Author Topic: Tire Sizes  (Read 345 times)

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Offline Diablo007

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Tire Sizes
« on: September 15, 2020, 01:51:21 AM »
I know there used to be a thread regarding rim and tire sizes but can't seem to find it.

My question is, will a 110/90 tire work on a 1.85 rim on an RD350.  I'd like sporty tires for the current build but have D.I.D. rims in 1.60 for the front and 1.85 for the rear.  To change to 1.85 front and 2.15 rear would mean going back to steel rims.
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T

Offline Yamaha 179

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Re: Tire Sizes
« Reply #1 on: September 15, 2020, 06:05:57 PM »
The stock RD rims. 1/6 and 1/85, work very well with 90/90 and 110/80 tires.  We were required to use OEM stock rims in Formula RD and those are the size tires we raced with and they worked, and looked, great.  I am partial to Avon's but there are very good tires of other brands that are a bit cheaper that work very well in both wet and dry conditions.
Lyn Garland

Offline Diablo007

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Re: Tire Sizes
« Reply #2 on: September 16, 2020, 12:22:51 AM »
Thanks Lyn!  For the rear tire size did you mean 110/90-18?  If not, will a 110/90-18 fit?
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T

Offline SoCal250

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Re: Tire Sizes
« Reply #3 on: September 16, 2020, 11:25:14 AM »
110/80-18 is the more common choice


EDIT: spelling typo correction
« Last Edit: September 17, 2020, 01:50:55 PM by SoCal250 »
79 Yamaha RD400F     77 Yamaha RD400D      91 Yamaha TZR250R
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Online m in sc

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Re: Tire Sizes
« Reply #4 on: September 16, 2020, 11:42:04 AM »
agreed. go for an 80 profile if you can.

Offline Diablo007

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Re: Tire Sizes
« Reply #5 on: September 17, 2020, 01:02:08 AM »
So...it seems that 110/90 is way easier to find in a set of tires; 90/90-18 and 110/90-18.  I even have a set of BT-45's right now.  They were in the shop and I brought them home for some reason.  Maybe the RZ350, but that takes 110/80-18 too, so who knows...

In any case.  What would the downfalls be of a 110/90-18 be?  What brands of tires would it be easy to find in a set of 90/90-18 and 110/90-18?
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T

Online sav0r

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Re: Tire Sizes
« Reply #6 on: September 17, 2020, 12:07:44 PM »
80 is shorter and should have a slightly less dramatic profile as a result. It also means shorter ratios. I run 90's, they are fine, 80's are probably fine too. The difference is 10mm.
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Online m in sc

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Re: Tire Sizes
« Reply #7 on: September 17, 2020, 12:11:05 PM »
agreed. its not that big of a deal.

Offline KANDY

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Re: Tire Sizes
« Reply #8 on: September 17, 2020, 12:55:03 PM »
100/90/18 and 110/90/18 on mine.
The bike came with that and I just ordered without checking it here. Wish I had this info before.

Offline Diablo007

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Re: Tire Sizes
« Reply #9 on: September 18, 2020, 04:02:17 AM »
Thanks everyone for the input.  Looks like I'll run the BT45's I have for now.

@Kandy; the tire sizes you listed are available in DP tires...you're running them on an RD with stock rim sizes?....  Hmmm....
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T

Offline quocle603

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Re: Tire Sizes
« Reply #10 on: September 22, 2020, 11:07:29 AM »
 :jacked:

Looking to change out my tires for my RD. Any suggestion on what brand/style I should run?
Do not underestimate the power of a two-stroke.

1975 Yamaha RD350 (modified), 1973 Yamaha RD350 (stock), 1971 Suzuki T500, 1981 Yamaha XS650 HS2, 1982 Honda MB5, 1980 Puch Maxi, 1979 Puch Magnum, 1993 Tomos Bullet, 2003 Malaguti Firefox F15 LC

Offline IR8D8R

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Re: Tire Sizes
« Reply #11 on: September 23, 2020, 08:03:23 PM »
Can we start a list of 18" tires that are available and proper? I was just looking at this subject online a few days ago. I don't profess to have any advanced insight into what's best. Other people with better knowledge will have to add opinions on quality and personal experiences. Most common I see are Avon and Bridgestone BT-45. The BT-45 were by far the most recommended when I bought mine from several sources.

I hope that the more learned people will weigh in. I am just basing this mostly on a couple hours of keyboard time not trial. My focus was simply finding matched tires available in the most discussed sizes for front and rear.

I am running Bridgestone Battlax 110/80 rear and 100/80 in the front on my RD 350 and I have been happy with the combo. This is apparently slightly unusual with regard to the front 80% aspect ratio. More common is 90/90 or 100/90.

Bridgestone: BT45. They are also available in 100/90 and 90/90. So are BT46 which are apparently a longer wear option.
Avon:AM26. These are available in a soft race compound also. I believe Lyn Garland carries these.
Shinko: 712.
Metzler: Roadtec 01 110/90 and 100/90;
Continental: Road Attack; Conti Go; Continental TKV 11/12 (front has a vintage look); Conti Road Attack 3. An acquaintance (and 2SW member) who's opinion I trust said that the Conti tires are awesome. I believe that he is using an ultra soft compound. If you are a So Cal canyon basher or Appalachian mountain rider they may be right. 

I don't like the idea of mixing brands and tires of different series/design. I am sure that there are probably super great combinations possible if you do. I just don't myself. I also don't really care about long life or mileage. I would rather replace my tires multiple times than low-side into a ditch once because my tires were hard. At the same time I'm not gonna put gum slicks on my RD. ...Ok I might if there were any.

We have some pipe and oil threads. Can we make one for tires in the Speed Shop??

IR8D8R