Determining Tire Width on my 950 Adventure

[RyanWilliamCantrell]

What's the most narrow tire you'll run on your 950/990, and why?

I've got a 950 Adventure, with Sun Rims on it from the PO. I'm quite sure they're 1.85 up front, and 3.5 in the rear.

It's currently got a 140 on it, and I was thinking of dropping to a 5.1 in the rear in order to increase my selection of tires (read, spend less money on tires).

Anyone see a problem with this? As long as the load/speed rating is high enough for the bike?

Shinko 700 series on KTM 950 Adventure... The 130/80-18 is 661 lbs max load, the 90/90-21 is 467 lbs.

So, is that to say that so long as my 950 stays under 1128 lbs I should be fine? (And that's at the max speed rating, which I'm not going to be running in the dirt).

The cheap Kenda K270 has the highest load rating of the 3. Why?! I know it has the lowest speed rating of the 3 has well, but if one is running off-road 80% of the time, and one is keeping their speed under the speed rating ~ what difference does it matter?


I'm not saying I'm going to run out and put K270's on my Adventure... I'm just trying to understand the load rating system as it applies to the Adventure.

Does the wider tire disperse the heat better? If so, why does it have a lower load rating than the more narrow 5.10 tire? Does the speed rating represent the heat dispersement better?



SCORPION MT 90 A/T
DESCRIPTION
* Tread pattern with big central knobs for straight riding stability and general V-shape orientation for high grip in traction and braking
* Optimized high-speed stability even when fully loaded thanks to size optimized carcass
* Good wet/dry grip thanks to new silica-tread compound, offering both mileage and regular tread wear performance

SIZE RANGE



80/90 - 21 M/C 48S
90/90 - 21 M/C 54S
90/90 - 21 M/C 54V TL


150/70 R 18 M/C 70V TL
110/80 - 18 M/C 58S
120/80 - 18 M/C 62S
140/80 - 18 M/C 70S
120/90 - 17 M/C 64S




Rally Raid 908
close up
Dual-Sport/Off-Road


* The dual-sport D908RR is designed to handle severe racing and cross-country conditions and provides exceptional durability and grip over rocks, hard ground and pavement.
* Designed specifically to cope with the speed, horsepower and weight of large displacement rally-type dual-sport machines.
* The D908RR is DOT-approved for road-legal use.
* Reinforced tread blocks yield exceptional traction and stability.
* Generous open space around the shoulder area provides ultimate traction in sand and mud.
* Heavy-duty casing for excellent bump absorption and allows lower air pressures for a larger footprint and increased traction.


SIZE LOAD/ SPEED INDEX SIDEWALL PART # APPLICABLE RIMS
RECOMMENDED RIM OVERALL DIAMETER OVERALL WIDTH FULL TREAD DEPTH MAXIMUM LOAD @ PSI
D908RR Front
90/90-21 55R 3233-21 2.15 27.87 3.70 14/32
D908RR Rear
140/80-18 70R 3133-93 3.50 27.24 5.83 16/32






Kenda K270 Dual Sport

* Provides a large contact patch for the street, yet offers predictable traction for off-road adventures.
* High mileage rubber compound.
* 4 PR and 6 PR. DOT approved-50% dirt, 50% road.
* P-RATED 94 MPH


lbs/kg TREAD DEPTH (MM)

lbs
Front

3.00-21 4PR 51P TT 3.2/81 27.7/704 450/205 32/2.3 1.85x21 9.0 8.33

3.25-21 4PR 57P TT 3.5/89 27.9/709 515/235 32/2.3 1.85x21 8.5 8.50

2.75-21





6.5
Rear

5.10-17 6PR 71P TT 4.5/114 24.8/632 760/345 40/2.8 3.00x17 14.5 14.15

3.50-18 4PR 56P TT 3.2/81 25.4/645 495/228 32/2.3 1.60x18 8.5 8.6

4.60-17 6PR 66P TT 4.5/114 24.9/632 650/295 40/2.8 2.15x17 13.0 11.6

4.00-18 4PR 64P TT 4.3/109 26.3/666 615/280 32/2.3 2.15x18 11.5 10.91

4.10-18 4PR 58P TT 3.8/97 25.2/640 530/240 32/2.3 1.85x18 8.5 8.66

4.50-18 6PR 73P TT 4.8/122 27.0/686 795/360 40/2.8 2.15x18 15.5 15.28

5.10-18 6PR 73P TT/TL 5.2/132 27.0/686 803/365 32/2.3 2.15x18 14.5 15.08