What have you done with your marlin today

[928cdu]

Re: What have you done with your marlin today

Hi Folks went for a drive today in my Roadster had it since early august 4th time out, sold a Stuart Taylor 7 to buy the marlin, had to change my driving style or will end up in a ditch, I know the roads in Derbyshire are not good, just like being in a horse and cart do all marlins have the cart springs at the rear? they will have to go, please help me, regards Ray.

Just a thought, what tyre pressures do you have ? 18-20 is the recommended..

[yousay54]

Re: What have you done with your marlin today

My tyres are 205.60/15 running 25 psi when first had the car 15psi like driving a jelly?.

[yousay54]

Re: What have you done with your marlin today

Not much help with the cabrio not got 10 grand to spend,?

[lizbillings]

Re: What have you done with your marlin today

Try 20 psi? 25psi does not grip well in a Roadster. You can get a Cabrio for much less than 10 grand.

[b_caswell]

Re: What have you done with your marlin today

Which roadster do you have? 205 with 15 inch rims seems over the top, giving too larger foot print unless they are very sticky tyres.

If you have adjustable shocks try backing them off so that the suspension is working.

[wiggiesworld]

Re: What have you done with your marlin today

Not much help with the cabrio not got 10 grand to spend,?

Yes, sorry, I've already slapped myself for that response, not very helpful.

Regarding the tyre pressures; IMO 25 psi seems a tad high though does depend on the tyre profile. I run 25 psi on a TVR Chimaera with 205/55 & 225/55's but that is a much heavier car overall. My Cabrio I run just under 20 psi, seems to give a good mix of compliance versus grip. This is similar to what I have used on previous kit car's. Seems to work OK.

Regarding the existing leaf spring/live axle; well I suppose it depends on how much you want to change it and what facilities you have access to. I previously ran a Dutton Melos which had practically the same set-up, as did a mate of mine. He converted his to a De Dion set-up, swapping the leaf's for coils and shocks. The De Dion he used was originally intended for an Escort mk1 rally car. Needed a reasonable (but not excessive) amount of fabrication but the end result was a vast improvement.

[yousay54]

Re: What have you done with your marlin today

Hi don't think I want to spend a lot of money on the car, stick with what I have, the wheels came with the car look good but big , thanks will try 20psi and take it from there.

[stevejgreen]

Re: What have you done with your marlin today

The reccomendation for lower tyre pressure comes because the Roadster is much lighter than a standard Marina but still uses the same suspension parts.
My feeling has always been, that most of the compliance in the suspension comes from side wall deflection, and that the difference between 13” and 15” wheels removes the large amount of possible deflection, as does higher tyre pressures.
I think of it by comparison to a F1 car, still running on 13” rims, and almost all of the ride characteristics are down to tyre pressure changes.

So maybe your wheel size is the root cause?

Tyre pressures discussed here.

[dcunn]

Re: What have you done with your marlin today

Ray
Suggest you experiment with very low tyre pressures, maybe even try as low as 12-15 and see if that improves things
Rgds DC

[stevejgreen]

Re: What have you done with your marlin today

One of the prime reasons for inflating tyres is to ensure that the bead does not roll off the rim when cornering. You won’t know when you have reached this point until you arrive at the scene of the accident, usually totally unprepared. There are no manufacture figures at which the bead rolls off the rim.

Under inflated tyres also have a tendency to overheat, reducing grip on the road under cornering and braking, after all it’s a very small patch of rubber that is between you, the road surface, and the scene of the accident.

There are numerous other factors to be considered I won’t bother with them but you get the idea.

I don’t reccomend making as step change from your existing tyre pressures, take it is small steps.

Its very much a personal choice to reach a result that is inevitably the sum of numerous vehicle and driver attributes, the ultimate goal is not to arrive unprepared and unaware at the scene of the accident.

[yousay54]

Re: What have you done with your marlin today

When I first had the car the tyres were 15psi took it for a drive, like a jelly but still had the 7 in my head, will just have to get used to my car, regards. Ray.

[yousay54]

Re: What have you done with your marlin today

Hi just another thought may need some new shocks? will have a look at some adjustable type to play with any ideas from Roadster owners what to use, many thanks, may not be down to tyres, weak springs etc, regards Ray.

[stevejgreen]

Re: What have you done with your marlin today

Hi just another thought may need some new shocks? will have a look at some adjustable type to play with any ideas from Roadster owners what to use, many thanks, may not be down to tyres, weak springs etc, regards Ray.

Spax do some nice adjustable s for the rear and they are also useful for the front.

Again, the rear suspension comes from the standard Marina, normally two leaf. The front uses the standard Marina torsion bar, two sizes are available, the standard are quite compliant but designed for a car with the engine above the front axle line, in a Roadster the engine is far behind the axle. Front shocks are Triumph Herald rears, not the standard Marina setup.

Weak springs are probably better for the weight distribution, but unless you have a method for identifying them after 40+ years, and comparing them to newly manufactured springs. To my knowledge there are 12 different part numbers to chose from, but some data is sketchy.

Have a look at the link in my forum signature below. Enough information there to keep you occupied for a month or two.

[petermarlin1798]

Re: What have you done with your marlin today

Took off steering and spare wheels for tidying, and ordered a cover for the spare. Trip St Ives-St Just on the coast road planned for Sunday.

[HairyDave]

Re: What have you done with your marlin today

On Saturday I took myRoadster for its first blast of the year. Lovely sunny ride out. It takes a bit of getting used to after my S1 Landrover. I must do something about the diff. 1800TC engine 4speed box and screaming, at 70mph. Van diff?