Radian, XJ/FJ600 cafe racer/resto-mod build thread.

Hello all.

In 2020 I bought a 600 Radian as project, this however has evolved into two separate projects.
This is what I bought, not too pretty in my opinion.

My intention was to restore it to as near stock as possible, however once I got it stripped down it became apparent that the frame had been chopped down by a PO. So with that in mind I decided to look for a frame that hadn't been attacked with a hacksaw or angle grinder, in due course a suitable frame was obtained.

The Radian so far with a stock frame.


I still have loads to do with it, but it runs. For whatever reason a PO changed the engine for a XJ/FJ600 lump, not sure why.

So on to the subject of this thread. I decided I wanted to build a cafe racer style bike with the left over frame. Rather than use the original Radian wheels I decided I wanted to use more modern 17 inch wheels, along with beefier front forks and a swing arm, but not too extreme as I'm not the best engineer nor do I have deep pockets and wanting to do the bulk of the modifications myself, I'm a big believer in the "built not bought" ethos.
I decided on Suzuki GSX600F (Katana) wheels and front forks, along with a swing from Suzuki GS500 as it resembles the the standard Radian swing arm. These items have been purchased for little money, the swing arm was actually gifted to me, however the s/a is little too wide at the pivot point 18mm or 3/4 inch, so after much measuring and marking, checking and rechecking the excess material was removed with the aid of a reciprocating saw and angle grinder, I will need to file it down by hand to get the pivot point down to the desired witdth.

A quick hash up.


It looks better than I thought it would, that's just my opinion, you guy's may have a different perspective.

I am looking forward hearing any ideas or criticism, constructive or otherwise from the community.

Cheers Andy

 

Wow you’re essentially building a bike from scratch. Are you going with twin shocks or monoshock rear suspension?

 

@Simmy Yeah pretty much from scratch, never thought of it that way. I thought of monoshock, but I would like use an air box of some sort and there won't be enough room for both the shock absorber and air box, so it will be a twin shock build and I think twin shock will suit the style of the bike.
I have started to fabricate an air box out of scrap 3mm aluminium plate, here in the UK the road sign plates are made of 3mm aluminium plate and I have a source for the ones that get replaced.



I also started cleaning the GS500 swing arm with an electrolysis bath.

It seemscto removing aclot of krud and rust, see how it goes. I used the same process to clean the inside of my Radian fuel tank with good success.
More to follow...

Cheers Andy

 

Please excuse the typos in the post above, a combination of big fat sausage fingers and iPad keyboard are a recipe for disaster.

It should say "It seems to be removing a lot of krud and rust, see how it goes. I used this process to clean the inside of my Radian fuel tank with good success"

Cheers Andy

 

Hi,..had some password issues but im on board..

 

ive used electrolysis on petrol tank insides followed by filling them with some awesome citrus stuff thats eco friendly but does the job of derusting...of course ive forgotten the name of it so i'll have to look it up..lol

 

Deox C
compared to what it was like this was pretty successful

 

@tobar good to see you here mate, I had similar results as you with my Radian tank, I couldn't get that bit at the bottom either.
Before

And after

I used POR15 as a sealer to line my tank.
On the subject of fuel tanks I would like to use a XJ550 (Seca) tank on my build as Radian tanks are a bit thin on the ground and really expensive, also I don't think a Radian tank will suit my build so much.
Or if I can't get old of a XJ550 tank I may use a XJ/FJ600 tank, however I am open to suggestions.

Cheers Andy

 

yeah because of that scab at the bottom of the tank i used 8oz tin of kbs sealer when the weather was warm last year..didnt use all the tin...prob 90% of it and it worked well

xj600 tanks all seem to be rotten...i got one for 50 quid that looked mint but id not spotted minute pinholes, but on the rhs towards the back...i got them brazed up but lost the decent paint in the process...
another had rot on the left side where the bike leans which when provoked turned into a big hole so that was binned
and my main one is the one pictured above, no holes and now lined

whereas the xj550 frame project i mounted an xj650 seca to tank that i purchased of ebay was fine and probably wont need lining...xj650 seca is the best looking imo

 

XJ650 tanks do look good, not many about though. There is an XJ550 tank on eBay for £55 but the description says it has pin holes in it, maybe not worth the hassle.

I'm not seeing a picture

Cheers Andy

 

A little off subject as this post involves my Radian's carburetors.
A PO had somehow managed to snap one of the float mounts off number 4 carb and attempted to glue back on (wtf). A replacement carb was sourced and duely arrived. It needed bit of cleaning up, I have blasting equipment but I decided sand would be too harsh to clean the aforementioned carb, so I thought I would try using soda crystals as a softer option to sand and I am very happy with the results.

The soda crystals I used where purchased from a super market, £2.00 for a 1 kilo bag, what's more I didn't use that much. I'm not sure what name soda crystals go under for the rotw. I used a blasting gun similar to this.

More soon, cheers

 

On this side of the pond we can (sometimes) get Arm & Hammer baking soda in 8# bags in the swimming pool areas of the dreaded WalMart. It works well in one of the cheap, plastic blasting guns.

 

@Fuller56 I found this link that explains the difference between soda crystals and baking soda or bicarbonate of soda.
https://www.thekindstoreonline.co.uk/blogs/blog/what-are-concentrated-soda-crystals-and-how-to-use-them#:~:text=No, soda crystals are not,at removing grease and stains.
I must admit that I thought it was all the same stuff.

Cheers

 

@AndyH64 Well, cool! That sounds like some pretty useful stuff. I wonder what we have that is similar. Amazon MUST have it. I just checked some stuff we have called "Bar Keeper's Friend" that I thought might be similar but in very brief research it is not. Good stuff but not even close.
Thanks for the info though.
John

 

Sodium Bicarbonate is cheaply available nearly everywhere - it isn't Baking Soda, which has something extra in it, salt and tartare or somesuch, and it is a lot more costly than simple Sod Bicarb.
Sodium Carbonate is also dirt cheap and available widely as Washing Soda - there are two types, the hydrated and the dehydrated. The hydrated is the most common, simply because it's harder to keep the water out of it, and if you really need the dehydrated version, it's easy to dry it in the oven.

Never mix up the above with Sodium Hydroxide. It will eat your dirt, your skin, your eyes, and your carburettor.

 

@Dave in Ireland thanks for the useful info.
@Fuller56 as Dave in Ireland suggests try sodium bicarbonate, there is loads of information on the web, the soda crystals I use is the same chemical compound as sodium bicarbonate.
This is what I use

Cheers Andy

 

That's Washing Soda, but if it works, it works.
Soda Bic is far, far cheaper in bulk.

 

My mistake, I got confused with carbonate and bicarbonate.
Na₂CO₃ is the formula for sodium carbonate. (Soda crystals)
NaHCO₃ is the formula for sodium bicarbonate. (Baking soda or bicarbonate of soda)
Let's hope any further confusion can be avoided and nobody gets injured and the desired results can be achieved.

Cheers Andy

 

All good info and useful info at that. Thank you all. But what is a little hydrogen between friends?

 

where are you at with this project?

 

@tobar Unfortunately I haven't had spare time to get anything done with it, car problems have been getting in the way, hopefully that is sorted so after a weeks holiday normal service will be resumed.

Cheers Andy

 

ha, ive got car problems too that's taking a while

 

@tobar Golf 1.9tdi with a knackered cam and followers, all done now apart from an oil leak out of the cam cover- the joys of motoring

Cheers Andy

 

Hi all.

This project has been put on the back burner for a little while due to health issues.
On the morning of the 15th of August I got taken into hospital with chest pains and subsequently I had 2 stents fitted. I am doing fine I just need to it easy for while.

However I have got all the bits and pieces to need to modify theGS500 s/a to suit the YX frame and I also came across a set of carbs for it, although they have been stripped, 2 of the air screws have been chewed by someone in the past, a stud extractor should do the trick and one of the float pin posts has been broken, again this should be repairable.

More as soon as I feel up to it.

Cheers Andy

 

Sorry to hear of your health troubles. I hope you get well and subsequently have the ability to complete this project.

I have two radians and a gs500. All are currently non running and were essentially given to me. I’ve often thought of using the rear wheel & swingarm setup from the gs500 on the radian. The gs has a lighter rear wheel with a disc brake AND the wheels look better (in my opinion).

I’ll be watching your progress. But for now take it easy and get well!

 

@chris123 I hope you create build thread for your project.

The GS500 s/a is a good choice for the Radian frame as they are very similar in appearance to the stock s/a, a little modification is required as the GS s/a is a little wider at the pivot point and whether you decide to go twin shock or mono shock.
Also using the GS rear wheel allows the use of modern tyres (tires).

Cheers Andy

 

I have managed to remove the damaged air screw with some difficulty as someone in the past had made a mess of it, clearly they didn't drill the offending item straight as the hole they drilled was way off centre, unfortunately as a result the threads are damaged and I won't be able to get an air screw back in.
That leaves me with three options.
1. Buy another carb or set of carbs, not easy as they are getting scarce (unless someone on here can help me out in exchange for some beer tokens)
2. Attempt a repair on the damaged carb, maybe drill out the air screw hole and make a brass insert. If anyone has any better ideas please share here as any ideas would be greatly appreciated.
3. Fuel injection, yes I know this sounds like a mad idea but I do believe it could work, again if anyone has any ideas or pointers with this, or simply to tell me that I'm a total raving f##cking idiot who has lost a grip on reality would be excellent thanks. I do have a set of throttle bodies from a CBR600 complete with primary and secondary injectors that were bought for a previous project, I could maybe use these with perhaps a Speeduino or similar.
Maybe someone has a solution I haven't thought of, there is no rush as I'm a long way off sorting the fuel system.
I am looking forward to the input from all out there in internet land, I am certain there will be some interesting ideas and potential solutions.
More soon.
Cheers Andy

 

On my health front I feel so much better since the cardiac stents have been fitted, also I am trying to stop smoking and eating healthier.

Cheers Andy

 

If you go down the FI route we probably will never hear from you again...
Anyway, I’ve had the issue with the mixture screw on my vmax. They were all pretty screwed up, I managed three of them with care and perseverance, but like you, one of them was beyond. So my fix was to set the carb up on my vertical mill, lined up on the hole under the thread (had to make a pointy thing to go in the mill for this). Then carefully bored out the thread to clean, but not as far as the step into the hole. Next step was to make an aluminium insert with a thread on the inside to replace the metal bored out. The first one was too slack in the bored hole, so I made one 3 thou bigger.
Pressed it in with some loctite, job done. Took me an afternoon, plus a metric fine tap. A lot easier than FI...
I may have posted some pics here...

 

@Minimutly your vmax fix is the type of thing I was thinking however I don't have access to milling machine. I was going to attempt this fix using my piller drill.

Cheers Andy

 

Well if you have really tight drill with no slop, do you also have a lathe? If so it’s do-able.

 

My drill hasn't done much heavy work so it should be good to do this, as long as I take my time. How would I make the hole flat at the bottom instead of been drill bit shaped,,if that makes sense.
I haven't got a lathe either.

Cheers Andy

 

You just drill the hole and make the insert “nose” the same shape. You will also need to clamp the carb squarely and accurately on the table.

 

Right I understand and I would check and double check for alignment.
I do have a couple mates with lathes, only problem is they live up in North Yorkshire, which incidentally is were I orginate from, so I might be able to get this job done the next time I'm up there.
Thanks for your advice, most useful.

Cheers Andy

 

@Minimutly can you remember what size the thread is for your vmax air screws? The XJ/FJ600 air screws measure at 5.7mm with a fine pitch.

Cheers Andy

 

No I don't remember, but I'll see if I can find out if theyre the same and what tap I used. 6mm fine I would expect.

 

@Minimutly I thought it would be an m6 fine thread tap.
Thanks again.

Cheers Andy

 

@Minimutly would it be a m6 x 0.75 tap I need before I order a set.

Cheers Andy

 

Sorry, missed this - will check tomorrow!

 

@Minimutly no problem.

Cheers Andy

 

M6x 0.5.. I used taper and plug.
See pics, the insert diameter ended up at 0.293 inches. It’s fairly thin wall, delicate engineering.
The drill is an old oddball, shortened with not so sharp edges, even then it drilled slightly oversize and I had to make a second insert. Pushed it in with some loctite..
You have to make sure you hold the body perfectly square, and using a pointy thing to locate the tiny enrichment hole, line it up and not let it move as you drill. Short drill is good because it doesn’t wander...
Don’t drill the tiny hole out....

 

What size mikunis are you using?

 

@Minimutly thanks great information, my carbs are 32mm.
I haven't come across a m6 x 0.5 tap. I'll dig deeper and see if I can fine one.

Thanks again very helpful.

Cheers Andy

 

I'm going to put this on the back burner for now as I don't think I have the skill set for this job.
However I have repaired a broken float pin post.


I am quite happy with the results, I should have used my piller drill instead of a hand held drill as I didn't drill it out quite straight, but it is functional.
I have also just about got the GS500 s/a modified to go in the YX frame, I still need to make shock absorber mounts for the s/a, although I am still toying with the idea of doing a mono shock conversation on the YX frame.

More soon.
Cheers Andy

 

Finally I've had some time and half decent weather today to make a start on the rear shock absorber mounts for the GS500 s/a. A few photos of what I've accomplished.


As always I look forward to hearing about the thoughts from you folks out in internet land.
I'm not going to weld them on just yet as I'm undecided on which shock absorbers to use. I do have a pair of stock Radian shocks which measure 320mm or 12.59" eye to eye. However I would like to use Yamaha XT500 rear shocks which are quite a bit longer at 365mm or 14.37" eye to eye, I do realise that using longer shock absorbers could potentially upset the handling by raising the ride height too much and make things interesting when it comes to negotiating a bend. My plan is move the newly made shock brackets further along the s/a towards the chain adjusters in a bid to help keep the ride height somewhere near to stock as possible (although the bike would look better with say 25mm or 1" higher ride height, thoughts please) and by doing this it will also help disguise the added length of the s/a.

More soon. Cheers Andy

 

If you move the bottom of the shocks further back, you'll also benefit from a more progressive spring rate, inherent in that design.
Exactly how much, I'd only be guessing, but it won't (shouldn't) compromise the handling.
Plenty of factory bikes had a slanted pair of shocks to gain this extra free suspension mod.

 

@Dave in Ireland. Thanks for your input, much appreciated. I seem to recall back in the 70s/80s (omg I'm showing my age) an off road bike having multiple bottom shock mount holes so the ride height could be adjusted simply by moving the shock along the s/a. Sadly I have no idea who manufactured these bikes, could even be more than one manufacturer.

More soon. Cheers Andy

 

Ooo, not much given the short travel of those shocks, and if you lean them too much you will be weakening the spring and damping rate. Most you can hope for is they are vertical at full compression.
And don’t bother with factory shocks, you need adjustable dampers, with selectable springs - ikon would be lowest cost reasonable quality, Hagon I’ve found good, not sure what else is available in the UK.

 

@Minimutly. I have found Ikon or Koni to be quite expensive. YSS seem to offer good quality at reasonable prices. Do you think it would best practice if I kept the shocks at the stock angle, maybe I could go for 340mm shocks just to lift the rear end a touch. Again thoughts please.

More soon. Cheers Andy

 

Hard to say without seeing the thing in front of me, but tilting away from vertical (well more accurately away from perpendicular to the swing arm) will weaken the shock, but give more travel. If you do this by moving the bottom out you weaken it and get less travel... it’s fairly simple maths really, but, the point at which the shock is perpendicular is the stiffest/strongest. Sorry, can’t be more specific. I would keep them near vertical, or near original.....