cynic-al en-US Sun, 12 Feb 2012 08:22:23 +0000 http://bbpress.org/?v=1.0.2 q http://singletrackworld.com/forum/search.php http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3482649 Sat, 11 Feb 2012 19:30:16 +0000 FraserCook 3482649@http://singletrackworld.com/forum/ <p>not much ice around today. muddy, but not stupidly muddy. Ground still a bit draggy. not too windy. sky grey. could be worse. Not really proper winter tho is it. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3448444 Wed, 01 Feb 2012 22:07:03 +0000 bigjim 3448444@http://singletrackworld.com/forum/ <p>So busy up there tonight, little clusters of lights all over the hills! Largely frozen solid, pistachio still liquid though. Bit icy but no major problems. Came back with a clean bike and bum, good stuff. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3445016 Wed, 01 Feb 2012 09:39:04 +0000 cake eater 3445016@http://singletrackworld.com/forum/ <p>Was up there last night. Great conditions, good mix of everything, hardpack, mud, ice and maybe some dust! Obviously cold in the open exposed bits where the wind was blowing. Great couple of hours. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3443502 Tue, 31 Jan 2012 19:00:55 +0000 redfordrider 3443502@http://singletrackworld.com/forum/ <p>Been up on the Pentland Hills for a run with the dog. Mostly frozen solid and probably good for riding. However, there are a couple of sheets of ice that could be a bit tricky. Might fit the Ice Spiker Pros on the 29er. <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/pentland-hills-thread/page/2#post-3435734 Sun, 29 Jan 2012 21:42:16 +0000 robgarrioch 3435734@http://singletrackworld.com/forum/ <p>Point of interest; took the offspring up white hill for a forage yesterday - man, there's some tree damage up there... aftermath of the new year gale I suppose. Them DH trails must be affected, though saw a bit of dirt ramping making use of a hefty pines bole. The big beeches that fell across the footpath that skirts the road next to scout camp had been sawn up though. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3434695 Sun, 29 Jan 2012 17:42:30 +0000 drookitmunter 3434695@http://singletrackworld.com/forum/ <p>I'm up in Aberfeldy for a few days but I'm normally available weekdays after 6 or weekends so let me know if there's anything I can help with.</p> <p>Drookit means soaked. Where I'm from (Elgin) Munter doesn't necessarily mean a woman - just a person who is a bit of a fanny and particularly ugly. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433417 Sun, 29 Jan 2012 01:50:03 +0000 bigjim 3433417@http://singletrackworld.com/forum/ <p><blockquote>As a foreigner in these parts can I ask what your user name means? </blockquote></p> <p>drookit to me means drowned/saturated, and munter is a bit of a derogatory term for a lass that is shall we say "no oil painting". I'm not sure they go together so I might have drookit wrong. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433300 Sat, 28 Jan 2012 23:27:43 +0000 stevenmenmuir 3433300@http://singletrackworld.com/forum/ <p>No fitba, we've got a bye this week, so Monday is good for me. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433291 Sat, 28 Jan 2012 23:24:40 +0000 TandemJeremy 3433291@http://singletrackworld.com/forum/ <p>Drookit - the rangers are being reorganised. I am awaiting them getting back to me with dates for trail repair days </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433286 Sat, 28 Jan 2012 23:22:24 +0000 couldashouldawoulda 3433286@http://singletrackworld.com/forum/ <p><blockquote>drookitmunter </blockquote></p> <p>Today's the day! Bloody perfect!</p> <p>As a foreigner in these parts can I ask what your user name means? </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433285 Sat, 28 Jan 2012 23:22:02 +0000 stevenmenmuir 3433285@http://singletrackworld.com/forum/ <p>Maybe Tuesday? Or Monday if fitba is canned. Just filled the flask with the last of the 2009 stuff. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433277 Sat, 28 Jan 2012 23:18:40 +0000 drookitmunter 3433277@http://singletrackworld.com/forum/ <p>I'm keen to help out with any repair work that needs done. I haven't up there in a couple months as it's in a pretty poor state, but normally up at least once a week. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433245 Sat, 28 Jan 2012 23:08:10 +0000 thebikechain 3433245@http://singletrackworld.com/forum/ <p>Was tempted tonight to keep riding up the hill but the lass had the tea and a bath on. She's the boss. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433236 Sat, 28 Jan 2012 23:05:44 +0000 couldashouldawoulda 3433236@http://singletrackworld.com/forum/ <p>Out tonight - proper crispy / crunchy almost everywhere I went. Just now trying to get blood flow restored to toes! </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433203 Sat, 28 Jan 2012 22:55:32 +0000 thebikechain 3433203@http://singletrackworld.com/forum/ <p>Steven - if it's icy, shout me. Will come. But not thursday.<br /> Bring some more of that SC n Bramble though. </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433155 Sat, 28 Jan 2012 22:35:31 +0000 stevenmenmuir 3433155@http://singletrackworld.com/forum/ <p>Set cold for a while. Maybe a frozen night ride this week, like old times <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_wink.gif" title=":wink:" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/pentland-hills-thread/page/2#post-3433047 Sat, 28 Jan 2012 22:00:22 +0000 pixelmix 3433047@http://singletrackworld.com/forum/ <p>As you would expect, crispy and icy today. Most mud on main routes is frozen, although Pistachio was still a bit mushy in places. Lots of smooth ice around to catch out the unwary. </p> <p>I've not ridden the Pentlands for a while but I did notice a lot of frozen tyre tracks around (presumably laid down in recent damp weeks) - certainly more noticeable than frozen footprints for example. </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/6#post-3421315 Wed, 25 Jan 2012 15:38:21 +0000 hock 3421315@http://singletrackworld.com/forum/ <p><blockquote>You are assuming that changing the weight of your wheels will have a greater effect than changing weight elsewhere, please explain why.</blockquote></p> <p>Hi Crikey,</p> <p>you answer a question with a counter-question, do you? </p> <p>I didn't assume anything in that post. I asked a simple question:<br /> Would you choose the lighter wheel or the lighter frame?</p> <p>If you care, give a simple answer to my question and we can take it from there.<br /> If you don't, keep arguing for the arguments sake.</p> <p>Cheers! </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/6#post-3419946 Wed, 25 Jan 2012 10:24:45 +0000 cynic-al 3419946@http://singletrackworld.com/forum/ <p>:glee: </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/6#post-3419888 Wed, 25 Jan 2012 10:10:23 +0000 bigsi 3419888@http://singletrackworld.com/forum/ <p>I'd just like to say that i no longer care whether it'll make a difference or not...... I'm just pleased to have my 1st 200 post thread. <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_redface.gif" title=":oops:" class="bb_smilies" alt=""/> </p> <p>Thanks to all that made it possible...... You know who you are <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_wink.gif" title=":wink:" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419867 Wed, 25 Jan 2012 10:07:03 +0000 TandemJeremy 3419867@http://singletrackworld.com/forum/ <p>two hundred! </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419858 Wed, 25 Jan 2012 10:05:47 +0000 bigsi 3419858@http://singletrackworld.com/forum/ <p>I think its about time for.........</p> <p><img src="http://www.motifake.com/image/demotivational-poster/small/1005/dedication-wrong-leave-internet-demotivational-poster-1272856078.gif"></p> <p> <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_lol.gif" title=":lol:" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419829 Wed, 25 Jan 2012 09:59:00 +0000 amedias 3419829@http://singletrackworld.com/forum/ <p>oh my god, are you lot still at it?</p> <p>the thread that keeps on giving.... </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419801 Wed, 25 Jan 2012 09:51:41 +0000 jameso 3419801@http://singletrackworld.com/forum/ <p><blockquote>In mountain biking you have at the most 8 inches of travel provided by the suspension plus 12 inches provided by your arms and legs effectively turning the entire bike into unsprung weight.</blockquote></p> <p>Fair point.. your body can't react as fast over repeated impacts in the way a damper can, so the whole bike's not really suspended in the same way. You want suspension to free your arms and legs to simply control / steer the bike, or pedal, more of the time. But you're right that a lighter bike is easier to hop and float over the trail too, it is unsprung then. Certainly is if it's a rigid bike.</p> <p>Lowering unsprung weight is probably more easy to show as a benefit than lowering wheel weight, as unlike the wheel weight point, it assumes the suspension is working ie you're not on the lab-conditions smooth surface. But it assumes you already have dampers and pivots that are sensitive enough to react faster if the wheel and swingarm is lighter (ie Propedal would cancel out a lot of that I think)</p> <p>A low pressure tyre deforming over a rock should reduce momentum less than a damper allowing the wheel to move over the rock, and certainly has less reduction in momentum that the impact lifting the weight of (a rigid, high pressure tyred) bike and rider over the rock. This is why a heavy fat-bike tyre can have suprisingly low rolling resistance - in this area it has super-low unsuspended mass - but it won't pedal up the hill so easily. </p> <p>This is why I think rolling resistance and grip / comfort are worth considering even at the expense of reduction in weight. There's a balance point somewhere but I won't pretend to understand the maths there. </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419733 Wed, 25 Jan 2012 09:32:53 +0000 jameso 3419733@http://singletrackworld.com/forum/ <p>What goes round in circles more easily, a light wheel or an internet argument?</p> <p>(Amedius, well said) </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419681 Wed, 25 Jan 2012 09:20:53 +0000 BruceWee 3419681@http://singletrackworld.com/forum/ <p>Actually, my original thought when I decided to post was about the sprung weight vs unsprung weight. I've been thinking a lot lately about how important unsprung weight is for mountain biking. Obviously in motorsport it is very important since the majority of the suspension is provided by the shocks.</p> <p>In mountain biking you have at the most 8 inches of travel provided by the suspension plus 12 inches provided by your arms and legs effectively turning the entire bike into unsprung weight.</p> <p>I've had a look but I can't find much information on this on the net, anyone read anything that talks about this? </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419658 Wed, 25 Jan 2012 09:13:09 +0000 BruceWee 3419658@http://singletrackworld.com/forum/ <p>One thing that is confusing me is the fact that everyone seems to be saying that they can tell when they are on a bike with heavier wheels but with some saying it makes no difference to speed while others are saying it does. </p> <p>I guess they best way to test this (since as far as I can tell there have been no tests done on technical off road trails) would be to fill the tyres with water for one run then do the same run without the water in the tyres but with an equivalent weight added to the frame taking care to keep weight distribution the same for both.</p> <p>Ideally the bikes and riders should be fitted with full data acquisition systems measuring heart rate, cadence, torque input, wheel speed, GPS speed, and suspension velocity.</p> <p>This test should be repeated using at least 10 different riders with five doing the increased wheel weight first and the others doing the increased frame weight first. The test should also be blind so the rider doesn't know whether he or she is riding the bike with increased frame weight or increased wheel weight. Comments from riders should also be taken into account and all riders should have similar fitness and technical ability.</p> <p>Anyone out there doing a Masters degree in sport science or engineering and looking for a thesis? </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419628 Wed, 25 Jan 2012 09:04:15 +0000 cynic-al 3419628@http://singletrackworld.com/forum/ <p><blockquote>I'd say that your analysis is very partial.. It doesn't attempt to quantify the effects of unsuspended weight on rolling resistance. It's valid on a smooth track, but not many mountain bike races are.<br /> </blockquote></p> <p>Why not look into the data on rolling resistance and see if it helps? Schwalbe published some research IIRC.</p> <p>Northwind...shame no one can match my big hit stamina or analytical skills.... </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419419 Wed, 25 Jan 2012 01:50:42 +0000 Kevevs 3419419@http://singletrackworld.com/forum/ <p>lose some weight. You'll ride faster. oh, and ride more, further, faster. I think that's it. and cut out the pies and beer. oh, and your expensive wheels will wear out. sorry it's not about the wheels. </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419407 Wed, 25 Jan 2012 01:03:27 +0000 bikewhisperer 3419407@http://singletrackworld.com/forum/ <p><blockquote>You've not even commented on my 500gm = 20s on a 90min race or produced any mathematical analysis of your own.</blockquote></p> <p>I'd say that your analysis is very partial.. It doesn't attempt to quantify the effects of unsuspended weight on rolling resistance. It's valid on a smooth track, but not many mountain bike races are.</p> <p>Although I don't pretend to know any maths to show the significance of the effects, I'd certainly say that the following points are true:</p> <p>1. Having less unsuspended weight (or less unsuspended inertial mass, as it's spinning) will allow the suspension to react quicker to bumps.. So less deformation of the tyres and wheel, less energy transfered to the ground, and less rolling resistance... So less slowing down over bumpy ground.<br /> 2. Having more reactive suspension (because of the above) will have the effect of sticking the tyres down better, giving the wheels greater grip on the corners.. So carrying more speed. After all, suspension is about traction, not comfort.</p> <p>These could each be equally as significant as the accelerative effect that you mention (well, actually they're the same effect!) so if 20s became 60s over 90 minutes.. what then? </p> <p>Last thing..<br /> If the wheels are constructed the same, then the lighter ones will be less stiff.. So might deform more due to pedalling forces and losing energy that way. Most light wheels aren't built like that though. </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419402 Wed, 25 Jan 2012 00:53:52 +0000 Northwind 3419402@http://singletrackworld.com/forum/ <p>This thread really is the point where Al jumps a shark (on a homemade fatbike obviously). It's hard to believe anyone has so much free time they'd choose to waste it like this... Ah well. </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419380 Wed, 25 Jan 2012 00:27:57 +0000 nick1962 3419380@http://singletrackworld.com/forum/ <p>I just put Crest stickers on my Flow rims and so everyone thinks that's why I'm faster when in reality I am a cycling Ninja </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419377 Wed, 25 Jan 2012 00:25:31 +0000 cynic-al 3419377@http://singletrackworld.com/forum/ <p>See my edits - apols for speed-reading.</p> <p>Night all, soft toys are waiting... </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419376 Wed, 25 Jan 2012 00:24:07 +0000 TandemJeremy 3419376@http://singletrackworld.com/forum/ <p>Cynic al- shame you don't want to think critically - two misquotes / falsification of what I said in one post. Nice</p> <p> <blockquote>loosing a kilo off the front tyre on the tandem ( a very extreme case and <strong>obviously other effects </strong>such as profile as well) was an obvious difference to steering at speed. </blockquote></p> <p><blockquote>Speeds are similar<strong> magnitude </strong>not similar speeds.</blockquote> </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419369 Wed, 25 Jan 2012 00:18:28 +0000 cynic-al 3419369@http://singletrackworld.com/forum/ <p><blockquote>skywalker - Member<br /> Where is your evidence Al? So far all you have done is disagree.</blockquote></p> <p>No, that's you. </p> <p>I've accepted much of the argument is unsupported by evidence on either side. You've not even commented on my 500gm = 20s on a 90min race or produced any mathematical analysis of your own.</p> <p>TJ - shame you have to reduce it to personalities so quickly, up to you, <strike>how you can say the speeds re similar is beyond me</strike>*. And I too see flaws in your arguments...your 1kg lighter front <strike>wheel...same tyre/pressure/terrain?<br /> </strike> the other factors would have too much influence for your judgement to be worthwhile IMO.</p> <p>And Northwind - without evidence it's pure conjecture...as some of my points are...but at least I have some arguments/analysis to back them up.</p> <p>EDIT TJ didn't say *! </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419362 Wed, 25 Jan 2012 00:13:08 +0000 TandemJeremy 3419362@http://singletrackworld.com/forum/ <p>Yes al - you tell yourself you are always right so you don't have to think critically. Your argument on this one is full of flaws but as usual its pointless to debate with you,</p> <p>Northwind - loosing a kilo off the front tyre on the tandem ( a very extreme case and obviously other effects such as profile as well) was an obvious difference to steering at speed. </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419359 Wed, 25 Jan 2012 00:11:35 +0000 skywalker 3419359@http://singletrackworld.com/forum/ <p>Where is your evidence Al? So far all you have done is disagree. </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419358 Wed, 25 Jan 2012 00:11:19 +0000 Northwind 3419358@http://singletrackworld.com/forum/ <p>You must be kidding? These guys might play your silly games... </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419356 Wed, 25 Jan 2012 00:09:48 +0000 cynic-al 3419356@http://singletrackworld.com/forum/ <p><blockquote>A word on placebo effect... Don't underestimate it. If your bike feels faster, there's a good chance you'll become faster.</blockquote></p> <p>And I say it again to you, as I do to skywalker....evidence? </p> http://singletrackworld.com/forum/topic/saving-circa-500g-on-wheels/page/5#post-3419355 Wed, 25 Jan 2012 00:08:26 +0000 Northwind 3419355@http://singletrackworld.com/forum/ <p>The steering difference with my Dymags on the motorbike (and binning a brake disk) was immense, to the extent I almost crashed first ride out. But that's gyroscopic forces with a much heavier assembly spinning at much higher speed so really difficult to make any meaningful comparison. I can't feel any steering difference going from my lightweight wheels and tyres on one bike to the dualplies and 721s on the other bike. </p> <p>A word on placebo effect... Don't underestimate it. If your bike feels faster, there's a good chance you'll become faster.</p> <p>Still... There's a whole industry of racers, and these days it's a science as much as a sport. When you look at the lengths they took to lighten Steve Peat's world champ winning bike, I think it makes sense to ask why they'd do that if it wasn't effective- the risk they took there was huge, they lost strength, punctureproofing... And then look at every single race bike at an XC event, if there's no meaningful difference shouldn't at least some of those riders be on beefier rims? </p>