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Posted: Tue May 08, 2007 10:31 am
by MichaelB
MAD GREEK wrote:Rode up Norton Summit Rd through fog to Mt Lofty. Found it was closed, so we rode down Greenhill Rd in the rain. Still not satisfied that I had been punished, we rode up to Skye behind Penfolds Winery via Coach Rd. Turn around Coach RD and back down it...reached my top speed ever 74.1km/h.

The round trip was 51.1km


Definitely nuts.

Minor kneee issue prevents some hill work at the moment, so my Mt Lofty escapades are at a standstill at the moment, but my top speed is 67.2km/hr - 12 tooth back cog and 50 tooth front is not built for speed !!!

Posted: Tue May 08, 2007 11:05 am
by mikesbytes
Michael you need a 53 / 11 like mine, to get the top speed up.

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Posted: Tue May 08, 2007 12:49 pm
by MichaelB
mikesbytes wrote:Michael you need a 53 / 11 like mine, to get the top speed up.


I am looking at various things for my bike, particularly if the Hong Kong trip goes ahead.

One of the many things is a spare S/H rear wheel with a 23-11 rear cluster so if I am doing the flat riding, the gearing will be better than the current 26-12 that I have (better for hills until I get my strength up).

Mind you, 67km/hr is quite fast enough - I continually get visions of what a potential spill might be like and remind myself that I only have a 6mm strip of rubber with a contact patch of 20 - 30mm long that keeps me in the correct riding position ....

Posted: Tue May 08, 2007 1:25 pm
by tuco
This max speed thing is a worry. We went down a hill on Sunday and my daughter got up to 54km/h for a short distance.

She reckons she only let go of the brakes for a second or two so I've told her to be more careful, keep the brakes on and most importantly not to tell her mother!

Posted: Tue May 08, 2007 1:34 pm
by mikesbytes

Posted: Tue May 08, 2007 2:01 pm
by tuco
mikesbytes wrote:Come on guys, time to join the 80kph club.


The only 80km/h I'll be doing is driving to the race start.

Posted: Tue May 08, 2007 2:11 pm
by MichaelB
mikesbytes wrote:Come on guys, time to join the 80kph club.


:shock:

No probs in a car. Pushbike, no seatbelt, 23mm tires - NFW !!

Posted: Tue May 08, 2007 3:43 pm
by MJF
Wuss. It only hurts if you stop suddenly... you know - hitting the tree, hitting the pole, hitting the car.

Actually, with the helmet standard being for a 25kph crash, it really makes you wonder what they were thinking of when they decided on such a low speed. My hybrid hits 52kph at a cadence of around 105... and I often wonder what would happen if I came off at that speed.

Michael.

Posted: Tue May 08, 2007 4:17 pm
by tuco
MJF wrote:Wuss. It only hurts if you stop suddenly... you know - hitting the tree, hitting the pole, hitting the car.

Actually, with the helmet standard being for a 25kph crash, it really makes you wonder what they were thinking of when they decided on such a low speed. My hybrid hits 52kph at a cadence of around 105... and I often wonder what would happen if I came off at that speed.

Michael.


The 25km/h was most likely set by politicians or a committee and not people who know what they're talking about.

Even if they were only setting it for 'around town' riders then a car hitting you moves faster than 25km/h.

Posted: Tue May 08, 2007 4:48 pm
by europa
MJF wrote:Actually, with the helmet standard being for a 25kph crash, it really makes you wonder what they were thinking of when they decided on such a low speed.


Oh great. I go faster than that with my daughter on her tag-along :shock:

Richard

Posted: Tue May 08, 2007 5:11 pm
by MJF
As crap as it would look, I'd prefer a helmet more like a motorbike helmet that covers the side of the head, and has a proper shell that doesn't shatter on the first impact (leaving you unprotected as you continue to bounce down the road).

The downhill racing guys seem to have got the idea. But I'm not into full-face myself.

Posted: Tue May 08, 2007 6:07 pm
by mikesbytes
tuco wrote:
MJF wrote:Wuss. It only hurts if you stop suddenly... you know - hitting the tree, hitting the pole, hitting the car.

Actually, with the helmet standard being for a 25kph crash, it really makes you wonder what they were thinking of when they decided on such a low speed. My hybrid hits 52kph at a cadence of around 105... and I often wonder what would happen if I came off at that speed.

Michael.


The 25km/h was most likely set by politicians or a committee and not people who know what they're talking about.

Even if they were only setting it for 'around town' riders then a car hitting you moves faster than 25km/h.


I thought it was 20kph. Am I wrong?

Posted: Tue May 08, 2007 6:43 pm
by europa
mikesbytes wrote:I thought it was 20kph. Am I wrong?


Of course. Why change the habits of a lifetime? :D

Richard

I've got no idea. I'm clueless. Not blonde though, the hair that's left is now grey :roll:

Posted: Tue May 08, 2007 8:46 pm
by MJF
I just did some research :shock:

The standard is for dropping the helmet from 1.5m, which has an impact speed of less than 20kph.

Read this. Old, but very interesting. I also found this publication which was even more interesting. I'll have to download and read the full report...

Posted: Tue May 08, 2007 10:00 pm
by Bnej
tuco wrote:The 25km/h was most likely set by politicians or a committee and not people who know what they're talking about.


It's to protect you from the fall. You're falling on to pavement not riding into a brick wall.

MJF read the current Australian Cyclist magazine, there IS definite evidence that helmets prevent serious head injury.

The literal, physical, attribute of a helmet is that it reduces the G force that your head is exposed to in the event of striking a solid object - such as the ground, or a vehicle windscreen.

If you are hit by a car, you are likely to be scooped onto the bonnet and windscreen. Some of the energy will be absorbed by the bonnet collapsing (for modern design cars), some by the windscreen braking, and the driver will be braking at the same time. The helmet helps you if your head hits the windscreen, or if you fall forward onto the road after the collision. The effective *impact* speed for your head will hopefully be less than 20kp/h, but even faster than that it's better than nothing.

e.g, struck from behind by a car travelling 50kp/h, you are travelling 28kph, the car will hit your bike & legs first, you fall onto the bonnet, hit the windscreen at an effective 16-18kp/h.

e.g, riding at 55kph through a bend, hit loose gravel on the road, tyres slide, you fall about 1.2m out of the lean directly onto the road. Yes it's going to hurt, and you're going to lose a fair bit of skin - but you may be saved from severe head injury.

tuco wrote: She reckons she only let go of the brakes for a second or two so I've told her to be more careful, keep the brakes on...

Pulse the brakes, don't drag them. I.e, break for a second, let go, slow down again, repeat. If you hold them on for a long descent, you can overheat your rims and lose your brakes/burst your tyres.

Posted: Tue May 08, 2007 10:09 pm
by europa
Let's not get excited about helmet laws. Worn properly, they help. The legislation though, was poorly executed ... and why should that be a surprise? It was also executed for poor reasons (to give politians fuzzy feelings). However, that does NOT change the fact that helmets do work and do help, and any bar the real rubbish ones, probably work to a far higher level than required.

Richard

Posted: Tue May 08, 2007 10:15 pm
by sogood
Oh no! Here we go again with that helmet thread... :?

Posted: Tue May 08, 2007 10:37 pm
by Mulger bill
MJF wrote:As crap as it would look, I'd prefer a helmet more like a motorbike helmet that covers the side of the head, and has a proper shell that doesn't shatter on the first impact (leaving you unprotected as you continue to bounce down the road).

The downhill racing guys seem to have got the idea. But I'm not into full-face myself.


You could look at the FOX Flux MJF.
Image

It might be a bit too MTB but it might work for you :? Me, that rear wing bizzo???

Shaun

Posted: Tue May 08, 2007 10:59 pm
by Mulger bill
mikesbytes wrote:Come on guys, time to join the 80kph club.


Still trying to crack 70, looks like I need taller gearing too...

Posted: Tue May 08, 2007 11:16 pm
by europa
Mulger bill wrote:
mikesbytes wrote:Come on guys, time to join the 80kph club.


Still trying to crack 70, looks like I need taller gearing too...


Breaking 70's easy - I do it every time I come down Flagstaff Hill :shock: Single lane traffic with no verge and all ... travelling at the same speed as the cars is the ONLY safety mechanism you have :shock: Bloody scary, especially as right at the bottom is a major intersection (four lanes each way) and you can't start braking properly until you're on the flat at the bottom. I've had my rear wheel lifting doing that stop and while I'm getting better, I've yet to be in the right gear when stationary. Dunno what it feels like, I'm too busy thinking about the cars.

Richard

Posted: Wed May 09, 2007 7:22 am
by Mulger bill
That sounds like one HUGE rush.

What sort of gearing do you run?

Shaun

Posted: Wed May 09, 2007 8:03 am
by europa
Mulger bill wrote:That sounds like one HUGE rush.

What sort of gearing do you run?

Shaun


52/11 on the fast end
26/32 on the granny :shock:

Richard

Posted: Wed May 09, 2007 8:57 am
by tuco
Did you people see that guy on SBS cycling show on Sunday crash face first into the cobble stones?

OUCH!

Posted: Wed May 09, 2007 9:56 am
by europa
tuco wrote:Did you people see that guy on SBS cycling show on Sunday crash face first into the cobble stones?

OUCH!


Didn't seem to bother the cobble stones much :roll:

Richard

Posted: Wed May 09, 2007 11:05 am
by MJF
Bnej wrote:MJF read the current Australian Cyclist magazine, there IS definite evidence that helmets prevent serious head injury.


When did I say that there wasn't evidence? Just because I linked to a fringe nutbag position paper, doesn't mean I agree with their position, I just though what they said was interesting in terms of the reasoning behind the mandatory rules and the effects.

Bnej wrote:e.g, riding at 55kph through a bend, hit loose gravel on the road, tyres slide, you fall about 1.2m out of the lean directly onto the road. Yes it's going to hurt, and you're going to lose a fair bit of skin - but you may be saved from severe head injury.


Except when you lose it at 55kph and go head first into something solid like a tree or a gutter. If you are travelling at 55kph and you stop on the first impact, you have to dissipate all the energy in the one impact. I sure as hell wouldn't be assuming it's going to be gentle bounces.

Obviously, helmets help - I just don't think they went far enough with the standards. My cruddy helmet from the 80's had an ABS plastic shell with high density polystyrene foam - a lot safer than my current helmet IMHO, except the way the straps attached (to the shell) created a peripheral vision blind spot.