When did shifters start not letting you click down in first?

Ok, I'm not good at brevity, couldn't figure out how to phrase topic. I test drove a '99 Suzuki GZ250 for a friend today. (he just got endorsement, I had to get the bike back to his house on various freeways and highways, bought in Washington, he lives in Oregon, yikes!)

Anyway, before buying it, he had me test it out. I noticed that if you're shifting, when you get to first, that's it, shift lever WILL NOT move down anymore. Same thing going up, you get to fifth, then it's like locked in place, unless you shift down.

I commented when I got back, "It won't let you try to go down from first." The old guy, who has a giant Vulcan, and was the husband of the lady selling the 250, said, "where would you go from first?"

I said, "well, nowhere, but every bike I've ridden lets you at least click the lever."

He said,."I never heard of that."

What?

 

Re: When did shifters start not letting you click down in fi

I have a 1989 Kawasaki Ninja 600. It has the same design:

In 1st, you can't click down freely

In 5th, you can't click up freely

 

Interesting, it makes sense, I just don't have experience with modern bikes. Another bizarre feature of the GZ250. I asked my friend on the way, "how many cylinders?" He didn't know. He's an engineer, but knows nothing about mechanical stuff. When I saw the bike I saw two header pipes and said "ah, it's some kind of twin." Wrong! One cylinder with a two-into-one pipe! Someone, please to explain this.

 

Howdy Mike, what I think Suzuki did with this bike is give it a 3 valve head; that's 2 exhaust and 1 intake, hence two exhaust ports, and 2 pipes.

 

Ah, I had previously seen some incorrect specs showing it as a two valve per cylinder bike. The Suzuki GZ250 forum I just found: http://www.gz250bike.com/forum/viewtopi ... w=previous

Shows that even they have this misinformation problem. Looks like it's four valves, so two exhaust valves is correct. Imagine a header for every exhaust valve on an XJ 700X, lol.

It may also have something to do with something Suzuki calls their "twin dome combustion chamber" or TDCC, I don't know. I wonder if it has two spark plugs, some singles do.

 

Your shifting conundrum is simply a result of design differences in how the shifter "indexes" the gears. The ability to still push the lever "down from first" is because in our style shift mechanisms, the 'mousetrap' is just "pawing at the air" when you do that; same for pushing it up further than top gear. A shift mechanism that operates altogether differently wouldn't have that idiosyncracy.

As for two exhaust pipes from a single cylinder head: all of the major manufacturers have at one time or another offered single-clinder bikes with dual exhaust headers due to two exhaust valves. Honda's 250 and 500/600s; Yamaha's SRX6, Kawasaki's big singles, etc. Quite common these days.

Oh, and in the 5-valve "X" head, there are three intake valves (and two exhaust) per pot.

 

I swear I learn something new everyday. Very interesting; I wasn't aware of this & thanks for sharing.

 

The shifter not moving in 1st or 5th gear is not a new thing. My 83 Venture and 86 V-Max are both like that. Its just a different design.