[Martyn_]

In my experience embs, it's mainly down to the state of the tyres. I've run stacks of oldies on my sport track with varying degrees of success.

Some needed nothing more than a bit of TLC to get the tyres gripping, others needed replacement tyres - luckily, I've got a huge bag of old part worn tyres, I can usually ferret around in there and find something that'll do the trick.

A lot of that is down to how much power is being put down - with the sloppy old cogs, axles and bearings it not too much of a problem, but when you've got something whacking out a fair amount of torque, things need to be a little better in the tyre department, I've found.

(I had to edit out the first word I had in there and replace it with "ferreting". Suddenly realised it has connotations not suitable for family viewing to our cousins down in the antipodes! Those aussie and kiwi network techies must fall about laughing discussing network issues!)

 

[Ember]

QUOTE (snurfen @ 27 Nov 2011, 10:36) <{POST_SNAPBACK}>(I had to edit out the first word I had in there and replace it with "ferreting". Suddenly realised it has connotations not suitable for family viewing to our cousins down in the antipodes! Those aussie and kiwi network techies must fall about laughing discussing network issues!)
Now that has me more than curious!

 

[chris99]

QUOTE (Ember @ 27 Nov 2011, 08:49) <{POST_SNAPBACK}>Now that has me more than curious!

Rhymes with tooting!

 

[Ember]

Ahhh... D'oh! See, I wouldn't even have thought that. It gets used for both meanings/occasions.

 

[stoner]

hi dopamine. funny you should say buy ninco track for the grip because iv,e sanded all my ninco track flat and i,m in the process of making mdf borders 3-1/2 outside and 2inch inside, aside from having to solder each track connection the whole lot is going to be glued to 4off 6by4 hard board base sections so i can break it apart if i move. the whole lot is going to be painted with lots of grey acrylic silk matt till i get an ultra smooth suface over the whole of the track this is to run 15volt magless for me and 10volt magnets for the grandkids. great that we,ve all got different ideas on the way to go. hope father christmass brings what you want. john

 

[Mr Modifier]

Hello everyone - I'm a bit late to this thread but here's my experience with ancient Scalextric cars on new Sport track.

I have loads of old Scalextric cars from the 70's and 80's. My favourite is a Porsche 935 (the whaletail) C.125. It's an early one without lights or magnet and the old style (RX?) motor.

The motor responded really well to a bit of lube. The rest of the running gear I replaced with new axles, pinion, contrate and tyres.

The original tyres on the Porsche are a joke - ribbed F1 rears - back AND front!!!

I replaced these with more recent F3 wheels and tyres which are the same overall diameter but narrower on the fronts. The tyres are rubber (the ones with GoodYear Eagle printed on them in yellow).

I trued the rear tyres - looking at them again I actually only trued them across about 3/4 of the width - rubbish Scalextric mouldings making the tyres convex!

The car is a hoot to drive on Sport. I haven't treated the tyres - just run them stock. I have to drive carefully for 4 or 5 laps but then the tyres seem to respond to the heat. It's nowhere near as fast as a modern car with magnets - it does a lap in about 12 seconds where my fastest lap is about 7 with a reasonably sorted Group C Slot.It. The Porsche does tail slide - but only when I want it to and you can get some very satisfying power slides around r4 curves when you get in the rhythm. It is even possible to balance the slide on the throttle (a 90 degree R4 is LONG).

I have quite a few cars from that era so there isn't going to be a problem getting cars with similar performance to race against each other - next step - chipping for SSD!

The car has to be driven differently and I'm wondering if that is part of the problem. If I hoof it on the exit of a curve the Porsche will come off. It has to be eased up to full power (or it twitches side to side) and, as the motor doesn't give much braking effect, eased down in anticipation of corners. Driven smoothly it is great fun and its top speed is quite quick. What I need to do now is experiment with weights to keep the nose down (so I can use the top speed and stay on!) I fully expect to get the lap time down to around 10 seconds.

Old tyres obviously need to be changed but I think it's as much about driving style as choice of tyre.

I'm now making Urethanes for my Porches, Escort Mk1's, Nissan 260z's and BMZ 3.0 CSLs and will run them magless on Sport with chips and a big grin on my face.

Anybody want to come round to play?!?

 

[Mr Modifier]

I just did some testing on an oval sport track to get some comparative times on different tyre compounds.

Sport track - standard analogue powerbase with a standard 16v 800ma supply.

I couldn't find my stopwatch so I used a digital metronome to get some ball park figures.

Car: C125 Scalextric Porsche 935 whale tail with no lights, no magnet and the old style RX motor. I kept the same front tyres on for all 3 rear tyre types (I used the F3 rubber fronts which are narrower than standard C125 tyres).

20 seconds for 5 laps on original tyres - ribbed rubber from the 1980's or early 1990's. Some evidence of cracking - pretty typical of these cars bought unloved from evilbay.

15 Seconds for 5 laps on new Scalextric F3 rubber tyres (these tyres were bought in a job lot of spares but were brand new in a sealed blister pack) tyres run naked (no oil). These were glued and trued.

12 seconds for 5 laps on Urethane tyres I cast myself using Polytek Shore A20. The moulds were made from a mint pair of Scalextric Large Superslix. I didn't have time for glueing and truing because the tyres were still in the bottles about 5 hours ago!!!

OK I didn't time to the nearest 100th of a second but it is pretty clear that you can get significant improvements from new boots.

 

[chris99]

QUOTE (Mr Modifier @ 11 Dec 2011, 13:39) <{POST_SNAPBACK}>I'm now making Urethanes for my Porches, Escort Mk1's, Nissan 260z's and BMZ 3.0 CSLs and will run them magless on Sport with chips and a big grin on my face.
Hi
Are you self taught or did you follow a tutorial which you could share as I think it's time to have a go at home-made tyres?

Chris

 

[Martyn_]

QUOTE (chris99 @ 13 Dec 2011, 11:43) <{POST_SNAPBACK}>Hi
Are you self taught or did you follow a tutorial which you could share as I think it's time to have a go at home-made tyres?

Chris
Hop on a plane to Bristol or Cardiff on Friday, and I'll take you down to Mr Modifier's house - he's going to show me how to do it Friday evening

Back to main topic, how are we getting on with the OP's original 70's and 80's cars (or was it 80's & 90's?) ?

 

[chris99]

QUOTE (snurfen @ 13 Dec 2011, 12:50) <{POST_SNAPBACK}>Hop on a plane to Bristol or Cardiff on Friday, and I'll take you down to Mr Modifier's house - he's going to show me how to do it Friday evening

Now there's an interesting offer but I think I'll wait for the video of Friday night's activities

 

[Mr Modifier]

OK back on topic -

There's a possible double-whammy here. Re-reading the original post it seems the 20 year old cars don't grip like they used to and there was a recent purchase of Sport track.

Old tyres get hard. Sport track is smoother and less grippy than classic track.

Result - slooooow lap times if you manage a lap at all!

For a laugh I dug out an old mini yesterday - a 1970's vintage I believe with original tyres on.

Lap time on the Amman Valley Raceway (Sport track) 31.179 seconds! Took the old tyres off - well they sort of crumbled off. Scalextric small superslix rubber tyres and I got 12.413 as my best lap. Urethane tyres in shore 20 hardness (pretty darned soft actually) and a slight improvement to 11.503 seconds.

So it would appear that new tyres are all that is required - regardless of what they are made of. OK urethanes will give a speed advantage but not if all cars are on the same type of tyres.

There are plenty of suppliers out there who are able to supply tyres for classic scalextric cars - just Google the model number along with tyres (i.e. "Scalextric C125 tyres") and you will find options.

 

[Mr Modifier]

QUOTE (chris99 @ 13 Dec 2011, 11:43) <{POST_SNAPBACK}>Hi
Are you self taught or did you follow a tutorial which you could share as I think it's time to have a go at home-made tyres?

Chris

Hi Chris,

Self taught but after a period of research reading threads on SlotForum and Googling the web. Basically came to the conclusion it was best to just have a go.

Here's the 2 minute guide to making your own tyres...

Get a sheet of glass (I use a glass chopping board).
Spread a very thin layer of PVA glue on it (wood glue).
Stick the tyres you wish to copy to the PVA.
Build a box with Lego Duplo bricks or some other convenient material around the tyres making sure gaps are sealed with a bit more PVA. Gaps between tyres and anything else should be about 10mm or more (more than that is waste).
Leave to dry for a couple of days.
Make sure glass is ABSOLUTELY LEVEL then fill mould with silicone mould making material (usually 20 shore hardness rating). Available from a handful of suppliers in the UK (not sure about France). Mix it following the suppliers' instructions. And YES pouring your first mix from one container to another to do a final mix IS important). Stir carefully to avoid putting too many bubbles in it.
Dribble the mixture into the centre of the tyres first to make sure you don't trap air. Then fill the rest of the mould.
Wait patiently for it to dry. If unsure - wait longer. I usually wait a week but it's probably OK after 3 or 4 days.
Pull everything off the glass (you might need a wood chisel to get some leverage).
Turn the tyres out of the mould. Peel the dried PVA of the tyres and you can use them!
Leave the mould to dry for another few days as this improves its life.
Next place the moulds on a flat surface.
Mix urethane of choice and add pigment as described (unless you want beige tyres). POUR QUICKLY INTO MOULDS but try to avoid trapping air.
TIP: don't mix too much urethane - as its working life is 2 minutes!!! (The silicone for the moulds will have over 30 minutes working life). I don't mix and pour more than 12 tyres in one hit - there's no time. If you pour too much simply skim the surface of the mould with a blunt straight edge, don't worry about this residue of urethane - it will pick off the tyres when set.
Wait 90 minutes (or as recommended by the supplier) and turn out your tyres.
Smile is a self-satisfied sort of way

Fit tyres to car and set new lap record.

How good are urethanes? Well - my MRSlotCar.CA group C mazda (it's a Slot.It rival and by far my quickest car at the moment) had the lap record on my track at 7.6 seconds. I put home made urethanes on a standard Scalextric Ferrari F430 super resistant and it went round in 6.6 seconds!

I am now making urethanes for my Mazda!!!!!

 

[chris99]

Mr Modifier - Great, thanks for the mini master class

- I really like the urethanes as they still allow some power sliding. They have really transformed some cars - apart from the Scalextric cars, old & new, my Pioneers have shown the most dramatic difference as they are so well balanced and you can really throw the back out on corners without de-slotting.
Have you played around with the different hardnesses of urethanes yet?

Cheers

 

[Mr Modifier]

Yes. I have shore 50 hardness and shore 20 hardness.

I am thinking of trying to find a harder compound to make front tyres with lower rolling resistance (except for 4WD cars of course!)

The shore 50 are softer than standard rubber but are stiff enough to avoid the need to be glued (at least not until they begin to lose elasticity) the shore 20 are very soft and peel off the rims under hard cornering so I think gluing them is a must-do.

I only run Sport track so my experiences are limited to that surface (I'm hoping to make a portable routed wooden rally track next year some time). Interestingly some cars do faster times with the shore 50 than the 20 and others do better on the softer shore 20. I can't prove it yet (not enough different tyres made yet) but it seems that the heavier vehicles go faster on the harder compound. It might be about rolling resistance vs. grip - the heavier cars would have too big a footprint on the softer tyres and the drag may outweigh the extra grip. Shore 20 gives a bigger (and better) difference with minis than shore 50.

By the way when I refer to light and heavy cars bear in mind that some big cars are light and some small cars are heavy when you think light and heavy in terms of downwards pressure on the track which is magnified by magnets.

There appears to be only small differences between the track times on either compound compared to their performance vs. plain rubber(which surprised me) and both compounds give a satisfying and controllable slide when you push hard around corners.

I am seeing lap times that suggest the right urethanes can give a 10% to 15% faster lap time than plain rubber. I don't treat my rubber so you may find some people saying oiled rubber is better than urethane. Urethane is less hassle than tyre potions and it really doesn't matter which you use as long as everybody is using the same.

It's early days as I have only been making the urethanes for a short while and have only equipped a handful of cars with them. I worked out that it would cost me over £200 to fit new tyres to my favourite/most often used cars and making my own will allow me to replace all tyres several times over for less than £50.

It's also quite satisfying racing on tyres you have made yourself.

 

[Martyn_]

Chris, it was a real revelation to go around Mr Modifiers and see how simple it was to make the moulds and tyres.

The key observations Richard passed on to me was the need to be meticulous in preparing the mixes, quick and accurate with your pouring, and just keep it all neat and tidy throughout.

Seeing a demo gave me the confidence to crack on and have a go myself. It really is as simple as described.

I can't quite remember who set the 6.6 lap record, to be honest

 

[Mr Modifier]

Well as chief test pilot for the Amman Valley Raceway Snurfen I think it's highly likely it was you who set the new record