired Renold motorcycle chain gent
"What is the efficiency of a chain? answer given "Around 98% is a value oft quoted and I cab send you test results that prove it". He did.
"What sort of efficiency would I get out of my 5/8 x 1/4 tear chain on our olde racing Atlast after a couple of laps of the Island?"
Answe "Your guess is as good as mine...it could be laying in the road....as many did"
TWO questions ...TWO answers
One could also read the 1980 BSc thesis done using a Triuph Bonny to compare a std primary belt system with a USA made QPD belt system, a system that was offered to Triumph in 1978 by Bob Oswald of QPD, along with a real electric start system..........
how the hell do |I do that????
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yama88
Chattanooga , TN
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Joined: 11/25/2003
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If you are into touring or cruising-definitely a shaft drive! For sport riding a chain is fine. I have owned both and for serious riding of any distance-you can't beat a shaft drive. Are you listening Harley?
Lar
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