George in disguise.

[Andrew G]

Look at the gearing
[img]http://www.timetriallingforum.co.uk/index.php?act=Attach&type=post&id=5403[/img]

[Ian A4size]

that looks like bottom gear on my cassette

[-Adam-]

Seriously, what is the point in having a chainring that big.

I think he must be trying to compensate for something!

[mrP(Boonen)VT]

That's not George, that's RichV

and I thought we had a big chainring on the tandem - that's 60 teeth, and looks small in comparison.

I guess he doesn't like his knees and he wasn't very quick either

[Andrew G]

No a real slouch eh Paul. . (He won the event).

I think the logic behind it George is he uses a huge chainring to use bigger sprockets on the back and therefore keep the chainline smoother. Obviously pushes big gears and using that ring probably means he's on a 17 or something at the back so the chain runs smoother than being tightly wrapped around an 11 all the time with a 56 chainring.

[richv]

It's all very well taking the mick but Nik Bowdler would make mincemeat of anyone in the club on a flattish time trial and possibly on a lumpy one as well. Probably one of the top 20 in the country if not in the top 10. Got the guts to do his own thing and I can guarantee you Andrew that he has a much smaller sprocket on the back than a 17. It's not a chainline issue he just rides huge gears. There are some good arguments (both mechanical and biomechanical) for riding big gears at low cadences. Just think of the added sail effect you get from a chainring that size. The main problem he has is finding a frame that will take the chainring without it sawing off the rear triangle

[Andrew G]

Thanks Rich, I'd read of someone doing it for chainline reasons must have been someone else.
Far from laughing I like it. I've been passed by many a rocket pushing big gears and they always looks very smooth. He must scare the life out of car drivers on dual carriageways once he's got the gear turning, I bet a lot of them do a double-take of their speedo.

[Andrew G]

[quote="RichV"] Just think of the added sail effect you get from a chainring that size

[richv]

Andrew I wasn't attempting to rubbish the chain line suggestion, I know there is neverending discussion amongst the track specialists about the benefits of getting not only the right gearing but also the best ring/sprocket combination to get that gearing and improve "efficiency" or "acceleration" depending upon what type of rider they are. Was just trying to say that Nik Bowdler simply pushes enormous gears at very low (compared to others) cadences.

The sail effect was slightly tongue in cheek although if a disc wheel gives you a sail effect then a large solid chainring should do the same.

There is no UCI limit on chainring size that I am aware of but there are many practical considerations. I wouldn't like to ride that bike round a tight right hand bend and as I mentioned above Nik has had trouble with frames where the chainring has rubbed against the rear stays. Add to that if you wanted to run 'normal' gearing on chainrings that size you would have to rengineer the chain (bigger and heavier) and the rear sprockets (bigger and heavier) and also the fact that TTs and road racing are very different in terms of aerodynamics, bio-mechanical efficiency etc and I can understand why nobody is running large chainrings. Also it is just plain ugly!

[Andrew G]

It may not be the prettiest but I admire the Obree-ishness of the invention and design. Similarly I saw a set of tri-bars someone had designed and built themselves on one of the TT forums. He’d used his existing base bar and made the extensions himself, mainly from plumbing bits and bobs. He ended up with a completely custom set up that fit like a glove for less than a stock set up would’ve cost .

I take your point on the handling on tight bends, and road racing where it would be a nightmare to use, I was thinking more of a rider doing something similar for a TT during a stage race or a World Champs.

Although there would be a weight penalty on the increased sprocket size and chain etc, this might be able to be countered by using lightweight components like a KCNC billet cassette and other engineering/carbon witchcraft, after all there is a minimum bike weight and the manufacturers can get below this quite easily with stock kit. I wonder if anyone has tried it, I doubt it but with the amount of money they spend on wind tunnel testing you think it'd be worth slinging a bike in while you're there.

[Toks]

Pah! he ain't got nothin on this guy
http://www.youtube.com/watch?v=7JtZkNXfes4

[mrP(Boonen)VT]

Andrew,
I beg to differ, but I believe that shot was taken in last years National 25, where he was placed 20th and Jason MacIntyre took 5 minutes out of him.

[richv]

As if you've ever finished in the top 20 in a senior national TT championship

I suspect it was also taken on the V718 in the last couple of weeks in an event he won with a short 20-minute 10 in February which by any standard is flying.

Talking about the 'Obreeishness' look at his saddle - what is holding it on? The effective seat-tube angle must be greater than 80 degrees! That is definitely not UCI compliant.

[Andrew G]

Don't worry Rich it's probably a kid's BMX saddle .
It was a report on the event you mention that I took the picture from but I don't know if the picture was from that event or an older one - looks like Feb clothing though.

[Dominic]

I think Nik Bowdler always wears leg warmers. He is not just good at the shorter distances. He was 3rd at last year's National 12 using the same gearing