http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense en-US Wed, 30 May 2012 01:17:04 +0000 http://bbpress.org/?v=1.0.2 q http://singletrackworld.com/forum/search.php http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117813 Tue, 09 Feb 2010 17:12:28 +0000 GEDA 1117813@http://singletrackworld.com/forum/ <p>This is a picture of my 29er. It is fast on the flat and just seems to keep going. In the snow it was 100% better than my 26 mountain bike as it just seems to grip. </p> <p>Handles like a gate though. </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117792 Tue, 09 Feb 2010 17:07:52 +0000 HTTP404 1117792@http://singletrackworld.com/forum/ <p><blockquote>then why does no one make a 32&quot; wheel</blockquote></p> <p>There&#39;s an optimum length for the wheelbase otherwise the bike would handle like a barge. Would have thought 29in wheels would be the max you could fit without having to stretch out that wheelbase.<br /> Other problems would be toe overlap - esp. on smaller frame sizes.<br /> Big wheels roll better - but given that people don&#39;t ride in straight lines and ride at variable speeds over different kinds of terrain it becomes a bit more complicated than bigger is better. </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117759 Tue, 09 Feb 2010 17:00:17 +0000 poppa 1117759@http://singletrackworld.com/forum/ <p>Well... work done = force * distance</p> <p>I&#39;m pretty sure it ends up being more energy for the big wheeled case...</p> <p> <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_confused.gif" title=":?" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117740 Tue, 09 Feb 2010 16:55:48 +0000 hilldodger 1117740@http://singletrackworld.com/forum/ <p><em>Its still a crap explanation form me and I do apologise for that. 4 hrs sleep in 36 </em></p> <p>TJ, I understand the gist of the explanation OK.<br /> It&#39;s just that the cycnical side of me just sees 29&quot; wheels/tyres/forks/framesets as an added retail opportunity rather than an appreciable advance in bike ergonomics <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_wink.gif" title=":wink:" class="bb_smilies" alt=""/> </p> <p>If it was that obvious surely someoine would have &#39;come up with it&#39; a bit sooner ?? </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117731 Tue, 09 Feb 2010 16:54:05 +0000 simonfbarnes 1117731@http://singletrackworld.com/forum/ <p><blockquote>Well, if your 26&quot; wheel is travelling the same vertical distance over a shorter period of time, it is being accelerated quicker, hence the vertical force is greater.</p> <p>And where does the energy come from that lifts the bike vertically over this bump? Well, that would be your kinetic energy you have due to your rolling speed. Therefore, you should lose less kinetic energy if your wheels are bigger, all else being equal.</blockquote></p> <p>except you forgot that the lower force is exerted for longer with the bigger wheel so magically the energy is the same, conservation of energy holds and perpetual motion machines still can&#39;t be made <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_smile.gif" title=":)" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117727 Tue, 09 Feb 2010 16:53:54 +0000 rootes1 1117727@http://singletrackworld.com/forum/ <p>i only bought a 29er as i&#39;m tall and wanted a bike where the wheels looked in proportion to the frame - sort of a scaled up average 26er 17&quot; but in a 21&quot; size</p> <p>d not care about the other arguments </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117669 Tue, 09 Feb 2010 16:39:07 +0000 MidlandTrailquestsGraham 1117669@http://singletrackworld.com/forum/ <p>I don&#39;t get why it&#39;s always 26&quot; v 29&quot; in these arguments.<br /> Surely, if 26&quot; is better than 29&quot;, then 24&quot; would be even betterer.<br /> And if 29&quot; is better than 26&quot;, then why does no one make a 32&quot; wheel ?</p> <p>Or maybe, just maybe, different bikes suit different riders and there is no &quot;better&quot;. </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117664 Tue, 09 Feb 2010 16:37:50 +0000 cynic-al 1117664@http://singletrackworld.com/forum/ <p>I can see teh argument - it&#39;s about the backwards force on the wheel when it his the 2&quot; bar, but Shirley there&#39;s payback when the wheel goes over the other side?</p> <p>May I also thank petesgaff for his stunningly witty, original and relevant post - I respond in kind. </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense/page/2#post-1117646 Tue, 09 Feb 2010 16:33:46 +0000 Spankmonkey 1117646@http://singletrackworld.com/forum/ <p>I think this is the vid mentioned, </p> <p><a href="http://www.youtube.com/watch?v=fYt6IqaHk_Q" rel="nofollow">http://www.youtube.com/watch?v=fYt6IqaHk_Q</a> </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117627 Tue, 09 Feb 2010 16:30:41 +0000 poppa 1117627@http://singletrackworld.com/forum/ <p>Consider both a 26&quot; wheel and a 29&quot; wheel rolling over a small bump. </p> <p>They both have to move by the same vertical distance to roll over the bump.</p> <p>BUT... the large wheel posesses a shallower rolling angle with respect to the bump, and contacts the bump earlier than the 26&quot; wheel would, and ceases contact with the bump later than the 26&quot; wheel would.</p> <p>Therefore although the wheel travels over the same vertical distance, it does so over a shorter period of time in the case of the 26&quot; wheel. In other words, the vertical acceleration force is greater.</p> <p>Now, remember that force = mass times acceleration?</p> <p>Well, if your 26&quot; wheel is travelling the same vertical distance over a shorter period of time, it is being accelerated quicker, hence the vertical force is greater.</p> <p>And where does the energy come from that lifts the bike vertically over this bump? Well, that would be your kinetic energy you have due to your rolling speed. Therefore, you should lose less kinetic energy if your wheels are bigger, all else being equal.</p> <p>This is all armchair science, so feel free to disprove. Just my tuppence worth.</p> <p>P.S. I think this should hold even if you consider that for the 26&quot; case you have greater force acting over a smaller time - the force increases more than the time decreases if you get what I mean.</p> <p>EDIT - Short version: Wot TJ said. </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117603 Tue, 09 Feb 2010 16:25:30 +0000 himupstairs 1117603@http://singletrackworld.com/forum/ <p>&#39;I think the OP was predicting the outcome of this thread by the chosen title.&#39;</p> <p>and so we have a winner! </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117598 Tue, 09 Feb 2010 16:24:28 +0000 futon river crossing 1117598@http://singletrackworld.com/forum/ <p>Bigger wheels roll better than smaller ones - fact. </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117575 Tue, 09 Feb 2010 16:19:52 +0000 WackoAK 1117575@http://singletrackworld.com/forum/ <p>I think the OP was predicting the outcome of this thread by the chosen title. </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117572 Tue, 09 Feb 2010 16:19:27 +0000 TandemJeremy 1117572@http://singletrackworld.com/forum/ <p>Hilldodger - yes I think you will be right - you are talking slight differences between the two MTB wheel sizes. Its just easier to see the effects when you exaggerate the wheel sizes.</p> <p>Its really much more complex because in a perfect world with a single symmetrical bump you would all the energy that has gone ito changing direction would be changed again ito forward motion on the downside of the bump. However as there are inefficiencies in any system in the real world the greater the change of direction the greater the inefficiencies.</p> <p>Its still a crap explanation form me and I do apologise for that. 4 hrs sleep in 36 </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117569 Tue, 09 Feb 2010 16:18:32 +0000 votchy 1117569@http://singletrackworld.com/forum/ <p>But there is no mention of the silly trousers, red nose, water squirting flower and the fire engine driven by dwarves with buckets of shredded paper associated with 29er bikes <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_biggrin.gif" title=":D" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117560 Tue, 09 Feb 2010 16:15:53 +0000 Stoner 1117560@http://singletrackworld.com/forum/ <p>hd - proportionate geometrical differences between the wheels is indeed quite small, but in the real world, the difference in rolling behaviour is quite noticeable.</p> <p>Ever seen the footage of the guy riding the 36er up a long flight of steps without any dougie lamkin skillz? <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_wink.gif" title=";)" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117554 Tue, 09 Feb 2010 16:14:44 +0000 The Pinkster 1117554@http://singletrackworld.com/forum/ <p><blockquote>29rs make you ride like a trail god.............fact.<br /> </blockquote><br /> Why do I need to ride <em>like</em> a trail god when I already am one on 26er? </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117544 Tue, 09 Feb 2010 16:12:23 +0000 hilldodger 1117544@http://singletrackworld.com/forum/ <p>But isn&#39;t the point that we&#39;re talking a &quot;quite big wheel&quot; vs a &quot;slightly bigger wheel&quot;<br /> I&#39;m sure there&#39;s mathemtical differences but for normally proportioned riders under most conditions I would doubt there&#39;s much of a practical difference </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117541 Tue, 09 Feb 2010 16:11:34 +0000 hungry monkey 1117541@http://singletrackworld.com/forum/ <p><blockquote>That&#39;s a slightly bigger difference in diameters than 26&quot; to 29&quot; though.... </blockquote></p> <p>but its the same principal.</p> <p>29ers are ace: FACT</p> <p>(i&#39;ve got a 26&quot;, a 29&quot; and a 700c) </p> http://singletrackworld.com/forum/topic/absoludicrous-pile-of-nonsense#post-1117536 Tue, 09 Feb 2010 16:09:47 +0000 TandemJeremy 1117536@http://singletrackworld.com/forum/ <p>Al - its hard to explain and I know we have reached impasse before trying to discuss vectors in text. Its about the change in direction of the wheel travel Imagine the path that the axle takes - a big wheel will have less sharp change in direction that a small wheel. changing direction takes energy. going over a 2 &quot; bump both wheels rise two inches. The smaller one does this over a shorter distance so the angle thru which the direction alters is greater - or you can considr it as the rate of change of height is greater.</p> <p>This is were the inefficiency comes from. </p>