Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Plus 4 Tyre size?

Hi 109er,

I didn't exactly test them, surely there are other tyres out there with an even better performnance, as you and your friends found out, but I have to say I feel the car firmly planted with the Yokohamas, be it in dry or wet conditions.

I "trust" it with them, if this expression makes sense. While I have driven many other cars with many other tyres without this feeling of "trust" from all the imperceptible litle signs the cars give their drivers (mostly, but not always, through the wheel).

Just as a curiosity, I use a slightly higher tyre pressure (1.8) for road use, and a LOT higher in competition mode (2.2 when I used these Yokos, 2.3 with the Toyos).

I use 1.7 bar too. I find it a reasonable compromise between comfort and handling. The type of shocks and or the settings make a lot of difference too. If the combination of rear shock settings and tyre pressure is too high the car gets a bit "tail happy" wanting to step out in accelerating out of corners.

Hi Mario,

yes, I agree with your view. The Yokohama C-Drive are a very good choice for the Morgan. Given that we don´t drive in the wet, it is the best tyre I can think of for the general use that a Morgan gets.

Interesting that you use more than 2 bars on the track. I have to try that when I get the chance.

2.2 bar is 32 psi.

Mario do you find with the standard Yokohama at that pressure you tend to get a more controllable drift. I find that at the lower pressure I normally run the back tends to step out, give it some opposite lock and then it grips suddenly requiring a rapid correction instead of a nice controlled drift. Probably a function of being a fairly car and grippy tyres.

The only time I really tested the effects of tyre pressure was in 2012 at the Estoril track.

Of course tracks aren't roads, their smooth surface allow us more inflated tyres and having a better "flank" rigidity (not sure of the right words, hope this makes sense) will prevent exactly what you described, a sudden loss of rear grip followed by a 180º

2.0 made me have a few moments when I tried to find the limit of the rear tyres adhesion in sudden, sharp cornering. The fronts would go wherever I wanted, but the rears had some problems to follow. In sustained long cornering the car kept some indecision between under and oversteer, making it a bit tricky to get a good exit speed for the main straight (Estoril has what you might call a "inverted Parabolica" as last corner, meaning its still a long right corner, but closes slightly at the end, while the Monza one opens at the end)

2.2 was much better compared to 2.0. In sharp cornering the rear tyres didn't complain and the car never got (or menaced to get) out of shape. In sustained cornering, as I tried to go faster each time, the limit of the car became quite clearly the front tyres, with the fronts showing signs of reaching the breaking point long before I had any worry with what I felt at the rear of the car, always stable.

I got to say by the end of these tests the tyres looked like they had begun to melt. Thankfully they didn't

The TOYO tyres are different beasts though and their rubber is so grippy that your greatest concern is the the lateral forces in cornering don't affect their shape and contact patch. SO yuo need to up the pressure to a point where you can really throw the car into the corners with full confidence that it'll hold grip, driving it almost like a go-kart.

I recorded a video of the front wheel work during a climb, that's a TOYO R888 pressured up to 2.3 (when cold) doing what it was designed for.

Love your videos.

Thank you. After a few years they have become a bit repetitive so in 2013 I started fixing the gopro to the car in odd places

Hello,
Has anyone yet tried tyres with the following dimensions ?
195/65 15...

Main question is : ok I get 1cm and the speedometer gets cheated 3.5%, but is there any other catch???

Cheers,
Vladimir

I changed to this dimension in order to gain 1 cm ground clearance. With these tyres the speedometer is exact. The catch is that the load index of tyres in this dimension typically is higher than such a relatively light car would need.

Harald

Only disadvantage I found it more difficult to put my hand over the front wheel to locate the grease gun onto the top grease nipple. Ground clearance improved and speedo reading more accurate.