HomerSimpson

Bump?

A question for those that know about things mechanical: On Sunday I was riding the Paarl funride, and I kept hearing a rattling noise whenever we went over rough road, and at first I thought my bottle cages were loose. The noise disappeared when we hit smoother road and I forgot about it. Then, about 30km from the end I swear I heard a pinging noise (sounded like a good quality metal part hitting the road and bouncing away) and shortly afterwards the rattle returned with a vengeance. As I changed to a lighter gear to head up a little roller I noticed that all was not well. Closer inspection revealed that my rear cluster was quite loose (had about 1 mm of play). Not having any tools that would do any good at that stage, I selected the small ring in front and rode home just using the middle three or four gears of the (Shimano 105 10 speed) cluster. When I got home I saw the lockring had completely unscrewed. Now: Has anybody experienced this before? Why would this happen? Surely the lockring cannot unscrew by itself? Is there anything that could possible have fallen of in the process (the metal pinging sound refers)? My logic tells me that nothing could have escaped (not anything intact, anyway) Any thoughts (other than telling me this would not happen if I rode Campy)?

We do? I have been using WD-40 for the past 8 years, for both road and MTB. And I've done 3 Stellenbosch MTB mudfests without any hassles or sign of chainsuck. The results on chain life on the roadbike is pretty good as well. But getting into an argument about oils and lubes is second only to one about religion..... Use whatever works for you...

Plenty of nice places to stay in Ladismith and surrounds.

Can't believe that 7Weeks is close to being as difficult as K2C (have not done K2C, but 7Weeks is like a road race on gravel, mostly). Stunning scenery through the Poort. HomerSimpson2010-02-15 08:22:20

Just saw in the Eikstadnuus that the cyclist suffered a "badly damaged leg" and is at present still being treated in the local Medi-Clinic. According to the report the (male) cyclist clipped the curb and fell in front of or under the truck. From the above it would appear that it was purely an accident. In the same report, it was said that a woman (aged 20, and american visitor) suffered only minor injuries when her bicycle was struck be a train at a level crossing near Stellenbosch last Saturday.

[quote name=Johan Bornman I think that will go right through a thin-walled alu bike as well. On my alu waterbottle cages the bottle has already abraded half-way through the cage itself' date=' and that is 6mm thick! It is quite weird, but a soft water bottle with grit, will abrade a harder surface with no damage to the water bottle. I see this in Rox poplocks uite often, where an aluminium shaft moves in a nylong bush. The nylon remains perfect and the aluminium suffers. [/quote] The fact that the water bottle (polyethylene) is quite flexible and that the material is actually quite soft means the grit digs into the water bottle which then acts as an abrasive. I found this whole thread quite illuminating (I have seen similar damage on Alu frames, both road and MTB), but JB's comment on the apparent lack of damage to the water bottle really caught my attention. I just checked the water bottle (old) on my MTB parked in my office and you can quite clearly see pits and short, deep scratches on the surface of the bottle (bottom third of the bottle) HomerSimpson2010-02-12 05:05:15

That is the worst section of the road coming into Stellenbosch from that side. Narrow, high curbs, nowhere to go if there is a problem. And at any time after 7:15 in the morning, the traffic is heavy. Not the place to be on a bike. I hope the cyclist is OK....

Shaun231 and ccc2 make valid points here. This situation will unfortunately probably lead to some rides eventually disappearing from the calender, or at least not being considered as league events. On Sunday, the 62 km ride was started at 08:40 to prevent the league bunches and the faster funride bunches (A-G) mixing with the 62 km riders back through Stellenbosch and on the narrow sections of road just before Spier and on the Annandale road, not to mention at the finish. If the 62 km ride had started immediately after the long ride most of the funriders would have been on the road at 07:45. This would have meant that at around 08:45, the first of the short route would have done about 35 k's which would have put them on the road into Stellenbosch at about the same time as the elites. The rest of the racing groups and the majority of the 62 k riders would have met up in Stellenbosch and just beyond. So the only way to avoid this was, I guess, to start the 62 k ride late (which meant these riders had to deal with the traffic both going out and coming back) So the organisers are stuck with a catch 22 situation. Safety of the racing and fast funride bunches, or making things easier for the funriders in the 62 k ride. The real problem (to my mind) is the nature of the race/funride route. (A) Joining long and short routes will always be a problem. (B) Having to take cyclists through a fairly busy town between 09:00 and 11:00 on a Sunday morning is not really desirable. I have a feeling that this particular ride will not be able to exist in it's present format for too much longer. I think it is time for the race organizers to start thinking about alternatives. And spare a thought for the PPA marshals who worked at Sunday's ride...there at 06:00 a.m and most only got to start with the temps at the end of the medium route, at about 09:20.... HomerSimpson2010-02-09 02:26:37

Pedals. Just tighten them. Had the same thing on my Cannondale last couple of weeks. Also do a search; this topic has been discussed quite regularly.

I have a map (electronic) of the tracks as they were pre-fire (PM an e-mail ad. and I'll mail it to whoever wants it)....I know the two "river" single tracks have re-opened, as has the downhill section of the XC course on the south side. Elioti is still closed, but all the Canary trails are available. Are there other new trails on the South side Bos? Where?

I'm guessing someone just went tubeless??

Please advise what happens to Stan with CO2 Bomb' date=' been trying to figure this out since i saw the warning on the Stans packaging. So far my Stans / CO2 combo sems to be working fine, allthough I have not had a hole in the tire yet, but it sealed the bead area just fine? [/quote'] It's not that drastic, but if you expose Stans (for example) to a CO2 atmosphere, you get a gradual change of pH as the CO2 is absorbed by the water. So, over time, the rubber coagulates and the latex is no longer. So it stops working, and you have to refill. This will not affect the tyre, just the life of the sealant inside the tyre. So if you are out riding, and get a puncture, and use a CO2 bomb to re-inflate, you are probably shortening the lifetime of the Stans. I can't give exact numbers, but in the screening experiments we did it looks like about a 50% reduction when we compare CO2 to "normal" air.

Johan' date=' it "preserves" the latex (which is just another word for an emulsion) by keeping the pH basic. The surfactant (both the natural one that comes from the tree and the ones that gets added to the synthetic latex) is cationic. If the pH goes low, the surfactant stops working and the latex coagulates. In the rubber emulsion the rubber is the oil part. You can try just plain vinegar as well. Add the acid, rubber coagulates, you can in fact squeeze into a ball and bounce it (demo we sometimes do for schoolkids and science teachers).

Get into the bush as soon as you can. MTBs are supposed to be ridden in the mud. And enjoy it (falling over is part of the overall experience).

The slime tubes do work...most of the time. I use them, and, for example, at the Seweweekspoort MTB ride three weeks ago I picked up a slow leak on the loop at the top of the poort. Saw several damp spots on the tyre, used the pump to re-inflate and had no further problems. Took out the tube at home, saw I had three puncture marks (not sure if they all occurred during that ride), put the tube back in and am still riding on it. On the other hand, two years ago I punctured (not a very large hole) during Lourensford and pumping the tube merely forced the slime out without sealing the puncture. One of the messier tube changes I have had to do! With the price of the slime-filled tubes getting ridiculous, (about R90 now) I will probably go tubeless soon.

Just a quick note on the compounds used for road tyres (someone said something about these being fancy polymer compounds): they are all still by and large butyl rubber (some are rubber blends, but essentially all are butyl). Butyl has a low gas permeability, and more importantly does not oxidize very easily (unlike natural rubber or butadiene rubber for example). Chances of your tyres degrading before they are worn through are pretty slim. Having said that, I have one old tyre in my garage which spent about 12 years on an old Peugeot Rapport (from 1988 to 2000) which is pretty much a collection of rubber crumbs held together by dirt and brittle fibres.

Go speak to Linus v Onselen at Flandria, they have a group that rides every a.m. Also some weekend longer rides.