R1100GS fork swap & more or my HPF build

I know (and I'm glad) it's been done but here's my go at it.

The project:
Getting Miss Piggy here on a diet and improve her nimbleness so that this thing rides a little bit more like a proper dirt bike.

So far:
Twobrothers exhaust cat-elim: -18lbs,
ABS removal: -11lbs,
SS brake hoses: like I'm gonna tell if something add weigth!(although they probably don't)
Elkas front and back: same as above

In near future:
Front frame mods and fork swap
21inch ktm wheel
Front brake swap

Later:
Trimming the absurd Corbin sofa
Trimming the rear fender,ligths, etc.
Rear frame reinforcements
Headlights replacement

Beware as this may take a while. I view this bike as a work in progress. Basically, I looked all over for a perfect bike and could not find it. So instead of buying something else and modify it, I decided to keep what I had and pimp it until I am satisfied or fed up and take up knitting.

Mind you, I'm a fan of the shaft drive and boxer engine, both for feel and extended intervals of maintenance.

The bike is old and has some solid mileage so it's no garage queen. I also happen to ride it more than I wash it and it shows. Please forgive me or look in another direction.

Enjoy.

I was about to change a leaky head gasket when I saw that my right cam chain guide went south. Where I live, the summer is short so a trip to fleabay got me an 70K mile block for 200$.

I locally found a 04 CR250 frame along with a 04 YZ250 set of forks and turned to fleabay for a front GS frame so I could still ride the pig while working on the project.

As of today, the frames are cut and ready to begin the welding phase.



Since the pegs where still on the CR frame, I had no reason not to upgrade the vintage items that came stock on the GS


My TIG welding friend will come pick the frame parts in a day or two and I'm looking around for a 21 from a 20mm axle KTM as the hub on theses can be fitted with big single rotors from the 640 adventure.

YZ fork awaiting their new life:

cool projects!

Ive wondered if standard pegs would fit the GS mounts before.

The width is perfect, I had to drill the frame holes to accommodate the bigger CR pins, and drill a small hole on one side for the spring end to enter the peg mount as the CR springs mirror each other whereas the GS ones are identical. I also had to grind the bottom stopper on the CR pegs to have them at a right angle. took about 45 minutes. PBR kept it's cool.

Good to know thanks!

I'm in.

Looking Good Fabrice, question why use a KTM front wheel. Why not use the YZ450 front wheel spacers and axel etc. What do you intend using the bike for? bush bashing or keeping it on the road. This is a discussion we had with Woody on which front rim width to use for different situations.
http://www.advrider.com/forums/showthread.php?t=604474
I have a 100GS front wheel fitted up to one of my 1100 with the standard telelever even that increases the off road performance by about 50%
WR

Subscribed! Keep the pics commin'

Dan.

Hi WR, I choose the KTM wheel for multiple reasons:
1- Excel rim
2- 20mm axle, same as the YZ so I get to use the YZ axle and (hopefully) spacers. Everything will just bolt on to the forks.
3- I will be able to use a KTM rotor from a 640 (300mm)or 640adv(320mm) since KTM hubs are all the same. I could not find an easy match in Yamaha's line up.
4- KTM wheels abound on ebay and they are cheap too.

Motocross brakes will not slow the pig down! I'll use the axle and spacers (/2 above)

Trail, road and travel.

Nice discussion but, like on your project, they kept the telelever. I want MX forks for a couple of reasons mainly:
-the reduced weight,
-the increase in travel
-strength: I think it will hold better in hard off-road and that the on road compromise will be ok for me. My friend has a 800GS and let me ride it for 2 weeks both to commute and off-road riding. After 1000km of mixed riding, I decided that I could live with a 21" on road no problem.

I hope I answered all your questions!

I ordered a KTM 21 on ebay that I'm still waiting for so no pics.

I got this tho:


This will take care of the welding.

Sorry for the shitty iphone pics, I'm a photographer after all High res pictures for the next updates I promise.

So for now, I'm waiting for the ktm rim and I need to visit my friend who owns a 690 to see if it's trick rotor fits an older ktm hub or if I'll have to go with a 640 rotor.

Fabrice thanks for the reply the reason I asked about the wheel is because the 450 I wrecked had an excel rim on it 1.67" which is best protected by the tire for hard off road. As for the Brakes and telelever I agree there is no way the std yz brakes will stop the GS but there are 320mm Discs available and a descent calliper is going to have to be fabricted up to suit. The telelever definetiley has its limits off road on rough surfaces you can go up to a certain speed but is to unstable above that. I had a we crash a couple of years ago and ended with one of these and a pile of spare parts as I repaired it myself. I am currently working on my project starting with a frame.
WR

Frame to look a bit like this an hopefully the bike should look a bit like the R900 RR
Bring on your build everyone I study I get fresh ideas. I wont hijack your thread.
WR

Thanks for the input WR. I wasn't sure on which rim to use actually and mine is from a 2004 YZ250. Don't know if any big rotor options are available tho. Anyway, I got a ktm wheel for 150$ so I'll probably try that first.

Nice project btw and don't worry about the highjack (if any), I'm here to collect info/input from others first and then to show my project and encourage people to start their own. So keep the ideas coming!

Talking about sharing thoughts, I was about to order a wider excel rim before reading WR's take on off-road and 1.67" rim being more protected by the tire so I have something new to try and will save a few $ in the process. Thanks.

I cant take credit for this these are words of wisdom from Woody

for serious hard-core off road a 1.6x21 is optimal max rim protection and better off road handling,,whereas the 2.15 is just too wide to handle the off-road hits and will bend for sure,,it does keep the sidewalls straighter for pavement work,,but it's a mute point when considering how much better the 19'' wheel works on the slab.and in the twisties

OBTW you can also go 1.85x21'' AND genuine tubeless X-laced to match your rear.....the front rim of a r100GS/PD will lace up to your 1100 hubs..these come in polished aluminum ,,we anodize them clear to match your rear oem rim
woody

WR<!-- / message --><!-- sig -->

Finally my friend Gary who teaches welding class was free and came over to my place to work on the project. I know how to weld but I'm not confident enough in my aluminum skills at this point to weld such a vital part (for me and for the bike ). Plus, Gary did at least 10 HD frame mods so far so he knows how it's done. I just have to watch him closely so I don't end up with a racked out rig.

The parts on the jig:


We made sure that everything was straight and Gary proceeded:




He then welded a 2x2 on the inside to give it strength:


Then, we made the side caps (no pics) but it was getting late and Gary had to go so I would have to finish by myself or wait some more time. Since everything was already straight and solid, I decided that I would give it a go. Please go easy on me as I only welded aluminum for about a foot long in my brief career.

First I made a reinforcement plate to put below the 2x2:


Then I capped everything for strength and to protect it from dust and other debris. I've cut the pieces a bit loose and had to do some filling on the bottom corners. Not the best look but it should be strong:


The final result. Notice the top gusset (angle cut 2x2) and that I placed the CR's neck an inch above to compensate for the 2 and 1/2 inches longer forks of the CR. This should leave room to adjust the sag with 12inches of travel versus the 6 or so the 11gs has. I will also have the option to slip the tubes in the triple clamps if needed:


Next time I will be trying the forks on the bike without brakes; I've not bought the rotor yet...

Stay tuned

wating to see the miss piggy when comes out from the plastic sugeron!!! it is going to be a babe!!!! nice job

I just hope it will be less expensive than a boob job...

Welds look good Fab