Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

BQ "Myth 18: Wide Tires Need Wide Rims"

Notices
Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

BQ "Myth 18: Wide Tires Need Wide Rims"

Old 07-01-19, 10:49 PM
  #26  
lasauge 
Pedalin' Erry Day
 
lasauge's Avatar
 
Join Date: Jun 2011
Location: Colorado Springs
Posts: 951
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 503 Post(s)
Liked 2 Times in 2 Posts
As others in this thread have said, I think Jan's conclusion is mostly correct, but the argument he's making to reach that conclusion here is just rubbish. The central problem with his argument is that he claims that people are choosing wider rims because it makes sidewalls stronger, but this is simply not true and that makes his points about sidewall flexibility and tire compression irrelevant. And his comments about the advantages of the "O" shape of tubulars is actually one that should encourage people to use wider rims, since a wider rim increases the outer circumference of a "Ω" shape tire. But perhaps the most ridiculous thing about this article is that in it he describes experiencing (but misattributes the cause to stiff sidewalls) the very problem that people in this thread have already mentioned and the reason why we need to be careful not to match tires with rims that are too narrow: if you don't have enough tire pressure, the sidewall can buckle and the tire can roll, which produces squirrelly handling, flats, blowouts, and crashes - and note that this need for higher pressure in turn limits the advantages of wide, supple tires.
__________________
Reach me faster by email.
lasauge is offline  
Old 07-02-19, 02:04 AM
  #27  
Lascauxcaveman 
Senior Member
 
Lascauxcaveman's Avatar
 
Join Date: Nov 2011
Location: Port Angeles, WA
Posts: 7,371

Bikes: A green one, "Ragleigh," or something.

Mentioned: 165 Post(s)
Tagged: 0 Thread(s)
Quoted: 1363 Post(s)
Liked 70 Times in 47 Posts
If it's a wider tire on a narrower rim, I suppose proper inflation pressure is a legitimate concern. I wouldn't run my 35mm Paselas under 50psi on my 17mm Alex rims, but you probably wouldn't, either. As long as the bead seats solidly and the tire is quite firm for your weight, I can't see how there is any any problem.

If the tire is so soft that cornering hard pops the bead out; then you have a problem.
__________________
● 1971 Grandis SL ● 1972 Lambert Grand Prix frankenbike ● 1972 Raleigh Super Course fixie ● 1973 Nishiki Semi-Pro ● 1980 Apollo "Legnano" ● 1981 Miyata 1000 ● 1984 Bianchi Limited ● 1984 Nishiki Landau ● 1984 Peugeot Vagabond ● 1985 Shogun Prairie Breaker ● 1986 Univega Nuovo Sport ● 1986 Merckx Super Corsa ● 1987 Schwinn Tempo ● 1988 Schwinn Voyageur ● 1989 Trek 400 ● 1989 Bottechia Team ADR replica ● 1990 Cannondale ST600 ● 1993 Technium RT600 ● 1996 Kona Lava Dome ●
Lascauxcaveman is offline  
Old 07-02-19, 06:11 AM
  #28  
mixteup 
Senior Member
 
mixteup's Avatar
 
Join Date: Oct 2017
Location: NW Florida
Posts: 368

Bikes: A Few

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 149 Post(s)
Liked 24 Times in 16 Posts
Originally Posted by SurferRosa View Post
This was a myth that I bought into for years until I purchased a '98 Cannondale f1000 mtb. It was running 2.1" knobbies on its narrow Mavic rims just fine.
I think the idea with mountain bikes, in having the tire much wider than the rim, is to protect the rim in rocky terrain - The rim being tucked in behind the bulge of the tire, out of harms way - No concern with high speed road handling here.
__________________
We are confronted by insurmountable opportunities ........
Pogo
mixteup is offline  
Likes For mixteup:
Old 07-24-19, 06:47 PM
  #29  
Ferrouscious
Some Weirdo
 
Ferrouscious's Avatar
 
Join Date: Dec 2017
Location: SW OH
Posts: 159

Bikes: '82 Austro Daimler Alpina, '71 C. Itoh, '86? Maruishi Excellence

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked 3 Times in 2 Posts
From the man himself... but you should find the limit for yourself (within reason)
Attached Images
File Type: jpg
squiggity.jpg (835.2 KB, 112 views)
Ferrouscious is offline  
Old 07-25-19, 08:43 AM
  #30  
Miele Man
Senior Member
 
Join Date: Jun 2014
Location: Ontario, Canada
Posts: 2,087

Bikes: Miele Latina, Miele Suprema, Miele Uno SL, Miele MTB, Bianchi Model Unknown, Fiori Venezia, VeloSport Adamas AX

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 314 Post(s)
Liked 35 Times in 29 Posts
Originally Posted by ThermionicScott View Post
I don't often start threads to be "provocative", but I didn't see a thread for this one yet, and was curious of the C&V Brain Trust's take: https://janheine.wordpress.com/2019/06/26/myth-18-wide-tires-need-wide-rims

It never would have occurred to me to think of narrow rims pinching tire beads close together as making it more tubular-like, and I'm still working through that concept.

It also seems to me that Keith Bontrager's intent when rolling MA2/MA40's into 26" rims wasn't necessarily to make narrow MTB rims, just to make lightweight ones. I'd welcome correction on that one.

I feel like the truth is somewhere in the middle on the rim width thing. Probably would have titled it "Do wide tires really need wide rims?"
I had some Schwalbe Pro CX Pro cyclo-cross tires mounted on narrow rims. All was well until I punctured the FRONT tire. Down I went. the entire tire stayed on the rim. This happened on two different occasions and I went down both times. Fortunately I was riding quite slowly each time. I figured that the risk of a crash in heavy traffic was too great to continue using that combination of 30mm tires on those narrow rims. I replaced those tires with 25mm tires and will put the Schwalbe CX Pro 30mm tires onto wider rims. I will NOT risk a front tire flat throwing me into heavy traffic. YMMV but it's definitely something to consider. What happens if a front tire flats and causes you to spill as you're sprinting through a left turn with oncoming traffic or you spill in some other traffic gap because your front tire flatted and then the front wheel immediately went out from under you? When my CX Pro front tire flatted I went down IMMEDIATELY with no warning at all.

I recommend that if you insist on riding a wide tire on a narrow rim that you take the bike and your pump to a school yard or a quiet parking lot and let most of the air out of the tire and see if you can maintain control on it. I know with the CX Pro tire on the narrow rims I had them on there was immediate loss of control if the front tire flatted or went very soft.

Cheers.
Miele Man is online now  
Old 07-26-19, 11:30 AM
  #31  
dddd
Ride, Wrench, Swap, Race
 
dddd's Avatar
 
Join Date: Jan 2010
Location: Northern California
Posts: 6,632

Bikes: Cheltenham-Pederson racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.

Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Likes: 0
Liked 33 Times in 32 Posts
Originally Posted by Miele Man View Post
I had some Schwalbe Pro CX Pro cyclo-cross tires mounted on narrow rims. All was well until I punctured the FRONT tire. Down I went. the entire tire stayed on the rim. This happened on two different occasions and I went down both times. Fortunately I was riding quite slowly each time. I figured that the risk of a crash in heavy traffic was too great to continue using that combination of 30mm tires on those narrow rims. I replaced those tires with 25mm tires and will put the Schwalbe CX Pro 30mm tires onto wider rims. I will NOT risk a front tire flat throwing me into heavy traffic. YMMV but it's definitely something to consider. What happens if a front tire flats and causes you to spill as you're sprinting through a left turn with oncoming traffic or you spill in some other traffic gap because your front tire flatted and then the front wheel immediately went out from under you? When my CX Pro front tire flatted I went down IMMEDIATELY with no warning at all.

I recommend that if you insist on riding a wide tire on a narrow rim that you take the bike and your pump to a school yard or a quiet parking lot and let most of the air out of the tire and see if you can maintain control on it. I know with the CX Pro tire on the narrow rims I had them on there was immediate loss of control if the front tire flatted or went very soft.

Cheers.
I'm just wondering here what caused your flat tires(?).

I've run inches-wide tires on i13mm 700c rims and all was fine since I kept a reasonable pressure of 25psi in them for my 180lbs of bike+rider weight.

I've had 2.6" tires on i51mm rims fold over in turn when the pressure was just a couple of psi lower than what that combination required, so it's not just the narrow rims that allow this. A given tire's needed pressure for use with wider vs. narrower rims isn't that much different, and much of any psi difference is simply the result of the tire achieving a smaller cross-sectional width on the narrower rim (which results in a proportionally-lower tension in the casing).

Tires that flop more may also better keep the tread cap facing the road surface as opposed to contacting the road near the edges of the tread (which also can become slippery from their infrequent scuffing against the road).

Also it seems like it will be the case that some tires are designed (tread cap width, etc.) to be used on narrower or wider rims than others, so one more consideration when choosing tires.
Just as how some tires are designed with a flatter tread contact area better suited to maximizing traction on lower-traction surfaces, while other tires feature more tread wrap to exploit sharper cornering angles on higher-traction surfaces.
dddd is offline  
Old 07-26-19, 12:10 PM
  #32  
Miele Man
Senior Member
 
Join Date: Jun 2014
Location: Ontario, Canada
Posts: 2,087

Bikes: Miele Latina, Miele Suprema, Miele Uno SL, Miele MTB, Bianchi Model Unknown, Fiori Venezia, VeloSport Adamas AX

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 314 Post(s)
Liked 35 Times in 29 Posts
Originally Posted by dddd View Post
I'm just wondering here what caused your flat tires(?).

I've run inches-wide tires on i13mm 700c rims and all was fine since I kept a reasonable pressure of 25psi in them for my 180lbs of bike+rider weight.

I've had 2.6" tires on i51mm rims fold over in turn when the pressure was just a couple of psi lower than what that combination required, so it's not just the narrow rims that allow this. A given tire's needed pressure for use with wider vs. narrower rims isn't that much different, and much of any psi difference is simply the result of the tire achieving a smaller cross-sectional width on the narrower rim (which results in a proportionally-lower tension in the casing).

Tires that flop more may also better keep the tread cap facing the road surface as opposed to contacting the road near the edges of the tread (which also can become slippery from their infrequent scuffing against the road).

Also it seems like it will be the case that some tires are designed (tread cap width, etc.) to be used on narrower or wider rims than others, so one more consideration when choosing tires.
Just as how some tires are designed with a flatter tread contact area better suited to maximizing traction on lower-traction surfaces, while other tires feature more tread wrap to exploit sharper cornering angles on higher-traction surfaces.
I'm not sure what caused one of the flats. I was riding out of a pedestrian walkway that connects two streets and went to make a 90 degrees turn and the front wheel instantly went out from under me. When I got up and checked the bike for damage I discovered that the front tire had completely flatted. The other time was as I was exiting a driveway from a park that was the terminus of an organized tour. As I was riding I noticed it was almost impossible to steer the bike. I immediately stopped and checked the tire and it was very soft but not completely flat. I walked the bike back to where a bike shop had set up a repair facility. they tried pumping up the tire but we could here the air coming out of the tire. Closer inspection showed a hole - probably a glass cut. Because those tires lead to instant loss of steering control if very low in pressure or if flat I took them off those rims and will put them on wider rims.

I shudder to think what would have happened had either of those two flats happened in heavy traffic especially on a very busy overpass that has entrance and exit lanes to the 401 highway (Ontario, Canada) which I would have be riding quite fast to get past.

Why those tires lead to instant loss of control I don't know or care. The fact that they do is enough for me to no longer use them on a narrow rim.

Cheers
Miele Man is online now  
Old 07-26-19, 06:35 PM
  #33  
rhm
multimodal commuter
 
rhm's Avatar
 
Join Date: Nov 2006
Location: NJ, NYC, LI
Posts: 19,139

Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...

Mentioned: 452 Post(s)
Tagged: 0 Thread(s)
Quoted: 1570 Post(s)
Liked 21 Times in 19 Posts
As long as you stay within certain limits, a lot of this stuff just doesn't matter much. For me, the difficulty is knowing when I get close to those limits. With that in mind, wide tires are simply much more forgiving.

Case in point: fat tires run at significantly lower pressure than thin ones. Therefore when punctured the air leaks out of a fat tire at a slower rate than out of a thin one. Furthermore, there's a lot more air in a fat tire than in a thin one. So when a fat tire is punctured, more time and distance goes by before you notice anything wrong. All that's very nice. But even so, there comes a time when so much air had been lost that handling deteriorates, and at that point the shin hits the fan.

Until that point, the relative widths of tire and rim aren't really critical to anything. Even so, I'm sure there's a point where a wide rim supports a squishy tire better than a narrow one. I hope I never find out the hard way!

Last edited by rhm; 07-26-19 at 07:03 PM.
rhm is offline  
Old 07-29-19, 10:36 AM
  #34  
ThermionicScott 
hungry
Thread Starter
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 18,862

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers)

Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 2214 Post(s)
Liked 201 Times in 161 Posts
Originally Posted by Ferrouscious View Post
From the man himself...
Note the date that was posted.

I find no virtue in clinging to one's original beliefs until death. It takes humility and courage to keep looking at an issue and asking oneself "What if I was wrong? What is the actual truth?" That's the basis of Jan's whole "journey of discovery" blog posts. "What if our assumptions were wrong? What would be better?" It's debatable whether he always lands in the right place , but this stuff tickles my brain to no end.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 07-29-19, 11:00 AM
  #35  
ThermionicScott 
hungry
Thread Starter
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 18,862

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers)

Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 2214 Post(s)
Liked 201 Times in 161 Posts
Originally Posted by Miele Man View Post
I had some Schwalbe Pro CX Pro cyclo-cross tires mounted on narrow rims. All was well until I punctured the FRONT tire. Down I went. the entire tire stayed on the rim. This happened on two different occasions and I went down both times. Fortunately I was riding quite slowly each time. I figured that the risk of a crash in heavy traffic was too great to continue using that combination of 30mm tires on those narrow rims. I replaced those tires with 25mm tires and will put the Schwalbe CX Pro 30mm tires onto wider rims. I will NOT risk a front tire flat throwing me into heavy traffic. YMMV but it's definitely something to consider. What happens if a front tire flats and causes you to spill as you're sprinting through a left turn with oncoming traffic or you spill in some other traffic gap because your front tire flatted and then the front wheel immediately went out from under you? When my CX Pro front tire flatted I went down IMMEDIATELY with no warning at all.

I recommend that if you insist on riding a wide tire on a narrow rim that you take the bike and your pump to a school yard or a quiet parking lot and let most of the air out of the tire and see if you can maintain control on it. I know with the CX Pro tire on the narrow rims I had them on there was immediate loss of control if the front tire flatted or went very soft.

Cheers.
So you haven't actually confirmed your hypothesis yet. It's also very possible that a 30mm tire simply has more ability to wallow when flat than a 25, and that the rim width might not make a significant difference. I'll be interested in how your testing goes.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 07-29-19, 11:14 AM
  #36  
Miele Man
Senior Member
 
Join Date: Jun 2014
Location: Ontario, Canada
Posts: 2,087

Bikes: Miele Latina, Miele Suprema, Miele Uno SL, Miele MTB, Bianchi Model Unknown, Fiori Venezia, VeloSport Adamas AX

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 314 Post(s)
Liked 35 Times in 29 Posts
Originally Posted by ThermionicScott View Post
So you haven't actually confirmed your hypothesis yet. It's also very possible that a 30mm tire simply has more ability to wallow when flat than a 25, and that the rim width might not make a significant difference. I'll be interested in how your testing goes.
Actually this was confirmed BEFORE I switched to the narrow rims. Those exact same tires used to be on wider rims and did NOT cause a wipeout when a front tire flatted.

Cheers
Miele Man is online now  
Old 07-29-19, 11:32 AM
  #37  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 7,127

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 94 Post(s)
Tagged: 0 Thread(s)
Quoted: 1748 Post(s)
Likes: 0
Liked 145 Times in 106 Posts
Threads like this remind me why I want to go back to tubulars. $$ vs skin. And now my all-time favorite tread is back. I can get tubulars with the super-sweet ride and synthetic casings that laugh at getting wet. (That tread - ribbed. Fine longitudinal ribs. The best tread for climbing out of ruts, cracks and back onto the pavement. Very good corning, Quite decent in the rain. A great all-around tread that is extremely good at keeping you upright. Why it disappeared for 20 years is completely beyond me.)

I've been riding the Vittoria G+ tires in 28c on skinny ribs. Love 'em. Ribbed tread. Grippy tread. Fast. They do flat from picking up objects. (Around Portland, OR, tire wire and small thorns. I suspect their tubulars do the same. I'll try sealant and a spare under the seat. If that works, I get: the supple casings, fast, grippy tread and the ribs I love plus a tire that can flat at any speed without issues. Tires to keep this old body with far too many crashes on it off the tarmac. And yes, I will have $200 glued and strapped on the bike. Perspective - that bike has a ti stem post and frame. $200 is play money. And every time I go to bed and have to arrange the foam pads around my old injuries - well $200 so I don't have to cut out a new foam pad for the latest?) I'll have to go back to the ritual of gluing tires. Tubasti! And I get to ride the magic carpets again. (It will be the first time I will have been able to do an A-B comparison of clincher and tubular since Vittoria's G tires share the same tread and casing. Also get to see if the old bump at the valve that nearly all tubulars had is still there. Tubulars at least used to be made like real magic carpets, by hand by artisans in Italy as opposed to artisans in Persia.)

Saturday I had the chance to pull the trigger on a $150 Campagnolo Veloce wheelset (with skewers, tires, wheel bag but no cassette) for $150. He'd probably take $125. Have his phone number. Do I? Getting tempted.

Ben
79pmooney is offline  
Old 07-29-19, 11:39 AM
  #38  
ThermionicScott 
hungry
Thread Starter
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 18,862

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers)

Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 2214 Post(s)
Liked 201 Times in 161 Posts
Originally Posted by Miele Man View Post
Actually this was confirmed BEFORE I switched to the narrow rims. Those exact same tires used to be on wider rims and did NOT cause a wipeout when a front tire flatted.

Cheers
Aha, good important data there.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 07-29-19, 11:41 AM
  #39  
ThermionicScott 
hungry
Thread Starter
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 18,862

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers)

Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 2214 Post(s)
Liked 201 Times in 161 Posts
Originally Posted by 79pmooney View Post
Threads like this remind me why I want to go back to tubulars.

Saturday I had the chance to pull the trigger on a $150 Campagnolo Veloce wheelset (with skewers, tires, wheel bag but no cassette) for $150. He'd probably take $125. Have his phone number. Do I? Getting tempted.

Ben
You've been talking about it long enough. Do it.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498

Last edited by ThermionicScott; 07-29-19 at 11:48 AM.
ThermionicScott is offline  

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

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.