Results 76 to 100 of 579
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07-06-2015, 11:47 AM #76
Look, you're pretty badly misinformed about this topic, and I really don't have time to explain the physics / mechanics of it to you.
If you're riding around with underinflated tires, well, you're slow.
On a side note, there have been MILLIONS UPON MILLIONS of mountain bikes built, sold and ridden with rims having an 18mm or under internal width, over the last 25 years. World championships were won on those rims. In fact, probably the vast majority of mountain bikes *ever* built costing over $500, have had rims under 20mm internal.
Last edited by Damian Sanders; 07-06-2015 at 12:14 PM.
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07-06-2015, 12:17 PM #77
You are the one who is misinformed and doesn't understand why wider rims are better. Just because something was done in the past doesn't mean it was better. If that were the case he'd all be riding fully rigid or hardtail bikes with 26" wheels. There is a lot of science behind why a wider rim is better on any type of bicycle wheel, this is especially true for tubeless. Just because you say it's so doesn't make it true. Try and find an article that explains(scientifically) why a narrow rim is better. If you google"why are narrow bicycle rims better" you get pages of articles by manufactures and bloggers/experts that explain why wide rims are better and none that extol the virtues of narrower rims.
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07-06-2015, 12:17 PM #78
Oh and as another side note, I ran 2.5" DHF's ghetto tubeless on XM719's for several years. Not problems at all when properly inflated.
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07-06-2015, 12:25 PM #79
Oh, I ran 2.35" Ritchie WCS Zeds on Deetz rims( a resized Mavic MA-2) and didn't have any problems. When I switched to a wider rim I noticed a big difference in performance. That's anecdotal, same as your post. There's science behind why wider rims and tires are better.
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07-06-2015, 12:43 PM #80
You're clearly regurgitating industry marketing and internet forum pseudo-science, and aren't even making a coherent arguement. Go back to MTBR.
I said in the FIRST POST OF THE THREAD that I'm running a 25mm internal width rim with 2.3" tires - that's actually a rim that is MORE than wide enough for the tire. It's also a tubeless profile rim with a tubeless ready tire.
Over the last 20 years the vast majority of 2.3" to 2.5" tires have been run on rims in the 21mm to 23mm internal width range. PERIOD.
Here's an actual article advising PROPER tire vs. rim sizing, from 2011:
http://www.pinkbike.com/u/richardcun...res-Burp-.html
They show tire distortion acurately, and address the REAL issue here - tire burping with tubeless. Wide rims do NOTHING to prevent pinch flats, and tire stability comes mainly from actual tire pressure. If you're letting out enough air to reduce stablity, you're also going to have a problem with pinch flats.
15 years ago racing downhill, I ran 2.5" 2-ply michelins on rhyno lites with 500g motocross tubes, at roughly 15 to 18 psi. Rims dented a bit but the tubes didn't flat. Tires stuck like glue. Very few problems with tires rolling off the rim. Rhyno lites are about 23mm internal. The reason it worked at low pressures was that the sidewall was actually very stiff, along with the tube, and could not be folded over easily.
Norm from Pinkbike: In terms of DH application of this theory it demands a balancing point to be achieved with rider preference there is too wide and too narrow. Yes a wider rim means a flatter profile. And yes that gives you good straight line traction. BUT it doesn't always mean better cornering traction. At high speed you will do 2 things when leaning a bike in to a turn with a tire that has a flat lateral profile. 1 you will have a reduced range of angle in relationship to to the surface the tire is on do to the flatter profile having less roll. Now for those of you who would say well i doubt many people achieve that kind of lean in a corner well fine there is my 2nd point to come. 2 With a flatter profile the tire will break traction much harsher under hard cornering because its like winding up a spring. with the "improved" traction at a now more limited angle of attack you are going to break traction latter once you have built up more energy in the side wall of the tire which makes it a less predictable and much harsher break-away-point. With all that said there is a reason that Dirt Bikes have a rounded profiles to there tires and they have offroad racing history all the way back to the 60's. Do they really think they have figured something out that motocross hasn't already.Last edited by Damian Sanders; 07-06-2015 at 01:14 PM.
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07-06-2015, 02:13 PM #81
So you link to an article that says wider rims are better? It also talks about Bontrager cutting down rims and how that was the genesis for narrow rims, what I said and have know since the early 90s. I had some of those rims and Deetz rims. The linked article also talks about dramatic increase in stability with wider rims and has a paragraph about why narrow rims and high volume tire are a bad idea. You're not too bright if that's how you defend your stance.
You're cut and pasted part is talking about extremes and rider preference, that is totally subjective and not what that linked article is even about. Even in the picture of the same tire on a wide and narrow rim the tire profile isn't rounded off, it's hardly changed. Every thing covered in that article is the exact opposite of what you're saying with the exception of "burping" for tubeless tires, which wider rims helps.
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07-06-2015, 02:22 PM #82
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07-06-2015, 02:25 PM #83
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07-06-2015, 02:41 PM #84
I too have run 2.5 or even 2.7 tires on "narrow" rims back in the day. It worked. I don't know if anyone is arguing that you *can* do it. What we are arguing is there is an *advantage* to a wider rim profile.
In the last 12 months I've run various tires of the 2.25-2.4 width on rims that varied from 23mm to 35mm (internal). I'm currently on a set of prototype rims with an internal width just shy of 30mm.
Guess what? I have more traction out of a smaller (and lighter) tire with less aggressive casing on the 30mm rims than the 23mm rims. This is a win to me. Sure I could run narrow rims with a wider DH casing tire and a tube (as you alluded to) and get similar results. But don't you see running smaller tires with less aggressive casing is adventagous?
The reason behind this is simple - a shorter sidewall is stouter. Or rather there is less leverage on it. It works. Try it! Watch an old 60s jeep with giant narrow rubber go through a corner. Now watch a sportscar with very little rubber height go through the same corner. There is less sidewall squirm rubbers all kept the same.
Sure if you go too wide you get weird tire profiles which is more a byproduct of tire companies lagging in this game than anything. And yeah, if we go way too wide your sidewall will be so tiny you'll be bouncing off your rim all the time... its a balance for sure. One I suggest we defer to motocross for what makes most sense.
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07-06-2015, 02:55 PM #85
The ultimate in future cornering technology
I mean hell look at fat bike tires. They're already losing tread.
I'm with JJ. Leaning in turns has no place in mountain biking. That's why the national average on built up berms is on the rise. Leaning is hard.Besides the comet that killed the dinosaurs nothing has destroyed a species faster than entitled white people.-ajp
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07-06-2015, 02:57 PM #86
Lets go back and try to figure out just what you are saying......
Yes, anyone who has worked in a bike shop, or read sheldon browns website, or has any sort of CLUE about bikes knows this. You are not a special flower.
Actually, no. Modern 559mm BSD wheels originated with ADULT schwinn utility / cruiser bikes in 1933:
https://www.google.com/search?q=Schw...Wk8LDsm-zuM%3A
In fact, they were one of the earliest if not the first clincher rim/tire in the country.
Yay. You can put wide tires on a CX bike. Who cares. Oh, 2.25" is too wide a tire for 29er's? Boohoo. 29er's suck anyway.
ALSO - FOR THE LAST TIME, PUTTING A NARROWER TIRE ON AN EXCESSIVELY WIDE RIM IS A CURRENT, STUPID, INDUSTRY AND INTERNET POSER FAD THAT IS GOING ON AND IS NOT GOING TO WORK FOR ACTUAL RIDING AND CORNERING ABOVE THE SLOW INTERMEDIATE LEVEL.
NO, THEY WON'T MAKE A TIRE ANY LESS PRONE TO PINCH FLATS.
MAYBE YOU DON'T CORNER HARD.
https://www.google.com/#q=maxxis+ardent&safe=active
IF YOU'RE ADVOCATING TAKING A 30MM INTERNAL WIDTH RIM AND PUTTING A CURRENT DESIGN 2.25" TIRE ON IT, YOU ARE AN IDIOT.Last edited by Damian Sanders; 07-06-2015 at 04:15 PM.
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07-06-2015, 02:59 PM #87
No, you can't read.
I also CLEARLY stated that I have gone from a 2.5" tire on an 19mm internal rim, to a 2.3" tire on a 25mm internal - because it does give a (slightly) more stable tire, which is a performance improvement. HOWEVER, I still run around 30psi+ so I don't pinch flat the tire and bend the rim. HOWEVER, the rim is about the max width that the tire was actually designed for.Last edited by Damian Sanders; 07-06-2015 at 03:41 PM.
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07-06-2015, 03:04 PM #88Besides the comet that killed the dinosaurs nothing has destroyed a species faster than entitled white people.-ajp
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07-06-2015, 03:13 PM #89
Here is the best counter arguement to the wide rim trend -
Norm: In terms of DH application of this theory it demands a balancing point to be achieved with rider preference there is too wide and too narrow. Yes a wider rim means a flatter profile. And yes that gives you good straight line traction. BUT it doesn't always mean better cornering traction. At high speed you will do 2 things when leaning a bike in to a turn with a tire that has a flat lateral profile. 1 you will have a reduced range of angle in relationship to to the surface the tire is on do to the flatter profile having less roll. Now for those of you who would say well i doubt many people achieve that kind of lean in a corner well fine there is my 2nd point to come. 2 With a flatter profile the tire will break traction much harsher under hard cornering because its like winding up a spring. with the "improved" traction at a now more limited angle of attack you are going to break traction latter once you have built up more energy in the side wall of the tire which makes it a less predictable and much harsher break-away-point. With all that said there is a reason that Dirt Bikes have a rounded profiles to there tires and they have offroad racing history all the way back to the 60's. Do they really think they have figured something out that motocross hasn't already.
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07-06-2015, 03:43 PM #90
All I know is I've been running mavic 819 rims for around 10 years and have been running a Maxxis 2.4 High Roller II in front and a 2.3 in the back, tubeless 30PSI front and back, any lower PSI I would have problems. I've been happy as a clam with this setup though.
I built up a new 27.5 Derby wheelset (40mm wide) not long ago for a frame I have on order, just for grins I tossed the Derby front wheel on on current bike (Same tire). Holy shit what a difference, I'm also running 5 PSI lower with no issues, have to say I'm sold on the wider rims.
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07-06-2015, 03:48 PM #91
Your point is noted. However...
"At high speed you will do 2 things when leaning a bike in to a turn with a tire that has a flat lateral profile. 1 you will have a reduced range of angle in relationship to to the surface the tire is on do to the flatter profile having less roll"
In extreme cases you are right. But remember we are slightly altering the profile/shape/sidewall height. And in my experience it works better.
"With a flatter profile the tire will break traction much harsher under hard cornering because its like winding up a spring. with the "improved" traction at a now more limited angle of attack you are going to break traction latter once you have built up more energy in the side wall of the tire which makes it a less predictable and much harsher break-away-point"
The break away point is actually *more* predictable for me. as there isn't the "squirm" "roll" component to deal with which is akin to a noodly pair of skis at speed.
Again, its all about wide - but going wide in moderation.
Also, dirt bikes have a much wider rim to tire ratio compared to mountain bikes. #justsayin
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07-06-2015, 04:07 PM #92
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07-06-2015, 04:24 PM #93
So what is the title of the article you linked? I read it as "Wider Rims are Better and Why Tubeless Tires Burp Air" is that not the title? I can read just fine. You can't admit that you're wrong and that what you are talking about is personal preference. Again the blurb you cut and pasted is talking about extremes, but still acknowledging that a wider rim is generally better. I'm done, clearly you can't or won't comprehend what a lot of folks, both riders and industry people, can clearly see. It's like arguing with a retard or a five year old.
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07-06-2015, 04:39 PM #94
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07-06-2015, 05:02 PM #95
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07-06-2015, 05:15 PM #96
Split, kook.
I cited an article that advocates using rims that are in the wider side of the RECOMMENDED range for a tire's ETRTO, when running tubeless:
You're saying that it would make sense to use a rim wider than the recommended range for a tire - a current foolish industry trend.Last edited by Damian Sanders; 07-06-2015 at 05:31 PM.
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07-06-2015, 05:29 PM #97
Yeah, but are wide rims 'Race Stock'?
Forum Cross Pollinator, gratuitously strident
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07-06-2015, 05:34 PM #98
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07-06-2015, 05:43 PM #99
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07-06-2015, 05:48 PM #100
I said wider, not 30-35 mm rim. How does it feel to be so stupid?
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