Trials Tyres Vs other Sizes

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Anthony Drake
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Trials Tyres Vs other Sizes

Postby Anthony Drake » Tue Mar 18, 2008 2:38 pm

Gday all
I Have been thinking about tyres lately. I need to buy a few for different bikes that need different sizes and was going to fit trials tyres all round , but now Im thinking that trials tyres are not the best at all they are just a regulation tyre for the sport of trials .Yes :?:
So I want to enter a hillclimb and fit the biggest bite enduro type tread .Who knows the other sizes that a TY can handle?
What do you think?
Thanks Drakey


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Re: Trials Tyres Vs other Sizes

Postby Trango » Tue Mar 18, 2008 10:21 pm

You have raised an interesting question Drakey. The TY could certainly handle an enduro type tyre but I am not sure if it would be a better option. The TY is not a high geared, high revving bike that needs a big knobby tyre to bite into the ground and find grip when the back wheel is spinning. A trials universal has a soft compound tread and flexible sidewall that moulds itself to the terrain for maximum grip.



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Re: Trials Tyres Vs other Sizes

Postby David Lahey » Fri Mar 21, 2008 10:51 pm

About why modern trials tyres are the way they are - yes you guessed it - they were originally made as a "control" tyre ie everyone had to use the same tyre type. The design was intended to have some off-road capability and also be suitable for riding on sealed roads (as happened in trials back then).
Roll forwards through the decades of trials tyre devopment and while modern tyres still meet the original "control" aspect which specifies things like tread width, block size and gap size, the other aspects of tyre construction have not been limited. Changes to the aspect ratio, rubber type, weight and carcass design have resulted in a tyre with performance that is light years ahead of what was originally known as a trials competition tyre.
I have ridden the Ty175 I still have with the trials tyres available in the mid 1970s and the difference in performance between those tyres and modern tyres on the same bike is stark.

Now about that lovely TY250 you are going to ride in a hillclimb contest and flog your mates on their whizbang modern off-road bikes.

You had better choose a hillclimb that it is very rocky or hard packed dirt and with lots of twists and turns or you haven't got a hope in hell. If it has gravel or loose dirt and is relatively straight, you will be so far behind them it will be embarrassing. The Ty250 is a very low powered bike so any decent slope you are limited to 3rd gear and about 25km/h. Many times I've been on charity trail rides on a TY250 and ridden the optional "hard" routes which are usually hill climbs.
If the hillclimb is very steep, gravelly and long, forget it (no traction with trials tyres).
If it is very steep but with good traction and long, forget it (can't go fast enough to get up the near vertical bits and even if no near vertical bits, eventually run out of power in 3rd gear).

If you are crazy enough to fit a knobby to the rear, it won't help because as Trango said, it is just too gutless to spin it up (which is what a knobby needs to work properly in gravel and soft dirt) and will feel terrible to ride on rocks, roots and logs.
If you enjoy action and excitement, fit a rear knobby and try riding over that large wet log you usually cruise over with a proper trials tyre. To find one that is narrow enough to fit in the swingarm and clear the chain, take a ruler to the local bike shop and have a look for yourself. Rears for 125 MX bikes are about the right width but some are 19". I bought a knobby for my M138 350 Alpina and ended up with something that just fitted but only after trimming the side of the knobs on the chain side. After riding it on gravelly hills I wished I had used a trials tyre instead (and that bike has lots more mumbo than a TY250).


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Re: Trials Tyres Vs other Sizes

Postby kembro » Sat Mar 22, 2008 7:33 am

I think the hill climb Drakey is referring to, is Knox's Hill climb. Just east of Leongatha, held in June or July. It's 140m with a couple of turns at the 90-100m mark.

The dirt is loamy with a bit of stone through it, as it's on the outside of a Quarry. It's a fairly knarly climb with most not making it up. The one's that get over come back to time, but it's more about getting to the top. They run a vintage class but only had a Bultaco in it last year.

If it was me i'd run a trials tyre and work around the ruts.




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