psycholist

If you pump the water in really slowly it can leave bubbles in the system that would be entrained in the fluid and come out if you pumped it through faster. Make sure you're bleeding from the lowest point in the brakes to the highest. The second slave piston is usually where the bubbles end up, so make sure the pipe from the slave to the brake lever is the highest point on that slave piston. On the more recent Maguras I found that bubbles stayed in the lever unless I pumped the lever slowly a few times while filling, so this is worth a try too.

Looks like there might be a few people travelling from Ireland for this - still trying to confirm numbers at the moment... With 3 people it should be under €100 a person...

Once the rim has bent it's almost impossible to get it running properly straight again. Properly straight would be straight enough that rim brakes work perfectly smoothly on it. If the wheel is a little bit out, but local out of trueness is below half a cm and the overall buckle is spread around the whole wheel it might be savable. Starting at the valve hole (This means that when you get to the valve hole again you've definitely made a full round) loosen all the spokes 2 turns and then see about bending the rim back. Trying to do this with the spokes at full tension will pretty much always make things worse. Once the rim is straight put one turn of tension back and then see about truing the wheel...

It sounds like a great idea. The design of downhill sections would probably have to be changed unless people are allowed to stop by jamming a foot into the tyre though, which doesn't exactly fit with the flowy style normally associated with brakeless... I can't see myself ever going brakeless though. Or entering a trials competition (In my defence I'm a shit rider and live in the west of Ireland, so travelling to the UK would take too much of my time and money).

Unless there aren't enough threads in the non drive side for the BB the thread into or the drive side threads aren't deep enough it'll be fine. Adding spacers on the BB axle for the cranks is pretty much guaranteed to chew the splines off your cranks as ISIS spline cranks are designed to fit on one position only on the BB. Make sure you still have a decent chainline too (Though I doubt 2.5mm will make that big a difference to you unless the chainline is already quite far out).

I'd ditch the spacer under the drive side BB cup. BB spacers are 2.5mm thick usually, so it'll change the crank spacing to 7.5mm on the drive side and 4.5mm on the non-drive side... You may still need to cut the barke pads down to fit them though.

If you want out and out bite and hold, the Hope trials brake is just plain amazing. The cable Avids aren't far off that either set up carefully with a good cable. I run a Magura Louise up front (203mm on 26" bike) and I like the combination of enough lock for front wheel moves with enough modulation for stoppies and braking in low traction. Hydraulic brakes adjust automatically for pad wear, so the brakes are fit and forget parts - a refreshing change from the amount of messing I used to have to do with Maguras to still end up with noisy brakes with worse performance.

Make sure that there are three long and three short pawls in the freewheel and that every second pawl is a long one. Rearranging the freewheel as described could be a very effective way to unscrew the freewheel from the crank without a freewheel tool too. Provided you get the tensioner out of the way or have horizontal dropouts...

I reckon you have to be wired correctly to make any use of brakeless riding - I've been trying to manual with pretty much no success for 15 years, skiing, snowboards, surfing etc. all make no sense to me because the braking system is based on carving/sliding rather than having a specific control to take speed off in a straight line. Basically I don't have the aptitude for the dynamic moves - I use the brakes less riding trials than I used to, but I couldn't stay confident without them. If you're a smooth flowy rider then brakeless will probably work really well for you, if you like to hop around it probably won't. I do think it takes the likes of Rowan Johns or Chris Akrigg to make it look good though, most people will just be able to do less with less control, but that doesn't mean it's not going to be fun ... I'd say try a trials session without using your brakes and see how that goes before going to the trouble of taking the brakes off...

A BB lockring tool will just chew through the edge of the cup of a SKF BB too thanks to the cups being Aluminium and the tool being designed to be used on steel. The tool you need is here AFAIK: http://www.chainreactioncycles.com/Models.aspx?ModelID=995 I've got one in my garage and I'm pretty sure that's what I used fitting an SKF BB to a friend's bike...

I'm running an Echo SL on my current bike based on Tarty's recommendation and it's absolutely excellent . The ENO was on my previous bike. The undersized pedal axles were a set DMR V8's, but I only assumed they were undersized based on the crank threads failing a little too often, I've never heard of this problem before. Replacing the pedals on the previous bike does seem to have fixed it as it has lasted for longer than it ever did before, but the guy I sold it on to weighs probably 20-30 kg less than I do, so it'll be a quite a while before he has similar problems.

I don't even trust aluminium forks ...

I run one of the Echo sprung tensioners and vertical dropouts and the setup works well. The tensioner doesn't use the derailleur hanger at all and if you land on it it folds out of the way (And since it sits inside the loop of the chain you'll hit the chain before the tensioner hits). It'd be perfect if the chainstay length on my bike wasn't just too long to allow the chain to be run with no tensioner at all, leaving the chain just under an inch longer than it should be, making the chain skip when pedalling up long slopes though it never skips on pedal kicks. I shaved about half a mm off the front of the dropouts a month or so back and was able to shorten the chain properly and now its perfect. The thing that annoys me with horizontal dropouts is that you have to keep adjusting them to keep the chain tensioned and once you adjust the chain tension you then have to adjust the brakes as well. Disk braked bikes particularly will have a very limited range of adjustment (Unless you go to disk mounts that slide with the dropout - I'm pretty sure those on the market couldn't survive trials use - or slots for the disk caliper to mount into, which compromises strength) before the edge of the disk starts to miss the pads.

In my experience all the threaded trials cranks I've used have failed at the threads - I would say half of those have been my own fault, but I did a lot less maintenance on cranks while I ran Middleburns and had no failures whatsoever in at leas 4 years using them. I've done for a couple of Echo CNC cranks, and 2 trialtech cranks in the last 2.25 years for comparison. I will say I'm slightly heavier than I was 5 or 6 years ago, and riding harder, but I'm not that much heavier and am not riding that much harder. Firstly all the screw-on cranks I've used feel like tightening the pedals hard will pull the threads out of them (I have a proper pedal spanner, but I tighten pedals into Shimano and Middleburn cranks a lot harder than I'm wiling to risk tightening into trials cranks because they're just plain soft), secondly the natural tightening action usually seen in pedals on bikes ridden long distances due to pedalling forward all the time doesn't occur as much in trials, leading to the pedals loosening because all they see is massive force for a small portion of the pedal stroke as well as enormous peak loads from landings, and thirdly the threaded interface for the freewheel to sit on is badly compromised by having two manufactured thread diameters for the cranks available and having certain cranks (Especially the Trialtechs) which don't have clearance to run a bashguard with a wider rim than it's base without a spacer or an angle grinding job on the bashguard. It's the spacer put between the crank and bashguard in my last bike build that lead the threads to strip off my current trialtech crank. Thanks to the post taking well over a week to get from the UK to Ireland at the moment I'm into my third week of having no working trials bike even though the crank was returned in the post the first working day after it failed all because of a poorly thought out crank design. The only good thing about the softness of trials cranks is that it tends to allow them to fail by bending rather than snapping, but my experience has been that the threads crap themselves long before either type of failure occurs. At least thread failures don't usually cause very nasty crashes, but it's not like Middleburns are failing all over the place and they don't get the thread failures either.

Try washing the braking surface of the rim with degreaser (Washing up liquid and a good scrubbing brush should be enough, making sure the pads are set perfectly parallel to the rim and sanding the pad surfaces so no contamination gets on them.

You may be able to get it working by spending a few p on washers to go between the booster and the brakes. Make sure there are plenty of threads holding the brake on though - usually when you fit spacers you need to fit longer brake bolts.

If you need a hand with the maths I can sort you out... Unless you can use equations to drive the picture like on CAD programs though it might not be feasible without a bit of calculation software running in the background of the website...

Very nice indeed ... More components you can change colours on and you're set ...

Yes indeedy - he continued the section brakeless for a bit (But not far) - possibly the first recorded brakeless trials riding though ...

Cutting disks give a sharper grind - aluminium mostly clogs angle grinder disks anyway, so you'd have to leave the disk on the one spot for a couple of seconds before there's any fear of cutting the rim too deep. After getting fed up with the amount of time I spent spent messing with Magura setup, gluing pads into backings, grinds and regrinds and still losing half the brake bite in damp grass after all that trouble I went to dual disk and would be very slow to ever go back ...

The final test for this would be to try to build the Tarty Rainbow bike... Can you set it up to choose colours from a bigger palette so people can match what they have more exactly? I wouldn't worry about putting in specific frames until everything else is done though - the point is to see how colours will look together rather than drawing a specific bike.

If it's these cranks: http://tartybikes.co.uk/product.php?product_id=10993&category_id=514 It definitely doesn't look like there are enough threads for a bashguard to fit, certainly not one of the Neon ones which are about 4mm wide at the base IIRC. The Trialtech Titanium bashguard is a little narrower, but still would compromise on the number of threads available in the crank to take the load from the freewheel, so unless you weigh nothing and don't pedal kick hard it's a bad idea...

Might be road tripping from Ireland - Depends on getting a few people to split ferry and diesel of course ...

If you want a bit of modulation a Louise is very good, if you want epic levels of bite and hold Hope trials disks are unmatched... The only downside of the Hope on the back of my bike is that I'll never learn to manual because it's pretty much on or off with nothing between... Last bike I could manual any distance at all on had Magura Kool stop pads and a light dead grind (back in 'day )...

As far as I can see the best possible thing you should be able to say about your brake is that it's boring. If it behaves exactly as you expect it to every time you use it you've pretty much achieved the braking holy grail. Unless it's consistently bad all the time of course... I got a dual disk stock bike at the start of the year and I would be very slow to suffer rim brakes ever again...