Wildguzzi.com
General Category => General Discussion => Topic started by: leafman60 on November 07, 2017, 07:46:53 AM
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It'll mimic a 90 degree twin with that 270 degree crankshaft.
In dealerships soon.
http://www.motorcycle.com/manufacturer/bmw/first-look-2018-bmw-f850gs-and-f750gs.html
More info-
https://www.press.bmwgroup.com/global/article/detail/T0275427EN/the-new-bmw-f-750-gs-and-f-850-gs
http://www.visordown.com/sites/default/files/styles/large/public/P90283508-highRes.jpg?itok=8at98e1q
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Bella!!!
And finally a 21 inches front wheel !!!
BMW gets it...
Piaggio? Not so much.....
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My 800 Triumph 800 XC is lighter than both of them. Triumph is supposed to announce their new 800s soon. Should be interesting.
Pete
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Are we supposed to get exited Haha, I have that already without a lot of extra junk whirring around.
•Extremely powerful and emotional sound, produced by a crankshaft journal offset of 90 degrees and firing interval of 270/450 degrees.
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Are we supposed to get exited Haha, I have that already without a lot of extra junk whirring around.
Extremely powerful and emotional sound, produced by a crankshaft journal offset of 90 degrees and firing interval of 270/450 degrees.
Yep. Giulio Carcano, Fabio Taglioni and any number of industrial engine manufacturers figured out a long time ago that a 90 degree V-twin gets the job done without a lot of extra hardware like counter-balancers, multi-throw crankshafts and water cooling. Now its become fashionable to make a parallel twin perform and sound like a 90 degree V-twin by adding lotso f stuff, and I think the only benefit is a slightly more compact and possibly cheaper to produce engine... with lots of hardware that wouldn't otherwise be necessary.
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Not sure about the extra hardware part. A good friend here took is late '60s Triumph twin and moved the crank 90 degrees. Megacycle ground him a new cam and he was pretty much set. Rode it cross country a number of times.
Pete
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Not sure about the extra hardware part. A good friend here took is late '60s Triumph twin and moved the crank 90 degrees. Megacycle ground him a new cam and he was pretty much set. Rode it cross country a number of times.
Pete
A late 60's Triumph with a 270 crank is smoother than stock, but I don't think many would say it's smooth enough for sale as a 2017 model. In order for a 270 degree crank vertical twin to be relatively vibration free, you still need a balance shaft but it is a less problematic design because the forces are less than with a 360 crank.
The Royal Enfield 650 twin website has a photo of their 270 crankshaft and balance shaft setup: https://royalenfield.com/motorcycles/twins/images/engin_inner.jpg
The F800 BMW with its 360 crank has giant bob weights under the crankshaft with an extra con-rod just to drive the bob-weights: http://www.ashonbikes.com/sites/default/files/images/BMW_F800_balance_5.jpg
Meanwhile a 90 degree V-twin achieves the same balance with just a single throw crankshaft and no extra balance hardware.
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The BMW version of the Africa Twin?
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Not sure about the extra hardware part. A good friend here took is late '60s Triumph twin and moved the crank 90 degrees. Megacycle ground him a new cam and he was pretty much set. Rode it cross country a number of times.
Pete
Dick Harris? I have met him and his cross country 70 Triumph 650 90 degree..
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Ben doing that for years on old XS650 Yamaha's. No counter balencer tho. Some say it's worth the trouble, some say not. Whatever.
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Dick Harris? I have met him and his cross country 70 Triumph 650 90 degree..
Rough, yes it is Dick. Last time I saw him and the bike was at the Norton Polar Bear ride a year ago.
Great guy.
Pete