Install a 16 Tooth Front Sprocket

[ucvro1]

Thank you cayuse....I haven't picked up a shop manual yet.

[jonathan180iq]

Gz250 Service Manual Download -
viewtopic.php?f=3&t=27

[ucvro1]

I took a whole half on hour out of my very busy beer drinking schedule to do the sprocket swap today. It was a very easy job thanks to the fellow who did the "how to" at the beginning of this thread (jonathan180iq), and the only specialty tools were the big socket and a $19 torque bar, the old fashioned "how far will the needle go" kind.

Adjusted the chain slack (1/3") and took it for a ride down US1.

I like this mod! This is my wife's ride, her first bike, but I have put some miles on it just to get a feel for it. Now after the mod I can see and tell you that I think this is a good idea for anyone who plans to ride these bikes on anything other than short city jaunts. I can't say that there is any measurable difference, but the engine just seems to labour less, squeal less at 55MPH and higher. First gear is now more somewhat usable rather than simply a place keeper below the usable gears.

All in all, I suggest this mod for all on these bikes. I am impressed and wonder why Suzuki didn't put a 16t sprocket on these bikes to begin with.

Nothing was lost, but a more "civilized" ride was gained, for lack of a better term.

Thanks guys...

[Water Warrior 2]

1/3 inch chain slack from top to bottom movement ?? Sounds a little tight to me. You need more slack for the chain with the rear suspension compressing and reducing the slack. It is better to have a bit too much slack than not enough when you hit a dip or pothole in the road.

[ucvro1]

Thanks Water Warrior. The chain did loosen a bit after the ride as everything achieved a balance. I have a little over about half an inch of slack and I re-tightened everything up in the back so I think all is good now...

[ironhead1530]

This mod is awesome. Took me about an hour as a noob (including travel time to autozone for 30mm socket). The bike runs soooo goooood now. The bike seems to settle in nicely at 55-60 and first gear in useable now. Great writeup by Jonathan.

[alantf]

Originally Posted by ucvro1

wonder why Suzuki didn't put a 16t sprocket on these bikes to begin with.

Because people like me live in the mountains

[Water Warrior 2]

Suzuki does a good job of gearing their bikes for the majority of riding conditions and expectations. OEM bikes right out of the crate with no mods whatsoever will do nicely for 90% of the riders out there.
Just for the experience I went up one tooth on the Vstrom front sprocket. That gearing made for a nice top gear RPM on the prairies at slightly above most speed limits. Back in the mountainous areas of home and all the curvy roads the stock gearing is the way to go.
Most bikes will feel better around town with a change to a larger sprocket up front but there is the out of town trade off that may not be of any real value and might actually make your ride more of a chore than a giggle.

[cibolorider]

My thanks go out to Johnathon180iq for the great post in the How To section concerning changing the sprocket on the GZ250 to a 16 tooth. I finished this mod today and I am very happy with the results. It makes my GZ run like I wanted it to. I got the same results Johnathon got and now I really feel like I'm riding a cruiser. Best $13 dollars I have spent on the bike. Thanks again Johnathon.

MOD EDIT - Post merged here.

[Skunkhome]

On chain slack , Since the rear sprockets are not necessarily concentric I would rotate the rear wheel while checking the chain slack and stop where it is tightest then adjust it at that point to have 3/8" ( book states 0.2-0.6" or 5-15mm) slack from top to bottom at the middle of the chain span. I would mark the rear sprocket with a dot of paint from a paint pen as a reference mark for future adjustments.