trapezeartist

I raised this as one of my points on this other thread but it was too many questions at once, and most of it has fallen by the wayside now anyway. So I thought I would address this one question again. My aim is to achieve a little bit of engine braking with the throttle closed, similar to a petrol bike. The Mecatecno I tried had this. Having studied the information on konrad's website, I'm proposing to use the microswitch in the Domino throttle to feed about 1 volt into the PRB connector. I'll use the PRB/FRB Y-piece to actually make the connection at that end, meaning of course that the FRB won't work, but that doesn't matter. To get the 1 volt, I'm hoping to pick up 5 volts from the feed to the throttle (or maybe the lighting DC/DC converter) and use a converter like this https://www.amazon.co.uk/gp/product/B07DK6WN63/ref=pe_4074371_1338459331_em_1p_1_lm. Does that make sense, konrad? If that's all OK, my only issue now is to understand the wiring colours. According to konrad's website, the main wires from the throttle are blue, white and black but I've got a connector marked T1 going into the throttle connector that has red, black and blue. The standard (non-EM) version of the throttle has blue, white and black, and the micro-switch wires are both green. However I've got a connector marked T2 that has white, brown and yellow. If I ever manage to sort out the conundrum above, I also intend to add an on/off switch on the handlebars to switch the engine braking on and off. Any thoughts?

The jerkiness on the clutch dates back to when I had petrol bikes. I've never used the clutch on my EM. Given the complexity of access to the clutch, I think I'll just go for some extended practice before diving into the alignment. Those Ergo levers look very interesting. I currently use Apico short levers but could certainly live with something shorter. I might give them a go for both clutch and brake.

EM Connect can be retrofitted to a 2023, but without the new display. However it is pretty uneconomic: £500 plus sending the bike back to Inch Perfect which is at the other end of the country. So that option is out. I can only find one OPTION connector, which is being used for TKO. Inch Perfect confirmed that. My understanding of electrickery stops at Ohm's Law. I did read up on voltage dividers and it pretty much puddled my brain when it came to devising a practical application. If I tried to do this I think it would probably go horribly wrong. It would also need a A/B handlebar switch to swap between normal maps and soft maps but I can't find such a thing. They are all on/off or horn-type buttons. Meanwhile your Regen Experiments page (https://www.electricmotiontech.com/home/em-epure-race/regen-experiments) has given me an idea for getting a bit of throttle-off engine braking. I'm going to be offline for a few days but will return to the subject and may try to consult you again on that.

Unfortunately the '24 command switch wouldn't work on my bike. It connects into the display, not straight into the controller, and presumably the display does something with the signal before sending the necessary to the controller. I think I'm back to learning how to slip the clutch smoothly.

That would be just the job, if it will work with a '23. I think there is a good chance as '23 and '24 are broadly the same bike. I'll give Symon a call today. Thanks.

I have now been riding an EM for 4 years but there are still things I think could be done better, and I'm wondering if they are possible. I would like to have a little bit of "engine braking" when the throttle is closed. I quite like the idea of the "Finger Throttle" on this page, https://www.electricmotiontech.com/home/em-epure-race/regen-experiments. If I understand correctly, this would be a straight bolt-on if I could get the right finger throttle. It could replace the present PRB-R (2023 bike) and the 0.8 volt would provide the engine braking. Right? I only ever use green and blue maps so I would like to get rid of the red map so that the sequence would be white-green-blue-green-blue-etc. I assume that is not possible as that stuff is presumably locked into the controller. My aim is to easily switch maps part way through a section. I've done it once or twice going from green to blue but I don't like the idea of going the other way as it would require two pushes of the button. There seems to be a danger of a hurried push-push becoming just one push and that might present a little surprise when going back on the throttle. The purpose is to get the punch of the blue map for climbs and banks but the sensitivity of green for tight turns. I'm thinking of a couple of other solutions. One would be to slip the clutch in blue but I haven't touched the clutch in all the time I've had EMs and I was a bit jerky with the clutch way back when I had a petrol bike. The other thought is to have the training button up on the handlebars in the form of push-and-release. So hopefully the detuned blue map would behave like green or perhaps even a little bit milder. I was looking at https://www.electricmotiontech.com/home/em-epure-race/wiring-diagram and it seems to suggest that the training map used the OPTION port on the controller up to 2021 and that then became the PRB from 2022 onwards. However PRB and FRB seem to just deliver variable or fixed voltage to the same port yet FRB was available on 2021 so how did they get training map and FRB then? Maybe I'm not understanding this right. I've found a blanked-off connector coming out of the controller with green, yellow and black wires. What does that do? I've just removed the lighting circuit from my bike in order to simplify the wiring a bit. I was also concerned that the 12v DC/DC converter was wired direct to the main battery without a fuse, though I've found a fuse on my 2023 that wasn't there on the 2021. No matter, I had already removed the front light so it makes sense to get rid of the back as well and simplify things a bit. Just out of interest, there was another blanked-off connector on the lighting harness with yellow and black wires, labelled S?BD (It's hard to read but I think that's it). Anyone know what that might do?

It makes sense to me too. That's the way Inch Perfect work with EMs. However, I think (just my feeling, no facts) they are selling a lot more bikes in their area than in other parts of the country. And the UK is a lot smaller than the USA.

"All Models Arriving Spring of 2021". That doesn't fill me with confidence.

Moving on to the front brake, I find it fiddly to install the front brake pads, anti-rattle spring and retaining pin before fitting the calliper to the forks. So I made this guide to hold the pads in place while the calliper is being fitted. Once it's bolted on, insert the retaining pin and push the guide out, tucking the anti-rattle spring in place as it goes. https://www.thingiverse.com/thing:6977705

It's good enough to use. Did a trial last weekend with no issues.

It was a slight (invisible) distortion of the housing caused by the bike landing upside-down. After much fiddling, poking and swearing I identified that when the half of the clamp that is integral with the housing was pressed hard against the handlebar, the throttle tube was binding against the bar. I couldn't get it to work by packing with a thin piece of plastic so used about three turns of PVC tape around the bar. I still can't tighten the screws as much as I would like but it is working now.

It's hard to tell, but I think that is the same length as the car version. I carry one bike in my Doblo car quite easily. It's a wheelchair conversion so the floor is lower giving extra headroom. OTOH I lose quite a lot of length due to the ramp.

I've just come across an issue with my Domino throttle. After a small inversion that has left the throttle with a minor scar in the plastic (which may be a red herring), it has become sticky. Off the bike or with the clamp screws loose, it is fine. As soon as I start to tighten the clamp screws the self-closing disappears. I've tried packing the clamps with a thin piece of plastic: no good. I've tried tightening the clamp screws with the throttle off the handlebar and it works fine. Any ideas? I'm reluctant to take the throttle apart because of the return spring and the alignment of the gears, but that is looking like it will have to be my next move.

Thanks chaps. But it wasn't intended as a trick question, Lineaway.

I have to agree with you. I'm all in favour of a time limit to keep the show from stagnating, but let's not turn it into a race. Also the point in a section where a rider gets a 5 does have an influence on the overall timing, which really makes that aspect a lottery. Perhaps a time limit (not necessarily the same every time) for each section would be much better than an overall limit for 5 or 6 sections.

If you're going to be miles from your car, surely personal safety comes into the equation too. Really, you shouldn't be riding alone, so that extremely comprehensive kit could be shared between the riders.

I broke the lever lug off my front brake master cylinder at the weekend so I need a new master cylinder. Are AJP and Braktec the same thing? I thought they were different but I've seen them advertised as the same.

I made a tool for holding the rear brake pads apart while fitting the rear wheel. It should work with any brake using a 3mm disc. There are two versions: V1 is the stronger one but needs the printer settings to be tweaked just right to make it a snug fit between the pads. V2 is more tolerant of a slight variation in dimensions but is probably less durable (but if you break it, just print another one). https://www.thingiverse.com/thing:6947125

I'm fairly new to the PRBR and have only done about 3 trials with it. Having previously had a FRB, I am still teaching my finger to use it in a progressive manner. Sometimes I just give it a small pull and expect the full effect, and other times I seem to pull it all the way back whatever. It's just a matter of getting used to it, I hope. I've also found the PRBR lever a bit difficult to reach at times. I had a rather alarming descent at the last trial when I missed the PRBR lever, then grabbed for anything in a hurry and got the clutch. More "getting used to" required. I don't use the clutch but I wouldn't remove it. I did consider replacing the clutch with the rear brake for a better feel, but I do want to learn to use the clutch someday. I don't think the PRBR totally replaces the rear brake either. Sometimes you need to lock the back wheel and only the friction brake will do that except in extreme conditions. You also have to learn that you can't feather from brake to throttle with the PRBR (or FRB) so sometimes you need to release the PRBR near the bottom of something and use a tiny bit of rear brake as you are transitioning to the throttle. If you open the throttle while the PRBR is on, nothing happens, so you give some more throttle, and then you get a bit of a surprise when you do come off the PRBR! I wish they had given the thing a better name too. It's such a mouthful.

I have always assumed it's manual. And they seem to give the rider a small amount of margin.

Following cascao's lead, I've now put the number board on Thingiverse for anyone who wants to make one. https://www.thingiverse.com/thing:6940919

The dummy brake pad is a neat idea. I currently use a cable tie to hold the pads apart while putting in the back wheel, but it's not a perfect system. I think I'll try making something as a spacer with a nice little handle on the top for pulling it out. A similar idea could work on the front too.

Way up near the start of this thread someone (ChrisCH I think) mentioned the virtues of "liquid hydrocarbons" as a fuel. That doesn't have to mean petrol, or any other petroleum derivative. There is a lot of work going into synthetic fuels and they have the advantage of running perfectly well in engines originally designed for petrol so all the millions of existing vehicles could use it. Even a pre-65 trials bike can go green, if you ignore the cloud of oil smoke following it around. A number of UK car racing classes are already using "sustainable" fuel (mostly alcohol-based) but synthetic fuels will come. Think of the chemical equation of the combustion of fuel. If you put energy in instead of taking energy out you can completely reverse it. At the moment the sustainable fuels are expensive, but economies of scale will bring that down. Then the only problem is how to produce enough electricity in a green way to support EVs, manufacture of synthetic fuel, domestic heat pumps and all the other things.

I have a new back tyre about once a year, and I've never changed a front in the time I've owned each bike. So in effect I'm spending about £160/year on tyres. That's the least I've ever spent on tyres in any of the motor sport disciplines I've indulged in. For the moment, I'm perfectly happy with that. If ever someone came out with some super-trick tyre that only lasted a couple of trials or cost £500 a pop, I would definitely want to re-address that. Something I've never quite understood is why all trials tyres have exactly the same tread pattern. Is there some long-standing rule somewhere that defines a trials tyre? Or has it been shown that that is the best solution to the problem? I would have thought an enduro/motocross pattern would be better in mud, though probably worse on rocks. When you look at something like X-Trial, I could imagine there being a benefiting using slicks.

I think you've got too much time on your hands. I've never done such a thing; it all comes off pretty quickly with use. Think of the F1 teams that didn't even bother to remove the paper sticky labels when they sent a car out on new tyres. The labels were gone after a couple of corners.