trapezeartist

I have an Airoh and it’s super light and comfortable. 900 or 950 grams I think. My old Shoei full-face weighed about 1700! I was tempted by the Zona 5 with the built in visor but was slightly put off by the 1200 gram weight.

Broadly like misscrabstick has said. It opens up the possibility of adding throttle position to the ECU map. Imagine having full throttle at the twist grip giving only 25% at the FI for trickling round some tight turns. Then with a flick of a thumb switch you go to full “quick throttle” mode to blast up a big climb. Basically like the current mode switches, but doing something useful.

It is! Have you not tried it yet?

Perhaps a better application of new technology would be fly by-wire. You could have radically different engine characteristics to suit the immediate conditions just in front of your front wheel. Much more useful than the current mode switches.

If you fancy a day down at Fry’s, blow_away, let me know. It’s good to ride together.

I think they are still running the same engines after 20 years because there is no reason to develop anything fundamentally new. Trials bikes are a mature technology so minor tweaks are sufficient. If one manufacturer develops a hybrid and is successful, they’ll all follow suit. In the meantime it is more cost effective to steer the development budget into “exciting new graphics”.

Toni Bou and I ride totally different sections, so I don’t think that’s proof enough for me. Weight back and dodgy throttle control: that’s me! I know I’m too on-off with the throttle (Mick Andrews told me so) but I’m working on it. I do like that feeling of burbling around something with the engine hovering just above stalling. People are giving me totally mixed messages about grip on mud so I think I’ll just park that one. They are also telling me the Montesa doesn’t steer as well as the Beta. I know I’m not good on tight turns so I need all the help I can get. But as I can never get the steering over to full lock maybe it doesn’t matter. At least this is something I can easily get a feel for when trying a bike out.

That is the most useful response I’ve had from anywhere. Thank you lineaway. I was tending to veer down the Beta route and I think you’ve just confirmed it.

Well of course that’s the obvious solution. But getting access to bikes to have a proper ride on some proper sections is not so easy. A few figure-of-8s around a car park doesn’t really tell the story.

Right then Montesa fans. I’ve asked a similar question on the Sherco forum. Tell me why I should buy a Montesa and not a Beta 200 or 250. Or not, as the case may be. The reason for asking is I’m thinking of changing fron twin shock to modern and it’s really hard to get my head around the pros, cons, problems and model changes of the various manufacturers. I’ve g it myself reasonably well-educated on the Betas so I need to compare. My budget buys me a 2014-16 Beta so a Montesa would be somewhat older.

The Beta 4T is quiet. Not so sure about the Montesa. It’s also about the quality of the sound though. I think like-for-like a 2T has more potential to annoy non-petrolheads than a 4T.

Only 30 years? My trials hiatus was somewhat longer, and no road bikes, enduros or anything else in between. I started with a Beta 300 4T and it definitely got the better of me. I switched to a twin shock Fantic 200 and got on better. But after a year I’m going to switch back to a modern 200 or 250. The Fantic is a lovely bike and more knowledgeable people than me will say it’s the best twinshock bar none, but I think you have to have a passion for classic bikes to ride them, and I don’t have that. I will continue to enjoy riding with the classic clubs though.

That's a neat summary, Lineaway. Perhaps I need to go and start a Montesa v Beta thread. I definitely am not in the hop and bop contingent. One problem with the Montesa is that you have to go at least two years older for the same money. And the weight?

Indeed there are, section swept. And I'd be open to any, but the amount of information to be absorbed is pretty mind-blowing. Which year the significant changes came in? Which year there were problems. Which year it was a fiery beast and which year it was all soft and friendly. I started this thread because I think I'm getting on top of the Beta info but then saw an attractively priced advert for a Sherco, so I thought I'd ask.

I would be looking at a 2014-2016.

Right then, Sherco fans. Tell me why I should buy a Sherco 250 and not a Beta. Or not, as the case may be.

Remember, Yorkshiremen don't understand that there is anywhere except Yorkshire. No doubt it is a good centre for trials, but so is the Westcountry (in the widest sense of the word). Dartmoor and Exmoor provide brilliant trials territory. I live further north, but less than an hours drive gives me the option of the Mendips or the Cotswolds, or I could hop across the bridge (now free!) and sample the delights of Welsh Wales.

Not in any way that you would recognise today.

I was in at the beginning of National Type Approval, but we never got very far with Type Approval of the Delorean before the company turned up it's toes. All the work was development and self-cert for the US market. (And some interesting preliminary stuff on passive restraints.)

Interesting.

Good point about the engine running backwards, SectionSwept. My Fantic does that occasionally at the moment. The improved chuggability (is that even a word?) of the exhaust restrictor is attractive and I would guess it would also balance out any top-end boost that might come from the higher ports. Provided there isn't a heat issue (and you guys are reducing my concerns on that score) it sounds promising. I've just been doodling some calculations and it looks like a 1mm extra base gasket lowers the compression ratio from 9.0 to 8.0. That sounds about right. Easier starting would be a bonus too. Costs of the two compression ratio options are closer than expected. Assuming the head has to come off to change the base gasket, and the engine will end up with two base gaskets, that's going to cost about £70. A low compression head and head gasket will cost about £85. Whatever ends up being the solution, I fancy buying a 250 will be the way to go. Unless a good 200 lands in my lap.

Has anyone ever made sense of the quoted compression ratios in the official Beta specs? 125: 15.9 (totally unbelievable!) 250: 9.0 300: 10.9 200: different again, but I don't have the info to hand now

An extra base gasket is obviously similar to a low compression head. As well as affecting compression ratio, it will also increase the squish clearance which will also be good for softening power. It will raise the port heights too. I'm struggling to get my head around what that will do. The higher exhaust may reduce power as the last bit of pressure will be lost. Higher transfers might reduce low speed power and restore a bit of top end. Am I right? Richening it up is an interesting idea. As an ex-karter, I'm naturally disposed to running as lean as possible so I'm going to have to rethink this a bit. How did you do it? Main jet or needle position?

I've played with quick and slow throttles on another bike. When I was an even rawer novice than I am now, I thought the slow was good. But then I found that occasionally I wanted a good handful of throttle without needing to move my wrist too far. So I'm not a big fan, but it's a cheap mod and I would almost certainly give it a try. Washer in the head pipe, nhuskys? Do you mean the exhaust? I would be a bit concerned about the back pressure and the effect it might have on cylinder temperatures. And I would certainly expect it to affect carburation. I had thought about a restrictor in the inlet, but that's really no different to adding a throttle stop. And a throttle stop is not much different to a slow throttle where it becomes impractical to wind it all the way round. These are the reasons I was thinking about low compression or retarded ignition. They would hopefully tame the engine all the way through the rev range.

There's a general consensus around these parts that the Beta 200 is the ideal bike for novices and other riders of limited ability. The trouble is, in the secondhand market, 200s are as rare as virgins in Essex. So I got to wondering what it would take to tame a 250 down to 200 level. You can get low compression heads at modest cost. How much difference do they really make? What about retarding the ignition? For sure it would reduce peak power to a manageable level, but would it then hurt the responsiveness or the ability to trickle around on next-to-no revs? Is it even possible with the CDI ignition?