I'm having to replace the RH Crank main seal (bike was consuming gearbox oil) so while I'm in there I thought about replacing the water pump seals as preventative maintenance.
In the end I decided 'if it's not broken, don't fix it'. I'll probably regret that, the bike's got 280 hours without any pump problems but I'm probably pushing a friendship at this stage.
I did take the impeller off to take a look and found that it has been rubbing on the housing. It's caused a small amount of galling on the back of the impeller, some flakes of plastic in under there and obvious rubbing wear on the housing.
My solution was to put the impeller in the lathe and take about 0.5mm out of the back recess. I checked periodically with bearing blue until I just had full clearance.
There was slight rubbing at the perimeter flange too but I solved that by rubbing the impeller on some wet & dry on a flat surface.
Previously I could hear the rubbing when I turned the impeller up to my ear. Now that's all gone. Pic after machining.
Hopefully this will avoid debris in the coolant, possible damage to the outside seal and potential failure of the impeller.
As an aside, just in case anyone comes looking:
The Primary Gear Bolt is RH thread with Loctite 243 on it. It took a really solid go at it with heat and a pneumatic impact wrench to get it off. I snapped one hex driver (not a top quality driver).
The seal, bush and O Ring all need replacing at the same time.
Pretty easy to remove the seal - pull the bush out with a couple of magnets then lever out the seal.
I've stripped the potting out of the old one with the intention of trying to find the failed component. I suspect it could be something cheap and easy to fix like a capacitor. But of course once the bike is running nicely the motivation to spend time locating a solved problem is very low!
Just a follow up.
I put a 1.5mm rubber washer cut from insertion rubber sheet between the top triple clamp and the nut. My thinking was the rubber would stop the nut from rotating.
It seems to have worked extremely well. I've not had any more trouble at all. Haven't had to touch it in the past 80 hours of riding.
A cheap easy fix. I suspect slipping an O Ring in there would do the job too.
When I follow that link from the US, it says, "$11,980.00 Tax included. Shipping calculated at checkout."
Yes, dollars. I realize your price includes VAT, whereas mine would not. But that can't possibly be right.
I get $18,158. Presumably AU$ for me. 1.5 times the cost of an ICE bike & still need to add in shipping & local taxes. I see a very niche market for this bike unless it is actually better performing than current ICE bikes!
I'll be interested to see the final AU distributor's pricing.
Yes. The OEM caliper wore grooves that affected function in just a couple of hundred hours. That can and should be improved.
8 hours ago, lemur said:
are you trying to build up a dimension on the brake pad steel backing plate?
No. Take a moment to look at the picture again and you should see the shim I made is in the front of the caliper where the pads bear on the caliper body. Where I photographed the cleaned up wear grooves as described in the post two above my 'solution' post. (below)
On 3/5/2024 at 6:37 AM, hugo_furst said:
Grooves where the steel plate of the brake pad rides on the aluminum caliper. Trials bike brakes usually lack the stainless steel protector found on Nissin and Brembo MX/enduro brakes.
9 hours ago, lemur said:
why not use JB weld epoxy
I like JB weld, but I'm not at all convinced that it's sufficiently hard, strong and abrasion resistant enough in thin sections to outperform aluminium. Maybe it is, but I'm not sufficiently confident to spend time on it.
I think some thin 1/2 hard stainless sheet would be far superior.
m As far as the m/c goes the seal does not seat properly, so you screw the tensioner bolt tighter. Once the brakes start heating everything goes bad. Good luck.
That can certainly be a problem, but I'm careful to keep the required free play, and if in doubt I take the top off to check for that little pulse of return fluid.
I did wonder if maybe I had too much fluid in the reservoir so the expanding fluid had nowhere to go, but I backed off the m/c cap screws while it was still hot and holding brakes and it didn't make any difference.
The master cylinder is probably junk. If you had a good brake guy, he could clean up the surface inside and just use a rebuild kit. Myself I would buy a new m/c and start over. I dislike what is normally the quota flow. There are several after market options. Nissin and a few others are available, but pricey and not a whole kit. I threw away the braktec`s on my Montesa 301 as I had been down this path before ( I still have a nissin m/c to an ajp caliper as a spare} I run the large ajp m/c to the TRS gold front caliper. Strong and dependable. You don`t want to ask about my clutch. LOL
I think I have it licked without any work on the m/c.
As the video in the post I just made shows, the m/c doesn't have anything much to do with piston retraction so this problem is unlikely to be caused by anything happening at the handlebars. The brakes always went on a treat, no complaints at all - it was just the release that was a problem.
Thanks for all the advice, including a key PM from @konrad
I was under the misapprehension that the retraction of the master cylinder piston before the feed hole opened was the main cause of retraction. I believe I've previously heard it's actually the seals, but it apparently went straight out the other ear.
The front of the caliper did have grooves from the pads bearing on it. I'd given them a bit of a file to reduce them but @hugo_furst's prompting encouraged me to clean them right up. I'd looked for that due to the way a slight rollback helped to release the drag somewhat.
So today I took the caliper apart again.
This time I inspected the seals carefully and could see slight ridges where they have been extruding past the groove on the outer side. The grooves appeared quite clean but I gave them extra attention and replaced the seals flipped from their original position so the ridges are now on the interior side. The seals felt quite supple.
I filed and scraped the pad bearing surfaces flat and square. I also filed the edges of the pads to remove the stamping roughness and put a small radius on the edges, hopefully this will reduce the scraping on the caliper surface and reduce future grooving.
I tried making a stainless wear plate but there is very, very little clearance around the pistons so I would need to do some more excavation of the caliper body to fit any stainless I have here in there - 1mm was too thick. Perhaps 0.5mm sheet might fit, but it needs to be carefully shaped to sit clear of the piston. Another day perhaps.
Now reassembled and very thoroughly bled.
They feel better than they have for a long time. Complete release with no noticeable drag at all. Hooray.
I'll try to remember to report back after they've got some hours on them to say if it's a lasting or temporary fix.
Thanks everyone.
EDIT. I forgot to add - Konrad sent me a link to this video showing quite clearly that it's the seals not the master cylinder that actuates the piston retraction.
I should also say - probably the 'correct' solution for this is a new seal kit. But I'm your typical tight trials rider so I'd rather spend hours faffing about than spend $100 on a kit! Besides, I learnt something new.
@bikerpet as you obviously know what you are doing all I can think of is that you have a crimped/kinked hose and the crushed part of it is not allowing full flow on the brake fluid return to the reservoir so stopping the brake pistons from backing off, it may be worth a check just to tick it off the list.
Good suggestion, I'll take a careful look. Although I can't recall seeing anything remotely looking like damage. You never know if you don't look though.
Thinking about it, it seems very unlikely - when I was bleeding with the syringe I could get a very generous flow up the hose with quite little pressure. Hmmm.
I obviously don't know what I'm doing because I haven't solved it!
The front caliper on my '21 TRS has an annoying tendency to drag constantly and I can't seem to fix it.
Couple of days ago on a long steep descent it overheated so badly I completely lost front brake. It wasn't from over use of the brake, it's a hill I've been riding a couple of times a week for quite a few years on a variety of bikes. I am very careful how I use the brakes and it's not a problem. But this time the brake was dragging really quite hard - it would start to skid a little on flat, loose dirt with no brake applied. I took it very carefully down trying not to use front brake at all, but it still completely overheated to the point of the disc just beginning to blue at one point!
Sometimes it releases a little better if I roll the bike backwards a bit.
I'm not sure it hasn't always had a bit of drag from new, but it certainly didn't bother me until recently.
Bike has about 250 hours, I ride on some moderately hilly terrain.
I've checked the fluid return hole is well and truly open when the lever is at rest.
Replaced pads.
I've removed the pistons and cleaned bores and pistons.
Re-filled and bled.
Still got more drag than I think it should - serviceable but not ideal.
I'm not totally convinced that perhaps my bleed is leaving a tiny pocket of air that's preventing the pads completely sucking back off the disc, but I'd be a bit surprised. I finished the last bleed with the caliper off the bike with a syringe on the nipple and giving the caliper good taps as I rotated it into different positions trying to encourage every last bubble to the bleed nipple. It's sitting overnight with a strap on the lever at present.
Rules for sports are completely arbitrary however you look at them. Why do we not put our feet down? Because we all agree that might be a fun little game to play. Why do golfers hit balls into little holes in the ground? Because they think that's a fun challenge.
So really what's the big deal if one group of players decide they agree to stop and go backwards for a bit? The best rider will still win if they compete according to the current (arbitrary) rules - that's the nature of competition.
It's also complete fantasy land to think that any form of non-stop or non-reverse is going to be able to be effectively judged. If they hop the front wheel, then the back, then the front, have they stopped? If they are headed generally right and they hop the front wheel left, then the rear left have they gone backwards? If you can hop a wheel away from an obstacle or barrier it's trivial to sequence the hops so you effectively give yourself room without a wheel ever turning backwards.
You'd have to be dreaming to think any observer is ever going to assess that accurately, consistently and fairly throughout two days of riding! Get real.
However ... the issue about the top of the sport not fostering a good pathway is real. I've got no trials experience outside my very limited local club riding world, but it's not hard to see that the current TrialGP and support class setup isn't proving to be a big winner for the sport overall. Fiddling with the rules here & there wont make a jot of difference to that.
It must cost a fair whack to ride a full season in any of the international classes - travel, entry, inability to work, bikes, minder, ...
So who's going to spend all that money? Most likely Mum's and Dad's who are supporting their kids in their passion.
Then those kids get bigger and the Bank of Mum & Dad starts to dry up.
Now they need to make some sort of living and still find time to train and compete. That living is extremely unlikely to come from the sport itself! So what happens? They ride for a couple of seasons and then say, "Man, this is way too hard! I'm sick of struggling to pay for the next meal or to fill the van to get to the next event. I quit."
So the already small field shrinks until finally there are half a dozen riders who command the lion's share of whatever money is available within the sport and can actually afford to dedicate their lives to a riding "career". In reality there's probably well less than a handful really making a worthwhile living out of it. Just guessing.
These riders who have the ability to spend years focused on developing their skills get good - really good. So the up & coming have no hope of really competing with them. The doorway to the dollars really only opens up when one of the true elite riders retires or falls off the pedestal.
That career is what? 10 - 15 years for most of them at the top? That's pretty good in sporting terms, so the relatively rubbish income (compared to tennis, golf, running, cycling ... any number of other sports) isn't a complete disaster.
That's never going to work!
The heyday of trials was when the top riders were really not much different from the run-of-the-mill riders. From what I understand most of them held down "real" jobs, travelled around on the smell of an oily rag and squeezed practice in between. Gradually the sport "professionalised" and concurrently went into decline. I could be wrong on that timing, I'm no student of trials history. If I'm more or less correct, there's the trigger for the disconnect between the elite and the grass-roots, not changes in rules.
Follow the money!
You might argue that most sports have gone a similar way and most of them remain successful. I'd suggest that trials just doesn't have the same mass appeal as "most sports". Speed is an easy sell to a lot of the population. Kicking, throwing or hitting balls is eminently accessible to a huge % of the population.
Trials is fundamentally a harder 'sell'. Where's the fun in riding really slowly? What do you mean I'll basically be rubbish for a good 5+ years?It's not like any number of sports where you can acquire the basic skill then hone it. How many years does it take most people to learn to get any real vertical lift off a horizontal surface? Or even to learn to hop front & rear, let alone hop ON the rear! I could go out and race around an MX track, albeit crazy slowly, and probably demonstrate all the fundamental skills of the pros - wheelie out from the start, get some air, perhaps even step the back of the bike a little bit sideways. No way known I can demonstrate a majority of the skills of the riders at TrialGP in any shape or form!
Dicking about with the details of the rules is irrelevant if you actually want to grow numbers, and I don't think that's on FIM's agenda at all frankly. They may give it lip service, but that's not what directly pays the bills. Follow the money.
The single biggest change to the rules that would make a difference would be to cap sponsorship to something fairly insignifcant. The full-time, fully supported pro's would evaporate, the skill level would come back down slightly and appear more achievable (even if it's not really) and you'd have a whole lot more people who felt they could have a decent crack at international level comps based on skill not money.
Perhaps even people who aren't Spanish!
I laugh at the way the term 'Pro' is bandied about for riders who are really as amateur as it comes. Not saying they are poor riders, just that in the true sense of the word they are not pro's because they aren't paid just to ride. That's a Pro in my mind. I don't see any "professional" engineers who work a second job so they can do engineering in exchange for a new PC every year!
So go for it I say. Let the tip of the elites play whatever game they agree to. All good. They'll still be spectacular to watch and be just as far removed from anything I'm going to be doing on my bike.
That's an interesting point of view. I have just a couple of things to add:
1. Max speed can be limited electronically on an electric motor. It doesn't have to rely on the motor running out of revs.
Yes, but when and how do you limit the speed? If you flick a switch that limits speed before a step, what happens at the top of the step when you now want to go much faster for the bigger second step? As soon as you introduce a control-ability you also need to provide means to manipulate it. Or you make it fully automatic and take it completely out of the rider's hands, eg. traction control, ABS, stability control - that's no longer trials as far as I'm concerned, boring.
11 hours ago, trapezeartist said:
2. The energy stored in a flywheel is proportional to the square of radius, not directly proportional. Hence high energy storage in a flywheel without a big overall weight penalty requires both speed and radius.
True, my error. Speed and radius are somewhat interchangeable but various physical realities can weight toward one or the other - space, material strength, cost. It's pretty hard to fit big diameter flywheels into the drive train of trials bikes, so speed becomes the more easily altered variable at a certain point.
11 hours ago, trapezeartist said:
3. At my level, motor torque is enough. At TrialGP level riders clearly need a big kick from a flywheel as well as motor torque. The question is, at what skill level does the crossover occur. I would submit that it comes in at a higher level on an electric bike due to the torque characteristics v. petrol. On petrol maybe the crossover occurs between Sportsman and Clubman. With electric, between Sportsman and Expert.
This is a far bigger topic than we want to cover here, but:
I'd argue that if motor torque is enough (without significant flywheel) then you're selling yourself short.
At TGP level the big kick is what we see and is so obvious, but what happens after that is just as important. Control and delivery of power is as important if not more so than absolute power. What they do is really only an extension far, far up the scale of your basic rollup - accelerate before the slope/obstacle, then let inertia (flywheel, bike & rider) carry you up. But they are doing all that in a few hundred milliseconds while turning themselves over backwards with their hips at the bars and doing who knows what else. Aint going to happen on throttle control alone, that's for sure. So that control is coming in part from a controllable, repeatable release of energy. And that characteristic is just as useful to a beginner as it is to a GP rider.
So I don't see there being a crossover point really. It's a continuum.
When I put a total beginner on a trials bike I turn up the idle a little so it wont stall so easily, then have them ignore the throttle and ride purely on clutch so they learn that the clutch is the most important control, not the throttle. From there it's just progressively developing clutch & throttle skills along the way, and bringing in more and more use of flywheel inertia.
I do this on both electric and ICE bikes (no, I don't turn off electric 'idle' for beginners, and yes my e-trials has a big, heavy flywheel & hydraulic clutch).
6 hours ago, rotors7 said:
This was the Mecatecno five years ago, with a gearbox.
It's interesting that their current bike is gear free, were they just after a super light bike or did they feel gears were unnecessary.
They've obviously got the facility to produce the gearbox should it be needed to compete with the EM.
I was so sad when they released the production version with no gearbox. Pretty much lost interest immediately.
My guess is that they 1. wanted to save cost, and 2. without sufficient flywheel they didn't get anywhere near the benefit out of the 'box to justify the cost.
Trials bikes power delivery systems have been finely honed over decades, it borders on stupidity to throw most of it out the window and start from scratch rather than start with what's proven and then work out what the new motor can get away without.
"Oh you ICE bike engineers have settled on engines that rev to around 10k, have big flywheels, large clutches and 5 gears. Right, well we're putting in a different spinny thing instead of your piston motor, so we're going to halve the RPM, throw out the clutch, the flywheel and the 5 gears." Brilliant.
Now much of a decade or so down the track and where are we?
Oh look, engine RPM has gone up dramatically, the clutch is looking suspiciously similar to an ICE bike, we've got 4 gears instead of 1 and I rather suspect the energy storage in the system is going to look fairly similar to an ICE bike. What a surprise! 🤣
🔥 (dons flameproof suit). Why is it that so many electronics type people can only see electronic solutions to mechanical problems? We end up with the "simple solution" being an insanely complex electronic/software system.
EM & their first attempt at an electronic clutch.
Or pretending that accelerating an electric motor is exactly the same as decelerating a flywheel.
Or cars that have touch screens with 532 different icons and menu items that you have to learn to navigate just to shift the heat from your feet to the windscreen - ever heard of a knob with discrete positions?
Drives me nuts!
yes, yes, I know. It's actually the bean counters who figure they can save 10c by adding software rather than putting in a knob. It's a conspiracy!
I blame the Golgofrinchans.
6 hours ago, konrad said:
I reasoned that an EV with a gearbox introduces an extra complication for the electronics.
I don't see that as a serious issue on an e-trials bike. How often do you really need to shift down gears on the roll on an e-trials? Pretty much never.
Just take a look at what the current single speed bikes can do in 'top' gear, and how we operate our peaky ICE bikes. It's staggeringly rare to drop down the gears while on the roll in a section, even rarer to do so while anywhere even vaguely close top RPM. Add in regen braking instead of using engine braking ...
Inhibit shifting on the fly (just build a really **** shifting gearbox, which the Spanish tend toward already) or move the gear lever where it's harder to reach, or throw in some electrical control if the shifter is moved while rolling ... many ways to kill that cat.
Given that usable torque is available over a huge speed range, I'm still struggling to understand the benefits of a 4-speed gearbox.
You're in the company of a lot of people, but I think it reflects a common misunderstanding. I completely understand how it's arrived at, I just don't think it takes into account some of the key aspects of trials.
For people like yourself riding easy route and without clutched maneuvers then you're probably on the money. But as soon as you start looking at maneuvers where the clutch is used it changes dramatically, even at relatively modest skill levels.
If you take something at the more extreme end of the scale, a splatter onto a big vertical say, then gearing becomes dramatically important. You want to accelerate from virtually stationary incredibly quickly in order to rotate the bike and generate lift. However you only want to accelerate to a relatively low speed (you really don't want the back wheel to hit that face at 50kmh!). So how do you accelerate super fast to a very low top speed? Answer - use a low gear. Using a high gear makes it virtually impossible to limit the top speed and extremely hard to get that really, really fast acceleration. Yes, the guns will use 2nd, 3rd & even 4th gear for some obstacles, but I believe they are selecting the gear to adjust their target top speed more than anything, which reinforces the idea that gears are really very useful. The same principle holds throughout the skill levels.
Bikes like the Pure Race and the Dragonfly with just one gear capable of 50-60kmh are massively limited in their ability to produce radically fast acceleration and low top speed.
I think there's also considerably more detail in there around why it's hard to replace a flywheel/clutch, but that's the crux of it.
I've had an electric trials with a 2-speed box, and I can absolutely say that it is dramatically different having that low 'trials' gear compared to just a single 'trail' gear.
I'm not convinced you need 4 gears, maybe 3. But making a 3 speed shifter is the same as a 4 speed except for the missing gear wheel - you might as well put in all 4 for the few extra grams.
The 17,000 rpm motor represents a massive upgrade, to my thinking. I've long thought the prevailing wisdom that trials needs a slow torquey motor is a big misunderstanding once you move beyond easy-route riding. The basis for my belief is that A. There is as yet no practical replacement for a flywheel & B. flywheels store energy proportional to the square of their RPM and diameter but directly proportional to mass, so it is more weight efficient to either spin a flywheel fast or make it larger diameter. It's harder to fit a big flywheel into the drivetrain of a trials bike than it is to make an electric motor spin faster, so best reward is likely to come from a high revving motor.
There is effectively almost no difference between useable torque at the tyre from a slow motor geared down a small amount and a fast motor geared down a lot.
Overall you gain far more by spinning a fast motor than a slow one - if you have a flywheel involved.
EDIT: I was quite rightly corrected about energy increasing by the square of radius also, updated the paragraph above.
Seeing this 17K RPM figure makes me tend to agree with @konrad that the VW logo on the bike might possibly relate to the motor? It's pretty hard to find quality motors of this power level and that sort of RPM range - pretty limited number of niche manufacturers and they tend to be astronomically high prices. So perhaps a deal with VW has given them access to a higher volume production motor at a good price? Not sure what VW would need such a motor for, but they're a massive, sprawling empire so who knows what they have in the stable. No clue, just makes me wonder.
No mention of the new motor. Seems odd not to mention the heart of a motor-cycle. Looks considerably smaller so presumably higher RPM. That's a good thing I reckon - faster spinning flywheel.
Appears it's finally received a decent sized flywheel, and a clutch to match.
This could be the long awaited e-trials that starts to nip on the heels of the ICE bikes. I'm staggered it's taken so long to travel around the circle and recognise there's good reason for a big flywheel, clutch capable of using that flywheel and gears to adjust power delivery characteristics.
@jonnyc21 I've never felt like the plastic safety clips would be either secure enough or comfortable. But assumptions are completely unreliable.
I've plenty of neck lanyards with them so perhaps I'll give one a try.
The other option I've used on other applications is to just butt melt the ends of the cord/webbing together. It's a little inconsistent but it does make a fairly secure weak point. Perhaps with an appropriate simple tool it would be easy to get a fairly consistent join?
before changing out the cord from elastic to something thicker unless I was able to come up with some kind of brake-away at the top where my wrist is that I felt would save me in the event it was snagged in a drastic way.
I remember thinking along those lines ages ago, but I guess I just got used to the light webbing lanyard (a Beta OEM lanyard) I have and forgot about it.
That's exactly why the neck name tag lanyards have that little plastic breakaway clip. I don't think I'd want to rely on one of those, but something similar.
Industrial fall arrest shock absorber devices use rows of lengthwise sewing that tear away, absorbing force as they break. That could be appropriate - Z fold the ends of the webbing over (so the stitching isn't in straight shear - that would be too strong unless you had very few stitches which would be susceptible to wear) then a couple of lines of stitching. On high load the stitching will tear down it's length before separating. Join at the back of the wrist.
I might give it a go with some old neck lanyard webbing.
I can see a cottage industry making non-stretch, breakaway trials lanyards. Thinking tiny-house cottage, perhaps tent size cottage even. 😀
Jotagas seemed to disappear a few years ago, and their previous website seems to have disappeared.
But I stumbled upon G2 Grup the other day and lo and behold
So do Unicorns exist?
Is anyone selling these bikes again or is this just wishful thinking from a bygone era?
Who'd have thunk the humble kill switch would get so much discussion. 😁
Lanyards - anything non-stretchy. Webbing off a conference lanyard works nicely. Or fancy coloured boot laces. Or paracord available in a zillion colours. Used them all and nothing to pick between them in my opinion. Elastic is junk - I don't really understand why the pros use it still. Must be a reason, they don't do anything for no reason at that level. My guess is so it's maybe easier to get their score card/transponder out at end of section - might save a time penalty one day? But if your hands off the clutch the bikes probably not running anyway in that situation. A mystery.
Mounting - agree with the cable tie mount instead of the steel sticky-outy clamp (but I haven't taken my own advice on current bike).
I make sure the top of mine points forwards so it gets pushed on rather than off when struck, also makes it hang on a little tighter when jumping off, which is not a problem with non-stretch lanyard, and avoids the odd engine death when jumping off but not ejecting.
Top pointed forwards also completely avoids the really disappointing engine death when you do a successful leap up through the bars on a bigger obstacle ... and knock the button off with your hip. Grrr.
Pros have their clutches much further outboard than me for super quick clutch response, which would be a disaster for me. So mounting like them doesn't really work so well without a big long lanyard, I like mine shorter so they're less likely to snag.
Magnets - judiciously take a cigarette lighter to the plastic lip that holds the magnet in and mush it over a little more. Solves the falling out in seconds flat.
Polarity - As above quick heat with a cigarette lighter (damn, there's no one at events wearing a flat cap and a ciggy hanging out there mouth anymore, so lighters are at premium), flick the magnet out (or pull it out with another magnet) and turn it over. Heat seal back in.
Spare magnet - any old magnet of appropriate size stored on a handy bolt head. Under the top triple clamp on my TRS. Cylinder base bolts are often convenient and out of the way. Enough to get me back home.
Dan I'm not sure what you're saying is quite right. Many reed switches are change over and they don't care about polarity either. Just use the mode you want, NC or NO.
Lineaway has a thing about magnet lanyards - seems to hate them with a passion for reasons that escape me. Those non-magnet lanyards would truly **** me and I can hardly remember when a lanyard caused me more grief than a bit of inconvenience opening a gate cross handed. Horses for courses.
It could be the electric equivalent to Tenaci Wong. Are those still being sold? Budget trials bikes never seemed to sell well but at this low price it could.
Tenaci are still around I believe, but as you say few get sold. Why would you buy that when a secondhand European bike is probably around the same money?
The Leopard might do better because there are far fewer options available in electric at that sort of price. I've kind of got my doubts though.
8 hours ago, konrad said:
I don't believe 600 Nm at the rear wheel and a top speed of 62 mph with a single-speed gearbox.
They're Chinese Nm & mph, not western. 🙂
But I wholeheartedly agree with you, it's not going to be within cooee of that sort of performance.
Looks like I can post again. My prior post was in limbo awaiting moderation - perhaps because it contained a Facebook link? That link showed a water pump on the old GG design where there now appears to be an encoder.
My impression about the original Plettenberg design was that it used an "observer algorithm" in the controller. This is better than Hall sensors, but computationally intensive. An encoder is more expensive, but better for an application like motorsports.
Blocking Facebook links is an entirely laudable behaviour in my jaundiced view 🙂
Here's a link to the original YT video your FB link linked to. Plettenberg GG TXE
The Pletty conversion used a water cooled motor, hence the pump. Begs the question - if the new bulge is an encoder then where's the pump, or is the motor aircooled? And if it's air cooled what does that mean? Have they reduced power output to prevent overheating? Have they changed motors? Did they find they just didn't need water cooling? Have they improved heatsinking out to the rest of the motor/gearbox housing?
I look at that new end bulge and wonder if it isn't simply a support bearing for the motor shaft? It seems quite strange to me to hang an encoder off the outboard end of the motor shaft, especially when that outboard end is almost certainly running in an oil bath for the clutch.
Not sure where you got the impression the original Pletty had an observer algorithm, presumably there was some mention of it at the time. But it seems odd when there's no mention of sensorless operation of those motors in Pletty's manual, but it does say halls are standard and other encoding options available.
Anyway it's all rather moot given we don't know if they're still using Pletty motors.
Looking forward to more info or videos coming out from GG.
It seems the new e-GG has a smaller battery than the early one. Maybe just looks that way with it lying down rather than standing up.
This is where a Jotagas could be far nicer conversion - that side mounted shock would allow a battery to run right back into the airbox area, moving mass back and down. But I suspect the Jgas suspension just isn't as good with it's simple direct connection.
Yes, but pause the video at about 15 seconds. You can see a bulge on the motor casing that I'm thinking is a rotary encoder.I don't recall that on the German conversion.
I looked up Plettenberg's manual - they use Hall effect as standard, but can also supply other options. Surprised me a little.
But then it might not be a Plettenberg motor in this prototype, or this could be one of their "custom encoder and positioning sensors."
I expect 2 speed is sufficient, but reserve judgement that a second trials gear might be useful occasionally. I can't really see point in reverse, anything added is going to fail or cause trouble at some point so cost:benefit doesn't add up to me.
I'm very firmly of the view that a clutch without a decent flywheel is only slightly better than nothing. To get the same performance electrically is going to be very expensive and take some major controller software development, if it's even possible.
The EM & the Dragonfly are no doubt very capable bikes, but I maintain they're handicapped by lack of gears & significant flywheels.
Maybe the GG will close the gap. Sadly I can't see the price dropping significantly for a little while yet.
Water pump modification. Main seal.but
in TRS
Posted
I'm having to replace the RH Crank main seal (bike was consuming gearbox oil) so while I'm in there I thought about replacing the water pump seals as preventative maintenance.
In the end I decided 'if it's not broken, don't fix it'. I'll probably regret that, the bike's got 280 hours without any pump problems but I'm probably pushing a friendship at this stage.
I did take the impeller off to take a look and found that it has been rubbing on the housing. It's caused a small amount of galling on the back of the impeller, some flakes of plastic in under there and obvious rubbing wear on the housing.
My solution was to put the impeller in the lathe and take about 0.5mm out of the back recess. I checked periodically with bearing blue until I just had full clearance.
There was slight rubbing at the perimeter flange too but I solved that by rubbing the impeller on some wet & dry on a flat surface.
Previously I could hear the rubbing when I turned the impeller up to my ear. Now that's all gone. Pic after machining.
Hopefully this will avoid debris in the coolant, possible damage to the outside seal and potential failure of the impeller.
As an aside, just in case anyone comes looking:
The Primary Gear Bolt is RH thread with Loctite 243 on it. It took a really solid go at it with heat and a pneumatic impact wrench to get it off. I snapped one hex driver (not a top quality driver).
The seal, bush and O Ring all need replacing at the same time.
Pretty easy to remove the seal - pull the bush out with a couple of magnets then lever out the seal.