Four Stroke Vs Two Stroke

[martyn32]

what are the main advantages and disadvantages of four strokes?

Also what is the difference in riding style?

thanks Martyn

[telecat]

The Main Difference is the Way the power is delivered. 2T's have a softer more linear power delivery because they "fire" more often. The "pulse" as the engine fires cna be modulated better as it does it more often. A 4T tends to be a bit more "ragged" as the bigger gaps between the "firings" take away the smoothness. Power and Torque tend to be comparable and 2t's gain rev's quicker which can mean you need to be quicker to react on the throttle, this is a strength of the 4T where the "spinup" is slower and suited to a true "no-stop" style.

This is of course relative and a good rider can work with both and have a good day at a Trial.

[martyn32]

thanks for replying so soon.

so you would have to be quite a good rider to transfer from (im on a 125 at the moment) a 2t to a 4t

[telecat]

It depends. Some riders really "take" to the 4T others don't. If you can ride a few to see how you get on I'd say you should be guided by that.

[martyn32]

thanks a lot.

[mrwhite]

Beware of jumping in with both feet, a 4t will generally take more effort to ride due to the weight, power delivery and alien ride in comparison to a 2t.

As with all bikes blag a ride and see what you think before committing.

Good luck.

[billycraig]

thanks for replying so soon.

so you would have to be quite a good rider to transfer from (im on a 125 at the moment) a 2t to a 4t

I've spent 2 years on a 125 2t and then struggled when I got back on a 250 2t (I always used to have a 280).

I've just ridden a 4rt in the Scottish and felt completely at home on it. To me it feels as though things happen a bit slower (as things do on the 125) giving me more time to pick lines and actually ride plus I have power there when I want it.

Having never ridden 4t I wouldn't of even contemplated it until I borrowed one. As others have said, get go. Make sure it's a good go if your new to 4t trials. I went to Pidcock's montesa test day and was allowed 2 hours to give the bike a go in all sorts of situations.

Edited May 12, 2011 by billycraig

[jeeves88]

ive been looking at this, debating what bike to get, between gas gas and sherco 250 or a montesa 4 stroke, and i cant decide really. farely rough on machine just maybe fancying four stroke due to its nature to be a bit more rugged, true false? any opinions obviously rag it and itll break but i would of thought there just be a bit less tempermental!

[gjbiker]

After years of riding strokers I tried the 4RT for a while and really struggled to 'gel' with it. Maybe I didn't give it long enough but I'm still glad I went back to 2t. Just spoke to a chap who in the past few years has the ridden the SSDT with a 4t. This year he rode it on a 2t and found it a lot 'easier', his verdict was that he should have never have swapped to the 4t in the first place?

On a more financial basis a 2t is a lot cheaper to maintain than a 4t, easier to work on and has less moving parts to go wrong. I can only speak for myself and my own personal choice but for ride-ability, maintenance and running costs I'm going to stick with the 2 stroke for as long as the enviro-police will let me.

Best advice as always - try before you buy if you can?

GJ

[scoobydo]

Interesting comments coming on here.

So here goes with my comments.

I have owned both 2 and 4 strokes.

Since changing from a 2 stroke to a four stroke my results have gone from a usual 5-10 place to a 1-3rd place ! And if any thing with less practice time to help !

One post has claimed that the four stokes are more ragged than a 2 stroke - what the hell 4 stroke have you been riding ???

My Beta 4 stroke is very smooth and whilst it is a 'communicative' engine (more so than a 2 stroke) my 4 stroke cannot be described as ragged ! Its soft and smooth and has been instrumental in me being able to up my game - very glad I made the swap and I would not go back to a 2 stroke.

[enrico]

Scoobydoo - without being disrespectful, can I ask what level / class you ride at? A lot of Expert level riders around our area (South East) went the four stroke route and have now gone back to 2-strokes. However, the 4-strokes are popular amongst those riding the clubman route (at least in our club anyway) which is possibly to do with the more straightforward sections and riding in the 'non-stop' mode.

I rode a 4RT for a few trials, which was kindly loaned to me for a while, and whilst I loved the engine she was a bit of a heavy old girl at the end of a long day. I am interested in the Beta 4 strokes, but found the 300 was a tad fierce on the initial takeup when I tried one?

[martyn32]

Thanks for all the replys, they have all helped and i will try to get a shot of a 4t before considering buying one.

thanks a lot

[motovita]

One post has claimed that the four stokes are more ragged than a 2 stroke - what the hell 4 stroke have you been riding ???

Yeah, lumping all 4 strokes together makes as much sense as considering one Trials tire as good as the next, since they all look the same.

[ham2]

The following sentence is from the Ministry of Stating the Bleedin Obvious .There are different 4 strokes just as there are different 2 strokes.

I have to qualify this post by stating that I'm a plodding clubman rider :-

I tried an early 4rt (without the programmable throttle body) and the 'punt' of torque surge just above idle made the bike awkward to manage ( I wouldn't have liked to contend with it, at the end of a trial, when I was tired)so that try-out formed my opinion.

Then,conversely... I tried a 4rt with a programmable throttle body (Laia Sanz?) and that was much smoother on the initial take-up ,made the bike much more user friendly,I didn't want to hand it back.

I purposely exhausted myself on my own bike(2 stroke) then went back for another go on the 4rt (PTB) which was much easier to ride tired??

I also tried a Sherco 320 4 st but I'm OK now, my arms are back in their sockets .

I can understand why experts need to put a 260/280/300cc kit on their Cotas', or look to a 300 Evo 4 St, or a Sherco 320 4 St.

[dgshannon]

what are the main advantages and disadvantages of four strokes?

Also what is the difference in riding style?

thanks Martyn

The most immediate difference is engine decompression. When you roll off the throttle, on a 4-stroke, it is immediate. This engine braking can be used to your advantage on sudden transitions to a downhill. Roll off the throttle, and you start slowing down immediatly, even before you get on your brakes. With a 2-stroke, you tend to have to pull in your clutch, and get on your brakes, to accomplish the same.

Likewise, when climbing a hill, as you reach the top on a two stroke, you roll off the throttle early, and let flywheel carry you the rest of the way. On a 4-stroke, you dare not roll off early, as engine braking is immediate. Instead, you stay in the throttle to the very top. Once at the top, close the throttle, and engine braking slows you immediatly, just that much earlier than on a 2-stroke, where you must disengage the clutch, and get on the brakes.

Maintenance wise, it is really nice not to have to deal with premix, but oil changes are a greater pain, with a filter, or filters, involved.

I rode 4-strokes for about 7 years straight. Two differnent brands (Scorpa & Beta) and three different models (SY175F, SY250F and Rev4T-250). Really enjoyed them all, with the Beta being my absolute favorite. Having grown up on 4-strokes, I was a died in the wool fan when the trials bikes showed up. Once switched, I swore that there was no way I would ever go back. But, when it came time to sell the last 4-stroke, one year of finding a buyer turned into two, which turned into three. In the end, an almost flawless bike had to be deeply discounted far below it's value, to get it sold. Once sold, the idea of paying over $1,000 extra for another 4-stroke just didn't sit well. Take a loss on the front end followed by a loss on the back end just didn't make any sense. In the end, I went with a 2011 Beta Evo 250 2T. Took a bit to readjust to the 2-stroke characteristics, but I am super happy with the decision. I am not a big obsticle, aggresive power, rider so that is why I really liked the smooth power of the 4-stroke bikes. The Beta 250 has amazed me in how smooth, and tractable, the engine is. It will lug down super low, and pull hard, just like the 4-strokes would. Just a super engine across the whole rev range. As long as there are 2-stroke engines, like the Beta 250, being made I will be more than happy on a 2-stroke. If I was stuck with only powerhouse monster motors, like many of the 2-strokes, I would be back to a 4-stroke in a heartbeat.