Climate

To the motorbike marshals ... thankyou all for a really thankless job. I'd just like to highlight the fact, that these guys do the job out of the goodness of your hearts ... not to get rich! Over the years, I've accumulated good memories of the times these marshals have made the road safer for our bunches ... the recent Burger is a case in point. These guys were fantastic, specifically on the way back to Stellenbosch, when the wind became a factor. I no longer own a motorbike, but if I did, I don't know that I'd be prepared to sacrifice a perfect Sunday morning, to cruise along in 2nd or 3rd gear for a few hours! Thanks again ...

No problem SkyLark ... would be keen to know what's happening with that idler gear on your RD though. Doesn't make sense that it's getting chewed up.

Okay - I misinterpretted your problem. Good luck with the project.

Maybe you can explain how I would benefit ... I've been gently trying to help you to understand that you can't get away from changing a gear at the back, if you change to a different gear in the front. It's been painful, even with spreadsheets to help get you on the same page ... so there are no assumptions made. That became clear when you started telling me I've got a problem with my gear changing technique (?) and in the same breath, continue to inform me that I should change to a different chainring, before I get down to the 3rd last sprocket on my cassette. You're trying to solve a problem, which is why you posted the issue on this forum - remember? Now take a step back, read this again carefully and guess what ... you'll see that Niner_Boy and I have been saying exactly the same thing. Do you get it yet ...

Nope SkyLark ... just because you don't understand something, doesn't necessarily mean the statement was incoherent. So there's no need to re-phrase ... you just need to benefit

One of the questions in your original post SkyLark, was when to change from big to small ring and vice-versa ... on a 9-speed cassette with just 2 chainrings, you won't do any damage, if you still have 2 sprockets available on the side of the cassette opposite to the chainring currently engaged. So the damage to the idler gear on your RD remains unexplained ... perhaps you can explain what's happening there.

From that statement SkyLark, I guess you found your maths teachers incoherent as well ... that involves numbers

Here's the path bud ... you cut it (and all this time, I thought you were looking for advice) "I'm running 2 X 9 speed : Chainrings 36t & 22t Cassette 11t to 34t I'm happy with the range - excellent top speed and granny speed Just theres a giant hole in the middle and I lose my cadence rythym... I can use 7 cogs of the cassette in either chainring , I have noticed I am totally chewing up my bottom RD pulley tho. Where should I ideally be changing up/down between the front rings - about 5 cogs from the top or bottom depending if I'm moving up or down? I'm thinking of changing the big chainring to 34t or maybe 32t , but I think 32t may be a little drastic but that is what a typical middle ring would be. But I may have a rather limited top speed with a 32t. What you chaps think?"

I don't have a problem with my technique SkyLark ... I'm simply responding to your post where you stated that "If the ratio is not almost spot on, the change up or down between front chainrings will also need a change up or down on the back cogs to maintain cadence - and doing that everytime is a load of bollocks!!" It should be simple ... but you're missing it! It won't matter whether you run 26/39 or 24/36 ... both ratios are 1:1.5, so the "holes" in your cadence will be the same. But to keep with your preferred ratio, let's assume that you're running 24/36 chainrings and are busy pedaling along in the middle cog on your cassette (you can't get further from the extreme ends of the cassette) and on the small ring, then your gear is 19~24 = 32.8 If you then change to the big ring, your gear will be 19~36 = 49.3 (which is a "hole", because you've made the equivalent of 2 cog changes on the casette, without a ring change). You now need to change up 1 cog on the casette to get to a gearing of 22~36 = 42.5 (which would effectively have been the same as changing down 1 cog on the cluster, without changing from the small ring (22~24 = 42.3) initially. But if you think one needs to have changed up to the big ring before getting to the 3rd smallest cog on your cassette (as in your previous post), you're effectively limiting yourself to a third of your gear ratios ... because, by the same logic, you need to change down to the small ring, before you get to the 3rd largest cog on your cassette. And since you've only got 9 cogs back there, you can't use more than 3 of them?!! The point I was trying to make in my original post however, was that even with the ideal chainring combination, you will always need to change a gear or 2 at the cassette, when you change gears to a different ring. So, if you've got enough power in the legs (as you suggest you have), then a "non-ideal" chainring ratio won't make a huge difference.

Even with a 1:1.5 chainring ratio, you're gonna have to shift 2 cogs at the back (if you shift to a different chainring), to simulate a single shift on the cluster. I've highllighted the gears for a 26/39 chainring combination, which is a 1:1.5 ratio. Now suppose you're in the 3rd smallest cog on your cluster, but still small ring (14~26 = 48.3) and you need a slightly bigger gear. In order to keep the most efficient path for your chain, you change to the big ring and your cadence will drop dramatically (14~39 = 72.4). Changing up 2 cogs on your cluster will get you to the 5th smallest cog on your cluster (19~39 = 53.4), which is still a bigger gear than you were in before changing to the big blade. Had you just dropped to the 2nd smallest cog and stayed in the small chainring, your gear would have been 56.3, which would have impacted your cadence more, than the single-click in front and double-click at the back. Gear Ratios 26x39.pdf

There will always be a "hole" in your range, when changing from small to big blade, unless the step up is so small that it isn't worthwhile shifting between blades anyway. I'm not sure what the actual tooth count is on your 9-speed cluster, but have highlighted what is most probably the configuration for 11-34 with a 22 and 36 tooth chainring combination, in the attached spreadsheet. This is of course calculated for a 26 inch wheel, but the argument remains valid for a 29er as well. You'll notice that from almost any cog on your cassette, if you change gear to the other ring, you'll need to gear down or up by 2 cogs on the cassette (depending on which ring you're changing to), to simulate a single cog change on the cassette without a ring gear change. This does not hold for the extreme combinations of 11-22 or 34-36 of course (when you'd need to shift across by 3 cogs on the cluster for the same simulation), which you know you shouldn't do anyway, since "cross-chaining" is a swear-word! Gear Ratios 2x9.pdf

Raceface ... all the best - you're lucky to be able to spend time together on the bikes (it can work out to be a lot of time, especially if you do some stage races together). Try giving WE a call ... he recently got the bike back, that he won the Rapport tour on ... and it Looks (pun intended) like it did on the day the tour ended.

She may not be the tallest person on that street, but if she were to lift that wheel on to the doorstep, it would pretty-much fill half the door. Those are indeed huge ... probably gotta use piano strings for spokes!!!

I'm not very diligent with my road wheels, but whenever I've acquired new MTB wheels, I've stocked a spare of the necessary spokes (or at least ordered them at the same time and collected later) ... which then go into my toolbox (goes with me on weekends away, etc). It's highly unlikely that you'll break more than one spoke at a time, but if you need it, there's no stress.

If rider safety wasn't important, we wouldn't wear helmets (don't know where you got that from). And I know of numerous occasion, when organizers of other events have been out in the middle of the night, in the pouring rain, changing route markers, to enable those that wish to ride, to get to the finish. I was lead to understand that permission to cross certain properties was requested from landowners for this event. The entire route is not open to riders and the general public. Since the race had been cancelled, the event was effectively complete, so we'd have been trespassing, to ride the route on our own. But by the time we'd made alternative arrangements to get collected, it was already 11 o'clock ... and the sun was shining!

I had picked up a stomach bug, so was suffering from nausea on the 3rd morning. But after forcing down some breakfast, I'd already fitted mudguards to our bikes and was replacing our resin disk pads with metal in anticipation of some mud, when my partner broke the news that the organizers had pulled the plug. Have to admit, I was relieved at the time, but only because I was worried about keeping my breakfast down ... my partner was really disappointed. We were both dressed appropriately, with proper rain jackets (it's easier to keep warm if you stay dry). But after having completed numerous Sani2c events in serious mud and cold, I was not expecting to be kept from getting to the finish. It was after all the longest of the 3 days, so we'd ridden conservatively for the previous 2 days, with the aim of finishing strong. We will be getting medals at a delayed presentation, but that doesn't work for me ... I collect my medals at the finish line. There's unfinished business right there, even if the decision to stop the race was the right one. But in order to complete that business, I reckon the organizers need to grant us first option at entries for 2012. Since the race is over-subscribed and I've already paid for a third of the race, which I haven't ridden, I think that's the least they can do.

Where did you get those Revolts from SFDT (or have you had them for a while)? I've been looking to replace mine, but they've been discontinued.

This idea is not new ... I took the attached photo's during the 2009 TdF (the material is apparently a mixture of kevlar and carbon).

I interpretted KE's commment ("To clear up any confusion around the crash, here it is from me: It was simply a problem with the disc pads that we changed the night before the stage. On the steep descends, the aluminium rotors were overheating and causing the brakes to ‘fade’ and loose power.") as follows ... they experienced over-heating problems in previous stages and attempted to address the issue, as they knew the terrain that lay ahead. However, whatever the pads were that they used, did not resolve the problem. The brakes simply over-heated again and unfortunately, KE suffered the consequences. Plausible?

I haven't done the maths on this yet ... am hoping to short-cut that little exercise with the help of some engineers out there. Is there more load on the disks (both rotors and pads) with a 29" than is the case with a 26". My first take is that the 29" wheel will actually be spinning slower and the reverse torque that the disks develop is related to the momentum of the bike and rider only (if considered in isolation)... and assuming that no skidding takes place. So the brakes do the same amount of work, irrespective of wheel size.

Sent you PM ...

I'd be keen to know what you mix in your bottles Agteros ... or what the product was that got you so grumpy. I first used High5 on an overseas trip 2 years ago, when we ended up doing more riding than anticipated and ran out of powder that we'd taken with us. A Belgiun friend gave me a few sachets ... it tasted good and it worked. No brainer - been using it since then ... and it lands here (sourced from Europe) cheaper than the well-known product (locally available) that I had been using before.

Sounds like you've got a spacer too many on the drive side of the crank ...

I won't add to the cleat/no-cleat argument, but I've heard a figure published wrt the difference between cleats with float and those with no float. Apparently, the loss is in the region of 3% when using cleats that float.

When I replace an RD cable, I release the cable by clicking the gear lever down all the way to where the cable is in its most relaxed state, before removing the original cable. Then screw the barrel adjuster on the derailleur all the way in (same way you close a tap). With no cable connected, the derailleur will also be in the relaxed position (usually the smallest cog ... unless it's a Rapid Rise model). Now connect the cable, ensuring there is no excess slack and tighten the pinch bolt. Then elevate the back wheel and start turning the crank. Nothing will happen, except that your back wheel starts turning. Click the gear lever once to get to the next gear ... typically, the derailleur won't actually move the chain to the next gear yet. While continuing to turn the crank, unscrew the barrel adjuster until the chain hops to the next gear. Note that you may have over-adjusted the cable slightly at this point (in which case you'll need to screw it back in a half turn or so). But cycle through the gears in both directions (up and down the cassette), before making the final tweaks.