Johan Bornman

I just don't see how a bleed can increase the hydraulic force. Let's say there is air in the system. Once you've pumped the lever, you have maximum force. After a few seconds, that disappears, but two pumps of the lever and you're back to maximum force. This is not what the OP described, hence my assertion that a bleed will not solve the problem. Why do I say they are crap? Well, let me start. They are extrememly prone to trapping air. Even the new ones. They are extremely prone to introducing air into a previously-perfect system with no leaks in the hoses. Other designs don't do that. If you read the Avid bleed instructions it reads like a comedy. If you don't agree, lay the Shimano and Avid bleed instructions (and special tools)next to each other and compare the steps. The pistons are very prone to getting stuck. The phenol resin compound they use for the pistons easily roughens up and get stuck. The fact that they use non-lubricious fluid inside there exacerbates the system. An oil-based system on that small scale overcomes the piston friction much better. I think oil is a superior fluid for brakes on this tiny scale. Ironically, brake dust is its biggest enemy. Lastly, those poofter levers with their sloppy pivots don't impress me. A ten-year old Shimano brake's pivots still hinge crisply. Avids seem to last one season before needing an overhaul. I think there are several better systems out there. The old Avid tests where they show the boiling point of oil vs DOT fluid is moot. 99% of people never get to a point where 12 extra degrees of C would help them. Do a casual survey of the number of Avid complaints on this forum compared to the other big brand. The fact that they work, and work for you, doesn't reflect the collective experience (experience in what the consumer receives) out there. Your mileage clearly differs and I'll respect that.

A couple of points. 1) Bleeding has nothing to do with your problem. Bleeding is only required to sort out spongby brakes. 2)Avid brakes are crap. 3) Replacing the caliper pistons and square rings will help for a while. 4) Avid brakes are crap. 5) They don't take oil, but hydraulic brake fluid. 6) Avid brakes are crap. 7) They have to springs to push the pistons back. In fact, there is no mechanism to push the pistons back other than a bit of flexibility in the piston square ring (rubber). Those springs you see on the pads are only anti-rattle pads. 8) Avid brakes are crap.

That's the right choice. Listen to RobMTB. Buying a new fork 'cause yours bottoms out is like buying new wheels because the air pressure in your current tyres is low. Even if you cannot find a spring off the shelf, it is easy and cheap to have them manufactured to spec. Installing the spring will take you 30 seconds flat.

That is very unusual and certainly not normal. You are at the coast, which exacerbates plating problems but the question is, do you use this bike on a stationary trainer too? Trainers with their resulting sweat waterfalls are deadly to bikes. I think this is a gaurantee issue. Take it up with your bike shop.

The devil is in the detail. They were open but the driver was still on holiday. A trip to Edenvale would have sorted the problem out. Should your bike shop carry those spokes in stock? No, I don't think so. It is impossible to carry all proprietary spokes - there are dozens and dozens of options per brand, nevermind multiple brands. These spokes are expensive and the cost of holding the stock is prohibitive. The solution lies in wheels using standard components - good old J-bend spokes.

I wonder how many people with No Blood at All are treated by the good doctor? He seems like a versatile fellow, looking at the different types of relationship problems he can solve. It does disturb me a bit that the going rate for one gooley is only R1600. Mine are insured for ten times that.

The right answer is no. No, it won't damage the shock. The Propedal mechanism is a little spring pressing against a mushroom-shaped(the stem of the mushroom is inside the spring) piece of metal that in turn presses against a hole. The round head of the mushroom sits against this little hole and prevents oil from coming through, in turn preventing bob. Should you take a big hit or drop, the oil simply opens the mushroom valve and oil goes through. No big deal. Should it bottom out severely, there is another mechanism to protect it in the form of a rubber bumper that handles bottom-out events. Go jump.

I like your style. Cuts through the crap.

You are lucky indeed. If you have the right terrain/roads, that looks like one fun veehaicle to ride. Post your finished project here, I'll come and visit you for a spin.

Thanks, I now understand. All commercial chain checkers (except for one) use the roller as a reference point. This is of course highly inaccurate and plays in the favour of whoever sells chains.

Interesting reading. I can't figure out what the difference is between chain joint wear and roller and chain joint wear. I'm also absolutely surprised that within brands, the wear rate differs between chains from different gruppo's. I just cannot see them using different steel for different chains. I think the test wasn't repeated often enough to smooth out the date. There is very little difference within for instance, the various chains in the Shimano line-up. I totally disagree with Tour's chain care tips and I wish they told us a bit more about how they measured the chains. I'm worried about their method of lubrication. They say they used the original lubrication for 5 hours, then cleaned and oiled the chain. This doesn't make all things equal since Connex ship almost clean chains and some brans ship them packed with grease. I recently came across some chain wear data from Connex/Wipperman. I've attached the PDF. Needless to say, the Connex chains came out tops and in complete contradiction to the Tour test. Tour claims that durability isn't decreased as chain width decreases and I would have liked to see a comparative 9/10 speed test to verify that. However, they measured elongation to 1%, which is double the sensible wear limit. Chainwear_Test_10_Speed_10-JUN-2010.pdf

I wonder how much fun it could be riding a tricycle on jeep track. The rear wheel will always track on the middelmannetjie giving you the roughest ride of your life. I actually don't see a use for his trike at all??

Are you using the modern aluminium-axle XT hubs or the older steel ones? The latter I found reliable, the former, I find unreliable. However, some people have a different experience with these. Did you know that Velocity has a new SL version of the Blunt? Much lighter and much cheaper than ZTRs. I only discovered these a week ago but I think I'll try a pair myself.

Tyre pressure should be terrain dependent. If there is the slightest chance that a rock will cause the rim to bottom out against it, up the pressure. I can see why people want to ride with tyre pressure as low as possible - traction is good then. However, a dented rim could spell the end of your ride or race. With new-tech rims such as Stan's rims that don't have a long sidewall, a dent could spell the end of the rim. Older rims absorb the impact in the sidewall, which can be bent back by a skilled mechanic. Stan's rims absorb the impact directly in the rim cavity.

It won't be a problem unless the rear suspension system uses the shock's top-out to prevent the suspension member from travelling too far. Basically, a longer shock will allow the suspension to top-out at a point 10mm further. With some bikes this could mean that the suspension member will hit the seat tube or something else. I don't have a Reign in front of me to work through it, but I'm sure you'll get it just looking at the bike. Basically, the longer shock wants to push the suspension a bit further in the unloaded position.

Nokian is a Finnish rubber and cable company zillions of years old. Makes all sorts of tyres for all sorts of vehicles. My all-time favourite Nokians are steel-studded for riding on ice. One day I'll find a use for them. I've had Nokian MTB tyres and they were fine and well-priced.

Of course, at R40-00 a pop they're a steal. 64 x R40 = R2560 for spokes alone.

No need to take it in. Fix it yourself. 1) Sand the brake discs with course emery paper =- 80 grit or so. Work hard at it, sanding all along the front and rear part of the disc on the braking track. You want to end up with a dull satin finish. No shiny bits. 2) Now remove your brake pads and sand them using a much finer paper. Again, sand until you find no shiny bits. Place a sheet of water paper (waterproof sanding paper) on a flat surface and lay the pad on that, face down. Now sand with a Figure 8 motion until all shiny bits are gone. 3) Replace the lot and go and break in your brakes. Do this by perfoming a series of gentle stops totalling about three minutes all in all. Shudder will be gone.

The best grease for that particular bicycle application (and all other bicycle applications bar Mavic freehub bodies) is that sticky ol'e tub of whassisname grease you have in your garage. As far as bicycles go, grease is grease.

PowerTap hubs have a particular problem. The spacer between the two bearings on the hub itself, is made from some very, very soft material and easily deforms. It is quite easy to see too. Once this spacer deforms, it puts an unnatural preload on the two hub bearings and they suddenly have to cope with a huge side load. They don't like this and binds. Further, Powertap hubs have a 1mm washer on the 15mm axle that sits at a different place depending on whether it is fitted with a Campag or Shimano freehub. I think the shim you made compensated for one of these two issues. Interestingly enough, the Powertap hub uses a freehub body from one of the other brands, but I've forgotten now which other freehub body is compatible with it. After my senior moment has passed, it'll come to me. It is an important little snippet since the Powertap version has a material flaw that causes the pawl cavities to enlarge prematurely. Replacing it with the "compatible" cures the problem.

Hairy, you don't say what type of Hub that is, so it makes a very specific answer difficult. Bontrager don't make hubs but use OEM ones - often DT Swiss. The freehub body on a DT Swiss hub is rubbish. They use two different technologies and I'm not sure which one is the worst. Further, freehub bodies are unique to the hub. There is no standard. Also, 9-speed and 10-speed use the same freehub body, but that's just an aside. In defense of Cycle Lab - there are no choices in when replacing freehub bodies. You take the part number that goes with the hub and put it on. No choice between cheapies, generics etc. Thus, if they replaced it, it is the right thing. No Chris King for you. Sorry. A freehub body that sticks is deadly for your bike. If it sticks proper (which it will, sooner or later if it displays symptoms like you describe), it rips the jockey out backwards, over the cassette and into the seatstay. Many bikes are ruined like that. Often the wheel also suffers. Have it seen to. A DT Swiss freehub body is fairly simple but finicky. I bet that if you open it, you'll imemdiately figure out what to do - simply scoop out the rust and gunk, clean everything, pray that the spring is not rusted through, and replace. It only has two pawls and they're eccentricly spaced around the hub and could fool you if you don't pay attention. If you post a photie of the hub, we can tell you how to open it. But my guess is a copper hammer and 17mm spanner will do the trick.

Barry, why don't you phone your Mirage wing designer friend and ask him to look up the meaning of "inert" for you? There is no contradiction. Further, resin isn't applied in layers. The carbon is applied in layers and soaked with resin. Get it? If not, ask your friend in point above. However, it seems like no matter what I say, you'll find a reason to nitpick and bait. Stop it, you're an adult. In Tech Q&A we DISCUSS issues and offer hypothesis and counter-arguments. Try and debate, not act like an idiot obsessed on focussing on one person's contributions. You are a moderator here and should be above such childish behaviour. Take a leaf out of Slowbee's book of impeccable behaviour. You don't like me. Who cares? Get over it.

Now that's a slot! Actually, its more like a gutter. What frame is that?

That's a bit small and will block too easily. I do them 6mm. One is enough.

Interesting. One never give much thought to water absorbtion by plastics and resins, but they do. Just soak a nylon brush and see how soft it becomes. The degradation you show Christie is quite a lot and if I give it a cursory thought, I'd say it would be most severely felt with water in the chainstays. I guess n the BB area the lay-up would be radial to prevent precession of the BB shell and the effect of water absorbed by the resin would be moot. But as you say, nothing good comes of it. Most of that damage could take two or three years to manifest - just enough to for gaurantee to expire. Preventing it is common sense.