Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Question of mass & physics

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Question of mass & physics

Reply

Old 03-15-19, 06:14 PM
  #1  
thehammerdog
Senior Member
Thread Starter
 
thehammerdog's Avatar
 
Join Date: Dec 2007
Location: NWNJ
Posts: 2,567

Bikes: Road bike is a Carbon Bianchi C2C & Grandis (1980's), Gary Fisher Mt Bike, Trek Tandem & Mongoose SS MTB circa 1992.

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 186 Post(s)
Question of mass & physics

Can using a larger volume tire like a 28 in anyway help with weight distribution on a wheelset with a rider weight limit?
can chubby use bigger tires inorder to ride his lightweight wheels ?
or is fat just fat and im to fat
thehammerdog is offline  
Reply With Quote
Old 03-15-19, 06:19 PM
  #2  
KLiNCK
Optically Corrected
 
KLiNCK's Avatar
 
Join Date: Nov 2011
Location: Toronto, Ontario, Canada.
Posts: 494

Bikes: 2012 Specialized Sirrus , 2012 Specialized Roubaix Comp

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 73 Post(s)
Need more information...
What is the recommended maximum weight for the wheelset?
What is your weight?
What style/conditions do you ride in?
KLiNCK is offline  
Reply With Quote
Old 03-15-19, 07:06 PM
  #3  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 11,254

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1624 Post(s)
Wider tires generally weigh more then narrower ones (all other things the same) so, yes, "weight distribution" does change. It moves more to the outer part of the wheel where the wider tire is. But I don't think that is really what you ask about.

Wider tires will better protect any rim from impacts. They tend to smoothen out the ride by better absorbing shock. But the load the rim sees is still the same, so to for the spokes.

In my ideal world riders use tires that are size/grade/design agreeable with the rider's needs/expectations, independent of the rim/wheel . Of course both have to be compatible with each other.

Don't expect wider tires to extend wheel life of make a too fragile wheel survive an overloaded situation. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Reply With Quote
Old 03-15-19, 07:09 PM
  #4  
thehammerdog
Senior Member
Thread Starter
 
thehammerdog's Avatar
 
Join Date: Dec 2007
Location: NWNJ
Posts: 2,567

Bikes: Road bike is a Carbon Bianchi C2C & Grandis (1980's), Gary Fisher Mt Bike, Trek Tandem & Mongoose SS MTB circa 1992.

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 186 Post(s)
Originally Posted by KLiNCK View Post
Need more information...
What is the recommended maximum weight for the wheelset?
What is your weight?
What style/conditions do you ride in?
i go about 215 lbs got old school rolph wheels siestre 1600gms i think 200lb limit ride style smoove only paved roads no drama on the bike in question just had them trued steel frame bike
thehammerdog is offline  
Reply With Quote
Old 03-15-19, 07:34 PM
  #5  
wgscott
VectorPotential sensitive
 
wgscott's Avatar
 
Join Date: Jul 2013
Location: The Timbers of Fennario (CL77)
Posts: 4,207

Bikes: Steel

Mentioned: 55 Post(s)
Tagged: 0 Thread(s)
Quoted: 2206 Post(s)
I'd be worried about spoke count. Fatter tires will protect the rims more.
wgscott is offline  
Reply With Quote
Old 03-15-19, 07:46 PM
  #6  
davidad
Senior Member
 
Join Date: Feb 2009
Posts: 5,682
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 265 Post(s)
Originally Posted by thehammerdog View Post
Can using a larger volume tire like a 28 in anyway help with weight distribution on a wheelset with a rider weight limit?
can chubby use bigger tires inorder to ride his lightweight wheels ?
or is fat just fat and im to fat
No. For most of us light weight components are a waste of money. When we get down to 6% body fat then we can worry about component weight.
davidad is offline  
Reply With Quote
Old 03-15-19, 08:29 PM
  #7  
TimothyH
- Soli Deo Gloria -
 
TimothyH's Avatar
 
Join Date: Aug 2015
Location: Northwest Georgia
Posts: 12,826

Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix

Mentioned: 196 Post(s)
Tagged: 0 Thread(s)
Quoted: 5699 Post(s)
Having a wider tire or larger air volume will not increase maximum weight limit of the wheels.


-Tim-
TimothyH is offline  
Reply With Quote
Old 03-15-19, 09:14 PM
  #8  
AnkleWork
Senior Member
 
Join Date: Jan 2013
Location: Llano Estacado
Posts: 3,187

Bikes: old clunker

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 480 Post(s)
Originally Posted by thehammerdog View Post

Question of mass & physics
Can using a larger volume tire like a 28 in anyway help with weight distribution on a wheelset with a rider weight limit?
can chubby use bigger tires inorder to ride his lightweight wheels ?
or is fat just fat and im to fat
Answer of engineering
Free body analysis: The distance between axles will not change, thus the weight distribution will not change.
Force path analysis: The rider's weight must be borne by the axles, bearings, hub shells, spokes, and rims regardless of tires.
AnkleWork is offline  
Reply With Quote
Old 03-15-19, 09:50 PM
  #9  
Bill Kapaun
Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 10,586

Bikes: 86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 595 Post(s)
A fatter tire will reduce peak impacts when hitting curbs, pot holes etc.
IF you rims are rated for a 200 lb. rider, a 215 lb. rider on SMOOTH pavement shouldn't be an issue.
Bill Kapaun is offline  
Reply With Quote
Old 03-16-19, 12:42 AM
  #10  
CliffordK
Senior Member
 
CliffordK's Avatar
 
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 21,347
Mentioned: 144 Post(s)
Tagged: 0 Thread(s)
Quoted: 7760 Post(s)
Originally Posted by AnkleWork View Post
Answer of engineering
Free body analysis: The distance between axles will not change, thus the weight distribution will not change.
Force path analysis: The rider's weight must be borne by the axles, bearings, hub shells, spokes, and rims regardless of tires.
A wider tire at lower pressure may well reduce shock (dynamic load/impact acceleration) on the components, which would be greater than the static load on the components.

Thus, there would be reason to believe that if one is very borderline, that it may tip one over the edge towards potentially being OK.

Also be careful with your riding. Watch the bumps.

But, as above, there might be benefits of building slightly stronger wheels.
CliffordK is offline  
Reply With Quote
Old 03-16-19, 04:45 AM
  #11  
thehammerdog
Senior Member
Thread Starter
 
thehammerdog's Avatar
 
Join Date: Dec 2007
Location: NWNJ
Posts: 2,567

Bikes: Road bike is a Carbon Bianchi C2C & Grandis (1980's), Gary Fisher Mt Bike, Trek Tandem & Mongoose SS MTB circa 1992.

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 186 Post(s)
I am very impressed with the technical answers and as usual we have many others that vary. I think I will just diet some more as weight is weight and I do not want to die on the road as I squeeze into my lycra just to have wheel failure...
The uber lightness is alluring when compared to the Mavic Askiums
thehammerdog is offline  
Reply With Quote
Old 03-16-19, 05:57 AM
  #12  
Lemond1985
Senior Member
 
Lemond1985's Avatar
 
Join Date: Jan 2019
Posts: 613
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 314 Post(s)
No diet needed. Just go on long rides, and eat what you would normally eat, had you not ridden that day. This will create a caloric deficit, and the weight will drop off slowly and naturally.

That's how I did it anyway, your health situation and mileage may vary.
Lemond1985 is offline  
Reply With Quote
Old 03-16-19, 08:58 AM
  #13  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 39,503

Bikes: 8

Mentioned: 164 Post(s)
Tagged: 0 Thread(s)
Quoted: 6158 Post(s)
23 to 28 is insignificant to this scheme of yours..

buy wheels with a greater spoke count... for a better sense of security..
fietsbob is offline  
Reply With Quote
Old 03-16-19, 04:20 PM
  #14  
ramzilla
Senior Member
 
ramzilla's Avatar
 
Join Date: Dec 2014
Location: 1/2 Atlanta GA 1/2 Fernandina FL
Posts: 2,330

Bikes: Vintage Japanese Bicycles

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 366 Post(s)
I'm a heavier 200+ lb rider myself. For reasons of safety I prefer larger tires. Larger tires = more rubber and, are generally more resistant to flats. It's one thing to get a flat tire when you're a 150 lb teenage boy. It's quite a different matter when you're a 220lb 63 year old man. One of my current favorite tires is the Michelin Pro-Tek series. They're a littler bigger than other bike tires. And, so far so good. No bad flats yet.
ramzilla is offline  
Reply With Quote
Old 03-16-19, 09:23 PM
  #15  
TimothyH
- Soli Deo Gloria -
 
TimothyH's Avatar
 
Join Date: Aug 2015
Location: Northwest Georgia
Posts: 12,826

Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix

Mentioned: 196 Post(s)
Tagged: 0 Thread(s)
Quoted: 5699 Post(s)
Originally Posted by thehammerdog View Post
I am very impressed with the technical answers and as usual we have many others that vary. I think I will just diet some more as weight is weight and I do not want to die on the road as I squeeze into my lycra just to have wheel failure...
The uber lightness is alluring when compared to the Mavic Askiums
Having gone from 200 lb to 165 lb last year, I would like to encourage you. The first 10 lb was noticeable when climbing.

Don't listen to too many people. You know what to do. Good luck and please post your progress.


-Tim-
TimothyH is offline  
Reply With Quote
Old 03-17-19, 09:14 AM
  #16  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 21,021

Bikes: Some silver ones, a red one, an orange one and a few titanium ones

Mentioned: 83 Post(s)
Tagged: 1 Thread(s)
Quoted: 2252 Post(s)
Originally Posted by ramzilla View Post
I'm a heavier 200+ lb rider myself. For reasons of safety I prefer larger tires. Larger tires = more rubber and, are generally more resistant to flats. It's one thing to get a flat tire when you're a 150 lb teenage boy. It's quite a different matter when you're a 220lb 63 year old man. One of my current favorite tires is the Michelin Pro-Tek series. They're a littler bigger than other bike tires. And, so far so good. No bad flats yet.
While there may be more rubber because of increased surface area of the tires, that doesn’t translate into more rubber to prevent flats. If you make an apples to apples comparison of tires (same brand and construction), a 23mm tire has the same thickness of rubber at the tread as a 35mm tire.

Additionally, a flat tire is just a flat tire. Weight of the rider makes no difference and age of the rider certainly doesn’t make any difference.
__________________
Stuart Black
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
An Good Ol' Fashion Appalachian Butt Whoopin'.
cyccommute is offline  
Reply With Quote
Old 03-17-19, 09:22 AM
  #17  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 21,021

Bikes: Some silver ones, a red one, an orange one and a few titanium ones

Mentioned: 83 Post(s)
Tagged: 1 Thread(s)
Quoted: 2252 Post(s)
Originally Posted by thehammerdog View Post
Can using a larger volume tire like a 28 in anyway help with weight distribution on a wheelset with a rider weight limit?
can chubby use bigger tires inorder to ride his lightweight wheels ?
or is fat just fat and im to fat
Your idea is a bit too simplistic. If you ride heavy in the saddle, a wider tire might help a little but only a little. If you ride light in the saddle, it won’t make a difference. It’s known as “ballerinas who ride like gorillas and gorillas who ride like ballerinas.” In other words, even a light rider who slams in potholes and road debris will damage wheels and bikes no matter how large the tires are. A heavy rider who unloads the bike by using their legs and arms as suspension can ride thin tires without worrying about damaging the bike or wheels.
__________________
Stuart Black
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
An Good Ol' Fashion Appalachian Butt Whoopin'.
cyccommute is offline  
Reply With Quote
Old 03-17-19, 09:41 AM
  #18  
wphamilton
Senior Member
 
wphamilton's Avatar
 
Join Date: Apr 2011
Location: Alpharetta, GA
Posts: 14,246

Bikes: Nashbar Road

Mentioned: 53 Post(s)
Tagged: 0 Thread(s)
Quoted: 2351 Post(s)
Looking at it purely from a "mass and physics" point of view for your specific question, as mentioned it's more mass at the circumference so yes the "distribution" changes in that regard. That will add some small amount of stress on the rear spokes and rim as you accelerate (I'd say insignificant compared to extant stresses). On the front wheel, a lesser effect on the wheel itself.

Regarding the increased tire volume, not mass. It will increase the duration of time where peak forces are applied to the wheel (decreasing impulse) so I believe that it DOES help the wheel withstand a greater rider weight. It that's enough to give the lightweight wheels greater longevity, that remains to be seen.
wphamilton is offline  
Reply With Quote
Old 03-17-19, 12:23 PM
  #19  
WizardOfBoz
Generally bewildered
 
WizardOfBoz's Avatar
 
Join Date: Aug 2015
Location: Eastern PA, USA
Posts: 1,580

Bikes: 2014 Trek Domane 6.9, 1999 LeMond Zurich, 1978 Schwinn Superior

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 545 Post(s)
Originally Posted by wgscott View Post
I'd be worried about spoke count. Fatter tires will protect the rims more.
This. A heavier rider will put more stress on the rims and spokes than a light rider and a tire won't change that significantly. Fatter tires will reduce the effect of strong bumps, preventing the tire from bottoming out and damaging the rime (also, the impulse force wphamilton mentions could collapse the rim I think) in the road for any size rider but the stress of the bump will be added to the stress caused by weight. Further, we don't know the tire size used by the mfr in setting the weight limit. That limit may actually account for a wider tire for a heavier ride. So I fear you'll still exceed the wheels intended design limit. While there will be some safety factor in a manufacturer's stated limit, that limit does balance safety and likelihood of failure with the limiting sales by constraining the possible population of buyers. They don't put those limits on arbitrarily as a low limit also limits sales to some degree.

There's another issue. I weight 245#. I had a pair of Bontrager Race RLs on my bike. A good solid, strong, dependable pair of wheels with a good balance of stiffness and weight. I wanted to upgrade (lighter is better, right?) though, so I got a pair of Paradigm Elites off eBay. They were rated for my weight, but were lighter (and had lighter construction and fewer spokes). I went into my local Trek store, and Bill, a really experienced guy who was the mgr/head mechanic, told me "Given that you're a pretty big guy, I don't think you'll like the ride on those Elites as well as you like the RLs". Bill's usually right on bike issues (to a shocking degree*), and he was here. The Elites are great wheels, but for me the RLs work better. They're heavier with thicker spokes, so they tend not to flex as much. If only I could lose 40 lbs, those Elites would be sweet!

Upshot is that if a mfr suggests a weight limit, and you exceed it, there are two reasons you probably want to find a wheel that's a bit stouter: safety and performance. Your ride will be nicer and more efficient using wheels that match your avoirdupois. I found this to be true, anyway.

*I started working with bikes 45 years ago, and have a PhD in Engineering. So I think I know everything. Until I talk with Bill, who invariably throws out observations that indicate really deep knowledge, or a wrinkle I hadn't thought of. Humbling, but very helpful.

Last edited by WizardOfBoz; 03-18-19 at 12:46 PM.
WizardOfBoz is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service