Post crash oversteer

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jim280885
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Post crash oversteer

Post by jim280885 » Thu Jan 09, 2014 10:59 am

Hi gang

After my crash a few months back (lowside due to rear wheel locking mid corner) I've had the bike back on the road a few times now and it is understeering on the way out of corners. The rear end doesn't feel solid. I've made sure everything is tight and it does have new tyres on it but they are pilot pures which i'm familiar with. It tracks true. My next step is to start messing with suspension settings but they've not been changed since pre accident when it was handling great. I'm open to suggestions from you sagely bunch though.

Cheers, jim.

cobbadiggabuddyblooo
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Re: Post crash oversteer

Post by cobbadiggabuddyblooo » Thu Jan 09, 2014 12:12 pm

Did you change from a 60 series to a 70 series on the front???
This may be the culprit..
laughter is the best medicine

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fung
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Re: Post crash oversteer

Post by fung » Thu Jan 09, 2014 12:42 pm

Perhaps get the front off the deck and check for head bearing tight spots.
If its notched, and the notch is off centre it may feel like it wants to "push".
Similar feel if your rebound is too stiff in the forks or too soft in the shock relative to the forks.
I know you haven't moved the settings.
I WOULD RATHER WEAR OUT THAN RUST

jim280885
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Re: Post crash oversteer

Post by jim280885 » Thu Jan 09, 2014 9:09 pm

Steering head bearing had crossed my mind, i'd just been too lazy to check yet, and I ssuspect they have never been done so i might have them done anyway. and you may be right cobba. I was running a 70 pilot pure before i wen to the dunlops I had on when I crashed, but they may have been a 60 and i'd just forgotten, as the new pilot is a 70 as well. Which direction should i go with the suspension to better suit a 70 profile? (I think the dunlops are the only tyres i've run with the r6 shock so far too so yeah, hopefully its just a matter of tuning to suit.)

Thanks for the input guys.

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Tarwetijger
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Re: Post crash oversteer

Post by Tarwetijger » Thu Jan 09, 2014 9:17 pm

Be sure to check that your bike really is in good condition.
My bike has been crashed and got repaired. (Also with a locked rear wheel, but the bike got on its left side while it was a right hand corner. I suppose the guy highsided it, but I have not seen it happen).
Only years later I discovered, by coincidence, that the front rim was warped.

cobbadiggabuddyblooo
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Re: Post crash oversteer

Post by cobbadiggabuddyblooo » Fri Jan 10, 2014 12:12 am

The dunlops also have a different shape too and I've found the michelins to be more of a rounder tyre than the peaky centre of the dunlops. Good chance this is your culprit. If you still have the original ball type steering head bearings and not replaced with tapered Just take the bearing race out of the steering head and check inside where the bearings ride. No need to remove the cup from the frame and If there is anything you can feel just lightly polish it with wet n dry ,clean and repack the bearing race and put it back together. Try and keep these bearings Inplace as long as you can as they are a better choice of bearing than a taper bearing for this application and if well maintained will last the life of the bike in most cases. :wink:
laughter is the best medicine

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sherlock
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Re: Post crash oversteer

Post by sherlock » Fri Jan 10, 2014 11:51 am

You could also check the wheel alignment with a string line to ensure everything is straight.
elementary my dear.....

cobbadiggabuddyblooo
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Re: Post crash oversteer

Post by cobbadiggabuddyblooo » Fri Jan 10, 2014 12:16 pm

12mm difference... As its height is no loger 60% of the width but 70% of the width so raising the height from the road to the axle from 72 to 84mm. The actual height of the whole wheel will be raised by 24mm.
60% of 120mm = 72mm
70% of 120mm = 84mm

So try dropping the forks to compensate before you start tinkering with suspension and steering head bearings.. :wink:
laughter is the best medicine

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fung
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Re: Post crash oversteer

Post by fung » Fri Jan 10, 2014 12:23 pm

Tyre pressures checked?
I WOULD RATHER WEAR OUT THAN RUST

jim280885
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Re: Post crash oversteer

Post by jim280885 » Fri Jan 10, 2014 2:40 pm

Cheers guys

Yeah pressures checked (although on a servo gauge :/ )

Its funny you say that bout the pures cobba I sent the PM with the blather about the pures tipping in quicker before seeing this BUT I STAND BY IT! lol
Anyway, yeah i didnt like the slower steering of the q2s at all - but i'm led to believe the pures weigh less (??) so maybe thats why they feel like they steer quicker. I did find the q2s entirely trustworthy though (except for an inability to stave off wayward backpacks :wink: )

Whats the word on the steering head bearings? I'd heard that tapered ones are the bees' around the way. But not so for the trx? Glad if thats the case though cos I can be pretty sure mine will have the originals in it.

A mate of my old mans recalled an incident similar to that Tarwetijger due to a security chain/padlock thingy. I guess I have my lack of reflexes/ability to thank otherwise I might have tried to catch it and ended up going the other way. I'll get a string line onto it tomorrow too.

Thanks again.

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