How does weight actually matter?
11-20-11 | 12:34 AM
#26
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From: Coupeville, WA
Bikes: 84 Raleigh Technium- 89 Shogun Mt. Bike-96 Miyata 914
My commute is about 14 miles of varied terrain. I weight 200 lbs and am in pretty good shape.
Typically takes me 55-65 min. on my skinny tire road bike vs 70-75 min on my fat tire (38 lbs fully dressed) fenderbeast.
That said, I usually ride the fenderbeast. If I was that worried about 10 min. I would drive.
Typically takes me 55-65 min. on my skinny tire road bike vs 70-75 min on my fat tire (38 lbs fully dressed) fenderbeast.
That said, I usually ride the fenderbeast. If I was that worried about 10 min. I would drive.
11-20-11 | 07:49 AM
#27
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From: Pearland, Texas
Bikes: Cannondale, Trek, Raleigh, Santana
The impact of rotating mass doubles as you move from the center of the axle (where it's not rotating at all) out to the tire surface although it's not enough to be significant for reasonable variations in component weights.
There's about a 150g difference between a heavy rim (DT585 or Velocity Deep V) and a light but durable rim (Kinlin XR-270/300, Mavic Open Pro although some would argue that those aren't durable enough). There's another 180g separating a heavy tire (32mm wire bead Gatorskin) from a light one (23mm GP4000S). That's 660g for a pair of wheels.
As an upper bound you can treat all that mass as being where the rubber meets the road. With a 75kg rider + 9kg bike combination having that 660g as rotating mass instead of elsewhere on the bike means the rider needs to provide less than 0.8% more kinetic energy to reach a given speed. With an extra 660g in the rims and tires bringing the bike weight to 9.66 kg the rider needs 1.6% more kinetic energy to reach a given speed.
That's just within the accuracy limit of bicycle power meters and the effect on time to accelerate (especially in a sprint) is a lot less because most of your power is going into overcoming aerodynamic drag.
Lighter tires can be easier to accelerate but the physical effect comes from the reduced rolling resistance that goes with having a thinner, more flexible carcass to deform as you roll down the road. The psychological impact from what things sound like changes peoples' perception too.
There's about a 150g difference between a heavy rim (DT585 or Velocity Deep V) and a light but durable rim (Kinlin XR-270/300, Mavic Open Pro although some would argue that those aren't durable enough). There's another 180g separating a heavy tire (32mm wire bead Gatorskin) from a light one (23mm GP4000S). That's 660g for a pair of wheels.
As an upper bound you can treat all that mass as being where the rubber meets the road. With a 75kg rider + 9kg bike combination having that 660g as rotating mass instead of elsewhere on the bike means the rider needs to provide less than 0.8% more kinetic energy to reach a given speed. With an extra 660g in the rims and tires bringing the bike weight to 9.66 kg the rider needs 1.6% more kinetic energy to reach a given speed.
That's just within the accuracy limit of bicycle power meters and the effect on time to accelerate (especially in a sprint) is a lot less because most of your power is going into overcoming aerodynamic drag.
Lighter tires can be easier to accelerate but the physical effect comes from the reduced rolling resistance that goes with having a thinner, more flexible carcass to deform as you roll down the road. The psychological impact from what things sound like changes peoples' perception too.
Brad
11-20-11 | 12:07 PM
#28
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From: Novi Sad
Bikes: Heavy, with friction shifters
I get the picture. The reason for asking was a tempting option to get a neat racing road bike from a friend for relatively small amount of cash. It is under 11 kg (alu frame, carbon fork). It is tempting to give it a try. I've ridden heavy mountain and hybrid bikes all my life. Fat tires, big heavy frames, racks, fenders etc.
From what I've learned in this thread, for me it would be more gain to just put slim tires on my current hybrid, but I'm still entertaining thought of getting a road bike (as well as a fixed gear one). Second hand, so I can sell it if it doesn't suit me.
From what I've learned in this thread, for me it would be more gain to just put slim tires on my current hybrid, but I'm still entertaining thought of getting a road bike (as well as a fixed gear one). Second hand, so I can sell it if it doesn't suit me.
11-20-11 | 12:39 PM
#29
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From: Pearland, Texas
Bikes: Cannondale, Trek, Raleigh, Santana
I get the picture. The reason for asking was a tempting option to get a neat racing road bike from a friend for relatively small amount of cash. It is under 11 kg (alu frame, carbon fork). It is tempting to give it a try. I've ridden heavy mountain and hybrid bikes all my life. Fat tires, big heavy frames, racks, fenders etc.
From what I've learned in this thread, for me it would be more gain to just put slim tires on my current hybrid, but I'm still entertaining thought of getting a road bike (as well as a fixed gear one). Second hand, so I can sell it if it doesn't suit me.
From what I've learned in this thread, for me it would be more gain to just put slim tires on my current hybrid, but I'm still entertaining thought of getting a road bike (as well as a fixed gear one). Second hand, so I can sell it if it doesn't suit me.
Brad
11-20-11 | 02:00 PM
#31
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Does a 5 - 9 kg lighter bike really make some noticeable difference?
which I do with my commuters every day. I don't even want to know how much my Surly Troll weighs right now with the studded tires installed. It's also an air-drag monster. Getting it up to full arterial-bridge-crossing speed (27-30mph for ~1/4 mile) is tough work at the moment.
Last edited by mechBgon; 11-20-11 at 02:06 PM.
12-07-11 | 12:30 AM
#32
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From: Novi Sad
Bikes: Heavy, with friction shifters
Thanks for replies. OK, I went for the road bike racing frame, got shimano 105 groupset, and am looking for decent wheels, seat, bars. It will be nice, fast and light. My first ever bike without fenders. Rrrrrrr!
The original bike, with Dura-ace groupset was under 9 kgs, mine will be a bit heavier, but below 11 kg.
The original bike, with Dura-ace groupset was under 9 kgs, mine will be a bit heavier, but below 11 kg.
12-07-11 | 07:16 AM
#33
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From: Pearland, Texas
Bikes: Cannondale, Trek, Raleigh, Santana
Thanks for replies. OK, I went for the road bike racing frame, got shimano 105 groupset, and am looking for decent wheels, seat, bars. It will be nice, fast and light. My first ever bike without fenders. Rrrrrrr!
The original bike, with Dura-ace groupset was under 9 kgs, mine will be a bit heavier, but below 11 kg.
The original bike, with Dura-ace groupset was under 9 kgs, mine will be a bit heavier, but below 11 kg.
Brad
12-07-11 | 07:27 AM
#34
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From: Rosanky, Texas
Bikes: Steel is real. All others need not apply.
If you are not a top level professional, you should be more concerned about your weight and not the bike's. It's cheaper to get fit and loose weight and a lot better for you.
12-07-11 | 07:50 AM
#35
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From: Ohio
Bikes: Surly Long Haul Trucker
I have done some experiments with this myself, having a 21 pound road bike, and a 40 pound touring bike. What I have found is that 95% of my rides are on the touring bike, especially my centuries and 80, 90 miler day rides. And I ride mostly alone. I carry things to make the ride enjoyable along the way, and can carry an extra layer to make things more comfortable along they way. Its a different type of riding than a light road bike ride, but I find it more enjoyable.
When I want to go on a quick, hard ride, though, I take the road bike. It is more nimble, and FEELS much faster. Hills are much easier to climb. And on light bikes, their is a sense that you can kick ass of whatever hill or terrain you are on. On the heavy bike you have to slow down and respect the terrain. And the certainty of handling I get going downhill on the touring bike is awesome.
As far as what I have figured out on average speeds and such, on a recent 35 mile road bike ride, I would have only gone 32 miles on the touring bike in the same time. Or I could have spent an extra 10 minutes on the bike. I usually expect that I go an extra 2 mph average on the road bike, and translate that into how many hours I am riding. For instance, on a 3 hour ride I will go about 39 miles on the touring bike, and 45 on the road bike. I find myself most often taking the touring bike just because of how much more comfortable it is though.
Light bikes make sense for lots of hills, fast paced group riding, those who are competitive with themselves, and racing. Other that that it is all just a feeling of efficiency, and based on how lazy we are, they sell because of that.
When I want to go on a quick, hard ride, though, I take the road bike. It is more nimble, and FEELS much faster. Hills are much easier to climb. And on light bikes, their is a sense that you can kick ass of whatever hill or terrain you are on. On the heavy bike you have to slow down and respect the terrain. And the certainty of handling I get going downhill on the touring bike is awesome.
As far as what I have figured out on average speeds and such, on a recent 35 mile road bike ride, I would have only gone 32 miles on the touring bike in the same time. Or I could have spent an extra 10 minutes on the bike. I usually expect that I go an extra 2 mph average on the road bike, and translate that into how many hours I am riding. For instance, on a 3 hour ride I will go about 39 miles on the touring bike, and 45 on the road bike. I find myself most often taking the touring bike just because of how much more comfortable it is though.
Light bikes make sense for lots of hills, fast paced group riding, those who are competitive with themselves, and racing. Other that that it is all just a feeling of efficiency, and based on how lazy we are, they sell because of that.
12-07-11 | 08:04 AM
#36
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From: NW Arkansas
Bikes: Too many to count
I went from a 38lb Wally MTB to a 27lb Trek hybrid. It was like getting out of an
SUV and getting in a Ferrari. Not just the weight, but the feel. The MTB had slicks
and that really helped, but the loose of over ten lbs was unbelievable. My average
speed jumped about five MPH, and my distances nearly doubled.
When I was near 300lbs, twenty miles was a big deal., now at 220lbs, fifty is just an
outing.
SUV and getting in a Ferrari. Not just the weight, but the feel. The MTB had slicks
and that really helped, but the loose of over ten lbs was unbelievable. My average
speed jumped about five MPH, and my distances nearly doubled.
When I was near 300lbs, twenty miles was a big deal., now at 220lbs, fifty is just an
outing.
12-07-11 | 09:00 AM
#37
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From: Warwick, UK
Bikes: 2000-something 3 speed commuter, 1990-something Raleigh Scorpion
A lot of marketing involves hype around lighter parts, and you can spend almost infinite £ ($, €, whatever) in trimming a few grams here and there from the bicycle weight. However, the heaviest part of a bicycle by far is the rider. The weight and physical fitness of the cyclist plays a much greater role in performance than the weight of the bicycle. I've passed some rather unfit people uphill riding expensive-looking road bikes while on my heavy 3-speed laden down with books.
Some of the perception of a lighter bike being faster and more agile might come more from the frame geometry. A rather heavy city bike will have more relaxed frame angles than a racing bike, which has more aggressive geometry and also happens to be lighter.
For competitive cycling, however, the cyclist is already at the peak of physical fitness, so these tiny weight reductions from lighter frames, 'aero' wheels, unobtanium bearings etc matter a lot more.
Some of the perception of a lighter bike being faster and more agile might come more from the frame geometry. A rather heavy city bike will have more relaxed frame angles than a racing bike, which has more aggressive geometry and also happens to be lighter.
For competitive cycling, however, the cyclist is already at the peak of physical fitness, so these tiny weight reductions from lighter frames, 'aero' wheels, unobtanium bearings etc matter a lot more.
12-07-11 | 09:40 AM
#38
Still spinnin'.....
Joined: May 2009
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From: Whitestown, IN
Bikes: Fisher Opie freeride/urban assault MTB, Redline Monocog 29er MTB, Serrota T-Max Commuter, Klein Rascal SS, Salsa Campion Road bike, Pake Rum Runner FG/SS Road bike, Cannondale Synapse Road bike, Santana Arriva Road Tandem, and others....
For me, the most noticable difference is actually the handling. The lighter bike is more responsive to changes in direction and attitude in turns or when I need to shift my bike from one line to another. It also is easier to "unweight" over obstacles or when shifting the overall weight transfer either forward or rearward. The advantages in acceleration and climbing are also noticable, but "flicking" around a 35lb. bike underneath you on a rutted trail at speed vs. a 20lb. bike is very noticable whether you weigh 100lb. or 250lb. Same goes for a road bike.
Reducing rotating mass by running a lighter wheel/tire combination increases the advantage in accelleration and to a lesser degree handling, and it is probably the best place to start a weight reduction plan, but reducing overall weight will improve handling regardless of your weight or experience. I believe this is why you hear riders talking about improved "feel" of lighter bikes.
Reducing rotating mass by running a lighter wheel/tire combination increases the advantage in accelleration and to a lesser degree handling, and it is probably the best place to start a weight reduction plan, but reducing overall weight will improve handling regardless of your weight or experience. I believe this is why you hear riders talking about improved "feel" of lighter bikes.
Last edited by Stealthammer; 12-07-11 at 09:45 AM.
12-07-11 | 10:08 AM
#39
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From: Oxnard, CA
Bikes: 2009 Fuji Roubaix RC; 2011 Fuji Cross 2.0; '92 Diamond Back Ascent EX
My lighter bike feels faster and I enjoy riding it more therefore I ride it longer distances. Whether the difference is only perception or whether it is actual, weight matters to me because I'm riding for exercise and enjoyment and the lighter bikes give me more of both.
12-07-11 | 10:23 AM
#40
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From: Novi Sad
Bikes: Heavy, with friction shifters
A friend is a former racer and he let me try his road bike. It was just very quick, nimble, although a bit awkward in the drop bars for me. When we rode a 10 km long, flat, nicely paved stretch of road, I was doing nicely at some 30 + km/h. However, whenever there was room for us to go side by side and chat, I saw him coasting most of the time?!? I was pedalling quite decently on my hybrid. Guess it was mostly about tyres (37 mm vs. 23 mm).
My current commuter (and everything else) bike is great, universal, but it weighs some 44 pounds (20 kgs). Plus it has a front shock absorber. Being super fit like I am I expect the road bike to be quicker on flats, uphill and downhill as well. Sports motorcycle riding has become too risky in my country (no race tracks, only public roads with lots of police), so my speed adrenaline will have to come from (downhill) cycling. For me 60 km/h on a bicycle feels like 180 km/h on a motorcycle.
If I don't like it in the end I can sell it for small amount of money lost (since I got all the parts second hand), or keep it as a backup bike.
My current commuter (and everything else) bike is great, universal, but it weighs some 44 pounds (20 kgs). Plus it has a front shock absorber. Being super fit like I am
I expect the road bike to be quicker on flats, uphill and downhill as well. Sports motorcycle riding has become too risky in my country (no race tracks, only public roads with lots of police), so my speed adrenaline will have to come from (downhill) cycling. For me 60 km/h on a bicycle feels like 180 km/h on a motorcycle.If I don't like it in the end I can sell it for small amount of money lost (since I got all the parts second hand), or keep it as a backup bike.
12-07-11 | 11:44 AM
#41
Half way there
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From: Durham, NC
Bikes: 69 Hercules, 73 Raleigh Sports, 74 Raliegh Competition, 78 Nishiki Professional, 79 Nishiki International, 83 Colnago Super, 83 Viner Junior
Hmm, I lost five pounds in the last 6 months, but added some weight to my commuting bike probably equal to my personal loss. I added new wheels - a dynohub in front and an IGH in the back along with fatter tires along with some other accessories. I find that my commute takes slightly less time now (same route).
While I don't think this means that body weight loss is more important than bike weight loss, I think it just shows that lightness is not the holy grail that some folks think it is.
-G
While I don't think this means that body weight loss is more important than bike weight loss, I think it just shows that lightness is not the holy grail that some folks think it is.
-G
12-07-11 | 12:10 PM
#42
It's MY mountain
Joined: Sep 2006
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From: Mt.Diablo
Bikes: Klein, Merckx, Trek
Correct - also when you're hoisting it onto a vehicle roof rack - I always worry about throwing out my back or getting a hernia when I load my tandem into my pickup. I can throw my light road bike in there without concern.
12-07-11 | 01:30 PM
#43
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From: Oxnard, CA
Bikes: 2009 Fuji Roubaix RC; 2011 Fuji Cross 2.0; '92 Diamond Back Ascent EX
Hmm, I lost five pounds in the last 6 months, but added some weight to my commuting bike probably equal to my personal loss. I added new wheels - a dynohub in front and an IGH in the back along with fatter tires along with some other accessories. I find that my commute takes slightly less time now (same route).
While I don't think this means that body weight loss is more important than bike weight loss, I think it just shows that lightness is not the holy grail that some folks think it is.
-G
While I don't think this means that body weight loss is more important than bike weight loss, I think it just shows that lightness is not the holy grail that some folks think it is.
-G
12-07-11 | 06:19 PM
#44
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From: Calgary, Alberta
This has been a really interesting topic to me. Thanks to Slaninar for starting it, and thanks for a lot of the comments in it.
I just want to add a couple of things. If you have a heavier bike, the ideal tire pressure will increase a bit.
And I was on an upper class bike site not long ago. They mentioned that going for the super competitive advantage of an extremely light bike, means you will get one that is not going to last as long. I thought it was decent of them to mention that.
I just want to add a couple of things. If you have a heavier bike, the ideal tire pressure will increase a bit.
And I was on an upper class bike site not long ago. They mentioned that going for the super competitive advantage of an extremely light bike, means you will get one that is not going to last as long. I thought it was decent of them to mention that.
12-07-11 | 06:38 PM
#45
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Bikes: 1986 Alan Record Carbonio, 1985 Vitus Plus Carbone 7, 1984 Peugeot PSV, 1972 Line Seeker, 1986(est.) Medici Aerodynamic (Project), 1985(est.) Peugeot PY10FC
For me personally, once I went "weight weenie" on my bikes back in the 80's, I could not have it any other "weigh"!
It's kinda like a disease, and obsession, constantly looking for that next little bit to eliminate from or change on the bike to make the numbers go down.
It all started back in the 80's when my younger brother and I stared at our only few miles old Peugeots back in college right after watching a great Criterium race and noticed that ....."we don't really need those honking big reflectors weighing down our wheels, do we"??
And it continues on even today.
Heck, I stressed out a bit last week when I clamped on the small plastic chain hanger on my Vitus Carbone (now at 17 pounds) bike's right lower seatstay that only weighed maybe 9 grams at most.....
Riding anything over 19 pounds is just no fun for me.
Chombi
It's kinda like a disease, and obsession, constantly looking for that next little bit to eliminate from or change on the bike to make the numbers go down.
It all started back in the 80's when my younger brother and I stared at our only few miles old Peugeots back in college right after watching a great Criterium race and noticed that ....."we don't really need those honking big reflectors weighing down our wheels, do we"??
And it continues on even today.
Heck, I stressed out a bit last week when I clamped on the small plastic chain hanger on my Vitus Carbone (now at 17 pounds) bike's right lower seatstay that only weighed maybe 9 grams at most.....
Riding anything over 19 pounds is just no fun for me.
Chombi
12-07-11 | 11:27 PM
#46
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From: SF Bay Area
Bikes: 2003 Lemond Zurich; 1987 Schwinn Tempo; 1968 PX10; 1978 PX10LE, Peugeot Course; A-D Vent Noir
Sounds plausible but simplistic. Weight is not the main determinant of durability. Frame and component materials and construction are more important. A well-built lightweight bike will often last longer (and work better) than a robust looking Wal-Mart boat anchor bike. Most 1970's proletarian French roadsters (e.g. UO-8) are fairly light, ride well, and at 40 years of age still have more life left in them than most of the newborn clunkers being sold to the mass market today.
12-08-11 | 01:21 AM
#47
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From: Novi Sad
Bikes: Heavy, with friction shifters
Frame and fork: 250 euros (used, second hand, 3 years old, mint condition)
Giant alu frame with a carbon fork - neat.
Groupset: 350 euros (unused, second hand)
Shimano 105 5703, triple.
Wheels (rims, spokes and rims): 70 euros (used for few 100 kms, mint condition)
Shimano 105 5600 hubs, 36 spokes. Front Rigida Chrina, rear Mavic CXP 22.
Tyres:
I'm thinking of Schwalbe Durano S red. Here's the link:
https://www.amazon.co.uk/Schwalbe-Dur.../dp/B0032TLAZA
The red ones would look superneat on the white frame with red letters. Are these tyres good? Roads are bad in my country. This one looks like a light tyre that is sturdy. Any other tyres worth looking into? Any half priced decent ones (these tyres will cost me some 70 euros pair here).
Seat:
This will have to come down to trial and error I fear.
Bars, seatpost, cables: will look for something of good quality steel/aluminium, not too expensive, simple.
Pedals:
I'll go for mtb style clipless, so I can use same pair of shoes on my commuter and the road bike.
Did I forget anything? :/
Giant alu frame with a carbon fork - neat.
Groupset: 350 euros (unused, second hand)
Shimano 105 5703, triple.
Wheels (rims, spokes and rims): 70 euros (used for few 100 kms, mint condition)
Shimano 105 5600 hubs, 36 spokes. Front Rigida Chrina, rear Mavic CXP 22.
Tyres:
I'm thinking of Schwalbe Durano S red. Here's the link:
https://www.amazon.co.uk/Schwalbe-Dur.../dp/B0032TLAZA
The red ones would look superneat on the white frame with red letters. Are these tyres good? Roads are bad in my country. This one looks like a light tyre that is sturdy. Any other tyres worth looking into? Any half priced decent ones (these tyres will cost me some 70 euros pair here).
Seat:
This will have to come down to trial and error I fear.
Bars, seatpost, cables: will look for something of good quality steel/aluminium, not too expensive, simple.
Pedals:
I'll go for mtb style clipless, so I can use same pair of shoes on my commuter and the road bike.
Did I forget anything? :/
12-08-11 | 09:19 AM
#48
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From: Pearland, Texas
Bikes: Cannondale, Trek, Raleigh, Santana
Slaninar, Unless it isn't done anymore, the new shifters will have the cables and cable housing included. You're unlikely to find seatposts or handle bars in steel, but I would choose aluminum over carbon fiber. Be sure the new handle bar's clamping diameter matches your stem.
Brad
Brad
12-08-11 | 09:44 AM
#49
Macaws Rock!
Joined: May 2005
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From: San Francisco, CA
Bikes: 2005 Soma Doublecross
I figure that since I am the equivalent of three medium weight bicycles overweight, there isn't much need for me to count grams on the bike. ;-)
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12-08-11 | 12:10 PM
#50
For The Fun of It
Joined: May 2007
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From: Louisissippi Coast
Bikes: Lynskey GR300, Lynskey Backroad, Litespeed T6, Lynskey MT29, Burley Duet
Rolling resistance makes a very big difference. If you take a 26X2.1 MTB tire off and put on a 26x1.5 high pressure tire you will feel an appreciable difference. When I switched my commuter from 700x38 low pressure tires to 700x32 high pressure tires it felt quite a bit better. In both cases my average speed over the same area increased a bit too. Although there was very little weight advantage to the narrow tires, the lower rolling resistance played out quite nicely.