Slow moving Z650 cafe racer project

[aPeMunky]

Hello folks,

Thought I should introduce my 1978 Z650B project, I bought it last summer as a non runner that had been left in a garage for sometime. I gave it a quick service, got it running (though not fuelling correctly) then promptly started to pull it apart at which point the project stalled for, what I'm sure will be the first of many times.

This is how it looked when I got it, incidentally it had 'Piglet Special' written inside one of the side panels so that might mean something to someone on this site?




Started to strip it down



and it is now residing in several boxes awaiting me to pull my finger out.

The plan is a stripped bare cafe racer style with a modern twist, no great heroics planned and the plan is fluid at the moment.

I would like to keep a clean, classic look but with beefier RWU forks, wider rims on same hubs, decent brakes, cafe racer seat, clip-ons, no body work, minimal electrics. The plan is too get the chassis build going, fit the standard lump to ensure it handles well then rebuild and sort the cosmetics and play with the engine.

I will try to keep you up to date on my progress. The first sticking point is the forks. I've tried to use the 'Search' facility but get back way to many posts and seem unable to filter them to anything meaningful.

I have a set of RWU SRAD 600 forks (similar length) I would like to fit which can not be carried out by bearing swap alone so I will need to swap the steering stems. They are approximately the same length but the SRAD stem thread is too low to fit the Z650.

The Z stem is slightly wider in diameter so either it or the SRAD clamp will need modifying to fit. The SRAD stem looks like it can be pressed out but the Z650 stem appears to be welded into the bottom clamp an looks like it can't be shifted?

So my question is how to remove the Z stem? Can it be easily pressed out? I'm sure this has been asked many times before but apologies I can't find the answer? Is this the sort of thing any local machine shop can carry out?

I live near Tonbridge in Kent so if anyone can recommend some where local to go that would be great as I will also require a few parts making up/ modifying.

Thanks in advance.

[GUYZED]

Looks like a good starting point for a project...keep the pics coming.

[kev edwards]

Munky, it may not be local enough for you but Saxon engineering at gillingham may be able to help, when i was a plating chemist i used them a lot for machine modifications and one off parts that i could'nt do myself, i took myself out to leigh a few weeks ago i used to work for smith kline and french and bridge chemicals before it was beecham and welcome, i used to go to the bat and ball for long lunch hours.

[aPeMunky]

Cheers Kev, I will give them a call if I can't find anything else local.

Bat & Ball closed about 2 years ago so we all go to The Fleur de Lis now, very handy since it's 30secs from my house.

Here are a few pics for inspiration:

Like these two for their shape:





Yeah I know it's a Hodna but...






Firestone Deluxe tyres look the part but won't be going for them on mine as performance and handling take a higher priority than looks (I will, no doubt,contradict myself numerous times in following posts though)

[saxon46]

you shouldn't put photo's like that up............



winters coming.........and what does that mean...........projects

I do like them I must admit.........must resist

on the other hand

[saxon46]

you shouldn't put photo's like that up............



winters coming.........and what does that mean...........projects

I do like them I must admit.........must resist

on the other hand

[ricky13]

The pics of the cafe racers are brill anymore info on them especially second pic
Good luck with your resto

[aPeMunky]

2nd pic is a 'Wrenchmonkee' creation, there were the guys that got me started on this track after Inman's article in PB brought them to my attention.

Plenty of grubby late night internet perusing has gone on since then to formulate a plan, problem is the plan keeps changing and no doubt will again but I've got to make a start.

Hopefully I will win a pair of brake discs tonight and then can start to get the front end bits 'n' bobs machined up as phase one is to get a rolling chassis. Playing around last night showed that there was just enough room to get the GSXR calipers mounted both sides and comfortably clear the spokes.

Too ask again - has anyone ever pressed the head stem out of a Z650 yoke? As it doesn't look like it is possible on mine.

If not possible then I have the option of getting another stem machined to fit or to try and cut/grind the bottom yoke off and machine the existing stem to fit the SRAD bottom yoke.

Pressing the existing one out would be far easier and cheaper though.

[Pigford]

I've pressed out Z1000 stems before - usually have a circlip in the end to stop them pulling thru - some may have a bead of weld - probably just grind it off

[ricky13]

hi again
a quick question if i was putting clip ons onto my bike as a cafe racer type can i fit a top yolk without riser clamps if so what one goes onto 36mm forks
the bike is 1982 twin shock 750
thanks

[aPeMunky]

Sorry no idea regarding suitable top yokes for a standard bike as I'm replacing the whole front end with something different and mating it to the existing front wheel. Maybe just fit a blanking plate over the existing handlebar mounts in case you every want to swap back?

Pigford - thanks for the reply, there is no circlip on my stem so I'll attack the base with a grinder as it is probably only a bead weld.
If that doesn't work then I might just grind the whole bottom yoke off.

[Ginger Bear]

Munky,

This is what I did the last time I needed to modify a stem. came from a Z1000J & was welded.

1. Cut off what you can.



2. Stick it in a lathe......... even a 'baby' Myford will do.



3. Machine it to fit your replacement bottom yoke.



This method is particularly useful if the replacement yoke was fitted with a larger diameter stem. Note the small 'lip' left on the bottom of the stem to stop it being 'pulled' through the yoke.

[aPeMunky]

Well done bear, that's exactly what I needed to know.

The Z stem is indeed wider than the SRAD one so I can get a lip machined in.
I also managed to get my bottom bearing off with some persuasive hammering, yours looks a bit rusted on there!

I won the front discs on ebay last night so I now know what needs to be done when the discs arrive.

Off to the machine shop soon...

[Royalratch]

Get in there.

Great reference bikes and great sounding project.

Not many mods needed to do this well. Swingarm and steerer really and you can then fit any forks, wheels and brakes you like. Best to get a proper outfit to do that kind of stuff as welding shock mounts and getting clearances for chainline etc can be specified for someone else to worry about.

For instance, I just showed up with a wheel, a brake caliper and a swingarm and said - make this all fit and bolt together with X clearance and X angle. Then call me when its done!

I'd love to have done more but time and tools not permitting.

[aPeMunky]

Cheers RR, thanks for the PM.

Well the forks/yokes are are in for machining now and will take a couple of weeks. I had a bit of a headache with the disc mountings as we couldn't find a way to make a fixture to mate the 5 hole mountings of the SRAD600 discs to the 4 holes in the Z650 hub in the space provided.

Luckily I came across this chap who can make one-off disc carriers, so he'll be making me a pair with 4 hole centres, correct centre diameter and offset for the SRAD calipers which should solve my problems.
I'll measure it all up when I get my front end fitted. Two of the bobbins were knackered so needed replacing anyway.

http://www.thediscdoctor.co.uk/Discs.htm

New wider rims (anodized Black) in standard diameter (19" front & 18" rear) have been ordered from Hagon with spokes. I will be building them onto the existing Z650 hubs which were disgusting but cleaned up nicely with steel wool and my secret weapon (oven cleaner which worked very well).

Tyres arrived 110 front and 150 Rear but this meant that the rear was too fat for the braced swingarm that came with the bike. Today I found out that it's not feasible to widen it so I'm looking around for another.
RR used a ZX6R J Swingarm that only needs minor modding and shock mounts welding on so I may go this route but I need to find out if there is sufficient clearance for my 18" wheel.

Looking forward to getting the various bits back but next month I start a new job with weeks of intensive training so I'm hoping to get a rolling chassis together before Xmas, fingers crossed.