[CMOTD]

Slot.It F22s have long been my tyre of choice for home use but it seems that they will be discontinued in the near future along with the similar N22. A new compound, G25, has been recommended to me by Tel (Savage) so are they any good? Only one way to find out - buy some and do a back to back test with a varied selection of tyres.

Details:
Track - 50ft copper taped routed mdf, matt emulsion, unvarnished paint surface.
Car used - Slot.It Merc 190 DTM.
Tyre prep - none apart from light sanding to remove shiny top surface. No oil, no glue. Truing, gluing and oiling will always change the characteristics but that is a whole different can of worms.
Temperature - a bit chilly in the garage today so performance slightly reduced with all tyres. 

Results and comments:
1) Scalextric stock. 10 lap average time 7.9 secs. Best lap 6.94.
Rubbish as expected.

2) Slot.It C1. 10 lap average time 6.1 secs. Best lap 5.79.
These are the stock tyres fitted to the car and are meant for plastic track so not that great on wood.

3) Wasp urethanes. 10 lap average time 5.69 secs. Best lap 5.53.
Urethanes are always better than original manufacturer stock tyres but rarely as good as decent rubber ones. They do last forever though.

4) Slot.It N22. 10 lap average time 5.46 secs. Best lap 5.38.

5) Slot.It F22. 10 lap average time 5.41 secs. Best lap 5.35.

6) Slot.It G25. 10 lap average time 5.42 secs. Best lap 5.32.

7) NSR Ultra. 10 lap average time 5.2 secs. Best lap 4.98.
These are always the canine round things in terms of ultimate lap times but come with the disadvantages that they have a very short lifespan and quality control is terrible. You are lucky to get a useable pair out of any packet. Probably essential at club level but I rarely use them at home.

Conclusions:
Best lap times are always a bit misleading as you can never hit the sweet spot with any consistency and the average over ten laps is a more useful guide so N22/F22/G25 are remarkably close with just a few hundredths of a second between them. Initial thoughts therefore are that the new G25 compound should be alright as a suitable replacement but longevity remains an unknown as I have not used them long term. They do seem a bit tighter fit on the rims than the other two. Mind you they come with a 46p price hike over the others and Pendle currently has stock of F22s so I won't be changing over just yet.

As always these are my findings as an average home user on my track on a particular day - your mileage may well vary depending on track type and skill level.

And Finally......
If you believe that  urethanes ruin the grip for rubber ones and/or vice versa - suffice to say that I duplicated the tests in reverse order and the results were, to all intents and purposes, identical.

[BAracer]

Interesting. So maybe no need to panic about the loss of the F22/N22 compounds.

[slotloco]

Interesting and quite thorough test Brian, thanks for taking the time to compare and share.
I hadn't heard of the urethanes vs. rubber supposed incompatibility debate before.
Personally, I cannot see how one would affect the grip of the other, unless one was pulling "rubber" off the track, or the urethanes were leaving dust marbles behind
-  so again, thanks for being so thorough. 

Those results indicate they will do well on wood in an "untreated" environment before the witches brews come into play.
[ as you say, that is a whole other alternate reality, "sliders"  seems an appropriate term :) ]

I wonder if others can give us some similar information on Scalextric, Ninco, Policar, Carrera tracks.

BARacer - Those that apply secret sauces will have an alternate reality. The G25 doesn't take the usual aliphatic solvents and oils well, so those folk will rue the loss of F22, N22, Hi-Grip and the old Ultragrip like the loss of a favourite pair of socks.
I know one sicko who has stockpiled over 100 mixed packets of the above items like a panic buyer gathering toilet rolls the night before Covid lockdown.

[BAracer]

Although I bought a Hudy, i am going to try and stay 'dry' for as long as I can. It's not a rabbit hole that interests me (yet!)

[slotloco]

Although I bought a Hudy, i am going to try and stay 'dry' for as long as I can. It's not a rabbit hole that interests me (yet!)

It was a rabbit hole I did not want to travel myself, but those in the club who did, laid a trail of liquid breadcrumb drips laced with aromatic solvents; so it was nose to the ground and follow or get lost back in the pack. 

So it became a case of "when in Rome . . .  "  sigh. 

But I draw the line at having tyres which smell like a gymnasium... 

[Nonfractal]

g25 tyre may be a good option for 

- endurance racing 
Harder Shure rating may produce lower wear rate

- digital oxigen racing 
The current n18 f22 tyres will no longer be available
DiSCA and other events will be forced to select new tyre options.

- proxy racing 
Doped tyres often fail to retain consistency after a few stages 

AlanW

PS.
Wintergreen? No! No way, no how, never , not ever...
PPS 
Hoarding is not a route that brings long term gains. When you are up against a whole club of racers experimenting-with and tuning-for new tyres, someone will eventually  find something that works better than your stockpile.

[CMOTD]

I hadn't heard of the urethanes vs. rubber supposed incompatibility debate before.
Personally, I cannot see how one would affect the grip of the other, unless one was pulling "rubber" off the track, or the urethanes were leaving dust marbles behind
-  so again, thanks for being so thorough.

Not an uncommon debate over here. Complete nonsense in my opinion but some UK clubs ban urethanes over this alleged problem. Running both types together has never given me cause for concern on either my home track or the club one. Our local club runs an IROC class with handout Scalextric Ferrari F430s fitted with urethanes and virtually every other class has free choice of tyres (apart from silicone which does cause problems). The outright lap record was once broken by an NSR ultra clad GT immediately after a full race session with the urethane fitted club cars!

P.S. You have people using wintergreen on tyres? Really? Are they mad? It has been banned at UK clubs since God was a lad. The active ingredient is toxic and can be fatal.

[rallyhub]

That is good news, Brian.
Where can I find urethane tyres in Europe?

Hub

[autoavia]

The problem with urethanes is that some produce dust which, on a routed wood track, temporarily destroys the grip for rubber tyres.

 At SSRC we run vintage race evenings once or twice a month on a Friday. Most of the vintage racers run Ortmann tyres because they have one of the widest ranges of vintage tyre types available.  On the following Tuesday club night when we run modern hard body cars with rubber tyres (usually F22) we find that initially there is no grip and the tyres pick up a lot of dust from the track. At first the grip vanishes after a few laps but if everyone cleans their tyres frequently during practice it improves over the course of the evening. 

 Ortmann use some kind of filler powder in the tyre mix. The dry powder is clearly visible in any air pockets in the tyre which come to the surface during tyre truing and we suspect that it is the powder which gets laid on the track as the tyres wear during racing. 
 So on our wood track there is definitely a problem with mixing Ortmann and rubber tyres but it is comparatively easy to resolve.
 I have run some other urethanes on modern cars during testing as we have been looking at using urethanes as a control tyre for some classes and there doesn't seem to have been any problem with loss of grip for the next person using rubber tyres on the same lane.

[CMOTD]

The Ferrari F430s I used as an example are fitted with Ortmanns and they cause no problems whatsoever. I mostly use Wasp at home but I do have a few cars fitted with Ortmanns and have not had a problem with them leaving dust either.
Tracks get a layer of dust whenever they are not used for a while so it is possible that it is not Ortmanns causing lack of grip. If I forget to vacuum my track then all tyres pick up some dust and need cleaning after a few laps. Soon sorted with some sticky tape.

I don't know an EU supplier Hub but Wasp post to the Netherlands at a very reasonable price. Just keep your purchases small to avoid the current VAT problems. If you get in touch with him direct, rather than through eBay, he would probably sort out a combined postage rate for multiple purchases. Email

Ortmann are based in Germany so there should be some EU suppliers. Googling 'ortmann reifenliste' could point you in the right direction.