Hello from the UK, Need help with frame size

[Cooperman1]

hello,

I've just bought a 1980 Yamaha 650 xs that I am looking to bobber, what my question is is does anyone know what drop this bike has had and what the strech is on the hard tail?
Will post pictures of the bîke once it's day time!
Thanks for any help!

This is the BSA bobber I just built.

 

[Cooperman1]

So please meet my new project!!! She's a 1980 Yamaha 650 XS SH US import! I've loved the shape of these bike in bobber form for a few years and the chance came up to buy a project bike cheap and as I had the space in the garage it would of been rude to say no!

The bad points are the engine is seized and the carbs are missing but pretty much everything else will be binned for a minimal bobber look, I'm looking forward to trying my hand at a 4 stroke engine and will get help to weld the hard tail onto the frame but I want to do as much in the garage as possible!!!

As she turned up, abit sorry for herself!!

I spent a hour stripping the bike to make her a bit more narrow so I could fit the car in and I'm pleased to say it worked! The tank and seat were just loose, I've removed the brake pedal, kick starter and centre stand and side stand and the car fits in!!!! The engine wouldn't kick over so I sprayed wd40 down the barrels to see if I could get movement after I leave it a few days.

This is the plan, it won't be a 6 month build like the other 4 but something I want to take my time with.

 

[fredintoon]

Hi Cooperman and welcome,
So, you bobbed a Bantam, eh? Do you know how much a resto'd Bantam would sell for? Ah well.
Some thoughts about your XS650 project.
Lose those ergonomically disastrous rototiller bars!
I used to live in the UK.
Going fenderless in a country where it's always raining is putting style way ahead of convenience.
And as an XS650's front fender also acts as a fork brace, I'd suggest you install one. I use a TKAT, there's several others
WD40 is NOT a penetrating fluid. Mix up and equal parts cocktail of acetone and automatic transmission fluid to use instead.
XS650 single front disk design is not optimal. Least cost upgrade is install a smaller master cylinder and stainless brake lines.
XS650's crowded ball headraces were OK in the 1890s but swapping in a tapered roller headrace kit is far better.
Hartail rake, stretch & lowering? There's a hundred or more list members who've done one. If each one posts you'll get
over a hundred sets of measurements. Each one will be different, every one of them will be right.

 

[Cooperman1]

Some interesting points raised.

Well a little bit of progress today and I got the correct post 1980 Mikuni BS34 CV carbs for the bike, they were only £24 of eBay!!
They seem in really good condition, I will give them a sonic clean and new gaskets at a later date.

I will be looking to do a 6" stretch to the frame with a 3" drop when the time comes to fit the Hardtail, also might use the mag wheels just to keep things abit different!