1981 GS750E (GSX750E) Dented Cafe Racer ( Currently doing GSX-R USD conversion)

LKS

Been Around the Block
Finally! :) I think I'm happy with the looks. I've been so afraid that something would be wrong with the front setup I've chosen. Either that the wheel would be too big, there would be too little ground clearance or that the wheel would be too close to the exhaust. The front is still incomplete, as it's missing fender, the headlight sits about 6-7cm too high, the brake rotors and brake lines are not there and so on. But I think the geometry is fine :) The gap between tire and exhaust is about 7cm. I think max travel for these forks are 12cm, but that's under really hard load. I'll drop the forks 12cm and measure the clearances.

Also, I always pictured the fork legs painted black, but now I think I might keep them anodized gold? What do you guys think?









I'll take some better pictures with the seat on soon :)
 

pidjones

Over 1,000 Posts
I've removed the lower races by slicing with a Dremel. Save the old one, and have a perfect tool for gently tapping the new one on. Even if the old one goes onto the seating area, it will easily come off. I save old outer races for installing new also.
 

LKS

Been Around the Block
I've removed the lower races by slicing with a Dremel. Save the old one, and have a perfect tool for gently tapping the new one on. Even if the old one goes onto the seating area, it will easily come off. I save old outer races for installing new also.
Clever:) I used the old bearing, and had to hammer i off afterwards ;)
 

LKS

Been Around the Block
Moved the headlight lower and liked the look. Also did a quick photoshop of the fork when compressed (like the Photoshop pro I am..
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). It seems the fender will touch the lower clamp just before the tyre hits the exhaust. I need to set compression and preload so this doesn't happen, but I don't think it'll be a problem. I'll also hook up a GoPro for the first few rides to see how the fork behaves.



 

brad black

Been Around the Block
raise the oil height in the forks to increase the air spring, that's the easiest way to limit travel without screwing everything else up.
 

chickenStripCharlie

Coast to Coast
looks fantastic. if i had a budget for that i would definitely love to go with spoke wheels.

I always loved the look of USD forks and spoke wheels on my BMW G650x dual sport. (Sold)


20170421_181111.jpg
 

LKS

Been Around the Block
looks fantastic. if i had a budget for that i would definitely love to go with spoke wheels.

I always loved the look of USD forks and spoke wheels on my BMW G650x dual sport. (Sold)


View attachment 232217

Nice bike! I checked out your Nighthawk build, and you really have fabrication skills :) Your bike already looks awesome, but if you really wanted spokes, wouldn't it be possible to make your own comstar adapters and match the adapter to some suitable secondhand spoked wheel?

Comstar adapter site with howto: http://motosynthesis.blogspot.com/p/products.html
 

chickenStripCharlie

Coast to Coast
Nice bike! I checked out your Nighthawk build, and you really have fabrication skills :) Your bike already looks awesome, but if you really wanted spokes, wouldn't it be possible to make your own comstar adapters and match the adapter to some suitable secondhand spoked wheel?

Comstar adapter site with howto: http://motosynthesis.blogspot.com/p/products.html

I've seen this before, but i'm not sold on the idea. When he drills his spoke holes he drills them at 90* .... I heard somewhere, maybe even this forum, that the hub holes for the spokes need to be at a certain angle? I don't know .... but it is certainly one of the options for it. The other being to just find new wheels and fit them on :)

At this point i was happy enough with the mags that i decided to finish the bike, THEN consider any changes to wheels down the road :)
 

LKS

Been Around the Block
So far, I'm using the stock GSX-R triples. They are 30mm offset, about the same as the stock GS triples. That means I'm getting about 2cm less offset than stock, as the GS-fork is leading axle. I don't think I will make it a priority right away, but if anyone has information on stock triples from another bike that fixes this problem I can start looking for a set. I've browsed through the tables in other forums, and didn't find anything, so if there really is an available solution (except expensive aftermarket parts) it would be a hidden gem.

If the steering is too sluggish, and/or if the front tire gets too close to the exhaust under fork compression, I think I will put adjustable triples on my to-do list for the winter.
I hope the cnc-router is working by then and I have a lot of large pieces of glued oak (kitchen countertops) that I get for free from a local store. They are awesome for doing cheap cnc prototyping.


Here's a prototype I made for the GS-fork. I didn't get around to mill them from aluminum as I decided to go for the USD forks instead.



43780539594_8896ac890f_c.jpg



Does anyone have either drawings (CAD) or pictures of suitable adjustable upper and lower triples?
 

chickenStripCharlie

Coast to Coast
To be honest the handling of my bike isnt really as much of a change as the numbers would lead you believe.

By far the biggest impact is the steering limitation. The tubes are bigger in diameter and sit further back so they come really close to the tank. It limits the turning radius more than I would like.

Definitely check for this if you havent already.
 

LKS

Been Around the Block
About to give the rotors and calipers a fresh coat of paint (the calipers aren't finished yet):



 

LKS

Been Around the Block
Painted the calipers with caliper (spray)paint. Very difficult to get an even surface, and i don't think that paint will take sanding very well. I have an anodizing-kit that I bought some years ago, that I haven't gotten around to try out. I think I'll strip these for paint as a winter project and anodize them black instead. For now, I'll live with the bad finish. I guess this kind of paint is more for protection than looks..


I also gave the "Ducati Monster Aluminium Performance Fender" (I think that's the original name) a couple of coats of aluminum base and BMW sapphire black.



I'll try it on and decide whether I want to keep it black. The finish looks awful without sanding and painted at too low temperature, so I'll throw in a picture of the same paint on the old forks:
42190752560_67896224cf_z.jpg



The fender is originally mounted like this:


But I've drilled the rivets and will make something like this:

 

LKS

Been Around the Block
Rolled the bike out to take some photos. This is definitely the look I'm going for
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What's left is (afaik); redo wires and cables, brake lines and pads up front, change rear brake reservoir and brakelines, speedosensor at rear disc, make the left footpeg on the lathe, make new support-rod for rear caliper, mount Motogadget Mini and gear-indicator in the triple, make gear lever plus connection rod, make brakcet for license plate and rear brake light, mount front indicators and some other minor stuff.. The list was longer than i thought..
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LKS

Been Around the Block
I measured the trail. Don't know how accurate you can measure it, but I think it's pretty close. I make it out to be 114mm, and I'm pretty sure stock is 107mm. 7mm longer, and I don't think that will be a problem for now. If I don't like it, I'll make new triples with 20mm more offset. That won't be until winter though ;)

 

LKS

Been Around the Block
Is the trail measurement with you on it? It looks pretty stable.
No, it's with the bike unloaded. I haven't adjusted sag either. It's about 20mm sag without me on. I'll take new measurements later, when I start do drive. I just wanted to see if I was way off or not. In the end, it's what it feels like to drive that matters, I think :)
 

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