MacFatro - Fatbike news and builds thread

16 inch wheels with 4 inch tyres might not be enough Velo, my kite buggy has 3 of those and dig in pretty heavily on dry sand - fine on the wet though.
 
The fore to aft footprint of these tyres is not as big as a 26" x 4" wide fat bike tyre, it is true but the width is the same. Its all about float. How much float on soft surface is dependent on rim width and how low a psi your using. If your running the recommended max of 30 psi you'll not have much float. I'll be running around 10-15 psi initially then fine tune from there. Low psi does mean increased drag but finding the trade off you can live with is part of the dark art of floation biking.
I do have a daft idea for a narrow track trike or fitting wheels in pairs although that might muck up cornering, so there are options.
 
velomaniac":15xeyete said:
The wheels will be on struts that extend below the frame/fork axles to move the BB upward. Also i'm building my bike as a floation bike for soft terrain not a fat mtb so serious off road capability is not an issue.
Finally i'm only at the choosing components stage and planning the bodges. No building has started as everything is dependent on funds, or in my case, lack of funds.

OK, will you be welding these struts on? At least you will be fabricating something to give you rear tyre clearance.
If yes why don't you get an old full suspension frame and dispense with the rear swing-arm. Then fabricate a seat/chain-stays substructure that bolts on to swing-arm pivot mounts and shock mount, making a rigid frame. That way you can position the drop outs to raise BB height and have enough tyre clearance on the seat/chain-stays.
 
I dont weld, its all bolt, clamp and bond. I know how I'll do it and I know I'll overbuild before I underbuild. Not likely to be lightweight as my last homebodged more conventional looking fatbike was 40lbs !
Front frame contender is a steel roadframe as its BB height is a couple of inches below axles which will reduce height of bike with 16" wheels mounted on struts below axles.
This bike will not win beauty contests but if I keep its performance requirements minimal it should not exceed its design parameters.
You should join in this silly comp, give epicyclo some proper competition. He's an engineer I'm just a bodgineer so even if my works, it won't be as good as his.
 
The thicker wall thickness of wheelbarrow tyres also increase the rolling resistance of the tyres at low pressure, a kite buggy and rider will be heavier than a bike but the load is spread over 3 wheels, I think getting started will be fine but the effort keeping those small wheels turning might be an issue.

I run my buggy at around 15 psi but push it up if I know I'll be on wet sand. On dry sand I need a fairly strong (20mph+ wind) to get the buggy moving at all. On wet I can run a decent speed with a 12-14mph wind.

I do only have a 2.5 mtr kite which is pretty small and I'm not sure how that compares to geared man power, but you might want to make sure your experimental frame has clearance for larger tyres in case you need them.
 
No chance, I'd get to the cutting all the bits stage then just say "what's the point?", shove it in the corner and try not to look at it again. :LOL:
I'm not a trained engineer either, just learned from experience and knowing how things work, like you more a bodgineer. Besides my MIG welder is effed.


F-you velo, noo ye've got me thinking aboot getting a BSO full-susser oot a skip and fabbing a new rigid rear end for it.
Naaawww, get these thoughts oot ma heid. :facepalm:
 
The Ken":2g84rsaq said:
:) why stuff it in a corner when you could leave it in your front garden on bricks :)

It was on axle-stands no bricks. :evil: Notice the past tense was, it's gone to somebody who is actually working on it. :roll:
Young guy with a decent car, no idea why he'd pay good money for the Corrado. :shock:
 
Just imagine if all the inventors of note (I'm not even remotely comparing myself ) had listened to the that'll never work mate, your wasting your time advisers of history :LOL:

Go on OCP, go on, go on, go onnnnnnnnnnnnnnnnnnnnnn, you know secretly you want to, dont repress the inner demon, the BSO is calling you, go on :twisted:
 
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