Dunlop 674 compound rubber
Discussion
Hello you Radical chaps, I have popped over from the TVR forum. Have been looking for some slicks to use on the Griffith for hill climbing so need a nice sticky compound. Dunlop are trying to sell me some 647 compound rubber that apparently is used for circuit racing on Radicals which makes me think it may be a bit too hard. Do any of you have 647 rubber? If so how does it compare to say an R888 when poking your finger into it ? My ideal would be an Avon A15 but they don’t have the right sizes.
Thanks
Thanks
Hi Steve
If it's the standard compound here's my view; Comes in very quickly is pretty tolerant of abuse and over heating. and if the geometry is spot on they last a fair while on my SR3. Might last less time on a heavier car though. I've not run 888s on my SR3 but tried them on my Tuscan the slicks would get my vote.
What are you going to use them for?
Simon
If it's the standard compound here's my view; Comes in very quickly is pretty tolerant of abuse and over heating. and if the geometry is spot on they last a fair while on my SR3. Might last less time on a heavier car though. I've not run 888s on my SR3 but tried them on my Tuscan the slicks would get my vote.
What are you going to use them for?
Simon
Simon T said:
Might last less time on a heavier car though.
Simon
Yes I guess the Griff is at least 300kg heavier than the radical.Simon
Simon T said:
What are you going to use them for?
Simon
I want to use them on a modified Griff for Hill Climbing so they need to be soft and sticky from cold. They are only available in slightly narrower sizes than I would prefer but if they are really sticky that may make up for it. From what you say I think they will be far too hard. Proper Hillclimb rubber would’t last two laps on a circuit. Simon
Edited by steve-V8s on Friday 6th March 14:29
Apologies in advance for the blatant thread hijack but while Simon is sharing his knowledge - if one wanted to have a go in a couple of Sprints would the Dunlop race rubber be suitable for this in your opinion or don't they provide enough grip from cold?
It doesn't matter if they aren't ultra competitive, I wouldn't mind doing the odd sprint just to get myself back into a form of competition again if only really to challenge myself. I previously raced gearbox karts and the tyres we used there were useless from cold and had to be warmed up if you didn't want to chuck yourself off the track - like ice for the first few bends.
Nick
It doesn't matter if they aren't ultra competitive, I wouldn't mind doing the odd sprint just to get myself back into a form of competition again if only really to challenge myself. I previously raced gearbox karts and the tyres we used there were useless from cold and had to be warmed up if you didn't want to chuck yourself off the track - like ice for the first few bends.
Nick
No experience of the Dunlops, but "several" years of Hillcimbing and anything other than real hillclimb rubber just doesn't get a chance to start working.
For uninitiated the whole climb can be over within 30s!
Avon A15 would be about perfect (as long as you ddn't do too long Sprints) pity you can't get them in the size. Have you asked BMTR what they can do for you?
For uninitiated the whole climb can be over within 30s!
Avon A15 would be about perfect (as long as you ddn't do too long Sprints) pity you can't get them in the size. Have you asked BMTR what they can do for you?
Your barking up the wrong tree there!
Rubber hard enough to race on, is going to be next to useless on a hillclimb, you would be much better off on list 1B road tyres.
You need to talk to the guys at BMTR race department, David or Peter to advise you on what they can offer to suit your wheel sizes.
Rubber hard enough to race on, is going to be next to useless on a hillclimb, you would be much better off on list 1B road tyres.
You need to talk to the guys at BMTR race department, David or Peter to advise you on what they can offer to suit your wheel sizes.
dsl2 said:
Your barking up the wrong tree there!
Rubber hard enough to race on, is going to be next to useless on a hillclimb, you would be much better off on list 1B road tyres.
You need to talk to the guys at BMTR race department, David or Peter to advise you on what they can offer to suit your wheel sizes.
I'd second that. If you can't find a size/compound combination to suit via BMTR, you might want to look at Kumho V70a in soft compound: http://www.kumhotyre.co.uk/Motorsports/KH_brochure...Rubber hard enough to race on, is going to be next to useless on a hillclimb, you would be much better off on list 1B road tyres.
You need to talk to the guys at BMTR race department, David or Peter to advise you on what they can offer to suit your wheel sizes.
I would be very wary of any advice from BMTR for anything other than a formula car or Radical etc.
From my personal experience in hillclimbing/sprinting(with a slick shod rear wheel drive saloon with over 400 bhp), and a mate of mine, they have provided some really duff advice, to the extent where my mate spent over a year trying to make his car handle and feel safe on the tyres they recommended, and only went properly after having to buy another set of a different construction which he originally wanted and was steered away from. With these new tyres he is currently bang on class record pace with a car that he now has confidence in.
If you need advice for Avon tyres I would go directly to Avon if you can even if you have to get them from BMTR!
I always feel it is a bit of a lottery what you get from BMTR compound/construction wise for anything other than a formula car.
From my personal experience in hillclimbing/sprinting(with a slick shod rear wheel drive saloon with over 400 bhp), and a mate of mine, they have provided some really duff advice, to the extent where my mate spent over a year trying to make his car handle and feel safe on the tyres they recommended, and only went properly after having to buy another set of a different construction which he originally wanted and was steered away from. With these new tyres he is currently bang on class record pace with a car that he now has confidence in.
If you need advice for Avon tyres I would go directly to Avon if you can even if you have to get them from BMTR!
I always feel it is a bit of a lottery what you get from BMTR compound/construction wise for anything other than a formula car.
The stadard radical compound is far too hard for Sprints or hill climbs, tyres are still comming up to temp after a good warm up lap of weaving, braking and spinning up the rears
Simon
www.tillingmotorsport.com
Simon
www.tillingmotorsport.com
Thank you for the replies plainly 674 rubber is not what I need. Have been talking to BMTR and they can supply some A15 rubber in the right diameter and width but it requires wider rims that I can easily get on the car. I have found BMTR fairly helpful each time I call but the basic problem is they don’t make the size I need in the compound I need. I was asking about the Dunlop 674 because it is what Dunlop Motorsport are trying to sell me on the basis that it is a very soft compound, a bit of surfing showed it was a radical circuit tyre which put doubts in my mind. For the last few years I have run Hoosier A6 compound ( which is for what they call auto testing) It is not as soft as a proper hill climb slick but works tolerably well on a warm day, because of the doller pound they are now rather expensive. I think a fair few of the smaller single seater guys run uncut wets which tend to be nice and soft. As suggested it looks like it will be 1b rubber this year, probably R888s
For those who have not been to a hill climb, you get a chance to get a bit of heat into the rears by spinning them before the start but you approach the first corner and the first breaking point with no heat in the fronts so they really do need to be sticky from cold.
For those who have not been to a hill climb, you get a chance to get a bit of heat into the rears by spinning them before the start but you approach the first corner and the first breaking point with no heat in the fronts so they really do need to be sticky from cold.
888s although great tyres, are not that soft to be honest - i raced on these last yr in a striker kit car.... and although i did a couple of sprints for fun - they really aren't soft rubber..
The Kumho V70 is available in 3 compounds - and the soft would be a much better choice for sprints/climbs... loads of the caterham and seven folk are going onto them now.. blackpool tyres (Tony) is particularly helpful..
Good luck whatever you choose...
The Kumho V70 is available in 3 compounds - and the soft would be a much better choice for sprints/climbs... loads of the caterham and seven folk are going onto them now.. blackpool tyres (Tony) is particularly helpful..
Good luck whatever you choose...
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