Tire Sizes 21" rim

[Night_Wolf]

Will a 90/90/21 tire work on the 1400 Intruder or do I have to buy the 80/90/21?

[WintrSol]

To be safe, you should look up some of the tire makers' web sites, and see what they say about rim size limits for their tires. The answer will likely be: probably; but looking it up should tell you which makers are comfortable with that much difference. One other thing, besides fit, will be the speedo will change, as the 90/90 will be somewhat larger in diameter, so be prepared to re-calibrate your perception of actual mph.

For reference, this is what Avon has for their Cobra tires (a good tire, IMO):
Model -Tire Size - Service Index - Rec Rim - Rim Min-Max - OW mm - OW Inches - OD mm - OD Inches - Depth mm - Revs per km - Revs per Mile
AV71 - 80/90-21 ----- 48H -------- MT1.85 -- 1.60 - 2.15 ----- 83 ------ 3.3 ---------- 688 ------- 27.1 -------- 5 ----------- 476 ----------- 765
AV71 - 90/90-21 ----- 54H -------- MT2.15 -- 1.85 - 2.50 ----- 94 ------ 3.7 ---------- 701 ------- 27.6 -------- 5 ----------- 467 ----------- 751
and for the AM20:
AM20 - 90/90-21 ---- 54H -------- MT2.15 -- 1.85 - 2.50 ----- 93 ------ 3.7 ---------- 700 ------- 27.6 -------- 5 ----------- 474 ----------- 758.4

Note that there is considerable overlap in rim widths. What I find odd is the difference in revs/mile between the AV71 and AM20, as the OD is the same.

[Night_Wolf]

Model -Tire Size - Service Index - Rec Rim - Rim Min-Max - OW mm - OW Inches - OD mm - OD Inches - Depth mm - Revs per km - Revs per Mile

AV71 - 90/90-21 ----- 54H -------- MT2.15 -- 1.85 - 2.50 ----- 94 ------ 3.7 ---------- 701 ------- 27.6 -------- 5 ----------- 467 ----------- 751
and for the AM20:
AM20 - 90/90-21 ---- 54H -------- MT2.15 -- 1.85 - 2.50 ----- 93 ------ 3.7 ---------- 700 ------- 27.6 -------- 5 ----------- 474 ----------- 758.4

Note that there is considerable overlap in rim widths. What I find odd is the difference in revs/mile between the AV71 and AM20, as the OD is the same.

I'll guess it's a typo