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PostPosted: Fri Feb 24, 2012 11:18 pm 
retrobike rider / Gold Trader
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GrahamJohnWallace wrote:
I had a bad experience when riding in the Mersey estuary when I had a large area of quicksand between myself and the shore. I ended up walking up to my knees in estuary mud whilst carrying my bike.


estuary mud is the worst stuff to ride i found.

the way it slows you down like an anchor, then if you do stop, you sink in, and if your not quick you lose your shoes!

i done lots of testing on it in the lake district, the pugsley didnt like it but managed, though i had to pick my lines and gears as once into it there not much room to change speed or grab a fresh gear, you have to power on across the top layer.

the moonlander i have performs much better on this terrain...

http://www.retrobike.co.uk/forum/viewtopic.php?t=179586

before you get a chance to take a picture, it starts to eat your bike...

Image

Image

keep the cranks turning and the moonlander floats along happily, even over muddy bogs...

Image


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PostPosted: Sat Feb 25, 2012 12:28 pm 
retrobike rider
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graham1975 wrote:
The wheel set with tyres must weigh around 5kg, all that alloy and rubber?


I don't know what the wheels and tyres weigh but in under the physical laws governing "Moments of Inertia" extra weight at the outer edge of the wheel will be an issue.

To quote from Wikipedia:
Quote:
Figure skaters who begin a spin with arms outstretched provide a striking example. By pulling in their arms, they reduce their moment of inertia, causing them to spin faster (by the conservation of angular momentum).


http://en.wikipedia.org/wiki/Moment_of_rotation

With FatBikes, evidence from the large slots in rim show that this issue is being addressed.

These days low pressure tyres don't have to be heavy though using puncture sealant is recommended as lightweight fat tyres are more likely to pick up thorns etc.

The effects of Moments of Rotation, where their is too much weight at the outer edge of a big wheel, can be large. Don't tell the 29ers, but according to the theory, large wheels even of the same mass as smaller wheels take longer to roll down a given slope. They simply require more energy to accelerate them.

In practice this is very noticeable. My 1983 Cleland where the tyres weigh 3lb each is noticeably slower than my Cleland fitted with lightweight Racing Ralphs.

The main effect though is on quick acceleration. The modern lightweight tyres are much more lively and can noticeably reinvigorate an old bike.

When it comes to Moments of Rotation, Alex Moulton is on the money with his 16" lightweight wheels and suspension. On hard surfaces you can really feel the difference. However, on anything softer than tarmac the wheels sink into the ground and the rolling resistance becomes horrendous. It can feel as if you're towing a car behind you.


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PostPosted: Sat Feb 25, 2012 1:03 pm 
retrobike rider / Gold Trader
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Fatbike tires by surly come in at 1440grams to 1660grams for what I have had.

Tubes are 350-660grams!

Complete, ie ready to ride fatbikes I have owned.....

Mukluk 37lbs
Pugsley 38 lbs
Moonlander 36lbs

That's before racks and tool kits etc bolted on!


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PostPosted: Sat Feb 25, 2012 7:11 pm 
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Y oh Y.... 40Lb for a hardtail, i just don't get it guys.


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PostPosted: Sat Feb 25, 2012 8:29 pm 
retrobike rider / Gold Trader
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You don't feel the weight when using the bike in the conditions it thrives on.

Same as downhill bikes weighing the same amount, do there job, you don't see downhill guys wanting sub 20lb bikes.

Strangely the fatbikes climb really well, the gearing and grip do there job, it's only on Tarmac and solid long rides where you notice the drag.

It's a strange bike to explain to people, you have to live with one or ride it in the right conditions then you see.


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PostPosted: Sat Feb 25, 2012 9:01 pm 
retrobike rider
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graham1975 wrote:
Y oh Y.... 40Lb for a hardtail, i just don't get it guys.


For riding on the flat, like on beaches, total weight is unimportant. On hills a heavy bike will be slower but this only matters if your in a hurry or don't have low enough gears to ride efficiently.

Many riders carry more body weight than is ideal and losing 10lbs of body fat is not as expensive as losing 10lbs of bike weight :twisted:

Low pressure tyres don't need to be heavy. 29" x 2.35" Schwalbe Racing Ralph tubless tyres weigh in at only 620g. And Schwalbe and others make 2"-3" tubes that weigh less than 200g. And with low pressures these 29er tyres work really well in mud.

Rims don't need to be heavy and wide either but with very low pressures tyres can float or even roll sideways when used on narrow rims. So I would not recommend this combination for high speed cornering or traversing excessive cambers.

The video below is a headcam view of me overtaking a fast rider on a classic Overbury's XC race bike. My Highpath Cleland may be taller, heavier and is no race bike, but its low pressure Racing Ralphs give it the advantage.

http://vimeo.com/17659045


Attachments:
File comment: 1988 Highpath Cleland
P1050292-1.jpg
P1050292-1.jpg [ 294.56 KiB | Viewed 294 times ]
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PostPosted: Sat Feb 25, 2012 11:43 pm 
retrobike rider / Gold Trader
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i know what you mean there, i lost 1 stone in bodyweight this year and im fitter this winter as i have an extra 400 miles in my legs, mostly all fatbike miles.

when people ask me does it take extra effort, i say yeah, but aslong as your riding you get used to it and im happy riding these bikes.


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PostPosted: Mon Feb 27, 2012 4:13 pm 
retrobike rider / Gold Trader
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8) pugsley went to its new owner in edinburgh today.....hope it serves him well :wink:


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