Is weight (or lack of) the be all and end all?

rolf_f

Chris James wrote:

I suggest you repeat the experiement on the same bike, adopting the same position on it, and put weights in your pockets.

I've got plenty of data for various routes - I just wanted to post something particularly statistically invalid! As I say, I thought I'd have been quicker on the uphill leg on the tourer but the traffic might have been worse on Monday and I think the wind might have been a factor too. All underlines the point though that you need fairly extreme changes to really make a difference.

rake

Rolf F wrote:

gethmetal wrote:

Rolf F, off topic, but how is the SAAB running these days?
They're getting rare now...

MOT'd on Monday - no advisories 8)

Did have a problem with the exhaust blowing though. First bloke tightened and replaced manifold bolts, second garage adjusted the tail pipe. Second garage then, when I went back and said it still sounded blowy, finally found the crack and welded it!

You're right on the rarity though - half our little Saab group have abandoned the classic 900 cause this year and bought Vauxhalls instead

is it the one with the chain drive? must be hard to find parts now. 9oo turbos were awesome cars. the engines came from triumph slant 4.

rolf_f

rake wrote:

Rolf F wrote:

gethmetal wrote:

Rolf F, off topic, but how is the SAAB running these days?
They're getting rare now...

MOT'd on Monday - no advisories 8)

Did have a problem with the exhaust blowing though. First bloke tightened and replaced manifold bolts, second garage adjusted the tail pipe. Second garage then, when I went back and said it still sounded blowy, finally found the crack and welded it!

You're right on the rarity though - half our little Saab group have abandoned the classic 900 cause this year and bought Vauxhalls instead

is it the one with the chain drive? must be hard to find parts now. 9oo turbos were awesome cars. the engines came from triumph slant 4.

It's the car in my avatar - and below! The engine is derived from the Dolomite but I believe it is a long way evolved. Parts aren't too difficult so far. It's a nice car - I love the turbo lag

flanners1

Chris James wrote:

I suggest you repeat the experiement on the same bike, adopting the same position on it, and put weights in your pockets.

Heavier descends faster, all other things being equal.

Perhaps, as a mechanical engineeer, I have more faith in the science!

It is fairly marginal though. Likewise for a 80kg bloke riding uphill on a 8kg bike or a 12 kg bike the difference in required power is only 4% but you'd get the impression it was about 50% from some reviews.

I guess that shows that the main difference between light and heavy bikes is mental.

The record for my local hill climb, Jackson Bridge route was held for many years by Chris Boardman.It might still be. I can't imagine his bike from 20 years ago would have been very light compared to modern day steeds, but it didn't seem to slow him down much on an extremely steep course!

(mind you, I do blame my heavy bike when I grovel my way up the course!)

Just what I suspected, almost pointless paying huge sums to save grams at the top end. My steel Nag just fly's downhill.

briantrumpet

Flanners1 wrote:

Just what I suspected, almost pointless paying huge sums to save grams at the top end.

...unless you just love the feel of a super lightweight bike. Just for once (as I'd had it serviced in town) I had the ride home from work on the SuperSix instead of the Giant Defy 4 (my commuting tank) - boy, did it feel nice. Worth every penny.

mfin

inseine wrote:

While I understand the science the reality isn't always so. When I bought my latest Giant TCR I got a complete bike (which I don't normally) it came with pretty basic wheels and I was thoroughly disapointed with the ride. Changing to a set of 1300g wheels transformed it. Since then I've changed everything else but the it was the wheels that made the differnence.

I agree with that completely, so many off the peg bikes come with wheels that don't match up to the spec of the rest of the bike. The 'feel' is transformed by changing them, I suppose that's why we have so many wheel threads. Suppose people will argue over speed gains, but anyone that's racing will most likely be doing so on reasonably good wheels at least.

Wheelie Bin

Just my jaded view on the subject - if you're bothered about weight, stay off the pies and chips, drink less beer and you won't have to spend time worrying about the weight of your bike.

Of course, you might be the skinniest, fittest person in Christendom, in which case I humbly apologise.