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Soften Mini rubber cone suspension
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Author:  Sven [ Sun Apr 04, 2021 8:00 pm ]
Post subject:  Soften Mini rubber cone suspension

Has anyone on here softened their Mini rubber suspension cones. My rear suspension (on my NCF Blitz - mini front same as a coupe) is way too hard. I bought new shocks for it, & got standard ones to save a few quid but now realise i should have got adjustable ones! Doh!!! Oh well, can always buy another pair. Hindsight....! :roll:
I’ve read in various places that you can drill out the rubber cones to soften them. Has anyone done this? Just wondered how much to drill out. Can’t find anything online, so looking for any info before i butcher them. :D TIA

Author:  Ken555 [ Mon Apr 05, 2021 9:50 am ]
Post subject:  Re: Soften Mini rubber cone suspension

The factory manual http://gtmcoupe.altervista.org/build/Manual.pdf page 53 says to turn some rubber off the outsides, so its a straight line between the metal rings.
.
I remember a Club newsletter with details of holes to be drilled, will see If I can find it.

Author:  Ken555 [ Mon Apr 05, 2021 9:55 am ]
Post subject:  Re: Soften Mini rubber cone suspension

Found it.
Click to be able to read.

Image

Author:  Sven [ Mon Apr 05, 2021 10:58 am ]
Post subject:  Re: Soften Mini rubber cone suspension

That’s great. Thank you Ken

Author:  Steve Shield [ Sat Apr 10, 2021 4:44 pm ]
Post subject:  Re: Soften Mini rubber cone suspension

Hi Sven
Have you considered the "Smootha Ride" cones supplied by Minispares? Supposedly softer and with a different progression. I have a pair in the barn somewhere that I plan to fit to the Primo when I re-commission it later this year. Probably too expensive just to experiment with but they do sell them individually/in pairs -- you don't have to buy the whole kit.
Unfortunately a major issue is that no-one actually seems to know the difference in the rate versus the standard spring.
When I was involved in the Coupe project I wrote to Alex Moulton to try to get some info but his response wasn't much help -- I think he either thought I was trying to get to his trade secrets or maybe he'd just lost it as he was pretty old by then. Whatever just my two penneth.
Rgds
Steve

Author:  Sven [ Sat Apr 10, 2021 8:45 pm ]
Post subject:  Re: Soften Mini rubber cone suspension

Thanks Steve. Yes i had looked at them - think the price put me off. If I remember correctly they were nearly £300 for the complete kit!
But I realised that my rubber cones were well passed their best. So decided to replace them first & see what difference that made. As it turns out quite a significant difference - the old ones were very compressed & hard, resulting in very little suspension movement. You’ll see the difference in the pic. Much softer but still think i need adjustable shocks too. Just waiting for a bit better weather to try it out. :D

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Author:  Gtm Jonny [ Mon Apr 12, 2021 11:32 am ]
Post subject:  Re: Soften Mini rubber cone suspension

Hello Sven,
Are you using hi/los? I think the top of the trumpet is important, the contact area will affect the way the rubber cone works.
Some of the hi/los have a larger platform for the rubber to sit on and so stiffen the ride.
I had mine machined to the same profile as the standard trumpet top. This did soften the ride.
John

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Author:  Sven [ Tue Apr 13, 2021 9:16 pm ]
Post subject:  Re: Soften Mini rubber cone suspension

Thanks for the info John. I have got hi-lo’s on it (they had Minispares stamped on them, so presume they were their own brand), but can’t remember what the tops were like. I'll check next time i pull them apart. :D

Author:  Ken555 [ Tue Apr 13, 2021 11:31 pm ]
Post subject:  Re: Soften Mini rubber cone suspension

And just to give an other option.

I have the donuts replaced with coil springs. Not coil overs, just replacement springs.
Image

Author:  kano nordie [ Wed Apr 14, 2021 6:13 am ]
Post subject:  Re: Soften Mini rubber cone suspension

Me too, bought from Minitastic, think they had 3 different spring rates?
I got the "soft ride" as I wanted the suspension to go up and down over our rough roads, but moved the ball socket cup 3mm closer to the inner pivot on my fabricated upper arms to give a stiffer rear spring.
John

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