Front Sproket Nut

The previous owner of my bike changed the front sproket from an 18 to 16 so my speedo reeds about 15-18% out. Ive got an 18 tooth but I'm having problems getting the sproket nut undone, too tight.
Has anyone experienced this and how did you overcome it?
I've tried a long bar, 1/2 inch rattle gun, it has a very strong lock tight on I think.
Thanks

Could try a heat gun on it 4 a while and a large bolt between the rear cog an chain, saves in stead of putting it in gear.
Just a thought ..................

Try getting someone to apply the rear brake for you ....................less chance of damaging something.

I changed mine just recently, had the other half with her foot on the rear brake. Breaker bar with a metre length of square steal tubing to go over the breaker bar. Be sure to hold the socket on the nut so you don't go off course and push hard. It's only the locktite that you need to break loose. Don't have your hand at the end of the bar just in case your knuckles hit the concrete! Putting the bike in gear didn't help, rolled through the compression. Good luck.

An old long torque wrench works well .Not a good one though .
Yep ,some-one with their foot on the rear brake .

Thanks guys, the heat gun might be worth a try, I had my 15 year front rower standing on the brake, its just very tight, we'll get it off eventually I'm sure and then hopefully my speedo might read a bit closer and not so touchy on the throttle

I just had another look at a few things, the chain has been shortend to 116 links, would it have to go back to 118 to fit the 18 tooth front sproket?

Paul 1250 wrote:I just had another look at a few things, the chain has been shortend to 116 links, would it have to go back to 118 to fit the 18 tooth front sproket?

Gearing Commander's calculations show almost 16mm difference in rear axle position (chain is 31.75mm shorter).  

So if you can push your axle that much closer before hitting the limits you will be right - but I'd be surprised if you have that much play.

I think Gus has done it at 116 links with standard gearing? There is a thread somewhere about it.

when you put it back on, don`t locktite it, torque it up then use a locking washer to hold it (fold tabs around the nut) as it should have one on it.

Thanks guys for all your advice
Paul

Why not just add a speedo healer? Or are you more worried about fuel consumption?

I looked into them, its nothing to do with fuel economy, I feel its a little too touchy on the throttle at low speed, that might be just me, 20 years out of the seat a lot has changed. I also think compainies like Suzuki pour a lot of money into development and there must be a reason they made it with an 18 tooth front sproket

I had the same issue when I changed my chain and sprockets over christmas. (17 tooth front 43 rear and RK GWX chain)

Fortunately I have a compressor and rattle gun which worked a treat. I purchased them from super cheap a while back for around $400 all up including hose and sockets. One of the best tools i have every purchased.

As with all bike manufactures gearing is always a compromise when building bikes. Its all about a happy medium for fuel, tyre wear, acceleration and top end speed.

Stick a stout piece of lumber (2 X 4) through the rear wheel on top of the swing arm with a towel under it.
Never leave it in gear as you can bend a shift dog. Also try shocking it with a soft blow hammer to break the loc-tite rather than slowly wrenching it with a breaker bar at first.