Posts: 2098
Joined: 7/31/2010
Location: Merritt Island, FL USA
What are the pros and cons of a wider or narrower front tire in HS race conditions?
Racing in FL, most of the time we have sand and roots, but a few locations have hard pack.
Choosing between 80/100X21 vs 90/100X21... How is one better than the other - where does one excel over the other?
Thanks!
2019 KTM 350 XC-F
Daytona Dirt Riders (DDR)
Floridatrailriders.org (FTR)
Posts: 999
Joined: 3/2/2011
Location: CT, USA
Wider front is going to be a bit more stable, tends to track better on hard pack. Narrower will cut into sand a bit more, and hangs up in ruts a bit less
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783
Posts: 132
Joined: 12/16/2017
Location: Lake Elsinore, CA USA
I rode with a 90/100 once and took it off before next ride. (I got it for free. Only reason I used it.) it would push like crazy on flat hard pack turns. I live in so cal.
Posts: 6148
Joined: 10/16/2014
Location: Buda, TX USA
Fatty fronts are like cheating in sand and ruts and rocks because they track so well and float above the trash. They also have bigger sidewalls for more flex which helps in bumps and hurts some on flat corners.
Posts: 9973
Joined: 7/25/2009
Location: Nor Cal, CA USA
I didn't like the way 90's turn in to corners, that was the most noticeable difference to me. When I would start to lean in approaching a corner the front was reluctant to lean with me and would push out causing me to dab my foot often messing up my cornering. Put an 80 back on and the problem was solved.
Posts: 9386
Joined: 7/6/2015
Location: So Cal, CA USA
agreed with slipdog and mxer807. I rode with them for a while and adapted to it, but it never felt quite right. Switched back to an 80 and all felt right again. I'd stick with the 80 if I were you
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Posts: 2098
Joined: 7/31/2010
Location: Merritt Island, FL USA
Sounds like with the sand we have in FL racing offroad, the 90 has more pluses than minuses?
Another comment on a different forum indicates you need to run the fork tubes up 5 mm in the clamps to offset the height difference of the 90. He indicate this resolved the push some mentioned... Just some additional feedback...
2019 KTM 350 XC-F
Daytona Dirt Riders (DDR)
Floridatrailriders.org (FTR)
Posts: 720
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Location: TX, USA
Edited Date/Time:
I had no luck with the 90 front, until I slid the forks up to compensate for the difference in tire height. After that, the 90 was almost like cheating on hard pack. I don’t think I’ve ever tried one in softer conditions...
Posts: 1781
Joined: 12/14/2010
Location: Temecula, CA USA
I don't like the 90/90-21 front for moto here in SoCal. Felt like it made the bike more difficult to turn and my front end didnt feel planted in ruts. This was even after messing with fork height and tire pressures.
For offroad and sandy conditions, i think you may find benefits. I wouldn't recommend it for moto, though.
Posts: 503
Joined: 1/16/2018
Location: USA
theycallmeebryan wrote:I don't like the 90/90-21 front for moto here in SoCal. Felt like it made the bike more difficult to turn and my front end ...more
90/90? I have a 90 at home and could have swore it was a 90/100. Is the 90/90 so you dont have to move the forks because the height would balance out?
Visually the 90/100 I have is about an inch or so taller than the 80/100,
Does anyone have a tire spec chart?
