Xs1100r

[bikerphil]

Pic of an 82 XJ11 front caliper, they are also the same as the 81 MNS front calipers...

[MPittma100]

Gusseting

Mike, it's got nothing to do with crash reinforcing etc. They're there to make the frame stiffer for better handling - no more.

As Tom has indicated with his examples, by him properly securing the frame tubing to the steering head and other frame mods with substantial weight reduction on his "ratbike" (more a work of art than a rat, by any standard), and comparing it with both a Stock E model and a Sport (5K7 /5N5), he's demonstrated that there is a definite advantage (at speed) to having the frames stiffer.
Have a look at any of the 80's era superbikes and they've all got substantial bracing around different areas of the frame.
I'm also pretty sure that the thinking behind the lower cradle bracing was an attempt to stiffen this area of the frame without resorting to the often used method of fitting solid engine mounts to make the engine a stressed member of the frame. It does work extremely well, but increased vibration during day to day riding probably wouldn't have been a big selling point for the average customer.

Just out of curiosity, wonder why they did that to the R and none of the other frames?

Mike

[crazy steve]

The XJ forks are really just a modified version of the Special forks and will fit the XS trees. There are some subtle internal differences, but nothing to prevent some parts mixing if done with care.

If you want to swap them as-built to a XS, you will need to mod the headlight ears for the balance tube and relocate the ignition switch; the tube will block the switch and steering lock.

For a bit more info, look here: http://www.xs11.com/forum/showthread.php?t=37399

[Schming]

Pic of an 82 XJ11 front caliper, they are also the same as the 81 MNS front calipers...

Thanxs Phil, I don't have any idea why I didn't notice the XJ forks and thier caliper mounts til now.
It'll be so much easier to adapt 4 pots to the XJ mounts than the SF's.
What the heck was Mammie Yammie smokin' when they designed or should I say botched the SF's forks.

Just out of curiosity, wonder why they did that to the R and none of the other frames?

Mike

My exact same query when I saw the gussets and bracing.
It'll take me til next fall to get started on my SF but I'm shooting for a "Hingeless Blend of the SF & RH " since we can't get the good bikes o'er here.

The XJ forks are really just a modified version of the Special forks and will fit the XS trees. There are some subtle internal differences, but nothing to prevent some parts mixing if done with care.

If you want to swap them as-built to a XS, you will need to mod the headlight ears for the balance tube and relocate the ignition switch; the tube will block the switch and steering lock.

For a bit more info, look here: http://www.xs11.com/forum/showthread.php?t=37399

Great tutorial Steve, thanxs, that answered some questions I had.
I believe I have a set of headlight ears that I can modify.
My goal is to modify my SF to be completly reversible if necessary.

[Mathh]

Just out of curiosity, wonder why they did that to the R and none of the other frames?

Mike

At the end of its lifecycle Yamaha wanted to boost sale figures in Europe, so they introduced the "much sportier" Sport version to battle against the newer and better handling Kawis and Suzis and Hondas of that time. To prove its better handling they showed the extra gusseting of the frame. It didn't help much to boost the sales.

[MPittma100]

Gusseting

At the end of its lifecycle Yamaha wanted to boost sale figures in Europe, so they introduced the "much sportier" Sport version to battle against the newer and better handling Kawis and Suzis and Hondas of that time. To prove its better handling they showed the extra gusseting of the frame. It didn't help much to boost the sales.

That makes perfectly good sense. The typical manufacturer battle to out-do their competition. Thanks for that explanation.

Mike

[Schming]

At the end of its lifecycle Yamaha wanted to boost sale figures in Europe, so they introduced the "much sportier" Sport version to battle against the newer and better handling Kawis and Suzis and Hondas of that time. To prove its better handling they showed the extra gusseting of the frame. It didn't help much to boost the sales.

Hi Math, are the gussets and extra bracing modifications you'd consider adding to a frame without, and do they, in your opinion, result in a noticably stiffer better than stock handling ?

[Mathh]

Well, according to TomB it makes a difference. I never rode one because I think it is ugly hahaha. Sorry for that if I offended someone

[Schming]

Yes, I do respect TomB's first hand experience with the gusseted and braced frame but your statement:

" To prove its better handling they showed the extra gusseting of the frame. It didn't help much to boost the sales. "

. . . got me to thinking did it really help the rigidity of the frame or just a marketing ploy ?

[crazy steve]

. . . got me to thinking did it really help the rigidity of the frame or just a marketing ploy ?

I suspect it was more of a marketing ploy...

One thing I'll add about the XJ forks; the XJ fender is considerably stiffer than the Special fender (and heavier), so a fork brace probably won't show as much improvement as you'd get on a Special. The standard front fenders are really flimsy compared to either of the others.

[Mathh]

Yes, I do respect TomB's first hand experience with the gusseted and braced frame but your statement:

" To prove its better handling they showed the extra gusseting of the frame. It didn't help much to boost the sales. "

. . . got me to thinking did it really help the rigidity of the frame or just a marketing ploy ?

It's not my statement, it was Yamaha's. To be honest: I think that amount of gusseting must have helped but it will depend on the rider to quantify.

[TomB]

If you want it quantified...

Get your forks set up right, oil grade, level, spring pre-load, alignment with each other.

Get some decent rear shocks.

Head bearings adjusted absofekkinlutely dead right or you're completely wasting your time, and I mean not over tight but NO play.

And wheel bearings, swing arm bearings, good tyres.

Get all that right and then and only then will you be able to notice the difference between braced and unbraced frames.

I ride like a loon, ask Math he's the same and ridden with me, and I got some bits wrong and thought the frame bracing made no difference, once new rear Koni's fitted I could tell.

If you don't want to do all of the above don't bother with the frame bracing, its not worth the hassle.

[Schming]

I suspect it was more of a marketing ploy...

One thing I'll add about the XJ forks; the XJ fender is considerably stiffer than the Special fender (and heavier), so a fork brace probably won't show as much improvement as you'd get on a Special. The standard front fenders are really flimsy compared to either of the others.

Good to know Steve, I'll make sure I get an XJ fender with the forks and wheels. IYO would it be prudent to match the final drive with the rear wheel ?

It's not my statement, it was Yamaha's. To be honest: I think that amount of gusseting must have helped but it will depend on the rider to quantify.

Thanxs Math, I appreciate your response.

If you want it quantified...

Get your forks set up right, oil grade, level, spring pre-load, alignment with each other.

Get some decent rear shocks.

Head bearings adjusted absofekkinlutely dead right or you're completely wasting your time, and I mean not over tight but NO play.

And wheel bearings, swing arm bearings, good tyres.

Get all that right and then and only then will you be able to notice the difference between braced and unbraced frames.

I ride like a loon, ask Math he's the same and ridden with me, and I got some bits wrong and thought the frame bracing made no difference, once new rear Koni's fitted I could tell.

If you don't want to do all of the above don't bother with the frame bracing, its not worth the hassle.

Good checklist Tom, I totaly agree with all the above, and I also want to work on bracing a swing arm properly.

Do you use polyurethane or solid engine mounts ?

[crazy steve]

Good to know Steve, I'll make sure I get an XJ fender with the forks and wheels. IYO would it be prudent to match the final drive with the rear wheel ?

To tell the truth, I'd use a lightened Special fender and fork brace over the XJ fender; it really is a heavy mother and can't be helping unsprung weight, although the swirly wheels are lighter than the XS units.

As to 'matching' final drives, they're all the same regardless of the rear wheel, just different finishes unless you're thinking of a 750/850 FD swap. Personally, I'm not a fan of the FD swap as it will reduce performance IMO.... and I like performance...

[TomB]

Do you use polyurethane or solid engine mounts ?

OE mounts, I'm not trying to use the engine for strength, I feel that the engine castings are not strong enough, I've seen many crashed XS1100's with broken rubber mount holes broken simply from the jolt of sudden stopping.

I do shim the OE mounts when fitting them, rolled shim around the mounts makes them tighter in the engine holes, but to bring the mounts back to new spec.