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Would lighter bike (-2kg) make a difference ?

Posted: 3 Nov 2017, 3:03pm
by fatbelly33
Hi All,
Advice please about bike weight, I've returned to cycling after a 10 year sabbatical & I'm loving my rides. I only do 60 minutes on the flat 4 or 5 times a week & I''m deffo feeling the health improvement. My bike is a 12 year old 531 Reynolds tubing with Mavic Cosmos wheels & Shimano 105 rear mech. I was thinking of treating myself to a new shiny bike, something like a 2017 BMC roadmachine RM02 which weighs 8.2 kg. Ive just weighed my bike & it weighs 10kg, would I notice the 2kg weight difference?? I was thinking that perhaps I should just change my wheels? Are new wheels a good investment in terms of bang for your bucks.

Thanks

Re: 2kg weight difference

Posted: 3 Nov 2017, 3:24pm
by NUKe
you would notice it initially but soon it would become insignificant, however you would have a nice new bike which if it makes you happy and you cycle more then its worth buying. ,which is always nice. it is often said that the best upgrade you can make for the money is wheels. only word of caution on the wheel front is low spoke counts are fine for lightweight race types, but if your of bigger proportions you might fond that light weight racing wheels flex too much. I had a set of low spoke 24 (I think) wheels which I could feel flex when I started to climb, I replaced it with my home built wheels and the bike handled much better.

your doing a perfect amount for getting fit again. I wouldn't call 1 hour for 4 to 5 times a week insignificant.

Re: 2kg weight difference

Posted: 3 Nov 2017, 3:25pm
by Tigerbiten
An extra 10kg in weight will slow you down by around 1 mph.
so being 2kg lighter, you will get round you route in not 60 mins but a blistering 59 mins ...... :lol:

On the flat, lighter bike will get up to speed quicker.
But max speed on the flat is dependent on both aerodynamics and comfort.
If the new bike gives you a worse ride on not smooth tarmac, the you could be slower.

It's mainly in the hills where any extra weight really matters.
But you are sticking to the flat, so not so important.

So without a good test ride, you cannot tell if it'll be faster/more comfortable or not.

Re: 2kg weight difference

Posted: 3 Nov 2017, 3:52pm
by fatbelly33
Thanks for the replies guys. I can't do hills really because whenever I do hills then my knees ache the next day, whereas if I stick to the flat my knees are mostly fine (its no fun getting old)

Re: 2kg weight difference

Posted: 3 Nov 2017, 4:08pm
by Brucey
at risk of pointing out the obvious

a) if you have not had someone ensure that your riding position and technique are correct, you could end up with all kinds of troubles, bad knees amongst them

b) if your bike does not have low gears yet, best spend your money on fitting those, and maybe hills won't cause pain in the same way.

If you are not very fit and carrying an extra load, you would almost certainly benefit from much lower gearing than would be typical on a road bike. It would most likely save your knees too. The idea is that you have low enough gears to twiddle up hills (as the need/inclination arises) should you choose so to do. Grinding up hills is unnecessarily hard work, especially if you are just getting back into it.

Saving 2kg (at vast expense) -and most likely still having gears that are too high for you- doesn't sound like good value to me. A 531 frame can be a very nice bike to ride, a 10kg bike is no way 'heavy' and revised gearing shouldn't break the bank or anything. In fact for various reasons it can be easier to implement lower gearing on older bikes than newer ones.

cheers

Re: 2kg weight difference

Posted: 3 Nov 2017, 4:19pm
by amediasatex
would I notice the 2kg weight difference??


this question always makes me chuckle slightly, and I don;t mean this in a disparging way but...

If you always ride a 10kg bike and then jump on a 8kg bike you will notice to variable degree, a difference. But from then on your'll always be riding an 8kg bike...so each subsequent ride will be the same.

ie: you only notice the difference when you change, from then on it's not a difference any more! :D

Anyway, back on topic, as above posts note it won't make much difference overall in terms of speed, especially if you ride on the flat, but it might feel nicer or more sprightly, but as Brucey says fit and appropriate gearing will have a huge impact on how enjoyable your cycling experience is. My lightest bike is by far the most unpleasant to ride, but that's because it's a light weight, stiff, high-geared race bike, and is used as such, in truth I don't enjoy riding it much, but it serves a purpose...the enjoyable bikes are the heavier more comfy ones :-)

Re: 2kg weight difference

Posted: 3 Nov 2017, 4:39pm
by hamster
Much of the difference in feel can be down to the different steering geometry - the modern bike may well be less stable and so turn faster. This feels great in racing and on short distance blasts - after 100 miles when you feel tired less so.

I have a fast titanium bike and a 1979 531 steel one with mudguards. Both have almost identical gearing (late 90's Campag) and similar wheels. Times over the same 100 miles with 2000m/6500' of climbing are within 10 minutes of each other...about 3%. By comparison, swapping my tyres from GP4Seasons to GP4000 gets me 1 minute per hour.

Re: 2kg weight difference

Posted: 3 Nov 2017, 4:42pm
by Si
As well as what everyone else says....bear in mind: you know your bike weighs 10kg because you have weighed it. If you are relying on the manufacturer's brochure weight for the new bike you might find it weighs a bit more than the listed weight. They often don't include the weight of pedals, bottle cages, computer, etc - all the bits that may have been on your bike when you weighed it. Plus they often weigh the smallest sized frame so if you need a larger one it may weigh more. Might not be 2kg after all!

Re: 2kg weight difference

Posted: 4 Nov 2017, 6:33pm
by nez
I have a Dawes Super Galaxy which is abt 14kg all up and a Specialized Roubaix carbon which isn't. I certainly feel the difference with the weight but also the stiff stays on the Roubaix (which is by no means extreme) means the feel of the power going through the back wheel is completely different. If you are feeling hills are doing in your knees I really think you should make sure you have the position right, as Brucey suggests.

sorry misattributed earlier post. :oops:

Re: 2kg weight difference

Posted: 4 Nov 2017, 6:42pm
by thirdcrank
I can't help noticing your user name. I think it was Robert Millar - a winner of the polka dot climber's jersey in the TdeF who now goes by another name I've forgotten - who pointed out that differences in bike weight are insignificant when compared with what most of us are carrying around all the time - me included :oops:

There's most benefit to be gained, especially climbing, by shedding the kilos yourself and very cost/effective. Set a target weight loss and reward yourself with a new bike when you achieve the goal.

Re: 2kg weight difference

Posted: 4 Nov 2017, 7:24pm
by fausto copy
We've just got back from a short break in the motorhome and while we managed to cycle just under 100 miles in three days, we did go to our favourite pub/restaurant for those three days too.
I weighed myself when we got back and discovered that I'd put on my usual 2kg extra winter weight already.

Cycling back to our village today after 25 miles and on a long steep climb, I thought I heard someone talking in a low gruff voice.
Mrs. Copy was way back and so I thought there was someone in the field alongside. Nope.
I then realised that the noise was rather regular and finally realised that it was me, wheezing at the end of each exhalation.

I'd just mentioned it to Mrs. C and she said that I always end up wheezing when I've put weight on.
So, 2 kg certainly makes a difference with me. :(

fausto fatbelly

Re: 2kg weight difference

Posted: 4 Nov 2017, 8:32pm
by foxyrider
From personal experience the oft suggested 'lose some off yourself' when bike weights are discussed is far from being the answer for a lot of us. Some of us have difficulty in moving excess weight - however much we want to.

I'd love to be 75kg again but it seems my body wants to be 85kg! Due to an enforced layoff this year I put on almost 20kg, its taken me four months to get back to 92kg despite riding up to 300km/12 hours a week and watching what I eat. You can't just take body weight off like an extra jumper, exponents of this method of weight saving I find are underweight sticks with Yorkshire pockets.

Whatever weight you as a person are, a lighter bike is often a fillip and a mental boost (beware though that the excuses vanish for poor performance!). My daily ride, with guards, lights, rack, tools, comes in at 10kg, when I had the 'best bike' out last week I could certainly feel the 2.5kg weight difference!

Wheels might give some weight saving but the tyres will probably make more difference to performance. Some of the most popular 'upgrade' wheelsets are actually quite heavy (Mavic in particular are no lightweights) so it's worth weighing your existing wheels before going shopping! I certainly have handbuilt wheels that are quite similar weight wise to off the peg wheelsets.

Oh and hills - avoid them at your peril, itsonly by riding them that you will really gain fitness and if you use the gears properly, I promise the legs will ache less almost on a daily basis. You can only get so far just riding the flat, I live/ride in the Pennines but even so after a few days riding in Holland I struggle on uphills - your muscle memory quickly forgets about the effort required!

Re: 2kg weight difference

Posted: 4 Nov 2017, 9:18pm
by profpointy
Whilst 2kg is only maybe 2% or so of the all up weight, from years of commuting I certainly noticed a significant difference uphill and from a standstill when I had my PC in my panniers or had been able to leave it at work. Atmittedly it was a fixie so I didn't have the option of dropping down a gear

Re: 2kg weight difference

Posted: 5 Nov 2017, 1:03pm
by gxaustin
I think 10kg is pretty good for a steel bike. It should be a comfy ride too. My bare Cosmos wheels have 24 and 28 spokes and weigh 765g and 1100g. Some of that will be the steel freehub. The rims look like Open Pro - or close. The hubs are ally and the spokes are straight.
I find fit is more important than a couple of kilos. I sold a carbon frame because it was too low at the front and too long even though it was a large for my legs/height. My heavier bike is much better for the rides I do. I did notice the difference fleetingly but now I'm lighter and fitter so I'm not bothered. I could save a bit with 23mm tyres instaed of 25mm and by changing my Brooks saddle for a light one. I could remove the mudguards too and the small saddle bag. It would come in just under 10kilos then.
By all means buy a bike but ensure it's a good fit. As others have said, add the weight of pedals (quite heavy) and a larger cassette, if needed, and allow for a bigger frame - it all adds up.
Exercise won't lose you weight in my experience - it gives you a great appetite though :D . Don't believe your Garmin when it tells you you have used 1,000 calories - you haven't IMO. It told me I used 4,200 cals yesterday and I ate a large piece of cake, a home made date bar, 2 bananas and 3 slices of toast extra. My weight has been steady for the last 2 years.
I started by losing weight first. Then when I had my eating under control (about 2 years worth of dieting) I started riding and lost some more.
I lost 50ibs - down to 11st 4lb - so 50lbs may not sound much to you but it was 25% of my previous weight.

Re: 2kg weight difference

Posted: 5 Nov 2017, 10:11pm
by BigFoz
Fast for a couple of days. 2Kg off you has both speed and health benefits...