question about flatland top speed riding.

willybeamish

hey everyone, to start off, ive spent my entire life riding bmx offroad and inner city, and have been racing motorcycles, top speed stuff, for years. also ride dirtbikes, skate, snowboard, you get the gist. my interest in top speed motorcycle stuff is waning, and im coming back to bikes more and more, and wondering where i can go to find information and like minded people who are into top speed bicycle stuff. nothing along the lines of aerodynamic enclosures or anything, more along the lines of low to moderately budgeted homebrew stuff for sustained high speed riding. motorized stuff interests me for sure, but i am specifically interested in sustained non motorized hi speed flatland.

huge/tiny sprockets, flywheels, whatever is whats going on right now....i am used to over 200mph, want to see whats possible with human power only...

i know this is out of left field, but if anyone can point me in the right direction, that would just be fantastic. the world of bikes is big, id rather not search for weeks or months when i can just ask.

thanks, nice forum

OffTheBackAdam

http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
152mph paced
http://answers.yahoo.com/question/index?qid=20080824235325AAa3tPp
81mph steamlined recumbant
http://en.wikipedia.org/wiki/Hour_record
56kph Hour Record
http://www.mapsofworld.com/olympics/records/olympic-records-cycling.html
Olympic Cycling records

rjeffroy

For sustained high speed on the flat you will looking at a recumbent, see

http://www.bhpc.org.uk/

FJS

Read up on Fred Rompelberg: http://www.fredrompelberg.com/en/html/a ... record.asp
He organizes training camps in Mallorca now..
http://www.fredrompelberg.com/

mididoctors2

OffTheBackAdam wrote:

http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
152mph paced

check out the two stage gearing!

big ring to tiny gog driving another big ring to tiny gog

you wouldn't want to crash..going to burn

willybeamish

thanks for the info.
unfortunately, or fortunately, what i am interested in doing personally wont involve streamlining, pacing/drafting, or recumbent riding, or short races.

the technology is definitely beneficial, and ive been reading up on all those people and topics....but i am really only concerned with non streamlined non pacing/drafting non recumbent long distance - many many miles, well see whats possible for myself, a balance between physical limitations and top speed would be greatly dependant upon the rider and the distance...and as such highly variable. just a man, and a contraption thats mostly bike that doesnt do much but get up to speed and go in a straight line like a locomotive...

in my ignorant mind i imagine a massive front sprocket carrying as much weight as possible, structurally and as much as the rider, myself, can maintain over the desired distance, to maintain as high a rate of speed as possible.

from just my modest research and knowledge of motorcycles i see it would be possible to rig up a multiple gear bike with a sprocket ratio of 7 or 8 to 1. the only way i could imagine that being sustainable over any distance with normal sized wheels would be to have a large range on the cassette and very heavy or heavily weighted front sprocket....something that takes a mile to get up to speed is fine....would be a bike built for one purpose, and im aware of what i would have to do to avoid death when doubling the sprocket as a flywheel.....weld on some additional pegs so i can hop off the pedals, additional brakes, and set a front derailer with the option of derailing the chain from the front sprocket as an emergency fail safe...

i have spent the last 7 years racing motorcycles at over 200 mph, safety is not my number 1 concern, but i wouldnt be here if i was a moron, minimizing risk is a necessity.

thats all i got right now. im aware of how abnormal it is, but to me it would be a blast to cruise at a ridiculous speed on a bike purely under my own power. i have no delusions as to HOW non functional such a purpose built bike would be.

i do however recognize the fact that ive never done this, or seen anyone do it, so while my rudimentary understanding of the principles might not be way off, i more than likely am completely missing something else really basic that someone reading this might realize is a reason what ive said is completely non feasible. if thats the case, please educate me here, id like to figure out how to do this. and keep in mind im a fairly fit person, and given to obsession, if this is something that works out for me, id be interested in seeing how far i could take it, meaning, how fast i could go, not being reasonable, thats just not who i am. when i want reasonable, i ride a bmx or walk. heheh.

for some reason rigging up a clutched flywheel seems like a less than pure way to attain my desired goal...no matter how much more logical it may be, it seems sort of like cheating. if it turns out to be the only option, i certainly would, but if i can avoid it and achieve what i desire, i will avoid it.

anyhow, thanks

Richrd2205

Willy

I think that the factor you're missing is power output & wind resitance. It's no great bother to rig up a bike that can hold a decent cadence at whatever speed, but overcoming wind resistance will be your main concern.
http://www.kreuzotter.de/english/espeed.htm will give you some idea of the speeds you'll be capable of without having to draft a motorized vehicle. Reasonable estaimates of(sustained) power outputs would be 150W for a non-cyclist, 300W for a fairly fit non-racer & 500W for a pro. Anything higher than this would be anaerobic & very short-lived (or require serious PEDs).
These are the reasons that you'd need to be either paced or faired & recumbent to have any sort of need of the gears you're talking about (pro's coming down mountains would look at at top gear at 120"-130", you're looking at 210"). Without a significant aero advantage over said pros, you'll never even be able to turn it for more than a few seconds.

In addition, Sam Whittingham recently beat his own world record for an hpv & it's now 82.6mph, I think...

mididoctors2

willybeamish wrote:

i more than likely am completely missing something else really basic that someone reading this might realize is a reason what ive said is completely non feasible.

air resistence is everything

Richrd2205

As a further note & after some quick sums, it appears that you'd need 8kW to turn the gear you're proposing, even in the (now officially banned) "superman position" that Graham Obree used. 8kW is way beyond biological possibility.
Think of youself as a fairly heavy 0.5hp engine & you'll get the idea..

NervexProf

Richrd2205 wrote:

As a further note & after some quick sums, it appears that you'd need 8kW to turn the gear you're proposing, even in the (now officially banned) "superman position" that Graham Obree used. 8kW is way beyond biological possibility.
Think of youself as a fairly heavy 0.5hp engine & you'll get the idea..

Spot on observation Richrd, re: the O.5hp engine - and I would add that 1/2 hp output by a human could only be sustained for a short period, i.e 1- 3 minutes at best!

redddraggon

i.e. if you sustain pedalling 53-11 at a decent cadence on a normal road bike or even a TT bike, on the flat, you'll be doing over 40mph - not a mean feat.

andrewgturnbull

HI there.

Have a look at the late Bruce Bursford's bike, more 10 years old now:

http://bikebrothers.co.uk/ultimatebike.htm

Cheers, Andy

mididoctors2

now thats what i call a gear

that must be one gigantic pizza that needs cutting

keef66

Yikes! You'd ground the chainwheel on a speed bump!

avoidingmyphd

er, sustained high speed riding isn't as niche as you seem to think. maybe you should get down the track and try some pursuiting? I think you'll find it much slower than you think though. And if you are as fast as you fancy, then 2012 awaits!

willybeamish

now im learning, thanks for the posts, ill read and respond

trust me, i understand aerodynamics

it takes 200 hp to go 200-205 mph with the right set up on a sportbike, and 400-500 hp with the same bike to do 230-240

its all that exponential hoopajoop

im not looking to break records, just maintain 25-35 mph speeds over sustained distances, instead of struggling. and learn and experiment. of course id love to maintain higher speeds, but both time i desire to put into this, and money, are a factor.

ill just give my info and ask what you guys what settup you think would make that happen

im 28, very very healthy, but relatively unfit, 145 lbs. when i used to excercise i ran 15 miles a day, walked 10, and maxed out leg press at 7 ish, and lifted weights for endurance, i used to be a personal trainer and yoga instructor, the whole 9. at that time could also run a 5 minute mile. all i did was excercise, every moment of my life, i know im capable of accomplishing anything, i hate mentioning stats, but the point is i know i can accomplish what might seem beyond reach for most people, its just about discipline. at the moment im at probably 1/5 the strength and 1/5 the endurance. i routinely hike 10-15 miles a few times a week to keep fit. im about to kick my ass into gear by hiking 130 miles in 7 days, then get into biking again. been running bits here and there, but nothing noteworthy

im 5-11, 30 inch inseam.

so what would you guys recommend in terms of gearing and some sort of additional weight for a flywheel effect, if any.....as i understand it, the more weight you can manage once you get it up to speed, the easier it is to keep there....so whatever my body can sustain the better....

i want to maintain 25-35 mph for 10s of miles, well say 30 miles at 30 mph for the moment, thats a good goal, flatland. easy to calculate. is it possible?

let me have it.

redddraggon

willybeamish wrote:

im not looking to break records, just maintain 25-35 mph speeds over sustained distances, instead of struggling. and learn and experiment. of course id love to maintain higher speeds, but both time i desire to put into this, and money, are a factor.

Normal, every day stuff will do you fine for 25-35mph, you just need to do plenty of training now......

willybeamish

then i want to know how to maintain higher speeds. whats feasible on a 26 inch mountain bike - where is the wall mph wise on a top speed settup for someone given my physical abilities.

redddraggon

willybeamish wrote:

then i want to know how to maintain higher speeds. whats feasible on a 26 inch mountain bike - where is the wall mph wise on a top speed settup for someone given my physical abilities.

What power can you output? How long can you output it? How aero can you get?

Too hard to answer your question really......

willybeamish

good questions. i look at it like this, ill get in as good a shape as i need to be to accomplish my goal, i know im capable. i would have to ask if someone would be willing to calculate anything for me if they would do so assuming i am a middle of the pack fit 30 year old male.

lets assume i can maintain 15 mph for 2-3 hours flatland on a regular beater 26 inch mountain bike. not really sure what gear ratio i prefer...i grew up on bmx, i know its a 12 or 15 speed and i keep to 2nd or 3rd most difficult. haha, i know i sound like an ass, but i really do know how to ride. im more of a doer than paying attention, but now i need to learn.

i would need to sit down on a stationary to establish power ?

biondino

Why exactly do you want to do this, Willy? I doubt there are any records you're going to break, and riding 3 hours at 30mph is pro-level stuff, and they have the best equipment they can get, not to mention they ride in a peloton most of the time.

To find out your power output you'll need to ride a bike with a power meter.

Tom Butcher

willybeamish wrote:

i want to maintain 25-35 mph for 10s of miles, well say 30 miles at 30 mph for the moment, thats a good goal, flatland. easy to calculate. is it possible?

let me have it.

25 mph possible on a fairly conventional time trial bike, 35mph not possible unless you have a non-conventional bike - I am guessing but I'd have thought that kind of speed for that kind of distance would require a faired recumbent.

Richrd2205

Willy

Looking at Kreuzotter ( http://www.kreuzotter.de/english/espeed.htm ) sustaining 25mph on an mtb with slick tyres at 100m above sea level and your stats would require 486W, which, if you can sustain, is getting towards pro level. Same speed & stats on a time-trial bike would require 277W, which isn't too tricky with a bit of training. From what you've described above, you can prob expect peak power to be 150-250W & that which you can sustain considerably lower, so training would be a good start, then working out what you want & why, then looking to get the right kit.
On my fast recumbent, I can sustain about 32-33mph on the flat at sea level for shortish (30min or so) periods, that's prob about 22mph on an mtb, & up to 50mph on a faired machine: kit means a lot when you're looking at sustaining speed over distance, I'm nowhere near competitive level, but am decently fit.
Someone will prob correct this, but IIRC correctly, elite level times for a 10 mile TT would be 18ish mins & 55ish mins for a 25mile, so 30 miles at 30mph on a time trial bike is going some. On an MTB, prob impossible...

steve2021

if you could run a sub 5 minute mile while running 15 miles a day (ie being relatively well trained) that indicates above average aerobic capacity, but not by all that much.

30mph for 1 hour on a normal bike would probably require the sort of aerobic capacity that someone who could run close to a 4 minute mile would have - so realistically that isnt going to be possible for you (as it isnt for all but a tiny number of people).

You might be a much more efficient cyclist than runner though.

25mph for 1 hour is a tough standard but many people can reach it - probably harder than, but in the same ballpark as, running a 5 minute mile - so probably that is a good goal to have in mind.

But achieving it will have relatively little to do with the bike, and lot to do with you. As someone once said - it's not about the bike.

drewster_70

It's slightly off topic, but there's a great YouTube clip of Dave Le Grys hitting 100mph+ on the M42:

http://uk.youtube.com/watch?v=BmpxJWAJbFM

andrewgturnbull

willybeamish wrote:

now im learning, thanks for the posts, ill read and respond

trust me, i understand aerodynamics

it takes 200 hp to go 200-205 mph with the right set up on a sportbike, and 400-500 hp with the same bike to do 230-240

its all that exponential hoopajoop

im not looking to break records, just maintain 25-35 mph speeds over sustained distances, instead of struggling. and learn and experiment. of course id love to maintain higher speeds, but both time i desire to put into this, and money, are a factor.

ill just give my info and ask what you guys what settup you think would make that happen

im 28, very very healthy, but relatively unfit, 145 lbs. when i used to excercise i ran 15 miles a day, walked 10, and maxed out leg press at 7 ish, and lifted weights for endurance, i used to be a personal trainer and yoga instructor, the whole 9. at that time could also run a 5 minute mile. all i did was excercise, every moment of my life, i know im capable of accomplishing anything, i hate mentioning stats, but the point is i know i can accomplish what might seem beyond reach for most people, its just about discipline. at the moment im at probably 1/5 the strength and 1/5 the endurance. i routinely hike 10-15 miles a few times a week to keep fit. im about to kick my ass into gear by hiking 130 miles in 7 days, then get into biking again. been running bits here and there, but nothing noteworthy

im 5-11, 30 inch inseam.

so what would you guys recommend in terms of gearing and some sort of additional weight for a flywheel effect, if any.....as i understand it, the more weight you can manage once you get it up to speed, the easier it is to keep there....so whatever my body can sustain the better....

i want to maintain 25-35 mph for 10s of miles, well say 30 miles at 30 mph for the moment, thats a good goal, flatland. easy to calculate. is it possible?

let me have it.

Hi willy.

Just for reference, what was your best 10k running time?

To answer your flywheel question... Any additional weight is pretty much a no-no. Power generation is so low that you can't mess around by adding extra weight. The equivalent thiinking is to use a fixed-gear (no freewheel, no derailleur), where the whole momentum of the bike (inc rotational inertia of the wheels) feeds back into the pedals if you start to slow. The 25mile record was set on fixed and stands at 45:57 (32mph).

You do need to have the right course for fixed, and pick the right gear.

To put things in perspective Willy, a good club rider would be able to do an hour at 25mph, 30mph is elite level, 35mph has not been done on a bike without aero fairing.

Cheers, Andy

Jez mon

Sustained 30 mph or above really needs either a faired recumbent or a car/motorbike to draft behind.

mercsport

Maybe a wee bit off what you maybe thinking but a 'real world' - not track - record worth having a crack at might be this one perhaps : http://news.bbc.co.uk/sport1/low/other_ ... 570339.stm

Another link : http://www.legslarry.beerdrinkers.co.uk ... rStuff.htm

a_n_t

willybeamish wrote:

im not looking to break records, just maintain 25-35 mph speeds over sustained distances,
im 28, very very healthy, but relatively unfit.

there's your first problem then.