CR500 vs CRF450

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Four strokes are here to stay and there is no arguing the fact that they are far easier to to ride. The power delivery is much more manageable which lets the rider go longer with less fatigue. Having said that, whenever you hear someone speaking about a bike they have just ridden for the first time, invariably you hear the reference to a 2 stroke motor. Statements like “it’s really snappy, it feels just like a 2 stroke”. Here’s a news flash, it can never respond like a 2 stroke. No matter how snappy the manufacturers make it feel. Beyond the mechanical aspects, the two motors feel completely different when riding and when sitting in the pits.

From a technical standpoint, a 4t motor has a counter balancer which makes the engine feel as smooth as silk. But it has a pile of compression, with a typical compression ratio being 11.5:1 or higher. This is why when you are riding along and close the throttle it feels like you are hitting the brakes. It makes riding 4t in the sand a total nightmare but it makes down hill right hand turns a breeze.

On the other hand, a 2t revs super fast because it has no counter balancer and a much lower compression ratio of 8.5:1. 2t’s also have a flywheel to keep the engine spinning which makes for little to no engine braking. Power delivery can be adjusted by adding weight to the flywheel making a 2t motor behave or feel more like a 4t motor. You still don’t get the engine braking though.

From a seat-of-the-pants perspective, a 4t feels like it is making power from the moment the engine is turned on to the point where the rev limiter kicks in.

Whereas a 2t feels like you are making no power until you get to the power band at which point it feels like someone has flipped a switch to ignite a rocket ship. Very exciting but can be difficult to control.

If you get around a group of guys who ride, for long enough, you are bound to hear an argument or two about which is faster a 2t or a 4t. Take a look at Thumpertalk sometime, it’s like a rivalry; the 2t’s against the 4t’s. Everyone seems to have a theory on this, from the fastest guy at track to the slowest guy at the track. People who have never even ridden a 2t even get into the thick of it. Even we, the humble fools at EDM sit around talking about what type of motor we are faster on. The topic of doing a comparison test has come up several times in many of these conversations. But the question was always how do we get a 2t that could be competitive with a current model 4t? We could do it with 250’s? but would that be fair? A 250 2t makes far more power that a 250 4t. Or should we use a 125 2t and a 250 4t. But that wouldn’t be fair either because a 125 2t power band is skinnier than Kate Moss.

We found our solution to this question by talking to the folks at Service Honda. A company that actually makes a current, as in 2008 2 stroke. The tricky part is they use a 500cc motor. This is good because we can use it against the 450 in the comparison as in “open class” This is bad because this motor produces a mind blowing 65hp making it a potential handful to manage on the track. The 2008 450 makes a healthy 52hp and few riders truly have the skills to utilize all of it. We were looking forward to a few exciting days of riding in the near future.

Every motor from Service Honda is hand built from individually purchased parts to build a 1998 model motor. Complete CR500 motors haven’t been around for years. All of the assembly is done at the Service Honda shop in Hammond, Indiana by two technicians. They assemble about 1,000 motors per year and carefully wedge them into the rolling chassis from a current Honda CRF250R. This process requires them to modify the stock aluminum frame to accommodate the CR500 motor, exhaust pipe and radiators. But everything else remains the same, 2008 Showa suspension front and rear. Super stiff, narrow aluminum frame with current geometry and ergonomics plus current plastics and seating configuration. Are we making our point here?

After some discussion with the Chief Technician at Service Honda, AJ Waggoner. It was decided the we would do a comparison test between a 2008 Service Honda 500AF (evidently Honda Motorcycle Corp doesn’t want them to use the CR designation) and our 2008 CRF450R. What follows is our experiences while doing the comparison.

After some consideration, it was decided we would take both bikes to 2 different tracks, one fast open track and one tight slower track and time riders on each bike for 5 laps. We wanted to be able to let riders ride in consistent, same day conditions.

For the track segment we contacted AMB-it (Identification and Timing) for their lap timing equipment. AMB has a system that utilizes a transponder unit which sends a signal each time the unit crosses the sensor or “pickup” that is placed under the ground across a section of the track.

A decoder (the red box in the photo) takes this information and either stores it for later download or displays it real time on your laptop computer and is accurate to .001s. AMB-it really made our lives easy with this system. All we had to do was plug everything in, zip tie the transponder to the test bikes and start riding laps. If you have a local track and want to keep track of your lap times, the AMB-it system simply rocks. They even have something called MyLaps where you can go online and check your lap times from previous events. If you want to improve, the only way to truly gauge improvement is by checking for faster lap times, either on the track or on the trails. Supercross uses AMB-it systems for scoring, amateur GNCC and Hare Scrambles racers should be familiar with the system, they have been using it for years. Amateur MX hasn’t caught on except at larger event like Loretta’s.

Back to the bikes. We started our testing at Iron City MX in Blacksburg, SC. IC is a pretty fast, wide track with small elevation changes, mostly 3rd gear with a few second gear sections. There are no power robbing sections but it can get slick. The track and conditions shouldn’t favor one bike over the other. Conditions were good with a few muddy sections and deep ruts in most of the corners. Lap times on this track are in the mid to high 1:20’s for someone like P.J. Larsen. These times will obviously vary depending on conditions but it should give an idea of where we stood. Aschmann and Segal were testing this day for us. On the 500af Aschmann was running pretty consistently at 2:00, Segal was running a bit slower at (with a cough) 2:18 on the 500af. On the 450F Aschmann was running about 3 seconds per lap faster at 1:57. Segal was also running faster laps on the 450 with an average lap time of 2:14.

The next track for testing was Mike Andrews MX in Concord, NC. Mikes is a tight, technical track that requires a good sense of timing and a set of balls for a couple of the jumps. The dirt is loamy in most sections, forming good ruts in corners with a few hard packed hard sections that can get slick on warm, dry days. The day of testing the air was cool and moist, conditions at Mike’s were about as good as they get. Neither bike should have an advantage here.

Our testers at Mike’s were Paul Aschmann, Mike Andrews and a few laps from an injured Tom Kraft. Segal was out with a calf injury. Mike says a fast lap at his place by a fast pro is in the low to mid 1:30’s he is running an average of 1:37.64 on this day on the 450. When he takes the 500 out he runs an average 1:41.45 for a differrence of 3.8 seconds. Next rider up is Aschmann. His five lap average on the 450 is 1:45.73. On the 500 his average is 147.32. A much closer difference of 1.59 seconds. Our last tester for the day was Tom K who, as mentioned earlier had an injury to his groin so he was not riding at 100%. He was still able to manage a respectable average on the 450 of 1:45.61. On the 500 he averaged 148.58 putting him at 2.96 seconds a lap slower.

So what did we find out from this test? Firstly, being familiar and comfortable on the bike you are riding is key to going fast. All of the testers in this evaluation have ridden and owned 2t bikes but none of them ride one currently. As we mentioned at the beginning of the article, each bike requires a certain style of riding and a rider must be used to this style in order to ride fast. Given the chance to ride the 500af for several days to re-devlop 2t cornering technique, our testers times would likely have been much closer on each bike.

Taking this into consideration, all of the lap times were surprisingly close. Second, more power does not mean faster. To be able to capitalize on peak power output a rider must be capable of dealing with that level of power. Third the Service Honda 500af is an amazing bike with a frightening amount of power that if respected is a peach to ride. Just don’t ride it at the end of the day when you are exhausted. You want to be at the top of your game when you climb aboard.

Taking to the trails.

We have access to an amazing network of trails very near to us in Blacksburg, SC so a trip there on the 500 was in order. Most of these trails are 2nd gear, tight single track lined with trees and a few rocks strew about for good measure with some first gear hill climbs and turns. Riding the 500 in here was a dream! Shift into second and leave it there was the motto. First gear had the front coming up every 3 seconds, second had it coming up every 5. It was such fun to flick the 203 lb. bike around and have all the power and torque of an XR600. If you are not looking to race and are not worried about being the fastest guy out there. The 500af from Service Honda could just be the most fun on wheels you can get. Think about it, low maintenance 2t motor with killer suspension and great ergonomics. What more could you ask for?


Opinions:
Paul Aschmann:

The 500AF is really fun, it has plenty of power, turns on a dime, the suspension is plush and in my book is the perfect bike – if you can hold onto it!.

The first time I threw a leg over the bike a couple of friends mentioned things like “uncontrollable”, “wheelie machine”, “bucking bronco” just to name a few, but in my eyes the bike was actually fairly pleasant. While riding the bike for the first few motos you find yourself holding on for dear life and end up with excessive arm pump but the fun really starts when you relax and ride the bike in a controlled and smooth fashion. It’s one of the bikes that make you feel like you are going slowly on but when you look at your lap times and they are just about equivalent to your own bike. I was surprised.

After riding 4 strokes for the better part of the last 4 years you really appreciate the smell of premix, high revving engines and people turning their heads, and although the 500 doesn’t have a power band per se, it definitely feels like it has one. It comes on around ΒΌ – 2/3 throttle and hits pretty hard.

Something that I didn’t enjoy about the bike was the gearing. I found it far from perfect for a MX track, 2nd seemed to be too much and 3rd too little. I couldn’t push the bike through a bermed turn in 3rd but 2nd caused the bike to be a little skittish. But this could easily be remedied however.

From a positive aspect the bikes’ power is more usable than a lot of people might think, but as mentioned, it does require you to have very smooth and precise throttle control.

Turning is great on the bike, it has the ability to hold tight lines and because of the power doesn’t require you to keep your momentum up like on a smaller bike. The bike really felt at home on a GP style MX track, the flowing turns and long straights really let you open it up and appreciate the bikes ability to go fast. The suspension was setup well enough to climb on and go without having too much difficulty adapting. Another item well worth investing in would be a oversize front rotor, stopping all that power with stock brakes became a challenge. Other than that, it’s the perfect /all-purpose/ bike.

Benjamin Segal:

This bike rocks! I am the kind of guy who likes a novelty ride and the 500 fits right in there. I’d like to take it to the desert and let it run. It’s kind of crazy to say that and at the same time think about how much fun it is to ride in a tight section of woods. Could it be… this the bike for all occasions? I think so. I also like the idea of not having to adjust valves or worry about timing chains and cams when I replace a piston. Plus the potential savings in maintenance could be substantial. A new top end kit for one of these is $290 for the complete kit through Wiseco and you probably have to do it once every two years.

In addition to this, the smell of 2 stroke oil takes me back to my early days of riding. It’s one of my favorite smells and I love to walk into the shop after a 2 stroke has been running.

Want one of your own? Go to www.servicehonda.com