TT-R125 unpredictable traction

I have an '05 TTR125LE that I can push pretty hard if I ride foot-out dirt bike style, but if I try to ride knee down it will break traction just as my knee is about to touch (usually at the rear) quickly and without warning. On faster sweepers I'd really rather knee down, so if there is something I can do that I'm missing that would be great. I'm hoping to be able to do something with my current setup as "real" supermoto wheels aren't in the cards at the moment.
My current set up is:
YZ80 fork raised as high as they can go in the triples
Rear raised from re-drilling rear shock mount to level the bike
YZ80 front wheel with 90/80/17 Pirelli MT75 @ 15psi
16 " TTR rear wheel in the rear with 100/80/16 MT75 @ 15psi

I am using all of the front tire, but there is about 1/2 chicken strip on the the rear

 

Not sure I can help much, but I have a set of MT75s and they give ZERO warning

 

Ask someone you are ridding with to watch you. The rear might be chattering, you might be dragging something(any scrapping noises before it happens). You could be bottoming the shock.

The chicken strips on the side more than likely is the rim is to narrow for the tire.

 

There's a few things I do body position wise on the mini, supermoto, or EX250 than riding a typical sportbike. It's possible that it's compensating for things like bottoming the shock or crappy tires, but it is what it is. That said, it's hard to demonstrate without being in person.

 

dont have the MTs but i have the diablos in 14"... they dont like to be pushed hard with an adult on them! I might try some BT45s next.

 

I'm going to shorten the fork this week so I can put the rear back to stock height. With it up so high it dramatically shortened the wheelbase and the swingarm is at a pretty radical angle. Hopefully that will improve things.

 

I would lower the whole bike as low as you can get it without scraping anything in a turn. I have never had any time on the Pirelli, but the BT45 sticks good on the Yamaha.

 

smj...... Lolol

 

So, I shortened the fork 4" which allowed me to put the rear back down to stock height. Made a big improvement, however right at the apex if I roll on the gas hard I lose the front. In that I realized the reason I'm using more front tire than rear is I'm using neutral throttle until I have the bike more upright at the exit. I'm going to lower the front a bit more to see if I can get some more weight up there. What tire pressures do you guys recommend?

 

Try pretending that you have mirros like a sport bike, and the put your head where it would be. That helped me get my weight forward. Also try turning your shoulders toward the turn. Body position is huge on these little bikes

 

I worked on body position quite a bit today, some were rather awkward exaggerated versions of my sport bike BP, lol

 

I had to roll my bars forward for the exact reason you're describing. I thought my BP was decent, but a friend suggested the tweak after looking at pics and I'll be damned if it didn't make a big difference.

 

I actually ran a mountain bike dh bar because it was about an inch lower at the grips to get my position lower.

 

Thanks guys!

 

Does it make any sense to run a flat bar or similar low bar to force the body down and get some weight on the front. I need to purchase a set of bars for my XR as a set I have are pretty bent.

 

I would go with the lowest rise bar you can get. I wouldn't suggest a mountains bike bar unless you can find a really strong and wide DH bar you like. The one I have is one I bought years ago. It is about 25 inches wide, and about a quarter inch thick 6061 aluminum. I think it was made by axium or something like that.

 

Also, I think most mountain bike bars are bigger then 7/8 in the clam area now. You have to have a 7/8 bar at the clam to fit the triples .

 

I went with low rise bars to force myself over the front end. Im 6'2" so tend to slide towards the rear axle...which makes the front lighter but I cant carry near the speed when I move towards the front.
These crash really good too!. (7 bins & counting)
http://www.powersportsplace.com/parts/tap-02-5271?seid=pspse1&gclid=CIbatLLJ-MMCFUM1aQodbaAABw

 

I had a ttr set up with the yz80 front end with 17" weld wheels, lowered forks by factory connection, works rear, both sprung for my weight. I rode it all summer and tried various different ride height configurations, all with the same result....a loss of traction with no warning, mostly the rear. Wrecked it 17 times in one month. Got tired of that and bought an RS125 with a crf150r engine....no more unexpected crashes!!

 

I think in my head I want an RS150R pretty badly, but am scared that once I actually got myself folded onto one, I may change my mind