trapezeartist

I had a brief ride with a cable tie holding the PRB lever in a bit. As near as I could get to the right spot appeared to provide some "engine braking" but it also put a dead zone into the throttle movement. One click more on the cable tie and there was about 90 degrees of throttle movement before anything happened. All this was done on a sloping field. I didn't venture into anything resembling a section. However the result was sufficiently encouraging to persuade me to go the next step with a potentiometer wired in. The parts have come so I'll be doing that over the next few days and then I'll go out for a little ride and decide whether I can live with dead zone.

I tried a quick-and-dirty experiment today to validate the theory. With the bike on a stand, I gradually applied more PRB while blipping the throttle. The first little bit did nothing (of course) but then I found a little spot where the throttle still worked but the motor slowed quickly on closed throttle. A little more movement and the throttle was disabled. So that little bit in the middle is what I need to use. I considered simply putting a cable tie on the PRB lever and while it worked in the garage, it's not a robust solution for riding. So I've jumped in and ordered a 10k potentiometer (I don't think it's a multi-turn, but hopefully that won't matter) and a JST connector so that I can wire it into the PRB/FRB Y-piece. Both items are pre-wired so I only have to identify the correct wires and solder the ends together. It will be a few weeks before it's done because the JST connector has to come direct from China.

Thanks Konrad. I'm getting the idea now. I'm just struggling to find the right thing on Ebay now. Some are described as single-turn and others are multi-turn (presumably that's what I want) and most don't say. Also I need to find one with reasonably chunky terminals that will tolerate my somewhat clumsy soldering skills.

I am very comfortable with stop-allowed trials. At a higher level they do need a time limit, though that's probably not necessary at club level. A few years back I observed at an Experts trial and the observers were specifically told to strictly enforce no-stop. The observers weren't happy at having to dish out 5s for what were very good rides, and obviously the riders weren't happy. Some were obviously trying to hold it in to avoid being seen as abusive to observers. Now that really opens up a new can of worms. Personally I struggle to understand the fun of dropping over 100 marks every day, but the riders in that situation know what they've signed up for so I suppose they are happy with it. The SSDT is now almost unique in providing a single route for everyone. Whether that makes it an 'out-of-touch dinosaur' or a 'unique challenge' is a matter of personal opinion. Certainly an attempt to provide two routes would add massively to the complexity of the organisation and would require some regular sections to be replaced where there isn't two viable routes.

I've watched a lot of SSDT video and virtually every rider is making momentary stops. Giving them all a 5 would ruin the event because there would be no difference in score between a good performance and a total failure. I think nearly all riders, observers and spectators understand the difference between those marginal stops and a failure that should be marked a 5.

So somewhere between 0.6V and 1.1V is the sweet spot for engine braking. It seems like a very small window. Can it be controlled that accurately?

I don't understand how that works. As I read it, the potentiometer replaces the PRB and plugs into the PRB/FRB connector on the main loom. So it's the equivalent of pulling on a little bit of PRB all the time. But whenever the PRB is applied, the throttle is disabled. That was why I was trying wire something through the micro-switch in the throttle.

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