Author Topic: Scottish cyclist Graeme Obree targets new world record (Read 23158 times)

Mr Larrington · « **Reply #50 on:** 30 May, 2012, 12:18:35 pm »

Quote from: Cudzoziemiec on 29 May, 2012, 10:44:06 am

[I enjoyed that, it was informative and clear. Interesting that Burrows would hate to see HPV events in the Olympics but would welcome them in the Tours.

They did this as part of the Tour prologue in Lyons many years ago - a head-to-head sprint between Pat Kinch in the Bean and Freddy Markham in the Gold Rush. There wasn't a great deal of run-up so speeds weren't huge by BM standards. Freddy won by a nose

Von Broad · « **Reply #51 on:** 01 July, 2012, 12:47:23 pm »

Nice to see him displaying a huge smile and enjoying himself.

Linear drive. In the kitchen. Love it.

<a href="http://vimeo.com/moogaloop.swf?clip_id=44814746&server=vimeo.com&fullscreen=1&show_title=1&show_byline=1&show_portrait=0&color=01AAEA" target="_blank">http://vimeo.com/moogaloop.swf?clip_id=44814746&server=vimeo.com&fullscreen=1&show_title=1&show_byline=1&show_portrait=0&color=01AAEA</a>

StuAff · « **Reply #52 on:** 01 July, 2012, 01:44:48 pm »

Quote from: clarion on 29 May, 2012, 03:34:07 pm

Have you seen CS7?

I see quite a few TT bikes out and about. Guy did the Whistable FNRttC on one last year, saw him at the Dun Run as well. Apparently his only bike. He wasn't particularly quick

eeymsmo · « **Reply #53 on:** 04 July, 2012, 07:46:09 am »

He's taken it out for a test run now:

<a href="http://vimeo.com/moogaloop.swf?clip_id=45034602&server=vimeo.com&fullscreen=1&show_title=1&show_byline=1&show_portrait=0&color=01AAEA" target="_blank">http://vimeo.com/moogaloop.swf?clip_id=45034602&server=vimeo.com&fullscreen=1&show_title=1&show_byline=1&show_portrait=0&color=01AAEA</a>

marcusjb · « **Reply #54 on:** 04 July, 2012, 09:16:05 am »

Well you always knew he was going to tackle the challenge in a different way to everyone else - but that drive system?? Hands up if anyone saw that coming?

I am not sure I would like to travel at 10mph on that, let alone 100.

The best of luck to him - he is an inspirational guy with just the right dose of eccentric engineer to make things very interesting indeed.

LEE · « **Reply #55 on:** 04 July, 2012, 09:23:24 am »

It seemed to require a lot of huffing and puffing to travel at 10 mph so I don't think there's any danger of it travelling at 100

mrcharly-YHT · « **Reply #56 on:** 04 July, 2012, 10:07:30 am »

Looks bonkers to me and I'd have expected that drivechain to lose a lot of power.

But YAH to GO for not letting convention get in the way.

Mr Larrington · « **Reply #57 on:** 04 July, 2012, 10:28:32 am »

Quote from: Oranj on 04 July, 2012, 09:13:14 am

Are lower recumbents harder to balance?).

Back in the 80s the theory was that you needed a seat height of at least 18" in order to be able to stay upright on two wheels. Then Matt Weaver and the Cutting Edge turned up at the Portland International Raceway event with a seat height of about nine inches. The road race was his first ever bike race, and he beat Fast Freddy Markham¹ in one of the Gold Rush variants by half a lap. After that nearly everyone went low.

1 - Multiple world record holder, former Olympic team member.

Biggsy · « **Reply #58 on:** 04 July, 2012, 10:47:50 am »

Quote from: Oranj on 04 July, 2012, 09:13:14 am

It looks utterly mad, and not a little unstable (is that to do with the low centre of gravity? Are lower recumbents harder to balance?).

He could have made it more stable with different frame and fork geometry, but presumably he carefully considered the angles right at the start. Let's hope it will be steadier at high speed!

More alarming to me is the closeness of his hands to the wheel and lack of shoulder and hip padding. The wheel may end up with a fairing over it, but meanwhile it looks as scary as hell even at low speed. The huffing and puffing is from nerves!

simonp · « **Reply #59 on:** 04 July, 2012, 10:51:29 am »

Quote from: mrcharly on 04 July, 2012, 10:07:30 am

Looks bonkers to me and I'd have expected that drivechain to lose a lot of power.

But YAH to GO for not letting convention get in the way.

+1 to both points.

Cudzoziemiec · « **Reply #60 on:** 04 July, 2012, 11:43:44 am »

I predict that even if he breaks 100mph this position and drivetrain won't make it big on the high street! But best luck to him and everyone involved in his project, I think it's great he's even trying.

Von Broad · « **Reply #61 on:** 04 July, 2012, 06:22:26 pm »

Quote from: marcusjb on 04 July, 2012, 09:16:05 am

The best of luck to him - he is an inspirational guy with just the right dose of eccentric engineer to make things very interesting indeed.

He's a great character. And a phenomenal cyclist too.

Having built a few conventional SWB recumbents in the past [and another to come] , and judging by those that have been building them a lot longer than me, no sooner do you get one up and running that you're looking to build the next. And with this kind of build, where empirical feedback drives your design [to a degree], it's seldom you get things just as you want them first time round.

It's easy to sit here and cast judgement, but depending on how he gets on in BM this year, if he enjoys his experience down there, he might be inspired to go back again. He's certainly been inspired to take up a challenge in the past.

TimC · « **Reply #62 on:** 05 July, 2012, 12:28:06 pm »

Barking - in the best possible way! A record-attempting recumbent based on steam engine transmission technology? You couldn't make it up! And you just know that, somehow, he'll make it work and will turn up as a serious contender on the day. I wish him all the very best luck there is.

And it's great to see the progress on video - thank you for that!

Tigerrr · « **Reply #63 on:** 05 July, 2012, 03:07:40 pm »

3 cheers for him I say - its great entertainment. I am really interested to see how he goes, based on my earlier dismissive comments. I still think he's going to fail spectacularly but the project is wonderful.

tom_e · « **Reply #64 on:** 05 July, 2012, 04:50:30 pm »

Looks a bit intimidating to start out.

I'm guessing the linear drive is to try and reduce cross-sectional area. Particularly with it being prone rather than pedals at the front, it wants to be small and well tapered back there. So expecting a fairing as small as humanly possible.

rogerzilla · « **Reply #65 on:** 05 July, 2012, 08:54:19 pm »

The estimator in me says those connecting rods will buckle too much with the sort of power input he's going to need, and they are considerably less efficient than a chain.

Kim · « **Reply #66 on:** 05 July, 2012, 08:59:07 pm »

Yeahbut as That Nutter Burrows is fond of pointing out, drivetrain losses are linear. Aerodynamics is everything at this sort of speed.

Canardly · « **Reply #67 on:** 05 July, 2012, 09:02:55 pm »

I watched the only vulcan bomber left flying today, doing things that 1950s aircraft should not be doing. Go for it Graeme prove em wrong.

simonp · « **Reply #68 on:** 05 July, 2012, 09:03:22 pm »

Maybe what this problem needs is a tandem version. Does the concept of hull speed only apply on water surface craft or does it also apply when fully immersed (in air or water)?

Feanor · « **Reply #69 on:** 05 July, 2012, 09:17:58 pm »

The hull speed thing relates to the way a boat travels over water.
It sets up a bow wave as it moves forward.
As the boat speeds up, the wavelength of the bow-wave increases untill you get to the point where the wavelength of the rising edge equals the hull length.
At this point, the boat is 'trapped' on it's own bow-wave.
It's sitting on a permenant up-hill.
It takes a large additional amount of power to push it on upthe hill onto the top of it's own bow wave, at which point it's planing.

As such, it's a surface effect, on the interface between the water and air.
So I can't see how you could get planing whilst immersed.

simonp · « **Reply #70 on:** 05 July, 2012, 09:20:02 pm »

Yup, not relevant. A tandem would also be even harder to control than that thing.

spesh · « **Reply #71 on:** 05 July, 2012, 09:51:00 pm »

Quote from: Canardly on 05 July, 2012, 09:02:55 pm

I watched the only vulcan bomber left flying today, doing things that 1950s aircraft should not be doing.

That delta wing can generate a ridiculous amount of lift - to quote an Air Ministry press release from 1958:

"At its operational height the Vulcan can outfly and outmanoeuvre any fighter in squadron service today."

They might have been exaggerating a little bit, but check out Roly Falk barrel-rolling the prototype at the Farnborough Air Show:

http://youtu.be/ffJ0WX1Xct0?t=30s

But I digress...

spesh · « **Reply #72 on:** 05 July, 2012, 10:07:07 pm »

Quote from: rogerzilla on 05 July, 2012, 08:54:19 pm

The estimator in me says those connecting rods will buckle too much with the sort of power input he's going to need, and they are considerably less efficient than a chain.

I'm inclined to agree. Still, fair play to the man for trying it.

Mr Larrington · « **Reply #73 on:** 06 July, 2012, 11:27:17 am »

It's a pity no-one has done any serious work on a tandem for this event for more than ten years. There were rumours at the tail end of last year of a collaboration on a tandem between a well-known HPV builder and Airbus, but then Airbus decided they had better things to do.

Rhys W · « **Reply #74 on:** 12 July, 2012, 05:27:26 pm »

http://road.cc/content/news/61807-video-graeme-obrees-record-attempt-recumbent-rolls-out

Author Topic: Scottish cyclist Graeme Obree targets new world record (Read 23158 times)

LEE

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