Fat bike dangers,a ...
 

[Closed] Fat bike dangers,a few Q's for owners

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Just finished reading an article in what fat bike and discovered a few disturbing facts about fb's
1,If the fb can be peddled up to a speed exceeding 20mph the giroscopic effect of the huge front wheel makes it almost impossible to turn the bars.Quote"fast flowing single track turned into a straight line decent into hell"
2,Assuming that you've found an arrow straight decent long enough and the fb reaches a speed exceeding 30mph the tyre growth due to the centrifugal forces causes frame and fork rubbing resulting in catastofic failure of one or both contact areas.Quote"three out of the four test bikes failed due to tyre rubbing resulting in a brused elbow and a grazed knee,any one who uses these bikes must have a death wish"

Now i'm normaly up to have a go at anything but these things seem crazy!
or am i just talking shite?
Your opinions please.


 
Posted : 04/11/2011 4:29 pm
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Never ridden a fat bike, but the physics there seems a bit off.

For the gyroscopic effect, I thought the force required was directly proportional to the mass (could be wrong). So increase the mass by twice as much makes the force required double. Which isn't a huge amount. Also I thought the force was proportional to rotations per second, so there shouldn't be a leap where you're fine at 19mph, but doomed at 20mph.

It's been a while since I've done this sort of stuff though, and we never went that in depth.

As for the tyre being pushed away from the rim and destroying the fork at high speed, that sounds like a dodgy tyre or pressure set up. Remember, it's very similar to a normal bike, just scaled upwards a bit.


 
Posted : 04/11/2011 4:31 pm
 GW
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*Fatbikes never reach 20mph as the owners deem that too dangerous a speed to hold hands.
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*may also be talking shite ๐Ÿ˜‰


 
Posted : 04/11/2011 4:40 pm
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I hit 60+ on the trails on my fatbike and huck huge gaps and do double backflips and never had any tyre rubbing problems ๐Ÿ˜‰
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may also be talking shite ๐Ÿ˜‰


 
Posted : 04/11/2011 4:46 pm
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daznal - Member
Just finished reading an article in what fat bike
๐Ÿ˜†


 
Posted : 04/11/2011 4:51 pm
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sounds like big bike corp propaganda to make you stick to there standard 26" and 29" bikes
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Or im just talking sh1te ๐Ÿ˜†


 
Posted : 04/11/2011 4:52 pm
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1) Possible but don't we lean our bikes around corners more than turn the bars that much?
2) What a load of bollox
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Or I'm just talking sh1te ๐Ÿ™„


 
Posted : 04/11/2011 5:13 pm
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this happened when my mate tried to pull a sick wheelie at only 2mph as the whole karma of the bike exploded due to too much weight on the back wheel

[img][url= http://farm7.static.flickr.com/6115/6310472950_5b7c8a0c01_z.jp g" target="_blank">http://farm7.static.flickr.com/6115/6310472950_5b7c8a0c01_z.jp g"/> [/img][/url] [url= http://www.flickr.com/photos/mhampshire/6310472950/ ]further down the spiral[/url] by [url= http://www.flickr.com/people/mhampshire/ ]SoFaKiNg.[/url], on Flickr[/img]

and i never talk sh1te 8)


 
Posted : 04/11/2011 5:30 pm
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God I wish "What Fat Bike" existed ๐Ÿ™‚


 
Posted : 04/11/2011 5:34 pm
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[url= http://forums.mtbr.com/fat-bikes/ ]The next best thing?[/url]


 
Posted : 04/11/2011 5:35 pm
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[i]What Fat Bike[/i]

Fat Wattbike anyone?

[img] http://www.peoplesrecord.org.uk/files/display/2664/fullsize [/img]


 
Posted : 04/11/2011 5:37 pm
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I followed a mate of mine on a pugsley down a 20% road hill and he was doing 34mph (i had a computer of my bike) and nothing like what you described happened.


 
Posted : 04/11/2011 5:41 pm
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(i had a computer of my bike)
Simulations don't count


 
Posted : 04/11/2011 5:44 pm
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"I followed a mate of mine on a pugsley down a 20% road hill and he was doing 34mph (i had a computer of my bike) and nothing like what you described happened."

Riding a small ugly dog down a hill cannot be compared to riding a fb


 
Posted : 04/11/2011 5:53 pm
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Riding a small ugly dog down a hill cannot be compared to riding a fb

You sound like you're talking from experience there. ๐Ÿ˜†


 
Posted : 04/11/2011 7:42 pm
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coastkids tyre 'rubbing' issues shouldn't be discussed on a family forum ๐Ÿ˜ณ


 
Posted : 04/11/2011 8:20 pm
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as someone who pass o level physics has to be said that op IS talking sh*te of the first order with gold stars and silver wings attached ๐Ÿ˜ˆ


 
Posted : 04/11/2011 8:32 pm
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,Assuming that you've found an arrow straight decent long enough and the fb reaches a speed exceeding 30mph the tyre growth due to the centrifugal forces causes frame and fork rubbing resulting in catastofic failure of one or both contact areas.Quote"three out of the four test bikes failed due to tyre rubbing resulting in a brused elbow and a grazed knee,any one who uses these bikes must have a death wish"

But on the new generation of "Infinite travel" fatbikes, the fork travel + seat/chainstays adjust, guided by a smart BRIAN shock system.
As the tyre become "thinner", there is less drag, so the bike accelerates, increasing the tyre growth. This continues until the tyre is infinitely thin and the bike passes the speed of light, leaving a trail of Higgs-Bosons in its wake. Fastest bike ever. FACT.


 
Posted : 04/11/2011 8:42 pm
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is the rider in sofakings pic wearing a gasmask?


 
Posted : 04/11/2011 8:47 pm
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is the rider in sofakings pic wearing a gasmask?

its a gas mask with a special stw tosh speak filter . not much from on these pages gets through it


 
Posted : 04/11/2011 9:11 pm
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Good grief never realised they could be so dangerous!

Thanks for letting me know daznal.

N E 1 want a used Fat Bike?

One carful owner.

Never gone over 20mph.
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. may be talking sh1te ๐Ÿ˜‰


 
Posted : 04/11/2011 9:12 pm
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umm, daznal, where did you read that? I hope you didn't pay for that review.


 
Posted : 04/11/2011 9:14 pm
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that's it the Pugley has to go
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. may be talking sh1te ๐Ÿ˜€


 
Posted : 04/11/2011 9:15 pm
 cozz
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did coast to coast this year on my pugsley - clocked 49mph on a downhill, did get a speed wobble so backed off

prob due to the fat bloke sitting on top of it not being very aerodynamic !!


 
Posted : 04/11/2011 9:20 pm
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I have issues when I hit circa 20mph as I am laughing and smiling so much I struggle to steer


 
Posted : 04/11/2011 9:25 pm
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I believe there is a solution to all that unwanted rubbing, ride on fat bikers;

[img] [/img]


 
Posted : 04/11/2011 9:26 pm
 Keef
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I rode at a tad over 20mph on my Frankenfat the other day,and my wheels exploded into a gazillion pieces,killing everyone with 3.4 miles radius.

Sorry,my mistake,that was on my 29er.


 
Posted : 04/11/2011 9:39 pm
 Keef
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and I may of made most of that last post up.


 
Posted : 04/11/2011 9:40 pm
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I find the handling gets a bit iffy over 75mph so I never exceed that. ๐Ÿ˜ฏ


 
Posted : 04/11/2011 9:48 pm
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[img] [/img]
124mph or so - while the wheels and tyres are light for a bike, rather a lot more than even a 'fatty' I suspect!


 
Posted : 04/11/2011 9:56 pm
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What happens if the speed of 30mph is achieved on a treadmill, so the fat bike's actual ground speed remains at zero?


 
Posted : 04/11/2011 10:30 pm
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v8ninety - Member
What happens if the speed of 30mph is achieved on a treadmill, so the fat bike's actual ground speed remains at zero?

That very dangerous. You get hit by a Jumbo jet.


 
Posted : 04/11/2011 11:00 pm