Johan Bornman

As a point of interest, no a tyre cannot stretch.

Tyres have a casing that's made up of bits of string that run diagonally from bead to bead at a 35 degree angle. This string is thin and made from something that doesn't stretch, rayon or silk (old fashioned tubbies) or other secret stuff. This woven casing contains is coated with rubber and you don't really get to see it. It's job is to maintain the tyre's shape no matter what the pressure. You'll notice that an inflated tyre stays the same shape no matter the pressure - unlike a balloon without al casing. Now, every so often an impact pinches the tyre on the rim and cuts one or two of these criss-cross strings. Now the tyre is "unbalanced" at that position and looks like a boxer with a broken nose. It will never run properly. Other tyres are just crap - Maxxis tyres are often out of true by 10mm. Others again, aren't uniform in side. Others are out of spec and won't seat where they're supposed to seat. I just move those tyres to the back where they don't irritate me.

Titanium definitely is a solution. On my old road bike, I have a ti seatpost and a alu stem. The bike is 19 years old but the stem only three. Every few years when I want to replace the headset I have to saw off the stem. The seatpost comes out without a problem. As for carbon and alu together. I doubt this was carbon. Although it is often called carbon-wrap, I think it is just a carbon sticker like that found on souped-up BMWs in Lenasia. Further, the seat tube is alu on the inside - again not really the carbon's problem. Anodising would work if you could anodize the inside of the seat tube. But I doubt it would work. Christie, can you anodize the inside of a 27mm alu tube?

Another option is the Aye-up. One of the kits comes with some bike mounts and a headband with attachments. It is quite a nifty little set with several battery options and a choice of spot or flood lights.

68000m climbing! Alex is on a 29" Linskey hardtail with Shiano stuff, tri-bars and in-frame panniers.

You need some rubber, or hydraulic grease. If you just want t do the occasional service for yourself, use standard red rubber grease. Available in little tubes from Builder's Warehouse in the car section. Hirch (something like that) brand. If you want to do it professionally, get Richem Hydraulic grease. It is a vegetable-based grease that doesn't attack seals. If you want a little bit of the latter stuff, come by with a small container, like a wasabi container you get from a take-away sushi-bar. I'll give you some.

You can't have your cake and eat it. Light hubs require small bearings. Small bearings are just not as durable as large bearings. Durable or light - choose one and live with it.

OK, for those of you interested in the problem and its solution. The problem is solved but won't go away. The seatpost in question was a carbon-wrapped aluminium post inserted into a carbon-wrapped seat tube. In other words, the seat tube was naked aluminium inside. Big problem this. As you can see from the photo, the submerged piece of post was quite long, compounding the problem. The carbon wrap stayed behind once the post was removed and itself was stuck. The aluminium on the post corroded underneath the carbon wrap, causing the post's Outside Diameteer (OD) to increase. Further, the seat tube corroded too, causing the tube's ID to shrink. This effectively throttles the seatpost in the bike, forming a very, very strong mechanical connection. Not a chemical bond, but mechanical constriction. To remove a stuck seatpost, chemistry is not the answer. Whatever chemical you intend getting in there - coke, caustic soda, whatever, cannot penetrate. The area of attack will only be a one-molecule thick ridge. Look at the post and you'll see why - the white on the aluminium indicates that the entire length of the post was corroded. It has to be a mechanical approach. In this case we had to cut the post off 40mm above the seatpost clamp and then saw through the side of the post. Since the post was in deep, a standard hacksaw blade was too flimsy. It flexed too much over that length. I had to purchase a 32mm blade and grind it down to 26mm to fit inside the post. Job done. How to prevent it? You can't. Regularly remove and clean the post and wipe it clean.

What a ridiculous thought. Besides the fact that it was a little inside joke between RAD and I, I have the freedom to choose exactly what bikes I want to work on and which not. If I don't like blue bikes, tough for anyone with a blue bike. If I don't work on kiddies bikes, I don't. What compels me to do so? And as for that vexatious little yapping dingle berry-infested dog in agreement with you, he utters a little yelp at every challenge I receive on this forum. He seems to get kicks out of it.

No need for correction, you're absolutely right.

I dunno. But you will be surprised what happens out there. Often the dish isn't out, but the wrong spacers on the axle, they swap them etc.

If something is strong enough, it is strong enough. A radial spoke wheel, like any other wheel, is strong enough to carry its intended load. However, durability, not strength is the issue. Durability = strength x distance.

It sounds like the wheel's dishing is out. There's a special tool to check that but as someone did suggest, if you reverse the wheel, it should now touch the other side. If that's the case, the dishing is out. If you are in the Northcliff area, bring it and I'll take a look. I'm not a doctor, but I will take a look.

Radial lacing is an less-than ideal way of designing a spoked wheel. It makes for a lighter wheel since the spokes are considerably shorter but its shortcomings quickly negate those. Firstly, a tangentially-spoked wheel has more spokes involved in each de-tensioning event as the bottom spokes loose tension. This is because the spoke crossing the one that's right at the bottom of the wheel, is in another zone and helps take up the slack caused by the load. This ensures that the wheel remains true for longer. A radial-laced wheel requires very high tension to remain true and this leads to other problems - specifically at the hub. Although many wheels are laced radially, the hub ideally has to be designed for that type of spoking. Two things need to be considered: 1) The flange has to be larger and thicker, so that the spoke hole circle can be more inward, leaving more "meat" at the edges to prevent the flange from breaking. This thicker flange also negates any widening of the bearing seat. Most hubs have press-fit bearings that require a certain tolerance. By radially spoking the wheel you're messing with this tolerance. On cartridge bearings this could mean that a failed bearing would seize and turn in the hub, thereby destroying the hub. On cup-and-cone bearings, the cup's effective diameter is increased and the balls now run on a larger circle. Although the cup can cope with that, the cone can't. Usually the balls now edge up to the edge of the cone's polished surface and even into the non-race area of the cone. Chris King hubs come with very specific warnings about this. CK bearings are so small that any change in bearing diameter as a result of a normal (not even radial build), requires the bearings to be re-adjusted. Most cheaper and boutique hubs (not so cheap, most of them), have CNC'd shells. These are not as strong as forged shells and have to be really thick and bulky to cope with radial lacing. This particular hub, a DT Swiss hub, was made for radial lacing, yet many of them failed in the field. From the photo you may notice the reduced spoke pitch diameter leaving a lot of metal on the outside perimeter and;, the thickness of the metal compared to other hubs. The cause of this crack was a faulty spoke. However, this doesn't put the blame elsewhere. A good 10% of all spokes have a little ridge behind the head that could introduce a stress riser. On the wrong place on a compromised hub, that is a problem. To the OP. As discussed telephonically, don't worry about the wheel. I doubt it has any sufficient tension to cause a problem and should a problem present, it will happen before the warrantee expires. However, Merida will have to honour that warrantee, since Shimano won't, as is clear from the official Shimano position on radial lacing above, To professional wheelbuilders. Radial lacing is to be avoided. It creates too many come-backs and wheels going out of true. One or two anecdotal examples to the contrary doesn't disprove that it happens. Obviously radial lacing is totally unsuitable for wheels with hub brakes and rear wheels where the hub shell isn't sufficiently large and heavy (like the Mavic one someone else posted) to transmit torque to both sets of spokes.

Yes, it is radially spoked on the one side. However, making a comparison with that hub and the OP's hub is wrong. This hub was designed for radial spoking, the other one not. Also, the method of spoke attachment is completely different.

Well, someone has to help the CSA fund its extensive club-level efforts in getting good skills on the ground for coaching and guidance of newcomers to this growing sport. And who pays for those nice club manuals and guides? And what about that nice, laminated list of forbidden substances cross-referenced to common over-the-counter medications, updated and forwarded to clubs each year. Who pays for that little bit of life and medical cover at sanctioned races they offer in return for each race's contribution to their fiscus? Who pays for that roving coach that visits clubs on Saturday mornings to show newbies how to work in a paceline? Someone has to pay for it. EDIT: This sarcasm. Yes, I know it is the lowest form of wit and all that.... I hate those dipshits. The most pathetic manifestation of their ill-applied waste of our money has to be that case where finisher number 3XX in The Epic got zapped for something innocuous that wont make him faster.

Pretty nifty

However....that looks like a Shimano hub which is not made for radial spoking. Am I right?

Supercomp is super rubbish. DT's second biggest folly.

About R19-00 give or take before of after Rand crash. I presume black, silver is cheaper.

@HappyMartin. I didn't mean to sound gruff. I could have tactfully said: "Not everyone will find this interesting and therefore please don't spoil the conversation if it is something you don't care about." Instead, it sounded like "Voertsek!" Sorry.

Speed is your friend. Go and have a look at Mode 1 steering. You'll see that unless you have speed, you cannot travel far enough in the short space of time you have to correct the balance. The analogy I can use here relates to the broomstick experiment. If the stick's top falls to the left and your hand reacts too slowly in moving the base of the stick to the left (directly underneath the top), then the top will outrun the bottom and the stick will fall. When cycling, the same happens. Your head falls over to the left and you have to get your bum underneath that head as quick as possible so that you remain in balance. You do this by steering to the left. However, steering alone doesn't move you, you have to travel forward to move left. Therefore, if you steer to balance and your speed is too low, you will not get your bum in the required position fast enough and you fall or....revert to Mode 2 balancing. Momentum per se is not what you're after, but speed is. Momentum is a function of speed and mass. But what I'm saying, is that you can get the same momentum by moving a higher mass at a slower speed and that will not help you steer quick enough. I'm just being specific when I say that velocity, not momentum is your friend.

No.

If you don't care, you don't care. Move on.

Just do the wheel experiment like I so laboriously spelt out. Try it, then ask specific questions. I really can't explain better than that.