trapezeartist

Blimey, you learn something new every day. I've never heard of zerk fittings. This must be something new and hi-tech and wonderful! Googled it: just grease nipples. So to all those zerks out there, I'll continue to call them grease nipples. If you're going to clean down a bike with a pressure washer it's pretty inevitable that the blast of water is going to get into the bushes. After all, the swing arm and mono linkage area is just the bit where mud accumulates and is difficult to remove any other way. So the ability for easy, frequent greasing seems like basic engineering and should be designed it. But if it's not, I like breagh's suggestion of using chain lube. After all that's a lubricant designed to find it's way into inaccessible places.

Although a heat pump is a brilliant device in the right application, there are limitations, especially with air-source (reversible aircon). The Coefficient of Performance drops according to the temperature difference between the evaporator and condenser, so the CoP is not that great when outside temperatures are very low. Also the condenser is liable to icing if the outside temperature is below about 8oC, which further reduces CoP either due to the ice itself or a de-icing mode. Ground-source heat pumps are much better, but the installation cost is much higher.

It says it's 240v, yet American normal voltage is 110v. So I presume it uses a three-phase supply something like our 415v system. Unlikely to be available to a normal domestic consumer, is it? Lots of power though, so it should warm up a garage quickly, at a price! (Unless American electricity is disproportionately cheaper than in the UK.) (Or is a three-phase tariff cheaper?)

Don't use petrol ("gasoline" if you're a yank) for general cleaning. Use paraffin, which is much safer. Occasionally you may need to use acetone, but on those occasions go outside and do the cleaning. Back in the sixties my father's garage used paraffin-fired blower heaters in the workshop, and they never set anything on fire.More recently I've used an electric fan heater in a single-garage-sized space.

Following a couple of mentions of Jitsie, I just went and looked on their website. The HT1 weighs 1100g. They don't quote a weight for the HT2, but it is "designed in Belgium" . Airoh quote "from 900g" for the TRR but as everyone quote their weights as +/- 50g I imagine 950g would be a better figure for comparison.

Lighten up, guys! It's only a helmet. Anyway, given the diversity of opinions, it looks like I'll just have to follow those who are supporting my own prejudice. I'm inclined to think weight is not critical, within the range that we might be talking about. For comparison I've just weighed my old full-face karting helmet: 1600g! And my neck had to support that while cornering at 1.7-1.8g plus shock loads. Admittedly not for 4 hours at a stretch, but I think comfort will take precedence and unless I really feel the need for the visor on the Zone 5 I'll probably end up with one weighing under 1kg anyway.

Probably somewhere between "hardly any" and none, but unfortunately that's not the point. It's the perception that gets people worried. There are just too many ambulance-chasing parasites around. (You may detect that I am not a great fan of the so-called legal profession.)

Is the weight of a helmet significant in trials? A lot of helmet descriptions on the supplier websites seem to make a big thing of it, but I can't see it being the most crucial factor. Fair enough if you race a car and the g-force is trying to rip your head off, but not on a bike going at a walking pace, surely. As an example the Hebo Zone 4 weights 900g, and plenty of others weigh about 950g. But the Hebo 5 with built-in visor weighs 1200g. Trouble is, I quite like the idea of a built-in visor for protecting my eyes between sections.

I'll second that. When I started karting we were running narrow 3/8 pitch chain on a 9T sprocket spinning at 15000 rpm. Chains lasted about one and a half hours, if you were lucky.

Obviously the "perfect" answer is to change sprockets and chain at the same time. The pragmatic answer is less clear. Using a worn chain means that the effective pitch has increased, so instead of distributing the load all around the sprockets all the load will fall on one or two teeth at the top. That is going to accelerate wear on the sprockets. Using a worn sprocket will eventually cause the chain to jump a tooth under load. (My first trials bike bought in 1969 did that when I first got it.) But generally you will change it before it gets that bad. Using a hooked sprocket will wear the chain and make it snatchy. My own conclusion would be that you should change the chain when it's stretch measures outside the acknowledged limits (which I've forgotten!). No need to change the sprockets as long as they look good. Change a sprocket if you can see the wear or hooking.

It's very confusing about which make and which year are the user-friendly engines and which are the fire-breathers. I'm starting to accumulate a few notes now whenever I find a comment. Trouble is, there is cinflicting information at times. I definitely take the point about the 200, and when you're dithering between a 125 or a 250, 200 seems a good compromise. I don't think I've seen even one advertised though, since I've been looking around.

Yes, "needing work" is a bit of an issue for me with a twinshock. It's not so much getting it into god mechanical condition, which is just a matter of time and money, but doing the tweaks to make it reasonably competitive in the modern environment. There's a lot for me to learn in that area and it would be so easy to buy something unsuitable.

Portishead, so I can easily get to the Cotswolds, Somerset or Exmoor. Thanks especially to oni nou and doc_d for allaying any fears about a 250 trying to kill me. I think that's the way I'll be going, especially as there are more 250s for sale so it makes it easier to find the right one. What year did Gas Gas start fitting the two-map ignition? That sounds very useful, but I have already logged the thought that I may just retard the static ignition a bit if I find things a bit fiery at first.

Thanks for all the replies. As expected, there are opinions going both ways but it's the reasons that help me sort out which way to go. It looks like it's going to be Modern. A further bonus that no-one mentioned is that all the training videos assume the use of a Modern. There seem to be clubs and events around my way that run a class for Over-50s or Over-60s on Moderns, so I won't have to compete with kids who can ride up cliffs and jump chasms.

Notwithstanding my other post that sort of assumes Modern, I'm still a bit split between Twinshock and Modern. When I sit here looking at photos and videos and whatever, the twinshocks seem to have the appeal. Then when I go to a trial, I come home fancying a modern bike. So come on experienced forumites: which way should I jump?

I'm coming back to trials after a short break (44 years), so I have to consider myself a total novice. One piece of advice I was given was to go for a 125 bike as it would be sufficient power but not enough to bite me. I have a little bit of a reservation about this. Is a 250 really going to be that unfriendly (I'm well aware of the need to avoid a 280/290/300)? I weigh about 80kg in riding gear, so rather more than the average youth rider that the 125s are aimed at, I would have thought. So as well as having to drag around a bit of extra weight, is a 125 going to be too lightly sprung for me?

And there was me thinking it had something to do with bacon, lettuce and tomato.

Thanks lowbrow. I managed to find a phone number on the AMCA website (eventually!) and confirmed that the trial is on.

Is there a trial at Breakheart this weekend? I've seen it on a fixture list but I can't find confirmation anywhere.

Nice one, Rabie. A voice of reason and clarity.

Back in the good-old bad-old days we used a rubber bulb blowing through a reed and a 6 inch metal cone. They were utterly pathetic and some didn't work at all. At machine examination, if one didn't work, every else in the queue blew theirs and the examiner would pass it.

Brilliant plan. He's a lucky Dad.

You've almost convinced me , but you've thrown a slight doubt onto something that I thought was a strength: the finish. A zinc-plate-and-passivate finish should be durable but I suppose if the passivation isn't done right then you've got plain zinc and that's quickly going to form a white powdery oxide. Is that what you're suggesting?

Getting back to first principles, motor insurance companies want to know about all your other motor claims because that may affect their assessment of the risk. That seems to me to be fair enough. If you fell off your Fireblade in the High Street, that may reflect on your level of risk when driving your car. HOWEVER, if you had your computer stolen from your house, that wouldn't affect your risk as a driver and there is no reason why you should declare that on a car proposal form. In my view, and I think this is what the OP is getting at, the second analogy is the one that is appropriate to having a trials bike stolen from a garage. With the benefit of hindsight, perhaps the bike should have been included on the house insurance as a high value item, rather like you might insure a pushbike or a piece of jewellery.

I'm thinking of coming back to trials after a very long sabbatical. Having looked around this forum and hoovered up as much information as possible from other places, it's clear that it's a very different world to the one I left. So while on the lookout for a bike I'm trying to understand the maintenance implications: What is the correct interval for changing gearbox oil? What is the best way to clean/lube a chain? What sort of life should I expect from tyres/chain/wheel bearings/head bearings/brake pads and any other consumables? I've seen a few people quoting life in hours. How do you measure "hours" on a trials bike? What other frequent (or infrequent) maintenance tasks have I missed? Please be gentle on me.