Where are you on the 110 or 120 rear tire width?

dang472
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Edited Date/Time 4/16/2024 6:21am

I’m a +40 vet who is just wading in the 450 waters after being a really stubborn 2-stroke guy. I’ve always been a 100 width for 125s and 110s on the 250. I ride mainly rutty Midwest tracks and hear from a lot of the locals that they run 110s on their 450s. The 120 looks pretty big to me. I’m building a second set of wheels for when we head farther south and it’s more sandy. My plan is to run the wider 120 MX14 in more sandy/less rutty conditions. 

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skyrebel88
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New Fairfield, CT US
4/16/2024 8:26am Edited Date/Time 4/16/2024 8:28am

In general I usually switch over to a bigger tire when I feel too much wheel spin when on the gas hard. Like the feeling of being on ice. Sloppier conditions out of a corner is a good place to feel it when the power kicks in whether you can manage a skinnier tire or a fatter one is needed to reduce the amount of wheel spin. Anyways that how I make that judgement call. id say go 120.

4/16/2024 12:54pm Edited Date/Time 4/16/2024 12:55pm

Actual tire widths will vary by model and mfg.

I could not tell a difference between 110 and 120. 

Seems like the 110 should be better where there are long ruts and the 120 should be better on hard pack turns, but since I couldn't feel a difference I buy 110's because they are lighter and slightly less money.

crc245
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Yorba Linda, CA US
4/16/2024 5:15pm Edited Date/Time 4/16/2024 5:17pm

I’d look into a Pirelli MX-Soft (their scoop tire) for those sandy conditions. Not only do they work extremely well, but Pirelli only sells 100/90-19 and 110/90-19 in that pattern, which makes it easy to understand for fitment. On that note, and as others have mentioned, tire sizing can be brand specific. Out of the few tires I’ve used recently, Bridgestone measured the widest in a 110/90-19 and Dunlop was smallest. Pirelli was right in between, except for those wide, meaty, and tall knob MX-Softs! A 110/90 is still fine for a stock 450, and I prefer them even in SoCal and on baked afternoon rides. 120/90’s are better in the acceleration chop (by far), but can feel a bit bigger and make the bike slightly less responsive. The 120/90’s also cost more, but seem to last a ride or two longer as well. With the MX34 revamp, Dunlop reps were quick to mention that 110/90’s are for 250’s (2T and 4T) and 350F’s, and the redesigned (lighter) 120/90 was their 450 recommendation. Recap: Can’t go wrong either way, test a few 110’s if you have them lying around, it’s all good. 

 

PS: All good so long as you stay away from that horrid Bridgestone 120/80 X30! Only production bike tire I want to immediately toss, and the acceptable, though iffy, list includes various Maxxis offerings and teeny/tiny 100/90-19 Pirelli MXMS used on CRF250R’s…

downonmonday
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Cornfields, IL US
4/18/2024 10:30am

110 for our type of tracks here in N. IL. 120 for the sand. 

The Shop

aees
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US
4/18/2024 3:38pm

As above said, you need to go by actual width of tire, not stated. 

Bridgestone 110 is like a Michelin 120 for example.

Pirelli and Dunlop 110 is pretty in the middle of sizes and they are fine for sand on 450. To small rear on sand makes the bike snake and handle poorly, but 110 is sufficient of bridgestone, Pirelli, Dunlop.

120 it gets tougher to turn. Since you anyway drop the forks and maybe a few clicks slower rebound in rear on sand, you have made it turn slower any way.

1
4/29/2024 12:36pm

I usually ride with a 110 but put on a 120 to ride this weekend, it was a hardpack slick clay with some embedded rocks and shale so I thought the wider tire would get better traction in those conditions.

I was wrong!  

I noticed the front was pushing. In my unscientific conclusion, when leaning the bike you dig the edges of the tires to find traction; turning with the wider rear I was exceeding the edge of the front tire before the edge of the rear could grab traction. This led to a noticeable front wheel push during tighter apexes.

I think the 120 rear may work well when paired with a wider front tire, for people that steer more with the rear, or for a sand track where it's unadvisable to ride front heavy. 

FGR01
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4/29/2024 1:00pm

One note to add.. the MX34 comes in both 120/80-19 and 120/90-19 to further complicated choices.. 

MxAddic
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5/1/2024 6:26pm

I am on 110 for everything but a 125. 120/90 is like a balloon tire.

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