Does Anyone Make A Trials Bike That Doesn't Overheat At Speed?

[nigel dabster]

I love the Beta 4T it runs more consistent than my 2T used to run. Get a Beta EVO 4T 300cc. It is jetted rich from the factory and will run flat out all day with no issues. It is a much cheeper bike too!

What a good idea, didn't think of that.

[corex]

Looks like a nice ride... way more Betas around here than Montesa, and Montesa has no real importer here now. Thanks for the idea.

[uhoh7]

I should mention I live in BC Canada, so I'm usually climbing pretty hard on logging roads. My Gas Gas would overheat to quick to really have fun, and I always felt like I was killing it ( not in the good way ). Are the 4 strokes any better than 2 strokes at speed for long periods?

I guess what I'm asking is, is it OK to climb 10km of logging road on a trials bike, and if it is which is the best one? Sounds like you sure have no problems on your Sherco, and obviously you know your stuff, so maybe there was a problem with my Gas Gas.

Thanks for whatever input you guys have, I'm sure my questions sound rediculous, but I'm halfway between a KTM 200 exc and a trials bike and thought this might be the place to ask. To picture the riding terrain here think "Last Man Standing" meets gnarly mountain bike trails

The O-rings in your 280 head are shot and your thermostat may be dodgy. (check the color of your oil too--waterpump shaft.)

Replace Orings and turn your fan on manually, you will not overheat. My bike 300txt used to act like yours. Now it never overheats--you can drive it at 50 uphill on two-track, it doesn't care.

I used to think there was no way to fix it (overheating), like you. Now I know the bike does not need to overheat.

That said, the 4 RT is great by all accounts, except it's fat. 20LBS heavier that your 280.

Also I use a small overflow tank, which works really well in case I forget to turn my fan on (I prefer manual switch)

The 280 cools better than my 300, but one can also upgrade to RAGA head and SSDT GMX radiator.

Edited October 8, 2009 by uhoh7

[corex]

Thanks man.

I liked everything about my 280 except the overheating... I guess I should have been looking for problems instead of thinking it was the bike.

Maybe it's back to a Gas Gas for me >>>

[uhoh7]

Thanks man.

I liked everything about my 280 except the overheating... I guess I should have been looking for problems instead of thinking it was the bike.

Maybe it's back to a Gas Gas for me >>>

The GG rep for overheating comes from the fact that once it gets real hot, it will keep getting hot till you replace the o-rings. In the SSDT what can happen is the rad gets clogged by mud and the rider does not catch it in time. I think what happened to me is that the thermostat was slow to come on or the water level got below it-- I did not catch it. Then once I tried to change the orings, I did not seat them right--it can be tricky, and the problem persisted. I lived with it for awhile--in the process my cylinder started getting ugly with score marks. Now this thing NEVER left me in the backcountry---I would just let it cool, add water, and put out. Last time with one ring stuck. So I sent it in to langcourt for a nikasil coat matched to a new piston with .06 clearance. Back together I was still having some issues, so I put the fan on a manual switch. Any climbs, I turn it on. Also added overflow so I could tell easy. With the overflow tank, if it gets hot, you stop the motor for 5 minutes, and it sucks all the fluid back in OR often you can just turn on the fan and it will cool back down on the trail.

The other issue, which I also had, was a worn water pump shaft (VERY common), which would not let pressure build in the system--and then some water would squirt in the oil. YOu get a water pump kit, and watch the video--easy fix.

Today my 300 will stay cool on climbs where my other bike, with it's fancy aftermarket radiators, starts boiling over. In fact despite many big climbs I have never boiled over when the fan was on---since I got it all sorted finally. These were climbs where I used to add water several times in the past.

Now if you REALLY want to get serious about staying cool:

I haven't put them on yet. The two piece Raga head holds more water than stock, and the GMX rad cools beeter than stock. That's the setup the GGUK team is using at the SSDT on their 300s.

I do know there is a 280 raga head at TRIALSPARTSUSA. The radiator must be ordered form the UK.

The 4s are cool but nothing rips like a good running GG.

He she was almost new:

by the end of her first season:

Edited October 8, 2009 by uhoh7