Five speed vs. six speed -- some surprises

[montesa_vr]

Many riders assume a six-speed transmission means a wider spread from top to bottom, so I put this together to help buyers make more informed decisions. Close ratio gearboxes typically improve acceleration and help avoid the kind of spread between individual gears that could be irritating in a situation like a hill climb. Wider ratio transmissions provide a lower low gear and a higher high, which means less stalling, crashing, and clutch slipping in difficult low speed maneuvers and better mileage, less revs, less noise, and less vibration while cruising. Since this is ADVrider, and the emphasis here is on adventure touring, I think it's important to know gear spread before you buy.

The list is in order from widest gear spread to narrowest. The first number is the first gear ratio divided by the top gear ratio. The bigger the number, the wider the gear spread.

The number following the motorcycle name is what the actual overall low gear would be if gearing was raised until every motorcycle had the same ratio (5.05:1, or about what comes standard on a DR650 or KLR650) in high. Of course that caused all the first gear ratios to jump higher as well, so sorting by first gear, the lower the first gear ratio, the wider the overall gear spread.

Or put another way, if you replaced the sprockets on all these motorcycles so that they all had exactly the same gearing in high, this is how they would end up in first. The higher the number, the lower the gearing, and the wider the gear spread.

I have put in a few new models, including the Honda CRF250L and a handful of recent KTMs. I also put in the 1983 KTM 495 MX, since it represents a new narrow in its 4-speed box. That was the first dirt bike with "upside-down" forks.

5.00	Montesa Cota 349	(6-speed)	25.25
4.97	Fantic 300	(6-speed)	25.12
4.41	Yamaha TY250L	(5 speed)	22.26
4.38	Yamaha DT175E	(6-speed)	22.08
4.00	Honda TL250	(5 speed)	20.20
3.90	Yamaha XT225	(6-speed)	19.69
3.82	Montesa V75 Enduro	(5-speed)	19.29
3.80	Hercules 250	(7-speed)	19.19
3.78	Honda CRF230L	(6-speed)	19.12
3.75	Suzuki DR125	(6-speed)	18.95
3.74	Can-Am 175 ASE	(6-speed)	18.85
3.69	Montesa Enduro 360H	(6-speed)	18.63
3.63	Kawasaki Sherpa 250	(6-speed)	18.30
3.54	Husqvarna 500XC	(6-speed)	17.89
3.53	Suzuki RS175Z	(6-speed)	17.85
3.53	Husqvarna 400WR 1984	(6-speed)	17.82
3.53	Honda XR200R	(6-speed)	17.81
3.51	Honda XR250R	(6-speed)	17.69
3.47	Kawasaki KE125A5	(6-speed)	17.49
3.46	Yamaha XT250 2008	(5-speed)	17.50
3.46	Honda CRF250L	(6-speed)	17.45
3.45	Yamaha TW200	(5-speed)	17.43
3.45	Suzuki PE175D	(6-speed)	17.42
3.40	Husqvarna TE610	(6-speed)	17.16
3.40	Honda XR200R 1984	(6-speed)	17.16
3.36	Yamaha WR250R/X	(6-speed)	16.99
3.32	Kawasaki KLR250	(6-speed)	16.76
3.29	Yamaha Tenere	(5-speed)	16.61
3.27	BMW G650X	(5-speed)	16.54
3.25	Pegaso 650	(5-speed)	16.41
3.19	Husqvarna 175XC	(6-speed)	16.10
3.18	Kawasaki KDX200	(6-speed)	16.08
3.18	KTM 530 E/XC-R	(6-speed)	16.07
3.18	Husaberg FE650E	(6-speed)	16.07
3.18	Husaberg FE450/570	(6-speed)	16.07
3.18	Honda XR650L	(5-speed)	16.07
3.18	KTM 500 EXC	(6-speed)	16.03
3.15	Kawasaki KLX250	(6-speed)	15.91
3.14	Yamaha IT200	(6-speed)	15.88
3.14	Honda XR350R	(6-speed)	15.86
3.13	BMW F650GS	(5-speed)	15.79
3.06	KTM 640 Adventure	(5-speed)	15.44
3.04	KTM 950	(6-speed)	15.37
3.03	Yamaha XT500G	(5-speed)	15.29
3.03	Suzuki DR350	(6-speed)	15.28
3.03	KTM 200 XCW	(6-speed)	15.23
3.01	KTM 520 E/XC	(6-speed)	15.16
2.97	KTM Freeride 350	(6-speed)	14.97
2.97	KTM 300 XCW	(6-speed)	14.97
2.93	Suzuki DR650	(5-speed)	14.77
2.88	Yamaha WR450	(5-speed)	14.52
2.88	KTM 690	(6-speed)	14.51
2.86	Kawasaki KLR650, KLX	(5-speed)	14.42
2.82	Honda XR400	(5-speed)	14.27
2.80	BMW G450X	(5-speed)	14.10
2.68	Kawasaki KLX450R	(5-speed)	13.51
2.66	Honda XR650R	(5-speed)	13.43
2.65	Suzuki DRZ400	(5-speed)	13.36
2.47	Aprilia RXV 550	(5-speed)	12.46
2.45	Husqvarna TE250	(6-speed)	12.40
2.21	Honda CR500R	(5-speed)	11.17
1.92	KTM 495 MX	(4-speed)	9.72

[crankshaft]

I mentioned in the TE vs G650X thread that the 6spd gearing was better than the 5spd X , but it looks like you proved that with some math. Its good to know that the butt dyno is in working order

[holycaveman]

Very cool


Lots of other things to consider also.

5 speeds with a strong torquey bike will pull harder longer than a 6 speed in like bikes.

Most manufacturers when going from a 5 to a 6 speed change all the gear ratios. But myself and most others would just prefer an extra top gear. Not a totally differant tranny. This way shifting would be the same, but you would have an overdrive for highway useage.

In other words, just change your primary gear ratio, and add an overdrive, NOW you would have something!

[djchan]

Nicely done. Anybody have the numbers for an LC4?

[montesa_vr]

Originally Posted by djchan

Nicely done. Anybody have the numbers for an LC4?

Thanks, and sorry about the LC4. I pulled the numbers once and wasn't impressed so I didn't save them, but the bike is too important to leave off this list. Here they are:
KTM 640 Adventure (5) 15.44
That puts the LC4 between the F650 and the 520 EXC. I have edited the list to include that information.

[fendermon]

Good job!

Everyone wants more gears, but we constantly dance around and/or wonder just how usefull those gears really are. For example, the first gear on a klx300 is so low that I found it about useless in the dirt. You would have to put cleats on the rear tire to climb anything that slow. There was a pretty long gap to second as well. I vastly preffer the evenly spaced five speeds on my xr4 or dr650.

-Dale

[montesa_vr]

Originally Posted by holycaveman

5 speeds with a strong torquey bike will pull harder longer than a 6 speed in like bikes.

[I] would just prefer an extra top gear. Not a totally differant tranny. This way shifting would be the same, but you would have an overdrive for highway useage.

On your first point, absolutely. Torque, off idle throttle response, flywheel effect, gear lash -- all those things affect how high your first gear can be before you run into stalling or clutch abuse problems.

And I totally agree on your second point. I almost never care about winning a drag race on a dual sport but every time I ride it I care about not having the engine drive me crazy on the highway. In fact, I wish they would go the other way -- spread out the five gears they already have and then add a sixth.

[FlyingFinn]

This is very usefull and interesting information.
Please add to the table, Honda XR400 (6) 17.18

--
Mikko

[Mike.Gail]

Food for thought: as opposed to having an actual 6th gear, why not swap out 5th for a slightly faster gear?

Thought process: The top gear is typically used in high-speed situations like superslabbing or smooth cross-country riding. When would you need the top gear stuffed up a technical singletrack in the middle of nowhere, in a place where getting up to the shiftpoint in fourth might make today the last bad day you ever have?

Obvious issues: Bearings, case clearance, powerband drop(ie getting below where you'd really need to be in the rev range to use the higer gear), price, and durability.

Would this be a functional option, or am I overthinking the process?

[montesa_vr]

Originally Posted by Mike.Gail

Food for thought: as opposed to having an actual 6th gear, why not swap out 5th for a slightly faster gear?

For a straight dual sport that will be either in the woods or between dirty sections on the highway, that would be a great idea. That's essentially what Honda did on my old TL250, and I could cruise down the highway at a relaxed rpm and still had a granny gear for the tough stuff.

On an adventure bike, however, that would be a problem. When you are touring, at some point your engine will be all out of power due to some combination of headwinds or the grade or high altitude or the big saddlebags you have sticking out behind you, and you won't be able to pull your overdrive 5th gear. Then you're stuck buzzing your bike's guts out in 4th, and now maybe you aren't keeping up with traffic. If you leave fifth gear alone and just add a sixth, as caveman suggests, you can loaf along in sixth most of the time and you still have your old fifth gear for more challenging situations.

I think for the bikes on the bottom of the list, a better plan would be for the manufactuers to just put a little more gap between every gear. If Kawasaki didn't want to spend the money retooling for a new crankcase to accomodate a six speed in the 08 model, they could easily have juggled some gear pairs in the existing box and spread out the ratios. So why didn't they? Because then their 38 hp, 442 pound motorcycle would have posted a slower quarter mile time in Cycle World's November road test. That's the mentality we have to get past.

[on2wheels52]

Any take on how your list compares to final overall ratios of the given bikes?
Jim

[Max Kool]

I don't know how to read the above figures.

If I understand correctly, you have "standardized" the total reduction to 5.05, and then taken the reduction for first gear right? What if for instance the jump from one particular gear to another is a large one, but first gear in itself is quite ok? I ride an Xchallenge for instance. When I first got it I found the second and third gear somewhat long. First gear however felt quite ok. I went down 1 tooth on the front and from then on the bike felt really good.

Until I removed the airbox cover and fitted a different exhaust. This seems to have increased the low end grunt of the bike, and now sometimes it feels like geared too short. I can do almost anything in second and it feels like I'm revving the bike at 70.



(Bottomline: I want a 6 speed gearbox)

[montesa_vr]

Originally Posted by FlyingFinn

Please add to the table, Honda XR400 (6) 17.18
Mikko

Well, not quite, and I see from some of the other responses that I am not being very clear. Let's walk through the XR400 as a sample problem. The Honda has a 34/13 gear pair for first (34/13=2.62), a 25/27 gear pair for 5th (25/27=.93), a 65/23 gear pair on the primary (65/23=2.83), and 15t countershaft sprocket with a 45t rear sprocket (45/15=3.0).

So the stock overall gear ratio in first is 2.62*2.83*3 = 22.2:1.
The stock overall gear ratio for fifth is .93*.2.83*3 = 7.85:1.

Now for purposes of my list, I need to gear the XR so high that the overall ratio in fifth is 5.05:1 So I go in there and start messing around with sprockets and I find that if I go up one tooth on the countershaft and drop the rear sprocket all the way down to a 31, that get's me in the ball park. Then I cheat and use an imaginary 30.9t rear sprocket, which gives me a final drive of 30.9/16=1.93. Now our overall first and fith gears look like this:

Modified overall gear ratio in first is 2.62*2.83*1.93 = 14.27:1.
Modified overall gear ratio for fifth is .93*.2.83*1.93 = 5.05:1.

So the actual entry in the list at the top would be:
Honda XR400 (5) 14.27

Which being interpreted means that compared to the other bikes on the list, the XR400 has a narrow spread of gear ratios and falls between the bottom two pairs, where I will add it.

[Garry]

I know I wish my DRZ "S" had a lower first gear for crawling thru nasties in tight woods (easily achieved with a larger rear sprocket), but then it'd need a sixth gear to cruise comfortably at an indicate 80 MPH.

That's what want right there: rock-crawling slow first gear and a highway gear that lets the bike cruise effortlessly at an indicated 80 MPH. Spread the other 3 or 4 gears around as needed. If the bike has enough torque a wide-ratio 5 speed would be fine.

[Flyin Phil]

Interesting post. I compiled a big table showing all the gear ratios of the bikes I was interested in before my last purchase.

What I did, which I think might be slightely more intuitive, and therefore easier for folks to follow, is divide the first gear ratio by the 5th gear ratio. This gives an "overall reduction spread" available, as if 5th was 1:1. Or alternately, first as a percentage of gearing multiplication, ie 330% of fifth.

I was looking at the more off road oriented thumpers (xrr, te610, lc4), and the wide 6spd on the husky was a huge upside to me. I had a tt350, and it had a wonderfully low 1st, and made good time in 6th still. The XT600 is pretty good as well, compared to many. My xr600r left a little to be desired here. It's essentially the same spread as an xr650r, just a different primary reduction.

I was very dissapointed when I ran the numbers for the xr650r. I even considered having a custom 5th made, for an OD.
Then I heard husky guys were swapping countershaft sprockets for varying conditions anyway, and I went for the brp. Now with some testing, I don't think it would work well, as I wouldn't want to deal with the resulting 4/5 gear gap.

All told, I find tires more restricting than the gearing. Running road oriented tires and geared up for comfortable highway cruising, I find the gearing less of an issue offroad than the tires, since the bike makes so much torque.

And when running knobbies, I don't mind lower gearing for dirt, since I wouldn't want to shred them going 120 kph on the highway anyway.

I'd still like to test a husky though...maybe when this ones worn out.

EDIT: I'd still take a wide ratio 6 speed if offered over a 5. And DEFINITELY over the narrow 5 I have now...hello, honda? Are you listening?
That would be the ultimate aftermarket upgrade, imho, if possible. Even a wider spread (3?)-4-5 set, leaving the lower 2 or 3 gears with a stock spread.

Edit 2: also, as others have said, there's definately more to it than overall spread. I've heard of guys swapping the higher 1st from an xr600 into the 650L's because they don't want to deal with teh huge 1/2 gear gap, giving up some gearing spread for a smoother shifting ratio...