Tire Size

[StreetSoldierFJ]

I Just bought a 1989 Fj1200 the last owner was 80 years old and not sure why he put a 140/90-16 on the rear Its really close to being replaced. So, I know the tire size is supposed to be a 150/80/16. I was wondering if you could say put a 160/70/16 on the rear or something a little wider than the 150. I see that they make the 160/70-16s classified as a Harley Davison Tire if you google search and they are hard to come by with different brands. I understand that the wider the tire the more leaning you need to do to take a corner it's probably not a good idea to be leaning a 500-pound bike. I just see people in groups and YouTube putting 17-inch rim and going from there I seen this one guy had a 190 on the back of his bike. It just makes it look so much Beefier.

[Bones]

There was a now late member who from memory fitted a 170/?/16 tyre to the standard rim with no apparent problems. The main reason people go to a 17" rim is because of tyre choice as decent tyres in 16" are getting hard to come by, plus a big fat tyre on the back looks way better.

[gdfj12]

With the stock rims, there are limited choices on a matched set of tires for the 16" rear, 17" front. The stock front rim is also on the narrow side for the stock tire size, at 3.00" x 17". Stock tire size is 120/70-17.

The stock rear rim is 4.50" x 16", tire size 150/80-16. Going to a 160/90-16 would increase your sidewall height by almost an inch (24mm). That will have the effect of making the final gear ratio taller. The stock FJ swing arm will easily handle a 160 or even a 170 width tire, although in my experience a 170 can start to rub the drive chain. Not sitting still, but while riding with the tire stressed, like when leaning over. At a width of 170+ on the rear you would probably want to look at modifying the sprocket setup to move them outboard for more clearance. There are a few popular mods to swap the rear wheel for a 5.00" x 17" rim, YZF600R for example, or even a 5.50" x 17" FZR1000, R1or even an FZ-1 rear rim. If you look through the files section, the mods area and search the archives of all of the posts, you'll find a lot of information to search through.

I'm partial to the YZF600R rear wheel swap because it uses all Yamaha parts, gives a good selection of tires to choose from and is fairly easy to do. Plus it matches well with the YZF600R front end swap. So now I run 120/60-17 fronts with 160/60-17 rears and have a wide selection of sport touring or sport or race tires to choose from.

George D

[StreetSoldierFJ]

There was a now late member who from memory fitted a 170/?/16 tire to the standard rim with no apparent problems. The main reason people go to a 17" rim is because of tire choice as decent tires in 16" are getting hard to come by, plus a big fat tire on the back looks way better.

Thanks Yeah, I had a feeling that it's because they don't make them anymore. I just want to get the bike running and pass inspection this year getting close to the end of the year don't want to create a project out of it at this point in the year. Next year I will look into getting a 17-inch rim and going from there, but I think I am going to order a 160 on the 16-inch rim for now. I will probably be doing a lot of riding throughout the winter, so I want a more beefer tire. I don't have a car at the moment and going to only ride the motorcycle up till mid-January or early February. Then take a 1 month break and get back on.

[StreetSoldierFJ]

With the stock rims, there are limited choices on a matched set of tires for the 16" rear, 17" front. The stock front rim is also on the narrow side for the stock tire size, at 3.00" x 17". Stock tire size is 120/70-17.

The stock rear rim is 4.50" x 16", tire size 150/80-16. Going to a 160/90-16 would increase your sidewall height by almost an inch (24mm). That will have the effect of making the final gear ratio taller. The stock FJ swing arm will easily handle a 160 or even a 170 width tire, although in my experience a 170 can start to rub the drive chain. Not sitting still, but while riding with the tire stressed, like when leaning over. At a width of 170+ on the rear you would probably want to look at modifying the sprocket setup to move them outboard for more clearance. There are a few popular mods to swap the rear wheel for a 5.00" x 17" rim, YZF600R for example, or even a 5.50" x 17" FZR1000, R1or even an FZ-1 rear rim. If you look through the files section, the mods area and search the archives of all of the posts, you'll find a lot of information to search through.

I'm partial to the YZF600R rear wheel swap because it uses all Yamaha parts, gives a good selection of tires to choose from and is fairly easy to do. Plus it matches well with the YZF600R front end swap. So now I run 120/60-17 fronts with 160/60-17 rears and have a wide selection of sport touring or sport or race tires to choose from.

George D


Thanks George I want a more beefer tire because I will be riding into the wintertime. I don't want to make any mods this far into the year. it's going to start getting colder to handle a project out in my driveway. So, I think I will go with a 160/?-16 this year. But my Question is if I moved that middle number down to say 70 would that lower my ride height a little? You said a 160/90 will raise high would a 160/70 bring it back down? the bike has a 140/90 on it right now seems just a tad bit high for me at 5 foot 10 inches

[Millietant]

With the stock rims, there are limited choices on a matched set of tires for the 16" rear, 17" front. The stock front rim is also on the narrow side for the stock tire size, at 3.00" x 17". Stock tire size is 120/70-17.

The stock rear rim is 4.50" x 16", tire size 150/80-16. Going to a 160/90-16 would increase your sidewall height by almost an inch (24mm). That will have the effect of making the final gear ratio taller. The stock FJ swing arm will easily handle a 160 or even a 170 width tire, although in my experience a 170 can start to rub the drive chain. Not sitting still, but while riding with the tire stressed, like when leaning over. At a width of 170+ on the rear you would probably want to look at modifying the sprocket setup to move them outboard for more clearance. There are a few popular mods to swap the rear wheel for a 5.00" x 17" rim, YZF600R for example, or even a 5.50" x 17" FZR1000, R1or even an FZ-1 rear rim. If you look through the files section, the mods area and search the archives of all of the posts, you'll find a lot of information to search through.

I'm partial to the YZF600R rear wheel swap because it uses all Yamaha parts, gives a good selection of tires to choose from and is fairly easy to do. Plus it matches well with the YZF600R front end swap. So now I run 120/60-17 fronts with 160/60-17 rears and have a wide selection of sport touring or sport or race tires to choose from.

George D

I think the rear wheel is actually a 3.5" x 16" George, so even thinner !!.

I agree wholeheartedly with you on the YZF 600 R (NOT the YZF R6 as some have mistakenly tried) rear wheel swap. It's simple to do, uses the minimum number of non-FJ parts (so is cheaper) and they're relatively easy to find (the bike was sold in the US for 10 years basically unchanged, except for paint).

I run a 170/60x17 Bridgestone BT 023 rear on mine, with a matched 120/70x17 front (but I also have a FZR 1000 3.5" wide froint wheel) and I love them.

Regarding the 140/90 tyre (tire.......to non UK riders) and the effect on ride height, I really wouldnt worry about that. a 140/90 is about 5mm max taller overall than a 150/80, and that means 2-3mm max difference in ride height. Far less than the usable tread depth you'll ride through when wearing a tyre out.

I'm barely 5'8" and my FJ's rear is raised by around 1/2" (shorter dog bones and the 170/60x17 tyre combination) and I have no problems with it being too high 

Personally, I'd shy away from "Harley" type cruiser tyres on a FJ, but then again, even though it's a 500 lb bike, I ride regularly with modern superbike riders and have no problem leaning it over to stay with (or ahead of) them in the corners  I wouldn't be as confident on harder rubber, different profile, "Cruiser" tyres

[StreetSoldierFJ]

With the stock rims, there are limited choices on a matched set of tires for the 16" rear, 17" front. The stock front rim is also on the narrow side for the stock tire size, at 3.00" x 17". Stock tire size is 120/70-17.

The stock rear rim is 4.50" x 16", tire size 150/80-16. Going to a 160/90-16 would increase your sidewall height by almost an inch (24mm). That will have the effect of making the final gear ratio taller. The stock FJ swing arm will easily handle a 160 or even a 170 width tire, although in my experience a 170 can start to rub the drive chain. Not sitting still, but while riding with the tire stressed, like when leaning over. At a width of 170+ on the rear you would probably want to look at modifying the sprocket setup to move them outboard for more clearance. There are a few popular mods to swap the rear wheel for a 5.00" x 17" rim, YZF600R for example, or even a 5.50" x 17" FZR1000, R1or even an FZ-1 rear rim. If you look through the files section, the mods area and search the archives of all of the posts, you'll find a lot of information to search through.

I'm partial to the YZF600R rear wheel swap because it uses all Yamaha parts, gives a good selection of tires to choose from and is fairly easy to do. Plus it matches well with the YZF600R front end swap. So now I run 120/60-17 fronts with 160/60-17 rears and have a wide selection of sport touring or sport or race tires to choose from.

George D

I think the rear wheel is actually a 3.5" x 16" George, so even thinner !!.

I agree wholeheartedly with you on the YZF 600 R (NOT the YZF R6 as some have mistakenly tried) rear wheel swap. It's simple to do, uses the minimum number of non-FJ parts (so is cheaper) and they're relatively easy to find (the bike was sold in the US for 10 years basically unchanged, except for paint).

I run a 170/60x17 Bridgestone BT 023 rear on mine, with a matched 120/70x17 front (but I also have a FZR 1000 3.5" wide froint wheel) and I love them.

Regarding the 140/90 tyre (tire.......to non UK riders) and the effect on ride height, I really wouldnt worry about that. a 140/90 is about 5mm max taller overall than a 150/80, and that means 2-3mm max difference in ride height. Far less than the usable tread depth you'll ride through when wearing a tyre out.

I'm barely 5'8" and my FJ's rear is raised by around 1/2" (shorter dog bones and the 170/60x17 tyre combination) and I have no problems with it being too high 

Personally, I'd shy away from "Harley" type cruiser tyres on a FJ, but then again, even though it's a 500 lb bike, I ride regularly with modern superbike riders and have no problem leaning it over to stay with (or ahead of) them in the corners  I wouldn't be as confident on harder rubber, different profile, "Cruiser" tyres

So Are you saying that a 17 in rim from the YZF 600 R is a direct bolt on to the swing arms on the FJ1200??

[gdfj12]

None of the rear wheel mods are "direct bolt on". But the YZF600R rear wheel only needs the sprocket side spacer milled/turned to be narrower and the axle end of the brake caliper bracket needs to be milled  a little too. The exact measurements are in several write ups of the mod. If you have the skill to use a mill and access to one, or know someone who can do the work for a reasonable price, say a few beverages or some such.  then it's an easy mod to do.

[Millietant]

The precise measurements are to take 8mm off the thickness of the chain side outer spacer and 8mm off the caliper mounting arm where it butts up against the swinging arm.

As George said, if you don't have ability or equipment to do it yourself, any local machinist can do the jobs for you in a matter of minutes and it will cost very little. For my first conversion it cost less than the equivalent of $20. Now that I have access to a lathe and a milling machine, I can do them myself in under 30 mins total time. That's the only "work" that needs doing to make the wheel fit. The other "trick" is put the FJ sprocket onto the carrier with the "shoulder" to the inside of the wheel, not the outside as standard. This lines up the front and rear sprockets without the need to do any machining of the sprocket carrier.

To do the swap, you need the wheel, sprocket carrier, brake disc, caliper mounting arm and the wheel spacers from the YZF 600 R - all other parts are standard FJ parts (axle, brake caliper, torque arm, sprocket, brake hose etc).

John Cain did a write up on the conversion, which is a great starting point. I've modified John's instructions (to remove the bit about machining the sprocket carrier and added a couple of small extra "improvements" that I learned about as I went through the process).

[Pat Conlon]

We have the YZF600R rear wheel mod saved over in the Suspension Files: https://fjowners.com/index.php?topic=1567.0