1100 & 1200 Weight Differences?

[Little Pink Steve]

Hi Guys,

Looking to buy my first FJ as a rolling restoration and modifying project.  Looking to building a sporty roadster muscle bike thing.

I see that the 11's have been seen on the track and whilst the 12 increased in cc they also put on a lot of weight.

I'll be swapping the front end, swing arm, wheels etc.  But am I better off using an 1100 or 1200 as a starting point? Why did the 1200 put on so much weight?  I'd be looking to shed weight of either bike, so would the end result be about the same or would the 1200 still be considerably heavier?  If starting with the 1100 does the 1200 top end fit straight on?

The whole idea of this is mostly having a project, but I want the end result to be more sporty than touring.

Cheers.

[Country Joe]

Here is one source of FJ 1100/1200 weight. Of course it's a Wikipedia page so use the information are your discretion. Needless to say, even a FJ1100 is not particularly willowy. The easiest weight loss is to dump the OEM exhaust and install a light weight 4 into 1. The next best best weight loss on a FJ 1100 is to replace the 16" wheels with a later model FJ 1200 front wheel and a GSXR 750/1100 rear wheel. Or go all out and find a set of Marchesini magnesium wheels.
https://en.m.wikipedia.org/wiki/Yamaha_FJ

[racerrad8]

I'd be looking to shed weight of either bike...

On either bike there are many things you can do to drop the weight, and significantly.

First off the RPM S/S Exhaust System as a complete unit, it weighs less that just one of the stock mufflers.

Then you can drop in a Lightweight Lithium Battery.

You can loose the air box which weighs 4.2 lbs and use the RPM dual pod filters which come in at .8 lbs.

Those three items could drop the weight by more than 35 lbs over the stock Yamaha parts.

Then there is the wheels, especially if you get an early model with the 16" front & rear. Converting over to later model 17" wheels will offer another significant weight reduction in both wheels and tires.

Randy - RPM

[Little Pink Steve]

Thanks for the replies.

I suppose the information I am seeking is why does the 1200 weigh about 40lbs more than the 1100.  Given say by carrying out the same weight saving mods as suggested the nett result would be a 40lb weight difference. Is this just bloat Yamaha added to make the bike more touring friendly or are there fundamental differences, are the frames and engines the same? 

I know I'm not going to get something close the a modern bike, but that's not what I am trying to achieve (too old and too tall) but I Love the idea of a cool retro bike, with a beast of an engine modified with better handling.  Just need to decide which would be the best starting point, 1100 and upping (top end from the 12 or Wiseco) the cc or 1200 and junking excessive bloat before treating wither to the same weight saving or performance mods.

I get my bike data here http://www.motorcyclespecs.co.za/bikes/yamaha%20%20%20.htm. And always take the information with a pinch of salt.

[jscgdunn]

Welcome to the forum and sympathy for your moditis condition.

My bias as a tall (6'3) old (59) guy.  I have owned and ridden every model.  IMO the 1100 is somewhat lighter and feels a bit peppier, but really there is very minor difference in performance.  The fj series started out as a "superbike" in 84 but was then was used as a platform to invent and evolve the sport touring genre.   I like the last models (3xw) the best.  The fairing is a bit bigger and windshield  more straight up for more protection.  The frame is totally different and beefier and the engine mounting is more sophisticated to reduce vibration more. 

In term of swing arm mods, the 3xw allows an underslung later model (ie 2007 up) R1 swing arm.  This is because the upper shock mounting point is off set to the left, just as the R1 swingarm is, whereas this is not the case with earlier frames;  I do not know of an R1 conversion with an earlier model (but I am sure I will be corrected).  If you go with a later overslung braced swing arm, you may have interference with the subframe.

For the front end, no advantages to either platform, but I would recommend using the approach Fred used with the adjustable clip-ons for bars (I wish I had).  By the time get the top triple and bars your cost will be similar.  In all cases you will need to extend the forks.

There are many projects here  that go through all of this.

Have fun,

Jeff

[Little Pink Steve]

Welcome to the forum and sympathy for your moditis condition.

My bias as a tall (6'3) old (59) guy.  I have owned and ridden every model.  IMO the 1100 is somewhat lighter and feels a bit peppier, but really there is very minor difference in performance.  The fj series started out as a "superbike" in 84 but was then was used as a platform to invent and evolve the sport touring genre.   I like the last models (3xw) the best.  The fairing is a bit bigger and windshield  more straight up for more protection.  The frame is totally different and beefier and the engine mounting is more sophisticated to reduce vibration more. 

In term of swing arm mods, the 3xw allows an underslung later model (ie 2007 up) R1 swing arm.  This is because the upper shock mounting point is off set to the left, just as the R1 swingarm is, whereas this is not the case with earlier frames;  I do not know of an R1 conversion with an earlier model (but I am sure I will be corrected).  If you go with a later overslung braced swing arm, you may have interference with the subframe.

For the front end, no advantages to either platform, but I would recommend using the approach Fred used with the adjustable clip-ons for bars (I wish I had).  By the time get the top triple and bars your cost will be similar.  In all cases you will need to extend the forks.

There are many projects here  that go through all of this.

Have fun,

Jeff

Thanks Jeff,

Apart from the looks what's so special about the R1 swing arm?  What other swing arms find their way into the 1100's? I'm guessing that moving the mounting point on the frame over to align with the R1 arm could be doable.

[jscgdunn]

The r1 swing allows you to mount a late model r1 (or r6) wheel, plus they are plentiful; more importantly, the underslung bracing does not interfere with the subframe.   

There are other options from older bikes as well,  but I think the axle sizes will limit you to older/heavier wheels ( I am sure I will be corrected).  There are number of swaps in the files and project sections. Most require at least some machine work.

Moving the top shock mount is possible if you are a good fabricator welder.  The top shock mount is actually a limiting factor when adding a more modern swingarm.

Jeff

[jscgdunn]

A few mods here too:
http://www.fjmods.co.uk/MarcRittner.htm

[PaulG]

I wouldn't be too worried about the difference in overall weight between an 1100 and 1200.  It's more about the centre of mass (not the same as centre of gravity).  A heavier bike properly balanced can handle a lot better than a lighter bike with a lopsided bias.  Same as with cars.

Also how much coin are you willing or able to spend?  Money can shed a lot more pounds/kg of excess weight. Like Marchesini wheels, or an aluminum or titanium subframe. (ooooohhhh yum!  )

But in the real world the FZR/GSXR/R1 suspension conversions seem to do wonders for weight loss and handling, as evidenced by the numerous projects on this site. 

Just make sure you document as you go and post lots of info and pics here.  The machine must be fed.   

Good luck.

[Little Pink Steve]

I understand the principles of mass centralisation.  But does this not mostly affect how quickly one can lean the bike over and change the direction of lean?  When cornering is ia bike not trying to push itself away from the apex, thus when carrying extra mass multiplied by cornering loads the nett effect would be worse?

But a said and done, this is just going to be a play bike, not a big budget project.  No carbon fibre wheels on my shopping list.  The intention is to use used parts from more modern machines and take a Colin Chapman approach. I suppose in the end it'll boil down to finding a half decent FJ to start with as pickings are slim in my neck of the woods.

[Little Pink Steve]

Lo and behold a very tidy 1200 has appeared on Gumtree within the last few hours.........perhaps this is fate.

[PaulG]

I understand the principles of mass centralisation.  But does this not mostly affect how quickly one can lean the bike over and change the direction of lean?

For the most part yes. There are other factors like braking and such. But like you said...

... this is just going to be a play bike, not a big budget project.

Unless you were into some serious track time then maximizing the weight loss would be more important.  For a play bike to thrash around on the street then less so.  Unless it's just something you wish to pursue just because you want to. And there's nothing wrong with that    Besides once the major mods are done and you're riding, there will be the little details of shedding a bit here or there.  That's when the rabbit hole gets real deep.   

Do you have a time frame for when you'd like to see it complete  (more or less)?

[Little Pink Steve]

Hi Paul,

No track time, purely a road going bike.

No time frame,  it will be ride it, collect parts for front end swap, fit parts ride some more, buy parts for rear end swap, fit parts ride some more.  I'll be pulling parts, modifying/swapping/junking them then refitting and riding some more.  It'll be a rolling project, a hobby for years to come.  Mostly the work will be completed during the winter, don't want to miss out on summer riding. At some point, once happy I'll do a complete strip down for painting, powder coating etc.

I'm lucky in the I have a decent workshop (mill, lathe, 50t press, surface grinder etc.....even a spark eroder) at my disposal at work and often find myself with time on my hands.

[PaulG]

Sounds just like me.... minus the

...decent workshop (mill, lathe, 50t press, surface grinder etc.....even a spark eroder) at my disposal at work and often find myself with time on my hands.

If I ever complete  what I'd like to do, I'll be too old to ride anymore.  But that's the never-ending quest for the Holy Grrrraaaiillllll. 

  I too often have time at work.  But the only thing I can do here is reply to posts in the middle of the night. 

[fj1289]

I wouldn't be too worried about the difference in overall weight between an 1100 and 1200.  It's more about the centre of mass (not the same as centre of gravity).  A heavier bike properly balanced can handle a lot better than a lighter bike with a lopsided bias.  Same as with cars.

Also how much coin are you willing or able to spend?  Money can shed a lot more pounds/kg of excess weight. Like Marchesini wheels, or an aluminum or titanium subframe. (ooooohhhh yum!  )

But in the real world the FZR/GSXR/R1 suspension conversions seem to do wonders for weight loss and handling, as evidenced by the numerous projects on this site. 

Just make sure you document as you go and post lots of info and pics here.  The machine must be fed.   

Good luck.

Speaking of titanium subframes -- how's that secret project coming along Fred?!