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Knobby Knife - Traction without buying tyres


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#16 Johnnyboxer

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Posted 11 January 2012 - 05:36 PM

View PostOld trials fanatic, on 11 January 2012 - 12:59 PM, said:

Perhaps scrutineering should be a regular occurance? Obviously you are correct though however putting my CoC hat on if somebody protested i would have to look into it and if found to be correct then i would have no choice but to take appropriate action.

Not knocking the product as i personally think it's a good tool but the rulebook is quite clear on this. Perhaps in these economically challenging times the rule should be changed, which is another arguement, however at this moment in time it's illegal in competition.

Just saying :chairfall:
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#17 2/4

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Posted 11 January 2012 - 06:31 PM

Of course a sharp edge gives a competitive advantage - or why would we bother to buy a nice new tyre when the tread rounds off?

I confess I once sharpened the edge blocks on the 348 with a Stanley knife as they seem to do a lot of the work (they round off quicker) but I felt it lacked traction on cambers. I'd better hand back that Aberfeldy Two Day finishers award now I suppose.

#18 1oldbanjo

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Posted 11 January 2012 - 06:31 PM

The local club in the Kentucky/Ohio/Indiana area allows tire trimming as follows:

TIRES
In order to receive any awards, championship points or to compete as a member of a team, even though otherwise eligible, all class riders except Novice must have trials pattern tires fitted to the front and rear wheels of the motorcycle used in competition. Aids to traction such as spikes, chains, etc. may not be used. Tires may be trimmed to remove rounded edges but the original tread pattern must not be altered.

I am not sure that I would buy the Knobby Knife as the local dirt is not hard on tires and the rubber compound may be getting hard by the time the edges get rounded.

#19 petejohn

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Posted 11 January 2012 - 07:12 PM

Hi
Great tool, but it takes a long time to sharpen the edges, The tyre lookes messy as I dont mark it, just slice to sharpen the knobs. If you practice a lot its well worth the investment. Tyres are now quite expensive here,
So if you practice a few times a week well worth the effort, if you ride trials with little or no practice then a waste of time as one tyre lasts a long time.
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#20 Old trials fanatic

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Posted 11 January 2012 - 07:49 PM

View Post1oldbanjo, on 11 January 2012 - 06:31 PM, said:

The local club in the Kentucky/Ohio/Indiana area allows tire trimming as follows:

TIRES
In order to receive any awards, championship points or to compete as a member of a team, even though otherwise eligible, all class riders except Novice must have trials pattern tires fitted to the front and rear wheels of the motorcycle used in competition. Aids to traction such as spikes, chains, etc. may not be used. Tires may be trimmed to remove rounded edges but the original tread pattern must not be altered.

I am not sure that I would buy the Knobby Knife as the local dirt is not hard on tires and the rubber compound may be getting hard by the time the edges get rounded.
So i take it that Novice riders can run moto cross tyres ? Never knew that :popcorn:
The Victor Meldrew of Trials Central. Dont believe everything you read about me because the truth is much much worse !! LOL

#21 benwall

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Posted 11 January 2012 - 08:33 PM

View Posttoothandnail, on 11 January 2012 - 04:51 PM, said:

hence the "couple mm trim" comment.Some one cutting just to sharpen edges wouldn't bother me at all


I agree that someone cutting just a few mm to sharpen the edges is a good idea as it stops you buying a new tyre.

#22 Scoobydo

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Posted 12 January 2012 - 12:39 AM

EE Bah Gum ! And I thought that I was as tight as a knats chuff !
Get yer hands in yer pockets and get a new tyre bought yer skin flints !
Nowt like a new un ont back to make sure ya beat ya nearest rival :agreed:
That way you are supporting (propping up) your local trials dealer (he cant live on fresh air tha' knows !)

Oh and you dont have to go to the lenghts my nearest rival goes to to (try) and beat me - 3 new bikes in one year just to get a new back tyre ! (true !)
Plus another new'un already this year !

For all the tight arses out there - make sure before you change you pirelli X13's that you can deffo see what looks like bird dirt on the tyre (in other words it's worn down tut canvas) - that way ya knows youve 'ad yer moneys worth :thumbup:

You'll know ya Pirelli is jiggered when ya cant find any more grip on the section at the sand paper yard !

Edited by Scoobydo, 12 January 2012 - 12:43 AM.


#23 htrdoug

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Posted 12 January 2012 - 02:51 AM

View PostOld trials fanatic, on 11 January 2012 - 07:49 PM, said:

So i take it that Novice riders can run moto cross tyres ? Never knew that :popcorn:


Haven't seen anyone do that at a T.I. event,seems like a disadvantage to me :rolleyes:
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#24 sectionone

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Posted 12 January 2012 - 05:27 AM

Sharpening the edges should help in slippery, muddy conditions but in the dry stuff, cutting the lugs will decrease traction because you are reducing the contact patch. Knobbies have less traction than trials tires on rocks and logs because of the smaller contact patch. Reversing your tire for a fresh leading edge also reduces contact patch.

#25 Nigel Dabster

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Posted 12 January 2012 - 06:41 AM

View Postsectionone, on 12 January 2012 - 05:27 AM, said:

Reversing your tire for a fresh leading edge also reduces contact patch.
why is the contact patch different if reversed?

#26 Johnnyboxer

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Posted 12 January 2012 - 09:34 AM

Just buy a new tyre, it's only £65-£70

Count yourself lucky you're not buying roadbike tyres at treble the price :rolleyes:
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#27 NZRalphy

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Posted 13 January 2012 - 06:41 AM

Craig.... go for it mate... there are a bunch of rule nannies trying to stop you saving money..... at an event no one will give a rats a*** you have done it.
I'm not half as good as I think I though I was...

#28 GIZZA5

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Posted 13 January 2012 - 07:51 AM

View PostJohnnyboxer, on 12 January 2012 - 09:34 AM, said:

Count yourself lucky you're not buying roadbike tyres at treble the price :rolleyes:
Then your paying toooooooooooo much for your Tourance tyres for your GS <_<
If you can't beat em......get stickier tyres!!

Yorkshire War Cry....HOW MUCH??

#29 Johnnyboxer

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Posted 13 January 2012 - 11:20 AM

View PostGIZZA5, on 13 January 2012 - 07:51 AM, said:

Then your paying toooooooooooo much for your Tourance tyres for your GS <_<

A pair :banana2:
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#30 pindie

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Posted 10 March 2012 - 09:16 AM

Why not see the worn tyre as a great way of improving throttle control and traction finding skills? This way even on a grippy section you get to practice for low grip. Come the winter when you do get a new one you'll be well chuffed and be a better rider.





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