Modern Vespa

Since the master piston seal of the suspension lock of my MP3 seemed to be on its way out, and after seeing a video about the new Yamaha trike and its Tilt Lock Assist system, I tried something I 've been contemplating for a long time..

I temporarily "disabled" the hydraulic part of the tiltlock system, only keeping the cable-operated brake segment.

So far, I realy like the way it works now!

It's just like the recent Yamaha trikes. At first it feels scary rolling the scooter around with the front locked but the shocks still working, but you'll soon find that it won't drop easily. To me, it even feels more predictable on uneven terrain.

If I can't find a convincing reason to revert this modification, I'll make this change permanent. So instead of draining the system to fix the piston seal, I will just drain the system, and leave it at that. A drained system will not develop leaks, and it wil put less strain on the tilt lock motor, keeping that part alive for a few more years - and it will be less work when I have to replace the steering head bearings, knowing this time will come sooner or later .

A while ago I already disconnected the wire going from the tilt lock warning relay to the horn, which means the horn is still working, but it doesn't sound when the system loses pressure.

I tested switching on the ignition and starting the engine with the pressure sensor disconnected, to simulate the loss of pressure that will happen when I drain the hydraulic system later on - no problems here as far as I could tell (I don't check for, nor care about ODB2 error codes)..

How this works:


Remove these from the front shock brackets by taking out the front fender bolts..

Reinstall the bushings, otherwise you'll crush the brackets with the fender bolts..

This is how it still stands on its own without hydraulics.. Yes, jou can make it lean a bit because of the unlocked shocks, but it won't drop!

Deliberately locked at an angle, to demonstrate the remaining stability without hydraulics. Repeat: without hydraulics and deliberately locked way off centre!

hi,

Interesting...

I am not a mechanic and I just don't understand the difference between : with hydraulics and with what you did, can you provide more clarification in English terms, so you can put it to stand like in the picture but once you ride it it reverts back to like a two wheeler?
if so, what is the difference?

and why did you do it? if something went wrong, isn't it better to fix it, than lose the whole thing?
thanks,

The tilt lock system consists of two main parts driven by one electric motor:

One part is the cable operated brake caliper that keeps the bike upright. This is the most important part of the tilt lock system.

The other part of the system is a hydraulic contraption for locking the front shocks. This part of the system is only there to make the scoot stand "rock solid" without any movement possible in the front shocks - which is not strictly necessary to keep the scoot upright.




The only important change I made is that I disconnected the hydraulic part...

*** THE BIKE STILL LOCKS AND UNLOCKS THE FRONT EXACTLY LIKE IT ALWAYS DID. ***




The only difference is that the front shocks are allowed to do their job now even when the bike is locked upright, which means that the bike may lean a bit because the suspension can be compressed if you push the bike to one side, or if one side of the bike is heavier (i.e. exhaust side).

In practice this leaning proves not to be a big deal - it doesn't happen all the time, and it can even be countered by turning the handlebars a bit while parked, which will subtly change the balance of the scoot.

This modification also fixes the bouncing of the scoot when you roll it around. Rolling it over an obstacle at an angle no longer feels like you're wrestling a big bouncing monster, since its suspension is working as it should (it just feels like a big dead monster now ) .

Last edited by mono on Tue, 15 Jun 2021 14:43:56 +0000; edited 5 times

Oh, and for the "why":

I refuse to do a lot of work to fix something I don't really need

(Seriously, I hate working with brake fluid - I know how to drain, fill and bleed this system, but life would be better if those italians designed it for use with olive oil, instead of this corrosive and toxic DOT4 stuff, which seems impossible not to spill, will eat anything that resembles paint, plastics, gloves or skin, and seems to never really go away completely no matter how long you rinse..)

And I really like the tilt lock system this way!

IMO, the Piaggio engineers tried to make the "Tilt Lock" system look and feel good to inexperienced riders, while the Yamaha engineers went for simple and reliable with their "Tilt Lock Assist" system, which does the job just fine .

What if the olive oil is no longer a "virgin"

No problem, "ex(tra) vergine" is also fine ..

No virgin = Better "ride"

All things considered I have to wonder if there is any harm in filling the tilt lock system with mineral oil.

Won't it tilt under its own weight?

Since the tilt lock system seals are designed for DOT4 compatibility, they will very probably swell in mineral oil and make the calipers stick - which will surely not improve the ride .

Although, as a teenager I filled the brake system of my Yamaha RD50 with regular engine oil, which has been working fine for at least a few years... YMMV apparently..


For me, simply disabling (and ultimately removing) the hydraulic part of the system is not only an easy fix for a worn piston seal, but also an improvement in usability and reliability .

Fixing it is out of the question, unless there's some side effect I haven't noticed yet.

It won't tilt under its own weight, just like a brick standing on its side

Since the suspension can be compressed now while the scoot is locked upright, it will lean a bit when pushed, and it's probably a bit easier to tip over, but not by much.

It works just like the "Tilt Lock Assist" system of the Yamaha Tricity 300 now:

https://www.youtube.com/watch?v=djZIc1ZrgtI
(watch 0:00 and 6:19)

How does it handle being put on or off the center stand? When I take my bike off the center stand the front bounces around a fair amount. A few times I've forgotten to re-lock the tilt prior to taking it off the center stand and each time it toppled after swaying heavily.

Do you have to hang onto it more or have a more stabilizing stance when taking it off the center stand?

Do you straddle the bike via its step-through shape to stabilize it during the jostling when taking it off center stand?

Looks like a neat modification. I'm curious if weight can be reduced by removing the now un-needed hydraulics components for as demonstrated it locks just fine without them. There are a few tens of pounds to be removed which would boost performance and handling depending on how stable it is.

I don't have the center stand on the scoot anymore (it was scraping the road too often), so I can't comment on that.

I don't think you'll have a problem with the center stand. It will often lean to one side a bit, but it won't tip over on it's own. The scoot is actually more stable in those kind of situations now since it doesn't bounce anymore.

You need to have some trust in that however, since it might look and feel like it's tipping over at first. I can imagine one overcompensates for that, and loses their own balance as a result.

If you're not feeling confident about this, you might get an assistant to stand on the other side of the scoot when taking it off the stand for the first time, just in case - but you'll get used to the "new feel" very soon.

This modification will not save a lot of weight, the two rods I removed weigh next to nothing, and the hoses and calipers don't look that heavy as well.

I expect most of the weight to be in the electric motor and gearing that drives the system, and you need to keep that - unless you ditch the parking brake and connect the cable-operated tilt lock caliper to the parking brake handle of course, a mod I've also been contemplating for a while...

Maybe Jerry can shine some light on this? He removed and weighed the whole system as part of his naked mp3 project..

Thats a interesting mod mono. Having the suspension locked and going over a uneven surface like a roadside curb with the front wheels at an angle can be a bit of a handfull with it swaying back and forth. What i will do is remove the stainless rods and fit the bottom bushes back in place as you have done . Then rather than drain the fluid i will make up 2 plain stainless rods threaded at both ends to take nuts and have them captive in the hydralic cylinders that way i can give it a go and if i don't like it i can go back to standard.

I am being a bit daft here, why would you attempt to go over a curb with the suspension locked? especially at an angle no less?

Good idea!

Putting rods in the cylinders will prevent the horn sounding on startup (otherwise it would take a few lock/unlock cycles before pressure returns, just like with a brake caliper with the disk removed).

And it will also prevent any possible damage to the cylinders (maybe they're fine without this, but you never know - I should check mine, maybe they crush themselves without rods in them).

Sometimes it's the only way to get somewhere

When I get my MP3 out of the garage, I have to cross the doorstep at an angle in order to get the front of the scoot facing the street.

And often it's the only way to get out of a parking spot on the pavement. Over here they build everything way too small, and put lamp posts and other objects in the way - and stupid people park their bikes right behind your bike for example, so, often we have no choice .

You could also say why would anyone with a motorcycle licence be daft enough to buy a 3 wheeled scooter especialy one made by piaggio As you will well know with the bike bolt upright and locked if your pushing the bike and you go over a raised object like a kerb and and you don't go over it with both wheels at 90 degrees to the kerb the bike will rock about quite a bit and even sitting on the bike and paddleing backwards you have to be carefull .My disability also does not help and have to be extra carefull but even if i was able bodied it's still well known issue with the mp3. I'm going to try the mono mod and see if it helps me i can always go back to standard very easily.

[quote="mono")




This modification also fixes the bouncing of the scoot when you roll it around. Rolling it over an obstacle at an angle no longer feels like you're wrestling a big bouncing monster, since its suspension is working as it should (it just feels like a big dead monster now ) .
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Just done the modification and does everything momo says. Its well worth doing imo.

However i did encounter a problem in that the bike would not sit bolt upright at a standstill when locked , it was leaning to the right. After thinking about the problem and tilting the bike from side to side with it locked the bike would lean at a steeper angle to the right than the left before the opposite wheel would lift off the floor , My thoughts were that the spring on the right hand shocker was weaker for some reason than the left hand shock spring ( these were new shocks and springs ) . so i fitted a 8 mm spacer under the right hand shock spring to see if loading it would help lift the bike up so that it would sit level and it did it now the bike sits bolt upright.

My bike also tends to lean to the right a little, possibly because of the weight of the exhaust, possibly because the right shock has more wear..

This leaning can be countered by turning the handlebars a little, which will change the balance.
Also, leaning slightly to the left while locking the suspension will compensate for this...

I should have taken a photo showing mine leaning to the right ,i would not say mine was slightly and I also wondered about the weight of the silencer , however i have a Leovince one on the fuoco which only weighs around 2kg instead of the original of 8kg+. I got the impression that the right hand shock was softer than the left hand one and my shocks are the revised type and brand new . Just had a look at your original photo mine was leaning more.

My first impression was also that the right hand shock on my scoot might be weaker - but I have a new theory about this..

The leaning might be because we don't put the exact same amount of weight at both feet while sitting at the scoot and locking the front (moreso if one only puts one foot down instead of both - then you'll only take weight off the scoot at one side)..

Because we take more weight off the scoot at one side than at the other side, the front springs won't be equally compressed before locking, even while the scoot is exactly upright at that moment.

In the standard setup this difference doesn't matter because the springs are locked in the positon they're in at that moment.


Anyway, in my case the leaning got less after using the system this way for a few weeks. Maybe I unconsciously learned to keep my balance better while locking the front - putting the same amount of weight at both feet, or putting less weight at my right foot in case I only put one foot down. (I always use my right foot, so that would explain why the bike always leans to the right!)

Thinking more about this, my theory might be nonsense, as the parallelogram that holds the front forks should distribute the remaining weight equally to both - regardless of which side of the scoot is supported by the rider..

Although a sideways force (only one foot down) might change that distribution... Hmm, physics, interesting

Gotta run some tests on this theory

Just did some tests in the garage, and realised that the parallelogram becomes a rigid construction with tiltlock engaged, so it will no longer distribute weight (and therefore spring compression) equally.

I noticed that it's (almost) impossible to lock the bike 100% upright with only one foot on the ground, or with most of the weight on one foot. Although one might feel it's 100% upright, in reality it will be leaning a few degrees already. (This has nothing to do with the modification itself - leaning is just the only way to get more weight to one side.)

The same goes for the imbalance caused by turning the handlebars, which moves the contact point of the tires out from exactly below the center of gravity. If one turns the handlebars a tiny bit to the left after locking, the scoot will lean to the right a tiny bit, you might not notice, but the balance has changed.

The effect of locking the paralellogram while not locking the shocks, is that any amount of tilt or imbalance, once you get off the scoot, will compress the spring on one side a little bit more than on the other side. As soon as you stop supporting the scoot, the bit of lean or imbalance that was already present when locking will be amplified this way, becoming more noticable than with the standard setup.





My scoot stays perfectly upright every time - as long as I engage the tiltlock while supporting the scoot with equal weight on both feet, the handlebars turned in the exact position I'm going to leave them in, and the scoot locked at the exact spot where it's going to be parked. Otherwise the scoot will often lean to one side. Which does no harm whatsoever as far as I can tell.

I've come to the conclusion there's nothing wrong with the shocks of my scoot (other than being of low quality and old age) and I can totally live with the scoot leaning a bit sometimes



What's to gain by performing this mod?

The change in handling of the tiltlocked scoot is a matter of taste. I like it better this way.

If you also pull the relay that sounds the horn when the system loses pressure, you'll never have to repair the hydraulic part of the tiltlock system - just let it fail silently and ride on


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I set the lock with the bike bolt upright and with me standing over the bike not sitting on it and every time it lent to the right ,now every time i set it it sits bolt upright since putting a 8mm spacer under the right hand shock spring.So who knows whats going on :?

Wow, 8mm , that means your shocks differ quite a lot then..

Especially because the only thing that could lean the scoot so much after locking is a difference in spring rate.
(it's not about spring length or preload - that's compensated for by locking the scoot upright to start with)..

Do the coils of the shock (the one with spacer) "touch" in the tighter part of the spring now? (that would definately increase the spring rate).

Never looked closly if the spring is coil bound (touch) will look later. Remember i bought brand new later model revised shocks for my fuoco which are the same as yours from you photo, well if they had been the early type shocks they certaily would be coil bound on the closely wound bottom of the spring as there is a marked difference between the early and later front shock springs. My other thought on the leaning is that the bike IS heavier on one side than the other ,so i will try to weigh the fuoco under each of the front wheels if the bathroom scales will take it. I haven't been for a ride yet since doing the mono mod as it's been peeing down ever since.

YES the bike IS heavier on the left side than the right but by how much is difficult to be exact due to my bathroom scales trying to save the planet by cutting the power from the battery after a few seconds. It's at the very least 10 kg and may be 15+kg. I weighed the bike at least 6 times on each side with the bike as upright as i could . If i had someone else to help me with the task i would have seen if tilting the bike made any difference. As for the springs they are NOT coil bound (touching) i did measure the lower spring gaps on both sides with a feeler gauge and found very little difference in fact the gaps on the lefthand spring in some areas were smaller than the righthand side which has the 8 mm spacer !. Also from memory the springs on my old shocks (2008 Fuoco ) had smaller gaps than the new springs/shocks, this being as they are different in length and coils. I still haven't road tested as it's still peeing down ,hopefully tomorrow's weather is fine.

Just spent some time with my lovely assistant, a bathroom scale, and the MP3 on the concrete slab in front of our garage:

When exactly upright, my MP3 puts 62..63 Kilograms on each front wheel - pretty much equal..

When tilted (and locked) at about 10..15 degrees, the weight on the "high side" dropped to 28 Kilograms..

So yes, a bit of tilt can make quite some difference in weight distribution and spring compression.
(And my 2013 MP3 300 seems to be nicely "balanced"..)

Without the 8mm spacer under the right shock spring the bike was leaning to the right so with the spacer it now sits level so you would think its now evenly balanced or the bike is heavier on the right but my scale figures do not say that !. The left was in the 60+kg and right in 50+ kg ranges like i said it was difficult because of the scales switching off giving me no time to check if the bike was absolutly bolt upright. So for me i now want to get hold of another set of bathroom scales to see if i can get even figures like you. i did manage a 50ml ride yesterday as the rain cleared more or less and the sun dried the roads. I found no real difference in how the bike handled or did i ? as there was something that said it's different but not in a detrimental way even with the 8mm spacer fitted or was i just imagening it. But pushing the bike and paddleing backwards over low road kerbs is far safer as the bike without the suspension locks now does not rock about wildly.

I am looking for those instructions. Has anyone identified which wire it is. I see mention of a 50/50 chance of being wrong.

Update:
Is it the red/yellow wire at the horn?

I installed a second horn in parallel to the original one, so I had to cut both wires anyway.

Otherwise I would have just pulled the horn relay from its socket - sounding the annoying alarm is all it does..

(I can't even remember if the wires had different colours or not, I just tried which one worked - pulling the relay is by far the simplest option.)

I pulled the second relay from the left (standing in front of scooter) but the horn still sounded.
2008 MP3 500

The position of the relays is not always the same on every MP3, so if you pulled a relay but the alarm is still sounding, something else must have stopped working

Just try pulling another relay, or have a look at the circuit diagram - the relays can be identified by the colours of their wires.

Hydraulic oil would work fine
The system doesn't generate heat to be withstood as brakes do
DOT 4 is probably used, so as not to add yet another fluid to the list

It was the far-right relay. No more honking on key-on and everything continues to work!


photo

I have still not tried reweighing the front end but now i have put more miles on the brand new front shocks the fuoco now leans to the left so i'm going to remove the 8mm spacer from the right hand shock and see if the bike sits upright.

So now that i have removed the 8mm spacer on the r/h shock i find the fuoco sits upright so i assume the front shocks have bedded in and i don't find any difference in handleing.

Putting it on the centre stand ,i lock it then lift it's no different with the mono mod and as for pushing off the stand it's no different other than it's seems more stable as the shocks can move .I push off from the side of the bike.With my disability doing the mono mod has helped me and as for the abled bodied i say do the mod ,it may seem abit odd at first but after a short time you will get used to it. If i'd done this mod years ago i would not have dropped the bike twice.