Peugeot FE53 series 3 1994 Scoot

[Elektrey]

When you ride it this is what I would do

find a nice flat stretch of road, preferably clear of cars/traffic.
go WOT from stop and note the RPMs.
think of it as you are graphing the RPM vs time while you are WOT the whole time.
note the RPM at which you get the most acceleration, your powerband is near here.
then change the rollers so the majority of your RPM are near that when WOT.
heavier rollers lower RPM
lighter rollers raise RPM (in general)

[fe53series3]

May 6, 2015 15:14:29 GMT -5 Elektrey said:

When you ride it this is what I would do

find a nice flat stretch of road, preferably clear of cars/traffic.
go WOT from stop and note the RPMs.
think of it as you are graphing the RPM vs time while you are WOT the whole time.
note the RPM at which you get the most acceleration, your powerband is near here.
then change the rollers so the majority of your RPM are near that when WOT.
heavier rollers lower RPM
lighter rollers raise RPM (in general)

I'll report back on this, after testing.

[fe53series3]

So I tried this test today, but I could only get limited data, probably due to the knackered rollers.

Initial grip to drive, begins at 5k.
The revs then seem to rise very rapidly to 7k, but acceleration seems to lag behind..... the motor then crawls ever closer to 8k max, with speed increasing pro-rata.

I actually don't think any of this data is valid, due to the enormous flats on the rollers.

What I'd like to see is initial grip at around 3k...... at least then I won't be screaming the motor every time I stop and start.

That will also give me 3k to 8k rev range, as a starting point to tune around.

Tomorrow is VE day (Victory in Europe).... hopefully this won't slow the post down, but it might.
Saturday is the earliest they'll arrive.

[niz76]

Many of us actually shoot for that higher rev range before the clutch engages to give a more powerful launch. It does make the bike seem more "racey" by having to throttle up so much to get moving and feels a bit awkward in the beginning but one does tend to get used to it. If you really do want to lower the revs where the clutch engages you could look for some lighter/softer (usually stock) clutch springs. Heavier roller weights might give a similar effect by throwing the variator into a "higher gear" sooner- therefore lowering your takeoff RPM's. but like I said- most shoot for the higher revs at takeoff!
EDIT: BTW Happy VE day!

[Elektrey]

Yeah I myself am tuning my clutch engagement RPM to be higher to have more power at launch.

If I were you I would increase the RPM to launch to see if you can lift the wheel off the ground when going from a stop; at least then you "screaming the engine" would be reasonable lol, jk

Are you worried about stress on the engine/clutch from taking off at 5k? or just the noise?

[fe53series3]

Well I guess it just doesn't feel right.
I've got no 'slow running'.

For example, at home, I round a corner... go a few meters, and then stop.
I therefore have a choice:
On rounding the bend I coast to a stop, just short of where I want.
or
Round the bend, and wind up the throttle, just to push me those last 4 meters

That's not an exaggeration..... it happens every time.

This then reverses on the way out.
Yiiiiiiinnnng just to get me to the junction, then Yiiiiiiiinnnng to pull away.

Yes it's true.... the launch is pretty spectacular, but my god it's a pain when the bike has no slow speed.

My thinking is that it's because the rollers don't roll, so they can't be flung outwards easily.

Re stress, I don't know.
Presumably the quicker the launch, the more stressed the components, but I guess the variomatic drive must naturally absorb some of this shock...... but perhaps it wears the belt out much quicker?

Either way, I'll try and set it up for a happy medium, giving some slow running, without killing the acceleration.

[fe53series3]

Just been out for another run.
I was looking specifically at holding 6k and then opening the throttle.

The engine almost immediately hits 7k.
During this period acceleration begins, but then continues.

This is fairly close to mimicking the classic concept of 'a fixed ideal engine speed - with road speed relating to fuelling'.

IE. the engine can be setup for maximum efficiency, at a specific RPM...... the gearbox responding directly to the amount of power being produced, according to the quantity of fuel being fed to the engine.
Therefore road acceleration is a direct function of changing horsepower, rather than a direct function of changing engine speed.

These have been built (I've no link sadly)..... but they are better suited to industrial usage.
For nippy acceleration, a change in RPM is the way to go.

The variator drive seems to fit somewhere between the two.

Anyway.... I decided to pause on this post and check out what the web had got to offer, by way of definitive explanation.
Here is an extremely good comprehensive guide to the CVT concept, including moving diagrams and video.

What I found interesting was that the author specifically referenced the concept above, in that this is the goal of the CVT:

The whole point of the CVT is to keep the engine at the most efficient RPM by making the gearing variable, the CVT adjusts the gear ratio to maintain that optimum RPMs. Top speed will be achieved when the maximum horsepower hits the limits of drag (friction and air resistance).

It also discusses how the clutch plays it's part in holding back 'drive engagement' by changing the clutch springs for stronger springs..... requiring more centrifugal force to fling out the clutch shoes (to grab the bell housing).

We'll have to wait for the new rollers, before any judgement can be made on whether the FE53 clutch springs have been changed.
From what I've seen with the drive cover off..... the problem is related to the rollers.

Anyway, it's worth a read..... most of it is what we know, but a well written explanation can help in formulating ones own thoughts.

Here's the link:
modernvespa.com/forum/wiki-cvt-principles-how-it-works-how-to-improve-it-

[fe53series3]

I've got a rumble as I power off.

This is bad news..... it surely must mean a bearing has failed.
It just showed up today.

This casts a dark grey shadow over all future proceedings.
What a shame.

BTW The rollers didn't arrive today.

We can still do some testing next week, but the bearing situation is a bummer

[fe53series3]

I did some more testing today.
The vibration is greatest as the bike, when slowing, hits around 15mph.

There is vibration when slowing above this, but there is a certain moment, when the vibration increases.

I'm thinking it must be when the variator goes almost fully closed, creating maximum engine braking.

Assuming that this is actually a problem, it's hard to know which bearing is playing up.

[filip]

Nice project

FYI peugeot makes it's own engines that are similarly designed to hondas engines (maybe due to collaboration in the past, I don't know, and I don't really know when they started the production but from the pictures I can tell that it's a peugeot's own engine)

Some parts, like inlet valve fit, some don't(crank is different, cylinder fits with some mods etc).

As to the model, could it be a Zenith? They are very common over here.
I have a haynes manual somewhere for the speedfight/trekker/vivacity, I'll try to dig it up and scan engine revelant stuff.

[fe53series3]

May 10, 2015 14:39:47 GMT -5 filip said:

Nice project

FYI peugeot makes it's own engines that are similarly designed to hondas engines (maybe due to collaboration in the past, I don't know, and I don't really know when they started the production but from the pictures I can tell that it's a peugeot's own engine)

Some parts, like inlet valve fit, some don't(crank is different, cylinder fits with some mods etc).

As to the model, could it be a Zenith? They are very common over here.
I have a haynes manual somewhere for the speedfight/trekker/vivacity, I'll try to dig it up and scan engine revelant stuff.

Thanks for the useful additional info

Original name could be speedfight/trekker/vivacity, but also Buxy, or Hercules (or Dio derivatives).

We're just gonna have to roll with the flow..... the engine hasn't been stripped yet.
The potential bearing problem may be the catalyst for this.

I didn't want to go for an 'in the dark' strip.
As I managed to get it running, my objective was to get the basics of the bike right.... nicely tuned.... and then have a look at making it a bit pretty.

At least we have the rollers coming tomorrow or Tuesday.
More tuning fun...... and also, a better understanding of how the CVT work on this bike.

[fe53series3]

May 7, 2015 9:23:38 GMT -5 niz76 said:

EDIT: BTW Happy VE day!

End of hostilities........ possibly one of the better national holidays to celebrate.
I previously missed your edit.

Very nice!

[filip]

Hercules is the older type, also known as SV
Could be buxy, or speedake, or zenith. Confusing stuff

[fe53series3]

May 10, 2015 15:21:01 GMT -5 filip said:

Hercules is the older type, also known as SV
Could be buxy, or speedake, or zenith. Confusing stuff

Apart from solving the mystery (which is interesting in itself), I guess it doesn't matter.
At least Hercules is off the list

In the meantime, the main thing is that the Dio and FB workshop manuals seem to tell me what I need to know.

Anyway, I'm just editing a video re the new rollers....... so in a few minutes, I'll outline the progress that has been made.

[fe53series3]

The rollers arrived today!
Here's what I got:

8 off 25mm D x 17mm W 19g
6 off 19mm D x 17mm W 9g
6 off 19mm D x 17mm W 16g
6 off 19mm D x 17mm W 13.8g
6 off 19mm D x 17mm W 13.6g
6 off 19mm D x 17mm W 13.6g
6 off 19mm D x 17mm W 13.6g
6 off 19mm D x 15.4mm W 7.8g
6 off 19mm D x 15.4mm W 7.5g
6 off 19mm D x 15.4mm W 6g
6 off 19mm D x 15.4mm W 8.1g
6 off 19mm D x 15.4mm W 7.8g

Note: I needed 16mm D x 13mm W
None of them were the correct dimensions

However, I discovered that the '6 off 19mm D x 17mm W 13.6g' had a 16mm D steel insert.

So...... I placed a sharp knife on top of my original rollers, and scribed a line into the plastic of the above rollers.

With a diamond coated steel disc modded into my pedestal drill, I was able to grind the width down to 13mm.
I then removed the plastic cover, and chamfered the steel roller.

By good fortune, this created a 9g roller of 16mm D v 13mm W....... Bingo!
I repeated this to get all 6 rollers to 9g.

The cage and rollers were greased with hight temp graphite grease, and assembled.

While this was a whole lot of work that I didn't want to do....
... The fact was that the rollers that came out were 9g...... and the new, round, steel rollers, were also 9g.

So the test would be very meaningful.

Test Run

Previously the bike had drive at 5k RPM.
It now gripped at 4.6K

This in itself was a great improvement.
Further...... the general performance of the bike was so much better.
It was more responsive to the throttle.
It seemed like acceleration was better, even though that might be contrary to what would be expected.

The bike can now be ridden at a lower speed, and through the village, the revs have dropped.

It's still not perfect.
4.6K is still too high....... I'm not doing drag start races.
I want acceleration, when I'm on the move..... not from a standing start.

Clearly, by lowering the revs at launch, the power band becomes available, increasingly when it is required.

What's going on here, with the powerband?

I would suggest, that with the stock exhaust/silencer unit..... decent power is available at 5k...... but it comes on song between 6k and 7k (at the moment).
This may be gearing related.
So let's say the power band is 5k to 7k.

To take maximum advantage of this powerband, I need to be launching at around 3.8k.

From current experience with the steel rollers..... with slightly heavier weights, I should be able to tootle around the village at around 4.4k...
... and because the variator lags to RPM, I will be able to whack open the throttle and be immediately in the powerband, and accelerating....... to a much higher speed.

In this way, I can then take full advantage of the PHBN carb mod..... which was effectively wasted with the previous flatted rollers.

So 9g are definitively too light for useable acceleration, and also too light for low speed running.

Hmmmmmmm!..... so what do I order?
I'm thinking 11g.
That way, if they are too heavy, I can bore them out a touch.
I just don't know how 2g will modify the performance.
However, one thing is for sure...... 9g rollers may have been fine for a 12mm Gurtner carb; but for a 16mm PHBN, I'm going nowhere - though very quickly

Here's the vid I made: