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Tech Zone => Aircooled RD Tech Help 250cc and Above => Topic started by: SteeleRD on April 15, 2019, 10:42:31 AM

Title: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 10:42:31 AM
Hi guys just wanna double check before I go ordering some at my local tyre place whats the right size for the 250c in Avon Roadriders with standard mudguards showing two sizes on the avon site both described as front an rear.

110/80-18
90/90-18

update got an email back from Avon recommending

Please see below our recommended fitment for the below bike;

F – 90/90-18 Roadrider AM26

R – 110/80V18 Roadrider AM26

Thanks in advance,

Tom
Title: Re: Avon tyre sizes 250c
Post by: 5port on April 15, 2019, 11:26:49 AM
Hi Tom, there can be an issue here on early bikes.  You need to check your rim sizes because 1.60 fronts and 1.85 rears are common.  This can mean the popular premium tyres are not available in the approved sizes. Later models like the 2R8/9 have 1.85/2.15 and suit the popular 90/90, 110/80 combo.   Overall, a tyre that is designed for a rim width will be less suitable as the width is reduced.  I spoke to AVON tech and they said they could not approve sizes smaller than their spec.  However, there is the possibility that you can find a match in the old imperial sizes from the Yamaha spec, so, you might find that that covers it? 

5port
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 11:47:17 AM
Hi mate pretty sure it's got original rims on it I'll go an check them
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 12:33:00 PM
Just been out an had a look seems like shes still sporting original rims!  8)

Rear
Rims are Takasago 1.85 x 18 6G 103 Japan
fitted with 3.50-18 Metzler
Front
Takasago 1.60x18 6F 206 Japan
fitted with a 3.00 18 Metzler tyre
Title: Re: Avon tyre sizes 250c
Post by: 5port on April 15, 2019, 12:47:35 PM
Yes, they do look orig.  However, that leaves you with them both smaller than the tyre minimums.  You either: get a 1.85 rim laced on the front and a 2.15 on the rear-standard on some markets so no prob, or get smaller tyres- not easy to find good rubber smaller widths.

5port
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 12:54:24 PM
Thanks mate joys haha  :D
Title: Re: Avon tyre sizes 250c
Post by: 5port on April 15, 2019, 01:20:30 PM
Thanks mate joys haha  :D

I know!   ::)  However, modern-ish tyres on decent rims are great for modern road conditions.  Cheers

5port
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 05:34:54 PM
Indeed for now though going to keep it original wheel wise  8)

Know there's the Metzler Me77 and some by Pirelli
_________________________________________________
just got this back from Avon


Unfortunately a 90/90-18 is designed for a rim width of between 1.85-2.50” and a 110/80-18 is designed for a rim width of between 2.15-3.00”

Your rims are narrower than we thought, therefore we’d recommend the following:

F – 3.00-18 47S Streetrunner

R – 90/90-18 51S Streetrunner or 90/90-18 51V Roadrider

Mentioned to them it'l be worth putting a separate category for the rd250c as its recommending Road Riders which are incorrect.


 
Title: Re: Avon tyre sizes 250c
Post by: 5port on April 15, 2019, 06:11:52 PM
Honestly, it seems impossible to find reliable data on less popular tyres, esp on 18inch narrow rims.  OTOH, popular tyres like the BT45 and maybe the roadrider in narrow but correct 18 inch fitment are good.  I would certainly rate the BT45 as the best I have had on my RD's and for me, worth the price and getting 1.85 and 2.15 rims on my spokeys to fit them.  I guess that most tyres are better than the "Oh-No YOKO's!" in 1975 but, I think there is still a big difference between the best street (BT45) and the average (?whatever?) on the RD.  Just my opinion

5port
Title: Re: Avon tyre sizes 250c
Post by: Motty on April 15, 2019, 08:44:00 PM
Just replied to your other thread with the same recommendation as 5port. BT45 are what I am very happy with

Sent from my Moto E (4) Plus using Tapatalk

Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 10:08:41 PM
Anyone used Dunlop K82's :) they come in the right 3.00 an 3.50 size just remembered I've got them on my commando
Title: Re: Avon tyre sizes 250c
Post by: nerradw on April 15, 2019, 10:14:28 PM
Anyone used Dunlop K82's :) they come in the right 3.00 an 3.50 size just remembered I've got them on my commando

Just fitted k82s to my 400c with alloy wheels. Very pleased with the look, very 70s.
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 10:15:43 PM
Thanks mate :)
Title: Re: Avon tyre sizes 250c
Post by: tore on April 15, 2019, 10:43:46 PM
I am running heidenau tyres on my RD. They have imperial dimensions and Classic style as well.


Skickat från min iPhone med Tapatalk
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 15, 2019, 11:59:15 PM
Thanks Tore totally forgot about those got a set on my 350lc
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 16, 2019, 10:07:05 AM
Dunlop got back to me today :) K82's come in the correct sizes for the 250C (TT100 Replicas) anyone got any experience with them from a riding point of view.

Had a very long conversation regarding the 1.60 rim fitted by Yamaha

Narrowed it right down to those an the Metzler Me77
Title: Re: Avon tyre sizes 250c
Post by: Barnett on April 16, 2019, 04:42:49 PM
I have k82s on all three bikes, cant vouch for the 350, havnt finished resto yet. Cant fault them, excelent in all respects although bridgestones (bt45) just have the edge in my opinion, but they wear so quickly! you may want to look at michilin pilot in the imperial sizes, had them on the 650 before and had no fault with them, good allrounder, fairly boring tyre, good but not outstanding in any way!
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 16, 2019, 04:52:49 PM
Thanks Barnett no found anyone using the ME77's yet :) Dunlops are probably gonna be the way to go been super helpful today. I'll check the Michellin's out deffo gonna stick to imperial sizes.

Title: Re: Avon tyre sizes 250c
Post by: KGR33N on April 16, 2019, 05:36:03 PM
I have just bought a set of the Dunlop replicas as you call them for one of my 250 C's but not been out on them in anger yet as I am in the middle of a full refurb. I had them back in the day and they were great.

However on my other 250 C I inherited a Pirelli City Demon on the front and an Avon Supreme on the back fitted by the previous owner (McIver on here)....... Now I know you shouldn't mix makes and I am not shy of decking it over but I have been amazed at how good they are. They grip really well and it seems really easy to go from the vertical to full lean really quickly.....in fact they handle so well you have to be careful with how quick the steering is.......

So, why didnt I buy these instead of the Dunlops ? The only reason I have is that they are what I had on back in the day and I love the look / tread pattern / performance (albeit back in the day)..just hope they perform as good and dont turn out shite ha ha....

By the way I have enjoyed your thread. I miss my Dad so much he was my resident mechanic ha ha and I now have to do it all myself, but Im just a pen pusher and not very good......We loved going to the big race meetings together.......and he bought me my popsicle purple Fizzie and then my first blue RD250C so I can understand where you are coming from on your thread...

All the best with it regards Kerry

Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 16, 2019, 06:02:00 PM
Hi Kerry, Just want to say I really appreciate your reply great reading about you an your dad an the bikes. We are pretty much joined at the hip know I'm lucky to have that relationship with him so totally get you.

Main thing is ur getting stuck in an attempting it:) life is always about learning how to do new stuff

Metzler/Pirelli actually mentioned those sport demons when I contacted them never really used Pirelli before though although I've used tons of Metzlers on the modern bikes an the Norton's.

Shall be interesting as its been years since I've used Dunlops :)
Title: Avon tyre sizes 250c
Post by: KGR33N on April 16, 2019, 06:55:39 PM
I had Pirelli Diablos on my Ducati Hypermptard (bit off piste here) but They were very soft, little tread and I had zero confidence in wet weather as a result due to the tread issue.  They resembled slicks and when I went for an MoT it nearly failed on the tires ha ha till I pointed out the tread thats there goes all way to the edge and of requisite depth....I wont be going back there again.

I now have Michelin Pilots and after scrubbing in for a while they give a similar feel to what I said on my previous post RD post You feel you can deck them over for ever and I was suddenly full of confidence again.....result.....I guess you pay your money and takes your choice....hope the Dunlops go well for you ........
Title: Re: Avon tyre sizes 250c
Post by: SteeleRD on April 16, 2019, 07:30:56 PM
Totally get you ya can't beat what gives you confidence the m7rr's on the modern bikes have always given me superb feeling :) An the Avons on my elise is an unstoppable combination.
Title: Re: Avon tyre sizes 250c
Post by: Colin987 on April 17, 2019, 05:12:43 AM
Anyone used Dunlop K82's :) they come in the right 3.00 an 3.50 size just remembered I've got them on my commando

Got them on my 250A.

[attachimg=1]

Colin
Title: Re: Avon tyre sizes 250c
Post by: KGR33N on April 17, 2019, 09:06:40 AM
Dont they look great. The only conflict I had back in the day was running Dunlops but having the must have Michelin fork leg stickers as well at the same time...ha ha