Johan Bornman

Yes, I think you can buy such a kit for Rock Shock products. I can't help you though, since I replace each O-ring from a stock of loose O-rings and I haven't not yet memorised what fork requires what O-rings. But let me try....Rox dual-airs take two of 10 x 3, two of 12 x 3.5, , two of 3.5 x 12, two of 23 x 2.5, two of 27 x 1.5, two of 20 x 2.5 and some others I can't recall right now. I can't remember what that Ginko Biloba stuff is for either.

Do it like this: 1) Loosen the nipples to almost completely loose on the old wheel. 2) Tape the new rim onto the old one, matching the position of the valve holes. 3) Transfer each spoke to its corresponding position on the new rim and screw on a nipple. 4) Once you've done this 32 times, you can remove the tape, dump the old rim and tension, centre and true the wheel. @Eccentric: yes, the gadget will surely perk them up. I'll do yours for free.

I don't understand how a worn chain affects the device?

The local agents don't have these in stock. You'll have to import. You have to know what you're doing though or you'll end up with a frustrated project. It is important to understand the relationship between drop-out angle and chain slack. I recommend a spring tensioner if your drop-outs aren't vertical or close to vertical.Then, you have to figure out where the cable stop for the gearchangers will be. Often on frames not specifically made for these hubs, you have to modify things a bit. A wheel with one of these hubs in is very heavy. Much, much heavier than other wheels to the point of dropping it on your foot and you're injured. To remove the wheel in the field you'll need a track spanner. This is a big mother by saddlebag standards. Whether you get a Rohloff, an Alfine or a SRAM, there is always one gear that's very noisy and inefficient. It may even irritate you if you're fussy. Servicing these hubs isn't straight-forward and the oil you use is critical. With the Alfine hub, you also have to purchase seperately, a non-turn washer that fits your frame and a cassette joing and a sprocket. The largest they sell is a 20 tooth, which makes the gearing a bit to heavy on a 29er/road bike, but OK on a 26er.

The damper service is not hard but it helps to have someone around the first time to calm the nerves. Beer also works. Rock shock dampers and air pistons use O-rings as seals and you need some experience in measuring these up using a vernier. Some O-ring rules regarding hardness (measured in Shore), size tolerance and inspection, is required if you want to do things properly. Come and service your shock at my next Cape Town shock service workshop. Its on a Friday afternoon. Skive off work and come through to Durbanville. My schedule and details are posted earlier on here.

The answer to your question and the answer to your own explanation of what you really want to know, differs. Spokes stretch elastically about 2mm (for a roadbike or 29er wheel) when properly tensioned. They stretch plastically about 0.5mm during stress relieving, which is the second last phase of the wheelbuilding process. But that doesn't answer your question. You want to know if spokes can be re-used. The pragmatic answer is no. The J-bend ends of inbound and outbound spokes differ in their angle and they are already fatigued. Chaning the angle later on makes for a non-durable wheel. Spokes work perfectly well a second time round if you only transplant the rim without disturbing their original positions, but in a re-build it is very difficult to get them exactly in their previous posiions, hence my caution. Can you re-use nipples? If they are aluminium, no. Heavens, they're hardly good enough for first time use, nevermind recycling. If they are brass and not rounded off or contaminated with dirt, yes. I clean dirty nipples I want to re-use for whatever reason, in an ultrasonic cleaner. That gets rid of the find grit that makes your life hell when tensioning the spokes.

Car oil is fine for the application Skylark suggests. As thin as possible will be nice, and I think the 10Wwhatever will do the trick. As long as the oil can splash upwards and lube the upper end, all is well. It will NOT damage seals, coatings or the teflon coating on the bushes. I used it for years on my own forks but now that I do this professionally I cover my arse with the real thing, even though the dire warnings that Sky pointed out burns my arse.

You are right of course. I've fixed the date. I cited the date for the DIY Repair and Maintenance Course.

Clara Anna Fontein Durbanville. It used to be Kalk Bay but the roadworks there killed everything.

The 2012 Yellow Saddle Course Schedule looks like this: 2012 Course Calendar Repair and Maintenance Johannesburg 25 & 26 February 28 & 29 April 26 & 27 May 30 June/1July 25 & 26 August 29 & 30 September 24 & 25 November 8 & 9 December Repair and Maintenance Cape Town 24 & 25 March 28 & 29 July 27 & 28 October Wheelbuilding Johannesburg 24 & 25 February 15/16 September Fork Maintenance Workshop Johannesburg 07 April 2012 09 June 2012 Fork Maintenance Workshop Cape Town 23 March 2012 27 July 2012 26 October 2012 Bike Maintenance for Ladies 28 January 2012 10 March 2012 11 August 2012 For more info, e-mail me on johanatyellowsaddledotceeodotzeda

I'm presenting a wheelbuilding workshop on Saturday and Sunday 18 and 19 February in Johannesburg. There's a race on Saturday, so we'll start at noon only but finish late on Sunday evening. Those who don't race on Saturday can start early and avoid having to do homework before the course. The workshop will cover all the necessary wheelbuilding theory and you will then move on to a hands-on session where you will build your own set of wheels. The course includes the bible on wheelbuilding: The Bicycle Wheel by Jobst Brandt, a spoke calculator will lots of data on rims and hubs including the latest fashionable components, lunches and refreshments, tuition, a quality spoke spanner and course notes. Cost is R2800-00. E-mail me for more details. johanatyellowsaddledotceeodotzeda

That spec is still not good enough. All it tells you is that he fork steerer is 1 1/8th. All modern forks are threadless. You also need frame dimensions. Cane Creek is good but expensive. Giant, BBB, PRO etc are all good value for money. I don't believe the quality of the headset itself is important. Most are way above acceptable. The most important thing is that you get a standard bearing, not a proprietary one. Someone mentioned Chris King. Chris King headsets used to be stupid. American pride made the company refuse to pay license fees to Aheadset (Cane Creek today) for the invention that revolutionised the headset, stem and steerer. They then went ahead and designed their own version of it but not having access to important aspects of the patent, they botched it and Chris King headsets used to work loose on the steerer and damage it. I believe they now that the patent expired, have suddenly adopted the compression ring from Aheadset. Companies like that should not be rewarded for their pride. The license fee was minimal and the entire industry played ball except CK (and perhaps some others I don't know of). Cpnsidering how big a contribution to cycling the invention was, they should have been richly rewarded, not boycotted. Sis CK, it was a very poor show. Headset bearings are consumables. The fact that the front wheel shoots water directly into the bottom bearing is to blame. Your headset will last a very long time if you fit a short stubby mudguard or one of those lizardskin contraptions. However, no-one does this so it is uncool so no-one does it.

Supersport Cycles in Boksburg.

Spokes come in lengths ranging from 210mm t0 304mm in 1mm incriments. On top of that, they come in double butted, straight gauge, Laser/Revolution butted, flat and single-butted. Not to mention that they come in black and silver and don't forget to specify straight-pull, J-bend or threaded at each end. Perhaps you want to be more specific?

Some frames aren't sold with a headset and headsets are mostly frame-specific, so don't regret selling your frame with its present headset. External headsets are on their way out and mostly found on older frames with 1 1/8th steerers and simple straight head tubes. Here only the internal dimension of the frame is important - mostly 44mm. Modern frames with hydroformed and carbon head tubes, are shaped like hour glasses and can accept internal or integrated headsets. The primary difference between internal and extarnal is the location of the bearings - inside or outside the head tube. All integrated headsets are internal but the difference is that an integrated headset doesn't have a loose cup in which the bearings rest, they rest directly on the frame. Not cool. Integrated headsets are simple - top cap, top cover, bearing, nother bearing, seal and crown race. Internal headsets have to cups added to the mix. The cups have a critical dimension that has to match the head tube's internal dimension. Best to wait until you have the frame, take some measurements and buy a headset. Headsets don't have to be expensive. A Giant headset will set you back just over R200 and is superb. They use standard 36/45 degree bearings which cost R50 a pop. Don't bother with headsets using non-standard bearings such as the 45/45 ones found on Campag, Ritchey and the like.

It is easy as pie and well within the scope of the dedicated DIYer. The oil is not critical, as long as is fork oil in the 10W range - a few "Ws" over or below won't make a difference. You'll need a set of wipers and seals, two O-rings, some oil, some rags, a drain pan, some extra Omo for your clothes, a 10mm allen key, a screwdriver, large hammer, 4mm allen key and some beer. Do it. If you're daunted, e-mail me and I'll send you my schedule for fork service workshops in Cape Town.

Take the SID. It's remote lockout is the shiz. Further, I'm convinced that Rox is toughter than Fox, new pashima poofter cashmere coating notwithstanding.

You have a problem and a holistic approach is needed. That is a threaded steerer fork with a 1 inch headset - threaded naturally. These are completely extinct in South Africa and I don't know of a single distributor that still brings in 1 inch threaded headsets. Further, you may find that your stem will not come out of the fork - test that first before proceeding. What you have to do is scrounge around the older bike shops and find a new (old) fork with a threadless 1 inch steerer. You also need a new stem. Then, replace the headset with a threadless once inch headset that is still reasonably freely available. Giant brings them in at a very, very reasonable price. Buy two, since that will give you a spare set of bearings, which are also just about extinct. Then fit the new fork and a new threadless stem. 1 Iinch threadless stems are also very difficult to find and you may have to use a 1 1/8th one with a shim. These are available and some stems are even supplied with that - like PRO for instance. You can still find threaded headsets overseas, but be prepared to pay up to R1000-00 for a decent one like Ultegra. Should you go this route, take careful not of your availlable stack height on your existing setup and make sure the next headset doesn't stack too high. BTW, you don't get integrated 1 inch headset and the integrated(ness) is a function of the frame, not an aesthetic choice. You are after an external headset which is what you'll get by default.

Cheap bikes are made from high-tensile steel tubing. I'm not quite sure what you want to weld - the dropout to the fork blade perhaps? High-tensile steel requires a low-hydrogen weld. I assume you're using a standard arc welder? If so, buy low hydrogen rods from Afrox. However, I'm pretty sure the original was brazed, not welded but you're the one with the workpiece exposed on the bench.

My friend Brian received justice in the Randburg Magistrate Court this morning. In March this year he was knocked off his bike on Christiaan de Wet, close to Northgate. Those of you who know the road will know it is a wide double-carriage with ample emergency lane space on both sides. Brian was riding in the yellow line (illegally actually) on the left. A driver decided to overtake by moving over to the left and use the yellow lane as an overtaking lane. Being a right hand driver hit Brian before he could see it. Brian suffered severere injuries to his right elbow where the mirror clipped him. He spent many months in a sling and had to undergo reconstructive surgery to the elbow. The magistrate didn't believe the driver's excuses (swerving for a pothole, warning the cyclist by hooting etc etc) and he eventually changed his plea to guilty. He has previous convictions for negligent driviing and the magistrate said she is considering the maximum penalty which is R24000 fine and six years in jail. The accused plead poverty (the gold jewellry and Julius-style watch notwithstanding) and cited several other mitigating circumstances. The magistrate severely reprimanded him and said cyclists should be protected and the fact that they (cyclists) now resort to the illegal yellow lane is an indication of their fear. He was fined R16000 and a suspended sentence of six months in jail, suspended for ten years.

Hmmmm. So Powasol is acidic then?

I can say it and I do say it. I will demonstrate it to you. Brakes don't deliver power, they deliver force. The force will be the same, irrespective of air (provided that it is "pre-pumped"). Your analogy is flawed. To modify it I'll say it is the same as a 6-cyclinder engine that takes a few seconds to activate two of its cylinders. Once it has stopped misfiring and runs on all 6, the power is the same. The blown gasket analogy doesn't fit.

This is all very quaint and nostalgic and all that, but most people don't want tempremental stuff. I say that with full confidence because there are more Toyotas than Alfas on the road. Let me explain why I say air in the system doesn't have an effect on the power (force actually) that a brake produces. I thought I explained it before but clearly not well enough. Air in the system presents as a soft brake. However, when you pump it it comes up to full "power" and stays on full power until it is released. If you pause before activating the lever again, it will be soft again. Pumping it again, brings it up to full power. The travel and bite point after pumping is exacty the same as that of a healthy system and it will safely bring you to a stop, no matter how long the hill. Brake bleeding cures only two issues: 1)Air in the system 2)Renew old fluid. It is not a panacea for all sorts of other Avid problems. Simple hydraulics...

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.