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  1. #51
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    Quote Originally Posted by Fit4Life View Post
    At 180 lbs, I've found the best combination is 23mm front and 25mm rear.
    120 lbs here and I use 23mm soft tire up front and 25mm harder tire rear, too. 23mm tire with a triangular profile up front makes the bike turn in sharply, and 25mm out back for longevity. For all the talk about science and rolling resistance, not many folks think about using a different front/rear combo for maximum performance. Do Motogp bikes use the same tire for front and rear? No.

  2. #52
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    Quote Originally Posted by aclinjury View Post
    120 lbs here and I use 23mm soft tire up front and 25mm harder tire rear, too. 23mm tire with a triangular profile up front makes the bike turn in sharply, and 25mm out back for longevity. For all the talk about science and rolling resistance, not many folks think about using a different front/rear combo for maximum performance. Do Motogp bikes use the same tire for front and rear? No.
    That's not even apples to oranges, it's more like apples to steaks.
    I work for some bike racers
    I've got some bikes, some guns,
    and a bunch of skateboards

  3. #53
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    Quote Originally Posted by cxwrench View Post
    That's not even apples to oranges, it's more like apples to steaks.

    More like apples to bologna.
    “Statistics are like bikinis. What they reveal is suggestive, but what they conceal is vital.” -- Aaron Levenstein

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  4. #54
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    Quote Originally Posted by bas View Post
    What happened? I've been riding 23mm since like 2002, and 25mm was for heavier people, now new Trek Bikes come with 28mm ?

    What did I miss being out of touch for so long?

    (2003 Trek Madone 5.2)
    Hi.
    Things change. That is the only constant in the universe. "Change"

    There is a Swiss company that posted the spread sheets of rolling resistance a while back. I read the data and it made sense. This was done For different tires and widths of the same tires. I believe they did this on their own. As an independent party.
    What has become common knowledge is the fact that there is a correlation between your tire width, the tire pressure and rolling resistance.
    In a nut shell.
    While rolling on a road where the surface is irregular there are power losses due to loss of contact of the tire with the road. This loss of contact is due to the irregularities pushing the tire up against gravity.
    The higher the pressure on the tires the more accentuated this effect becomes.
    The old argument was that since you had less surface contact because the tire was thinner you will have less rolling resistance. This holds true for smooth surfaces like an indoor velodrome where the surface is polished regularly.
    On the road is different. The increase contact surface of the tire allows for lower tire pressures. This turns into the tire being able to suck up the micro bumps better, leading to less traction loss from bouncing. Understand this is micro bouncing. It becomes significant after many miles or hours on the bike.
    At some point the wider the tire is, the more losses due to Increased contact surface will increase to the point of the losses being higher that the losses due to micro loss of traction. This holds true for a mountain bike tire and so on.
    Another factor to consider is tire weight. The wider the tire the heavier the tire due to more material being used. Weight will add rolling resistance in the form of more mass to move.
    In addition , rider weight is a big factor here as well. The heavier the rider the more tire deflection. I believe 15% deflection is the max amount for good tire operation before you start messing the sidewalk thread.
    For me @200lbs I was running 23F/25B at 90psi/95psi. Contis 4000S. This worked for me. The ride felt suppler and more comfy.
    Could I tell the difference? Other than felling more cushy and comfortable I don't know if I was going faster with that setup. I believe the gains are there based on te studies, but we are unable to feel them physiologically.



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  5. #55
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    Quote Originally Posted by cxwrench View Post
    That's not even apples to oranges, it's more like apples to steaks.
    idk man, i think it's steak to beef jerkey

  6. #56
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    My 2007 Synapse came with 23 tires. I used them for many tire changes. When I switched to 25's at 90 rear 80 front the ride improved tremendously. I felt like the bike had a suspension put on it. I wish I had made the switch years ago. Never going back to 23's.

  7. #57
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    The following video summarizes much of the relevant science I use in wheel design:
    https://www.google.com/url?sa=t&rct=...dCWjrjjcAR51Fw
    Hey everybody, ride my wheels! They ride good, real good.
    I'm a wheel builder. SRLPE Wheel Works. Send me a PM.

  8. #58
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    Quote Originally Posted by 4slomo View Post
    The following video summarizes much of the relevant science I use in wheel design:
    https://www.google.com/url?sa=t&rct=...dCWjrjjcAR51Fw
    Interesting. So in the end it seems the biggest wattage gains to be made are in tire compounds and rim/tire combo. Weight made no difference and tire width and tire aerodynamics made negligible difference. Too high pressure is just as bad as too low pressure.
    “Statistics are like bikinis. What they reveal is suggestive, but what they conceal is vital.” -- Aaron Levenstein

    "Beware of geeks bearing formulas."
    -- Warren Buffett

    "Education is what you get when you read the fine print. Experience is what you get when you don't. -- Pete Seeger



  9. #59
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    Quote Originally Posted by 4slomo View Post
    The following video summarizes much of the relevant science I use in wheel design:
    https://www.google.com/url?sa=t&rct=...dCWjrjjcAR51Fw
    The video was very good. I never thought that the worn out tire will need more watts from wind resistance.
    Interesting how up to 100 grams of added weight on the tire are negligible for acceleration. And based on his computation of optimal psi I should be running 100. That is what I do.
    Thanks for sharing.


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  10. #60
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    Quote Originally Posted by 4slomo View Post
    The following video summarizes much of the relevant science I use in wheel design:
    https://www.google.com/url?sa=t&rct=...dCWjrjjcAR51Fw
    Great video. However it seems to leave room for each person to hear what they want to hear when it comes to tire pressure. 100psi or so is best, but then so is running super low pressure over cobbles, to the point where your rim bangs on the pavement once in a while. It made me think that on a typical ride that takes me over a variety of pavements, I'm sometimes too low, sometimes too high, and sometimes about right.

    Over time I've moved to lower psi (60 to 80 range on 25 or 28mm ties) because it feels good and makes my riding more fun. After seeing the video I suspect I often lose Watts to low psi, but since I'm not a racer I'm not worried about it.

    Wondering about worn tires, too. The video says a flat profile costs a little power. But I know I'm not alone in liking the feel of worn tires. Could it be that the flatter profile is more than compensated by less hysteresis loss?

  11. #61
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    Quote Originally Posted by bobf View Post

    Wondering about worn tires, too. The video says a flat profile costs a little power. But I know I'm not alone in liking the feel of worn tires. Could it be that the flatter profile is more than compensated by less hysteresis loss?
    I was thinking the same thing. I've had some worn tires that "felt" pretty fast compared to newly installed tires. I do seem to remember someone doing a rr test on a new and worn Conti gp and finding that the worn tire did roll easier. I'll see if I can find that.

  12. #62
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    Quote Originally Posted by dcb View Post
    I was thinking the same thing. I've had some worn tires that "felt" pretty fast compared to newly installed tires. I do seem to remember someone doing a rr test on a new and worn Conti gp and finding that the worn tire did roll easier. I'll see if I can find that.
    Every time I install a new tire, it's never quite round and it takes a bit of time for some of the flatter portions to stretch out. Sometimes tires also ship with a coating to prevent the rubber from drying out. Michelin tires have this thick layer of wax on them out of the box and it's super annoying.

    Anyway fretting over all of this, you may as well start cutting the whiskers off new tires left over by the sprues/vents in the mold...or stop caring and ride a tire is known to be fast in roll-down tests.

  13. #63
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    Quote Originally Posted by ceugene View Post
    Anyway fretting over all of this, you may as well start cutting the whiskers off new tires left over by the sprues/vents in the mold...or stop caring and ride a tire is known to be fast in roll-down tests.
    I cut them off. They make an irritating noise rubbing on my frame. 25c rolls so nice but Conti 23c tires are the largest that will fit in my Fuji SST. I still need to let air out of the rear tire to remove it.

  14. #64
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    Dimension

    I am with the OP, first post. After 5 years and probably 4,000 miles at over 190lbs rider weight most of the time, some at 200 lbs, I finally broke my rear wheel. The aluminum rim fatigued and the nipple area cracked and Mr spoke poke through. New wheel or wheels time. The wheel set is an old Neuvation 28SL something. Really light, and up until it died, never trued or tightened. Ever, zero maintenance. New wheel time. It is thin, IIRC a 19 or 23mm rim width ? The labeling is long gone. To consider a wider more comfortable new wheel, I want to compare it to what I have now, what fits.

    Where exactly are we measuring the rim ? Exterior or interior or exactly what ? I have calipers, mocrometer etc. - thanks

  15. #65
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    Quote Originally Posted by skitorski View Post
    ...Where exactly are we measuring the rim ? Exterior or interior or exactly what ? I have calipers, mocrometer etc. - thanks
    Both. The inside width is what determines tire width but both are often given by the manufacturer. The difference between inner and outer width is much greater on carbon rims.

  16. #66
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    Quote Originally Posted by skitorski View Post
    I am with the OP, first post. After 5 years and probably 4,000 miles at over 190lbs rider weight most of the time, some at 200 lbs, I finally broke my rear wheel. The aluminum rim fatigued and the nipple area cracked and Mr spoke poke through. New wheel or wheels time. The wheel set is an old Neuvation 28SL something. Really light, and up until it died, never trued or tightened. Ever, zero maintenance. New wheel time. It is thin, IIRC a 19 or 23mm rim width ? The labeling is long gone. To consider a wider more comfortable new wheel, I want to compare it to what I have now, what fits.

    Where exactly are we measuring the rim ? Exterior or interior or exactly what ? I have calipers, mocrometer etc. - thanks
    You mean 40,000 miles right? Unless you ride very little like once or twice a week 4K miles in 5 years is very very little per week about 19 miles per week?
    If that is the case then those rims were weak or got rusted at the nipples from lack of use.
    I highly recommend prowheelbuilder from GA. I have got all my rims done with them. About 3 sets. My Reynolds assault SLG (old racing wheels at 1450gm set) have over 25k-30k miles in them and are still going strong. now they are my everyday wheels.
    There was a post here about a very light aluminum clincher at 29 deep I think. Prowheelbuilder has them. I think it was a start up or something. They have them rated at 4 out of 5 in strength. I might get a set in the future.
    They aré toroidal wide and at 465gm. Very light for an aluminum rim. That is if you want aluminum.
    I'm into custom made carbon wheels. The key is to find a strong rim. Now days most high en rims are pretty wide. But make sure you check the internal/external widths.
    Probikekit has a special on Reynolds at 1099 for the assault set shimano plus 5% off. That is a steal for this rims.
    Good luck


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  17. #67
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    Char, I have never heard of any wheels lasting that long. That is amazing. I might have had 6-7,000 miles. One year was about 2,500. Weekend rides. So I just estimated and my free map ride app got discontinued. But lots of impacts, road cracks, all kinds of badness. My weight, or mass if you prefer has to be a factor. Anyways, if I get 4-6,000 miles on the replacements I will be happy, and about 25 lbs lighter. So a "23" is a 23mm wide rim ////////////////////?????????????????????

    Exterior ????????????????????????????

    Should be a universal term.

    Both. The inside width is what determines tire width but both are often given by the manufacturer.
    This is what is confusing and misleading. So a "23" is wut ??

    If I order a 205/55/15 tire from anywhere in the world in any language and ship around the equator twice, I have a 100% chance it will fit my wheel and car. Bike wheel, still don't have a straight answer.

  18. #68
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    With Vittoria CX 23s at $26 why would I need to go wider?

    The last century I rode on them was a 4:35, last 6 off road. No worries.

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  19. #69
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    Mic'd the wheel. 0.748 inches 18.9 inches Maybe a little worn.

    OUTSIDE MEASUREMENT

    a "23" or "25" would be considerably wider.

  20. #70
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    Quote Originally Posted by skitorski View Post
    Char, I have never heard of any wheels lasting that long. That is amazing. I might have had 6-7,000 miles. One year was about 2,500. Weekend rides. So I just estimated and my free map ride app got discontinued. But lots of impacts, road cracks, all kinds of badness. My weight, or mass if you prefer has to be a factor. Anyways, if I get 4-6,000 miles on the replacements I will be happy, and about 25 lbs lighter. So a "23" is a 23mm wide rim ////////////////////?????????????????????

    Exterior ????????????????????????????

    Should be a universal term.



    This is what is confusing and misleading. So a "23" is wut ??

    If I order a 205/55/15 tire from anywhere in the world in any language and ship around the equator twice, I have a 100% chance it will fit my wheel and car. Bike wheel, still don't have a straight answer.
    Hahaha you are funny but right. Any rim with an external width of 23mm and up is good.
    Picture that the standard tires are 23mm width mostly so the tire will be flush with the rim. There won't be light bulb effect that creates drag.
    Some manufacturers are going all the way to 25mm with the new trends. Which should be nice. I installed a 25mm tire conti4000s yesterday and it is wider than the rim. Not by much but I might be going back to 23s.
    About wheels lasting that long I learned like you the hard way. After 1 factory stans, mavic cósmics , and zipp 404, all cracked and lasting less than a year I decided to go custom.
    Like I said on my post above, I use prowheelbuilder to build my rims. They have strength ratings for their rims, rider weight and will talk to you about how strong you want them if needed be.
    Yes my current carbon custom Reynolds have over 20k on them. 200 miles per week average x 52 for 3 years or more.
    High Spoke count, brass nipples, good spokes and strong rims are the key. I run 24F/28R when available. Right now the Reynolds SLG are 24/24. 28 was n/a with the new models. I use American classic hubs always.
    I paid 1400-1500 for them and it was worth it as you can see they have lasted a long time.
    I am going to dismantle my old training aluminum rims 19mm external width and get the American classic hubs and build another set of carbon wheels. I wish they would have Reynolds at prowheel but alas no luck.
    Brother, spend the money on a good set of hand made custom wheels with at least 24 spokes each. 28 in the Back is ideal for us 195-200lbs guys although I am good with the 24 so far.
    Let me know man I am happy to help.





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  21. #71
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    Quote Originally Posted by skitorski View Post
    I am with the OP, first post. After 5 years and probably 4,000 miles at over 190lbs rider weight most of the time, some at 200 lbs, I finally broke my rear wheel. The aluminum rim fatigued and the nipple area cracked and Mr spoke poke through. New wheel or wheels time. The wheel set is an old Neuvation 28SL something. Really light, and up until it died, never trued or tightened. Ever, zero maintenance. New wheel time. It is thin, IIRC a 19 or 23mm rim width ? The labeling is long gone. To consider a wider more comfortable new wheel, I want to compare it to what I have now, what fits.

    Where exactly are we measuring the rim ? Exterior or interior or exactly what ? I have calipers, mocrometer etc. - thanks
    You measure outside distance from flange to glance as exterior width and inside from flange to flange as interior width.


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  22. #72
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    Quote Originally Posted by skitorski View Post
    ... So a "23" is a 23mm wide rim ////////////////////?????????????????????

    Exterior ????????????????????????????

    Should be a universal term.



    This is what is confusing and misleading. So a "23" is wut ??...
    In the past manufacturers just gave the outer width dimension for rims. That is all anybody really cared about back then. 19mm was very common on lighter aero rims. People found through experimentation that if you mounted a particular tire on a wider rim the tire would be wider. This increases air volume which is really what supports the load. This allows you to run lower pressure than you would on the narrow rim. The manufacturers who are really at the forefront of this trend - HED is one - will give both the inner width and the outer width of their rims. The inner width is the one that is going to determine the inflated width of any given tire. Ideally in the end you want the outer width of the rim and tire to be the same or close to for best aerodynamics. You will only find the mounted outer width of the tire on a particular rim by mounting and measuring.

    For example I have HED Ardennes wheels that are 25mm outside and 21mm inside. I mounted Schwalbe One 23mm tires and they measure 25mm on these rims.

    I understand the desire for universality but the technology is in a period of change right now.

  23. #73
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    The Neugent wheels I am going to order are "24" exterior. I tried to post the schematic of his wheels but it 404's. So these are less expensive light weight alloys and will be substantially wider than my current "19". This is adding weight, in the rim and the tires but I am sure I will survive the 85g penalty. I don't ride hard or often or long enough on my $399 Bikes Direct with $700 in upgrades to justify throwing more $$ at this. So Mr Nugent says with his wheels almost anything is Ok. Here's a link . ..

    Specifications

    Thanks for the advice and information. Better than the industry does. The Vuelta site does not easily disclose the simple width of their wheels. What I was considering purchasing from them turns out to have a width of 19mm %$#@ I also have thought quite a bit over the softer is faster and I may even grudgingly agree on that. Sort of like comparing rolling a ball bearing and soft basketball on a glass surface and a gravel road. So I hope to find a little softer ride at 90 instead of 120 psi heh heh heh.

  24. #74
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    Quote Originally Posted by aclinjury View Post
    120 lbs here and I use 23mm soft tire up front and 25mm harder tire rear, too. 23mm tire with a triangular profile up front makes the bike turn in sharply, and 25mm out back for longevity. For all the talk about science and rolling resistance, not many folks think about using a different front/rear combo for maximum performance.
    You seem to assume everyone's definition of maximum performance is the same as yours and/or has the same bike geometry you do. No everyone is looking to increase or maximixe the turning sharpness of their bike.

  25. #75
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    Quote Originally Posted by skitorski View Post
    The Neugent wheels I am going to order are "24" exterior.


    Should be a noticeable improvement.

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