Author Topic: Tire size conversion (Read 43089 times)

Lefty · « **on:** April 11, 2015, 05:54:33 pm »

I am replacing my tires with some Metzeler "Karoo 3" or "Enduro 3" units and am having a time trying to figure out sizing. From what I've read, it looks like a 120/90 will fit on the rear, but I want to be 100% sure before I make the purchase. What size is closest to stock for the front and rear?

wrk2ride_ride2wrk · « **Reply #1 on:** April 12, 2015, 12:19:14 am »

Hey lefty, not sure on the 90, looking at mine looks like plenty of room, wall height should be good but for what its worth if your thinking of something dual sport, here's what I have 120 / 80 & 100 / 90 and they are great on road or off. Surprisingly good wear on both of them after plenty of twisties and slabbing it to get to the dirt about 1000klms on the rear Dunlop D506, & 1500 odd on the frnt K460 atm.
However that rear does hum on the highway and the blocks are spread for more mud & dirt than road

J6G1Z · « **Reply #2 on:** April 12, 2015, 08:21:30 am »

Check out the PDF link about 3/4" below.

J6G1Z · « **Reply #3 on:** April 12, 2015, 08:30:47 am »

I'm real pleased with the Avon RoadRiders. My Ascot is a street bike only & does not go off-road. It does get ridden like a sports-bike though & those tires have never slipped on me in the corners even when dragging a foot-peg. Another classic tire is the old Bridgestone BT-45. These tires run a bit smaller per size as compared to others. I like the BT-45 tires, but I like the Avons even more. I like to run the narrowest low profile tire that I can fit to the rim. The bike corners much better that way. We don't have to contend with much horsepower & worry about rear wheel spin, so there isn't much need to go wider.

J.

Lefty · « **Reply #4 on:** April 12, 2015, 04:10:53 pm »

Thanks for the link J, that helps a lot.
R2WW2R, I am really liking the way your bike(and lots of other older street bikes that run DP tires)) looks with the chunky tires- I do quite a bit of fire road type riding & did a lot of reading. The Metzeler Karoo3 & Enduro3 look great & are pretty quiet/grippy on the asphalt from what I've read, so I"m going with them.
Thanks for the replies guys, Lefty

wrk2ride_ride2wrk · « **Reply #5 on:** April 12, 2015, 07:54:29 pm »

Yeah actually I would have liked more choices, but here in Jpn the range of imported tires / tubeless & in our wheel sizes is very limited.

While on the DP point, I'm now at 15w fork oil & 65mm spacers & 8lb of air in my forks. My rear shocks not sure what they're off, but they're working well.
I guess all in on weight, me, gas, and the stuff I tote its about 95-100 kgs.
Last ride was about 300klms on twisties & about 6 hours all terrain, didnt bottom out once, bike was well planted all day.
(The ride before that at 12w an 25mm & 8lb, I bottomed out all through and finally blew out the seals)

This is what I've settled on, gives me good rebound on the pot holes / rough stuff & is still good on the twisties.
Looking forward to your tire report and some pics fitted

Lefty · « **Reply #6 on:** April 12, 2015, 08:06:16 pm »

I will post up some pictures when I get them mounted up & thanks for the inspiration, R2WW2R!👍

johnnymot1 · « **Reply #7 on:** April 13, 2015, 09:52:07 am »

Definitely post some pictures lefty. I probably posted my most recent tire size type question in the wrong section, but have a similar question about largest size, primarily more for the front to run more of any "equal" size look, function with DP tires. I'm looking at going up a size on the front to a 110/80/19 or something similar for my latest modified FT I'm finishing up designed to run some light, improved gravel roads in the desert.

Lefty · « **Reply #8 on:** April 13, 2015, 06:56:31 pm »

Wow, this is a little difficult!
I'm searching for 120/80-18 and 100/90-19 Karoo3's & have found one place online that has a rear in that size, but I'm not seeing the front in the size I specified(thank you, R2WW2R!)- I'm going to stop in at a Guzzi dealer tomorrow who's a Metzeler dealer & see if they can help me.
Seaking of Moto Guzzi, they've got some wild models out there! The Griso 8v has a wild looking stock exhaust....

Lefty · « **Reply #9 on:** April 13, 2015, 07:23:50 pm »

Johnnymott, I like the look of a bigger front tire also, they look really cool on the older bikes, but Im not so sure about running a no fender set up on mine. I'm interested to see what you come up with.

wrk2ride_ride2wrk · « **Reply #10 on:** April 13, 2015, 08:00:39 pm »

Lefty Shinko has;
GP22 R 120/80-18

Dunlop Bronco line;
D603
D604
D605

Johnny they also have these, looks more like an adventure tire than dual sport;
SHINKO 120/80-18 62H E705

J6G1Z · « **Reply #11 on:** April 14, 2015, 08:22:11 am »

Be careful mounting up wider tires, especially in the front. I've wondered how much clearance there would be between the sidewalls & the fork tubes in case of a flat tire. If the tire were to go flat & become wider, it could bind up on the fork tubes causing an Endo.

J.

johnnymot1 · « **Reply #12 on:** April 14, 2015, 09:58:09 am »

The Shinko 705s are pretty decent looking. I've narrowed a few down with bridgestone, kenda, shinko and IRC that I'm looking over. It looks like the 19" front rim diameter is a bit of a limiting factor.

Agreed on safety over form on a wider front. I'm almost looking for a more "balanced" front/rear set up as much as anything. I looked over an old rim/tire combo off some of my FT parts sitting around and it's running a 4.1 rear tire that is nice, so if I can come close with a front rear set up safely I'll run them.

This bike is my "tracker" build, so I'm initially removing and running without a front fender, the race tech springs, randakks carb rebuild/re-jet, thumper stuff exhaust etc....Should be a fun bike. I enjoy building and riding these bikes so much, I sold my larger sport touring triumph tiger the other day to spend more time on the FTs.

Lefty · « **Reply #13 on:** April 14, 2015, 10:04:34 am »

I found a Metzeler Enduro3 in a 120/80s 18 for 139 shipped, but still am having no luck with the Karoo3 in my size. I did see one that's a 140/80, so that would be 20mm wider which might be too wide? Still looking & will probably have to settle for a different front tire.

Lefty · « **Reply #14 on:** April 14, 2015, 06:30:49 pm »

So I'm thinking I'm going to go 140/80 on the rear, which is 20mm wider than R2WW2R's 120/80, which is very close to the stock size. 140mm=5 33/64, which is a little less that 5 1/2". Has anyone run a 5.5" rear on their FT? I looked at my rear set up & I can get my index finger between the swing arm & the tire, and I feel pretty sure 10mm a side will clear.
On the front the closest to R2WW2R's 100/90 I can get is a 110/80, which would be 5mm wider on each side, and 10mm lower profile- the OE Dunlop I'm running is a good bit narrower than the fender, looks like a 1/2 inch or so wider on each side will work. If one or both don't fit, I can always return and then I'll at least know where to go from there.
Thanks for all your comments and suggestions, I really appreciate it, Lefty

Lefty · « **Reply #15 on:** April 14, 2015, 06:34:37 pm »

Here's what they look like, if you haven't already checked to see what they look like

Lefty · « **Reply #16 on:** April 22, 2015, 05:29:50 pm »

The 140/80-18 fits! It's starting to pour here, so I got a couple shots before I headed inside.

Lefty · « **Reply #17 on:** April 22, 2015, 05:32:14 pm »

I have no idea why That posted both shots twice?
Front will go on in a few days, stay tuned.....

wrk2ride_ride2wrk · « **Reply #18 on:** April 22, 2015, 05:42:18 pm »

good stuff ...if the dirt's not fly'n your not try'n!

johnnymot1 · « **Reply #19 on:** April 26, 2015, 01:04:35 pm »

Awesome looking tires Lefty. Glad to know the 140 fits in reality. I ended up going with a 120/80 rear and the 110/80 front shenko/kenda combination on mine.

Thanks for posting those shots!

Lefty · « **Reply #20 on:** May 15, 2015, 05:14:02 pm »

Finally I got the front tire done! I've mounted many tires over the years and this one was incredibly difficult to get on the rim,I thought the tire was going to rip apart toward the end.
Ride report- these tires grip on asphalt and dig in in the dirt, I love them!
No noise or vibration usually heard with knobby tires onthe street. They carve into turns really well, now I need to get springs for my forks....

News:

Author Topic: Tire size conversion (Read 43089 times)