GZ250 Cafe Conversion

[ruxpin76]

Well, I've finally done it.
I've probably bitten off a tough piece to chew, but I've been mulling over converting my beloved GZ into a cafe-styled "standard" instead of the cruiser that Suzuki intended. For a bit of background, I am a "reformed" mechanical engineer -- which means I switched majors to architecture when I got bored of calculus, but after completing most of my degree. As a consequence, I got a decent foundation of good design practice, structures, materials, and most importantly: machining and welding. I worked on the Formula SAE project at Pitt, giving me experience with fiberglass and more design, and I grew up racing kart-like vehicles, giving me more mechanical experience. That said, I plan to chronicle my conversion here in step-by-step detail, "simple" enough that the average knuckle-buster can follow along and attempt something similar. If it proves popular, I may produce some bolt-ons to make the job easier for the less mechanically inclined.

I'll catch up with the pics soon, but here's an outline of what I've done so far:

*PRIOR TO THIS PROJECT: did needle shim mod, added hi-flo filtro in place of stock, replaced gas tank.

in roughly chronological order:

*removed chrome covers from engine
*removed seat in normal fashion and removed latch from fender
*unbolted fuse block and relays from fender bracket
*removed tail and fender in one piece, disconnecting wires at their plugs and preserving parts
*removed battery wires from terminals and unstrapped battery, removing it.
*removed battery box
*unbolted airbox bootie and hoses from airbox
*removed airbox by sliding back into fender area (easy, and intact IF battery holder is removed!!!)
*clipped misc. ty-wraps holding wiring in original locations
*removed carb (disconnected throttle and choke cables and vacuum hoses) for jetting change
*removed gas tank for easier access

I have pics of most of this, step by step. The tools I've used so far: 10mm wrench, 10mm socket, 14mm (choke nut)
side-cutting pliers for ty-wrap removal, phillips screwdriver for clamp removal.

My digital cam is 14MP, so bear with me as I download and resize the pics to post. I'll be posting them here and on photobucket, so don't worry if you don't see 'em all here. Let me know if there's more that you want to see.

Tonight's to-do list: remove front fender, tape for trimming, trim, sand edges, reinstall.

[ruxpin76]

I've also removed the passenger seat from the fender assembly. It's nicely shaped to re-use as the main seat for the cafe project, perhaps. I have noted that there's a metal bracket underneath the fender that gives the rear end much needed additional support. I plan to replace it with a directly welded piece between the shock mounts or a bolt-in in the first fender-support holes. If that's clear as mud, just wait for the pics to see what I mean. IIRC, I had to add a 7mm allen key to the tool list to unbolt the seat...

[ruxpin76]

Further mods will include a main battery relocation to tail, uni-style air filter to replace airbox, and some rear fender improvisation to shield the air filter from rain spray.

[JWR]

Sounds like a fun project , keep us updated with pic's

[ruxpin76]

Did the fender mod to "sportbike" style today...posting pics tomorrow, God-willing...
And adding to the list of mods: longer rear shocks to gain some clearance and add chassis rake (reduce steering rake, though...) and possible front-end swap if I can find compatible triples that use the same bearing set...
More tomorrow...

[ruxpin76]

Sorry for the delay in pics... finally got 'em on the computer, but resizing will take a bit. Will post back here when I got 'em. Current stage: frame marked for tab/bracket removal. Additional mods for the list: new tubing for seat support.

[ruxpin76]

Bike Status:

Currently the bike is stripped, and I'm going to remove the forks and engine and rear swingarm assy so that I can trim the excess bracketry off and have the frame stripped and powdercoated again. While it's stripped, I'll drill and tap the holes for the rearset on the traingular rear pivot support and get my clip-ons, etc. worked out. I'm also converting to a MX-based carby with on-carb choke and single pull throttle cable. Will post back later. Cheers...

Fender Trim:

[ruxpin76]

Fender will be lowered .500"-.750" shortly...

[ruxpin76]

UPDATE:

Bike has been marked for extra bracket removal, and I've found that a Honda CB175 tank's inner circles fit the GZ's rubber tank pucks PERFECTLY. They are, however a bit high on the gas tank, so I'm moving the GZ's pucks to the topside of the chassis tube and reworking the rear tank mount. Pics to follow.

The rearset (passenger pegs) are being relocated about 6" forward and 1" down, on the "triangles".

I've decided to raise the cafe seat a couple inches ABOVE the stock seat location, and affix a sealed battery on the underside, in the area where the tubing triangles normally covered with the sidecovers are. It will barely be visible, and makes installation far better than trying to get the battery out to the tail. It also helps with weight distribution.

That's it for now. I still have a ton of pics, but they're all HUGE. That's what a 10MP cam does for you, I guess.

Drop me a line if you get too impatient for updates. Or need some GZ parts (Tank, airbox, air filters, rear fender assembly, rear fender, passenger or main seats, main footpeg assemblies...)

[emory70]

good to see a quality redo of the bike. i was interested in a cafe conversion for mine, but after riding a triumph thruxton, no thanks.