Peugeot FE53 series 3 1994 Scoot

[fe53series3]

Idle is at around 1400rpm.

But don't forget..... one of my primary objectives is to have drive at 3k.
and this ties in to a desire for a progressive launch (from 3k).
The last thing I want is a launch at the current revs.

My belief (could be wrong) is that I'll still have great acceleration, once initially moving.

This IS going to be tested...... I'll fill the rollers with whatever comes to hand.... and if I'm wrong about the acceleration, I don't mind..... I'll report back.

The bummer is that it is unlikely to happen tomorrow, as my son has dumped a party on me at last minute, so the house needs re-jigging for potential disaster

RE throttle control..... this is just a fact.
Up to 3.8k the throttle grip has full control.
Above 3.8k..... the engine hits a feeding frenzy, and it runs away.
I may be able to record that on my laptop.

Personally I'm not concerned about that.
It can easily happen when not under load, at these revs.

Note the carb is not fully setup anyway, because I need a definitive setup to tune to.

Let's see what happens with heavier rollers.

My prediction is that I'll be able to tootle along through the village, and when I whack open the throttle, I'll get all the acceleration that I have now at launch, because 4.6k will occur when I'm already moving (using sub 4.6k power that is currently being wasted as heat).

What do you predict?

[Elektrey]

it shouldn't run away and your acceleration is tied directly to your horsepower produced by the engine minus the horsepower of drag and rolling resistance.

horsepower is directly related to RPM and doesn't change with anything else I don't think.

if you launch from 3k you will have to use the engines horsepower from 3k-4.4k where if instead you launch at 4.4k you will accelerate as fast as the clutch shoes can go from disengaged to fully engaged, which is quicker than the acceleration from the horsepower from 3-4.4k

[fe53series3]

May 12, 2015 20:05:07 GMT -5 Elektrey said:

it shouldn't run away and your acceleration is tied directly to your horsepower produced by the engine minus the horsepower of drag and rolling resistance.

horsepower is directly related to RPM and doesn't change with anything else I don't think.

if you launch from 3k you will have to use the engines horsepower from 3k-4.4k where if instead you launch at 4.4k you will accelerate as fast as the clutch shoes can go from disengaged to fully engaged, which is quicker than the acceleration from the horsepower from 3-4.4k

Okay..... that's a friendly bet!

But your first opening paragraph deals with rolling resistance...... yet there is none, when the the bike is not moving..... and that's when the clutch bites.... when the engine has clearly just 'come on song'.

Re HP being directly related to RPM is a point open to wide discussion........ but your 3rd paragraph is directly relevant.
I believe that HP at 3k will get me moving, and the HP at 4.6k will get me moving even faster, because I'm already moving, and then I'll begin to enter the powerband (which is broad due to the stock exhaust).

The initial movement from rest (the biggest negative) will have been accomplished, and the engine will be at the stage where it would have been breaking this static position.

At this point there is no wind resistance...... we are effectively good to go.
So it will be acceleration from standstill at 4.6k
or
Acceleration from (say) 10mph at 4.6k.

While clearly the sense of accelerating from 0 to 20mph will be hard to replicate....... the actual acceleration should be greater, and longer lasting.

Just to get you worried about your bet (why not)

Let's imagine that two identical bikes race each other.

One is at a standstill
the other is approaching the start line at tickover, but moving.

As the approaching bike hits the start line, both bikes whack open their throttles.
Overall, the one that is moving, will clearly beat the one at a standstill. 

The higher rpm launch bike, may take advantage of the powerband... but it's cost  so much, just to get the bike moving.
The initially lower revving bike may be initially marginally behind (or not).... but the acceleration will still keep coming.

[niz76]

I do understand the problem as my scoot CVT is setup kinda "racey". Just to roll slowly through a parking lot I have to really rev the throttle for engagement (6k) and then I can kinda feather off and keep driving slowly but only for like 100 feet then I gotta whack it again and repeat... so yeah it seems like I'm "hot dogging it" but really just trying to drive slowly lol. The stock exhaust makes great power down low with a real wide powerband so it sounds like your goals are probably realistic.

[Elektrey]

I think the power at 3-6k on your scooter is way more than mine because of your stock exhaust. My pipe takes all the power and puts it at like 8-9k.

Maybe a better way to solve your problem is to get an expansion exhaust? It will let you control throttle at lower revs way easier because there isn't much power there. you can also launch later.

[fe53series3]

May 12, 2015 21:18:55 GMT -5 niz76 said:

I do understand the problem as my scoot CVT is setup kinda "racey". Just to roll slowly through a parking lot I have to really rev the throttle for engagement (6k) and then I can kinda feather off and keep driving slowly but only for like 100 feet then I gotta whack it again and repeat... so yeah it seems like I'm "hot dogging it" but really just trying to drive slowly lol. The stock exhaust makes great power down low with a real wide powerband so it sounds like your goals are probably realistic.

Thank you niz..... that's exactly what I'm experiencing!
Except for me, the cut to 'no drive' is stark.

Nice to find that somebody believes I might be on to something here.

The thing is..... 
I'm gonna load up the rollers, and try to get the front pulley moving a bit earlier.
If I can get bite at 3.4/3.6k I'll consider that a fair test........ It'll be 1k lower than where we started, and just below the circa 4K powerband entry point.

To reiterate:
Principal being that I can then tootle off, and whilst moving, be on the cusp of the power band........ 

Hey!..... if this fails to deliver the expected results, then fine....... that's the way it is.
But if I was a gambling man.... I'd bet on a win for this theory.

So what's the pass criteria?

1. Low Speed Running

Sadly I can't give you a speed, because my front wheel speedo gearbox is stuffed.
However, I'll know if the scoot can wander along, without being on the bare limit of 'loss of drive', even while the motor is a live wire.

2. Instant Acceleration

While choosing to go slowly.... the powerband that previously launched you from zero, should now be available.

Notes:

What will be interesting, is how this will affect 'high speed' launch from zero.
It will not match the previous drag start launch....... but how many times do you need that?
What's clear, is that the launch from zero should be positive IE. No bogging.

The launch is outside of the powerband....... but 99% of road-going vehicles launch outside of the powerband; including our 50cc AM6.
Why not the FE53?

Posted by Elektrey7 hours ago
I think the power at 3-6k on your scooter is way more than mine because of your stock exhaust. My pipe takes all the power and puts it at like 8-9k.

Maybe a better way to solve your problem is to get an expansion exhaust? It will let you control throttle at lower revs way easier because there isn't much power there. you can also launch later.

Yes, it really does look like the powerband starts at 4k.
Look at the pics on pg 3....... there is no expansion pipe..... the manifold sort of runs into the silencer.

Your suggested solution.
I see what you're saying...... I hadn't thought of it like that. 
But do I need the powerband any later; if I can launch successfully at 3K to 3.5K?

Apart from that, as noted elsewhere... I rescued the exhaust system, and I'm not going to just bin it..... particularly as we are now trying to tune the rollers to it.

If we bought another pipe, the problem would simply move elsewhere.

I think we need to follow through with the theory.
Not only because that's good fun.... but filling the rollers, is much easier than buying a new exhaust system; and is zero cost.

Anyway; we are going to try with heavier rollers.

[Elektrey]

If you can launch at 3-3.5k then no I guess no need, but if you get a pipe you can gain speed since your top power will be at a later RPM and therefore a later MPH at the given highest gear.

I checked today when I took mine out and I was able to quickly engage the clutch and just sort of baby the throttle to move very slowly, even did it to get it into the garage inbetween a car and some tools.

clutch engages at like 5.5k and powerband realistically starts at like 8.1k for me.

[fe53series3]

As yet it's not clear to me how your setup allows low speed running, when I lose drive....
.... but can we pick up on the launch settings later, when I've modded the rollers.

The thing is... we need to discuss 'flatting of steel rollers, in under an hour of running'.  

It is almost beyond belief.
I discovered it when removing the rollers to attempt to increase their weight.
I could hardly believe my eyes.
If this has happened to steel...... what would plastic have looked like?

First have a look at the video:


I've examined the aluminium ramps..... there is slight wear on 3 ramps.
However, there is no wear at all on the stamped steel ramp cover plate.

Anybody any ideas on why the steel would be flatted so quickly?

[fe53series3]

continued....

The steel cover plate is no. 34

It must be a harder steel than that of the rollers, as it shows not a single sign of rubbing.
I used carborundum paper under a small file, to check for any proud areas, but no.
The plate ramps were then buffed on a felt wheel.

The alloy ramps appear to be little worse than when the rollers were fitted, other than minute burring on 3 ramps.
The alloy block numbers are:
GR1-88
TIC-9
HM
RIR

Clearly with the steel wearing like this, I don't want to running for long, with them fitted.
Once I've got an idea of 'weight performance', I must buy some plastic covered rollers, to protect the alloy ramps.

I would have thought it would have been better, if it had been well anodised, to ensure that all the wear occurred on the replaceable rollers.

Roller Infill

I've used tile grout.
I baked them at about 40 C for a few hours, then after cleaning them up, for another hour at 80 C.

To bind the cement, lacquer was repeatedly sprayed on one side, and then on the other, until no more lacquer could be absorbed.
They are now baking again at 40 C then I'll put it up again to 80 C.

I have no idea whether this will infill will survive the vibrations.
The principal is that the cement will have become resin impregnated.

If they end up looking really solid, then I'll try them.

It's a bit dodgy, but I just didn't have enough two part epoxy to hand.
Let's hope that the lacquer acts like an epoxy.
 

 



 

[fe53series3]

Continued.....

The roller infill has hardened up nicely.
In fact I lacquered each roller face, 3 times....... the third time after baking.
This established the classic shiny surface.

Taking the rollers to 200 C left the lacquer sticky, but on cooling was rock hard.

Weight was circa 11g.
4 @ 11g
1 @ 10.9g
1 @ 10.8g

I dropped a glob of oil based black enamel paint onto one surface of each, baked them @ 90 C for ten minutes.

I then finished them off with my heat gun
The paint swelled up, under the skin.

After cooling, tried the heat-gun a again, but the paint surface was solid.

Therefore....... the key is to get the paint very hot, and then let it cool.
By doing this, the paint becomes hard, and doesn't want to return to a liquid state.

With the added enamel weight, I'm hoping to be able to equalise the weights.

The rollers are looking good for installation tomorrow.
As usual, a lot of messing around..... but it's all useful info.

If they pass final inspection tomorrow, then they'll be fitted, and we'll discover whether we can gain slow speed running, an acceptable launch, and very good acceleration from crawling pace.

[fe53series3]

I got the rollers fitted today

3 @ 10.8, 3 @ 10.9 - close enough, and I staggered them.



First Impressions

It's a completely different scoot.
It feels like a bigger engined bike...... the acceleration just keeps coming, rather than being over in a flash.
It launches with greater control..... a less frenzied launch can be had...... or a fast start, though less acceleration from standing start.
Drive is now available for slow running, and while slow running...... if the throttle is whacked open, the bike surges forward, and keeps accelerating.

Clutch Grip

This now occurs at 4.4k (as compared to 4.6K).
Not a dramatic change at all.
2g additional roller weight, yet only a 200 RPM launch improvement.
I haven't tested with the cover off, but I'm guessing now, that the clutch springs have the most influence.
 
Trying to quantify what has happened

The front pulley is now geared higher.
Therefore when it has drive, the bike will go faster, for a given RPM.
Hence now, I have slow running....... the engine no longer has to be screaming, just to keep the bike rolling forward.

Previously the bike was on the limit...... now the drive is positive.... it feels engaged.
The RPM change is minor, but the effect is much greater than the figures would indicate.

9g to 11g - is it the best way forward?

I believe, that what we were looking for, was an earlier clutch grab.

This came, as a result of modding the front pulley movement, but we now have higher gearing, and lower RPM.

Surely the best solution would have been to have earlier clutch grip, and perhaps a minor raising of the gearing (say to 10g).
OR
No change of gearing..... but a much earlier clutch grab.

The reasoning behind this is, that if the clutch grabs earlier....... we need lower gearing, to cope with the 'less power' that is available at launch.
What we have now is higher gearing, and lower revs at launch.

It works....... it solves numerous problems....... but it is clearly not ideal (it's not tuned!).

A straightforward, earlier clutch grab, would have provided all the benefits we were looking for, without additionally raising the gearing.
An earlier clutch grab, would have created a similar effect to raising the gearing, but with improved slow running, whilst creating less adverse acceleration effect.

Conclusion

It's definitely a better bike now, in all the core areas of rideability.
It also takes more advantage from the PHBN carb mod....... that can feed the requirement for power, as the bike continues to accelerate at speed.

However...... as Bill Clinton once said "it's the clutch springs, stupid!"

If they grabbed a little bit earlier, we could run with 10g rollers.
If they grabbed a lot earlier..... say 3.6/8K...... we could run with 9g rollers.
(Launch RPM possibility is still unclear at 9g, due to the increased gearing @ 11g)

Perhaps a new drive belt, and new clutch shoes, would deliver that...... but weaker clutch springs would be immediately on the money.

Notes:
The CVT drive system certainly proves the rule....... when tuning..... changing one element, has a knock on effect on other elements.
Yet also..... changing one element, may demand other changes, if full advantage is to be gained.

The PHBN carb mod exemplifies this.
The changes made, have enabled a gain to be seen from the carb mod..... but I actually think that the carb mod has somehow made the gearing mods work (just).

The real question, is whether we can isolate specific changes.... clutch grab, front gearing, rear gearing.

The problem appears to be, that stock clutch springs are too strong, in order to balance the engineering restrictions forced into place by politicians.

In effect.... with a weak engine...... a delayed RPM launch is needed to spice up the bike.
With restrictions being removed.... we don't need this artificial vivacity; we have the power to drive forward... and keep going.

Our problem is..... where to get the damned clutch springs?
Or is there another way to get it to bite a bit earlier?

I guess I need to know the spring load, and dimensions at rest.
It may then be possible to find a slightly weaker set of springs, in order to achieve launch just a bit earlier, whilst maintaining a low gearing, to give the oompfh.





  







 














 

 





 

[Elektrey]

Glad to see it worked out for you!

Looked up parts on racing planet and it appears the speedfight series 3 uses the same kind of clutch springs as my bike!

I've got a gunmetal polini set here I can ship to you for just shipping cost (shouldn't be too much there really small).
Just make sure they are the correct size these are 8mmx31mm.

[fe53series3]

May 16, 2015 15:56:28 GMT -5 Elektrey said:

Glad to see it worked out for you!

Looked up parts on racing planet and it appears the speedfight series 3 uses the same kind of clutch springs as my bike!

I've got a gunmetal polini set here I can ship to you for just shipping cost (shouldn't be too much there really small).
Just make sure they are the correct size these are 8mmx31mm.

That's a very friendly offer Elektrey........ thank you for that!

I think I first need to try to research on the current springs, to establish their specs.
We are not sure that the FE53 matches the Speedfighter series 3 specs.

Is it a coincidence, that my FE53 is also series 3?
If the Speedfighter is circa 1994, then it is highly likely the same - my scoot might be a Speedfighter

What sort of revs, do you think, the gumetal polini springs would grab at?

[Elektrey]

on my scooter they grabbed at like 4kish and the stock springs grabbed at like 4.5kish

I don't know if the clutch for my scoot is just light or what.

You may have a hard time lowering your clutch grab RPM much lower than 4k.

[fe53series3]

May 16, 2015 18:26:12 GMT -5 Elektrey said:

on my scooter they grabbed at like 4kish and the stock springs grabbed at like 4.5kish

I don't know if the clutch for my scoot is just light or what.

You may have a hard time lowering your clutch grab RPM much lower than 4k.

I guess the difficulty with relating clutch grab to engine RPM, is that the RPM of the clutch changes with the front pulley gearing.
With heavier rollers, the front pulley activates at a lower RPM, hence why my clutch is now grabbing at 4.4k

Perhaps my bike clutch originally grabbed at 4.5k, but with a slightly worn belt, and slightly worn clutch shoes, and heavily flatted rollers, it started off grabbing at around 5k.

With 9g perfectly round steel weights, the grab began at around 4.6k...... say 100rpm later due to worn components.

Now with 11g rollers, it is grabbing at around 4.4K.

I found a very useful, comprehensive roller chart for all scooters:
www.firenzee.com/gy6/Factory%20Roller%20Weight%20Sizes.pdf

Find the Peugeot section: You'll see that most are listed with 8.5g rollers.
Mine were 9g.
If they were the standard rollers (since 1994 they could have been changed)........ then my bike would be a Suab, speedfighter, or speedfighter LC.

However the bodywork is all different for both Squab and Speedfighter.

I have to conclude that the 9g rollers in my bike were non standard.

Your Gunmetal Springs

I found this description:
www.spi-parts.com/polini-set-of-clutch-springs-aprilia-derbi-dilera-italjet-malaguti-piaggio-vespa.html

The key info stated is:

GUN METAL springs will engage at 1000RPM higher than your factory springs.
GREEN springs will engage at 2000RPM higher than your factory springs.
YELLOW springs will engage at 3000RPM higher than your factory springs
BLUE springs will engage at 4000RPM higher than your factory springs

While these are not the exact spring for our models, I believe these ratings will be standard across their range.

This differs to your own experience, as you found the Gunmetal gripped earlier than stock.
I wonder....... could your Polini springs have been specced to a different bike, and so were actually weaker?