[StuBeeDoo]

Three of my classic rally cars have had that much use that I've worn the tyres out already.

After much research, I decided to go for Urethane replacements as the idea of a bit more grip appealed.

Before the tyres arrived I did some comparisons with all three cars. I noted the times for the standard tyres dry and clean, then with the tyres oiled and left until they were dry (no tramlines left on kitchen towel) and again 24hr after the oiling.

One car (I won't bore you with all three as they were similar anyway) gave a 7.0sec lap with dry tyres, 6.2 with the tyres freshly oiled and 6.6sec after 24hr. So those were my "control" figures.

Then the Urethane tyres arrived. The rubber tyres hadn't been oiled for a couple of days. I ran the cars again and the dry tyre times were the same as before.

I then fitted the Urethanes and ran the cars again before doing anything to the tyres. The times were similar to those when the rubber tyres had been oiled 24hr before - about 0.3-0.4sec better than the dry standard tyres. I was reasonably happy with that. But then I sanded the tyres, doing as I'd read. Shock! Horror! The cars had no traction at all.

I carefully cleaned the tyres using gaffer tape, and then cleaning fluid, then gaffer tape again. I checked that none of the tyres are spinning on the rims - they're not. The lap times are now fractionally worse than with the standard tyres (dry).

This morning, I've done it all, except the sanding, again and the times are roughly the same as the starting figure with dry rubber tyres. But what's really puzzling me is that running a thumb over the tyre tread the Urethanes feel stickier than the rubber tyres.

Do Urethanes get better with use? Or would I be better sticking to standard tyres? It's Sport track, BTW, if that makes any difference.

TIA
Stuart.

 

[356speedster]

Oil!

Urethane tires do not like the oil film left on the track by other tires. On a "dry" track the urethanes will be superior, but as soon as you start to oil the rubber tires things even out. The question is more about if you want to mess with the oil or not.

Some good reading here: http://www.slotcarouthouse.com/viewtopic.php?f=8&t=497

Tore

 

[Scorpus Flex]

yeah you will need to clean all the oil off your track before using uerathene tyres, they do not like any wet substances at all. also if your running with magnets your not getting the best out of the uerathenes because they are good at letting the car have a bit back end slide but still some grip to go again.

 

[Flange]

That's because urethane tyres are utter rubbish .... , get yourself some slot it f22s

 

[Ember]

I almost exclusively use urethane tyres on my track. Either MJKs or homebrews from a friend. I've tried other tyres but have discovered urethanes give me the most consistent reaction no matter the ambient temperature or humidity.

I have tried the Slot.it F22s mentioned above, but found them impossible to true without the use of a specialised machine. An investment that I simply can't justify.

The grip level of urethanes will improve with use, but it is more about the track surface changing than the tyre changing.

Everyone finds a tyre they like eventually. I was just lucky enough to find mine fairly quickly.

Embs

 

[dangermouse]

What grit sand paper did you true them with? I hit them with 800 grit wet and dry used dry and then 1200 grit used dry and then I put a drop or two of water on the tyres to polish them up. Tyres should be flat and nice and smooth. They may sometimes need a little polish up. To clean them use water and a rag or some shellite wiped on with a rag.

cheers
DM

 

[StuBeeDoo]

Thank you all for your input here.

I'm very grateful. And thanks also to rick1776 for the PM on this subject.

I should have mentioned that my tyre of choice is usually Slot.It P6 (2nd choice is NSR Supergrip), but they're not available in the sizes I need for these particular cars.

I did experiment with fitting bigger wheels, so that I could use my favoured tyres, but then the tyres fouled on either the body or chassis.

So, what's the best way to remove the oil residue from the track? I suppose I'll have to dismantle tha track and clean it piece by piece.

I must admit I never thought about oil residue - if I had, i probably wouldn't have done it. I just kind of assumed that if the tyres weren't leaving marks on the kitchen roll, they'd be fine. This has possibly given me the answer to another problem I have. A few of my GTs have inexplicably lost grip over the last few weeks. It probably ties-in with when I started tyre-oiling on my rally cars.

I'm away to try Dangermouse's wet & dry idea, for starters.

 

[Ember]

Rub the track surface over with methylated spirits or isopropyl alcohol. It should remove any residual oil.

 

[StuBeeDoo]

QUOTE (StuBeeDoo @ 24 Sep 2011, 14:23) <{POST_SNAPBACK}>I'm away to try Dangermouse's wet & dry idea
Well, that made a bit of difference - especially to the A110.

Not so much difference with the Sunbeam (strange,

as it has the same tyres as the A110) or the mkII Escort. I've put the mags back in those 2 for now

as they're waaaaay behind the rest of the field - a good 10%.

QUOTE (Ember @ 24 Sep 2011, 14:41) <{POST_SNAPBACK}>Rub the track surface over with methylated spirits or isopropyl alcohol. It should remove any residual oil.
I've got some Meths (hic), I'll give that a go later. Thanks.

 

[wayne69x]

Stu

I use 3in1 oil when I true my urethane's to keep the heat out and polish them then wipe it off with the Asda super cheap baby wipes. I use WD40 on my scalex sport track every now and then to clean it. I run no mags or weight and my grip is great. I would try my urethane's on your existing set up before ripping your track to bits.

When I first went over to urethane I cleaned the whole track with baby wipes to get the dust off (loft track). I have had no issues at all.

I don't think Flange's rather odd comment about urethanes is the opinion of all slotters but its horses for course's. I dont like messing on oiling tyres and cleaning the track all the time. Once you get the setup right with urethane its consistent as Ember said. Its tolerant to varying conditions way more than other tyres.

Wayne

 

[Flange]

If you glue and true and treat rubber tyres properly they are far superior to urethanes .. Just depends on how seriously you want to take it i suppose

 

[Ember]

Not everyone wants the hassles of constantly treating tyres. Nor is it legal in many clubs.

 

[356speedster]

QUOTE (Ember @ 25 Sep 2011, 05:25) <{POST_SNAPBACK}>...Nor is it legal in many clubs.

Or most proxy series, so if you want to build and tune cars for proxies you need a clean track to test on.

Tore

 

[martini917k]

some urethanes need a ultra-smooth finish; they can get the "squeegee" effect of silicones. Simple Green cleaner is great for polishing the urethanes @ high grit levels(800+).
the Slot.it C-1 tires are very good on wood & well-rubbered tracks.

 

[StuBeeDoo]

QUOTE (Ember @ 25 Sep 2011, 04:25) <{POST_SNAPBACK}>Not everyone wants the hassles of constantly treating tyres.
Me for one! That's why I wanted aftermarket tyres for these 3 cars (oh! and my 'Grale as well, but that's not involved in this thread).

 

[Scorpus Flex]

well done rubber tyres do offer more grip, but that doesnt always mean better. if you have a lot of grip in tall narrow cars such as old escorts, vw beetles or even classic minis the cars are very likely to tip over if you go fast into the corner. with the uerathene you can slide that car around the corner a bit so its a lot less likely to tip over.

if your not racing competitivly then you should just go for whatever tyre you find the most fun to drive. if all your cars of the same type have the same tyre then there is no problem.

 

[356speedster]

Another option is to focus on the track maintanace.

You can get great grip with most stock tires if you just run enough laps to get the track properly "rubbered in". It can take a couple thousand laps (without magnets) but with some effort you can get it done in a week or two.

The trick to maintain that rubber film is to clean your track and tires with water, and/or wipe off dust with a microfibre dust cloth (swiffer), and try to limit the use of siliconecone tires, as they seem to erase the rubber film.

I've been using this method the last couple years after messing around with all kinds of aftermarket tires, oil, masking tap, etc.. and my track has great grip with stock tires from Ninco, SCX, etc... Some stock tires are still difficult though, and the urethane tires is a great option that will work well on a track maintained like this.

 

[StuBeeDoo]

QUOTE (ironman @ 25 Sep 2011, 12:18) <{POST_SNAPBACK}>if your not racing competitivly then you should just go for whatever tyre you find the most fun to drive. if all your cars of the same type have the same tyre then there is no problem.
This is pretty-much what I'm after...... Fun to drive.

My thanks to everyone for their input. I've spent the whole of this morning trying-out different methods mentioned here.

I think I've settled on the following method.........

1) True the Urethane tyres using 1200 w&d with 3in1 on.
2) Clean the oil off the tyres using a strong washing-up liquid/water solution.
3) Dry with kitchen paper.
4) Roll the car over a strip of gaffer tape a few times.
5) Run the car for 5, or so, laps.
6) Repeat steps 2,3&4.
7) Run the car for 5 timed laps and note the result.
8) Start the whole process again and compare the time results. When the differences in times are marginal;- job done.

As a result of this I've also discovered that rubber tyres I thought were clean because they weren't leaving trails on gaffer tape aren't clean at all!

Clean them with the solution, dry them with kitchen paper and run them over the gaffer tape again............. Thick black lines!!

I've actually found some decent gains in the Urethane tyres. I'm going to run one of my Time Attacks later to confirm it all.

Once again, thank you everyone.

Without your input I'd have never formulated my tyre cleaning regime.

Best regards to you all,
Stuart.

 

[martini917k]

eliminate the oil from your routine. the oil & solvents in it will degrade your tires over time; unless you use a suitably aggressive solvent to clean them, which will also have a negative effect. just lube during sanding w/ water for the urethanes if you can't get Simple Green. the rubber tires don't really need to be lubed during sanding & 600 grit is the finest I would go on soft rubber (under 30 Shore).
I have made dozens of sanding boards using hardboard, rubber cement, & fabric backed sandpaper that work very well.

 

[StuBeeDoo]

Right. Time Attack completed. For info, the track is approx. 100ft/33mtrs, and the cars with Slot.It P6s are doing low 12s/high 11s laps. My Integrale, with some very dodgy/bodgy ill-fitting and out-of-round Urethanes does 12.0sec, and the slowest of the cars on P6s (Sierra Cosworth) does 12.3. The very best non-mag RWD car is the Scalextric C2118 Impreza at 11.7 sec.

The A110 isn't far short of where I think it should be - it's doing 12.5/12.6 sec laps. In comparison, the Sunbeam and mkII Escort are still off the pace. 13.1 best for the Sunbeam and 13.5 for the Escort.

I'm starting to think that I need to smooth the ribs off the tyres on the Sunbeam and Escort - they're still struggling for traction. It's all improvement, though. This morning the Escort couldn't better 7.2sec over half the distance. I know that with more grip (from my experience with oiled rubber tyres) the two slowest cars are capable of Time Attack times quicker then 12.5sec.