Concentric v Monobloc

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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spookefoote1956
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Concentric v Monobloc

Post by spookefoote1956 »

The spares scheme hasn't got any 389/1's left. Amal have told me I'm going to have to wait until August. Do I cut my losses and chuck a concentric on the 56 G80?

Does anyone have good experiences with these and what specs are required for a 56 G80s engine.

Cheers, Chris
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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ajscomboman
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Re: Concentric v Monobloc

Post by ajscomboman »

Bit of a Marmite one this is, some love concentrics others loathe them. I'm pretty neutral as I've had good and bad results with them. Monoblocs I find are easier to tune and would always advise going for that type especially as the bike originally had one and therefore the specs are documented. A concentric was not around and therefore no specs exist, general rule of thumb is that slide number remains the same, pilot is usually 25, needle in the central notch and the main jet is reduced by 20% from the original spec. Pays yer money takes yer chance.
david pollard
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Re: Concentric v Monobloc

Post by david pollard »

try hitchcocks, 01564 783192 good service and price!!
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spookefoote1956
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Re: Concentric v Monobloc

Post by spookefoote1956 »

Hussah! I got fed up with Amal so I cancelled and gave Hitchcock's a try. They don't have a 1 5/32" so I called Surrey Cycles. Success (had to pay about a tenner more). He's got about three left so get in there if it's crossing your mind.
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
leswaller
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Re: Concentric v Monobloc

Post by leswaller »

ajstdrchris wrote:Hussah! I got fed up with Amal so I cancelled and gave Hitchcock's a try. They don't have a 1 5/32" so I called Surrey Cycles. Success (had to pay about a tenner more). He's got about three left so get in there if it's crossing your mind.
I posted the fact that Surrey Cycles had them in stock a couple of weeks ago, but was hammered for not supporting club spares who didn't have any! :headbang: :headbang:
Les
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spookefoote1956
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Re: Concentric v Monobloc

Post by spookefoote1956 »

Well I'm not hammering you. I am most grateful for the suggestion. I had tried to get one from the spares scheme to show solidarity of support but they didn't have one. I don't see any problem shopping elsewhere if your main shop's not got what you want. So many thanks again Les.
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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