Flat track project

[Pipes]

Hi,...My name is Shaun and I have been visiting this site for a little while now and thought it was about time I joined properly.
I am from the UK and I am currently building a flat track inspired XS.I have been 'trying' to build it or a little over a year now due to work commitments etc.The governing factors for the build is try and do everything myself where possible,keep things to a sensible budget and ride the thing when finished.
I am not new to building bikes but I am always learning when getting involved with a new model so I may look to you guys for advice from time to time and hopefully post updates as I go..that's if I remember to take photos as I have a memory of a fish haha...

Thanks guys.

 

[GLJ]

Welcome
Pics Pics
Without pics it ain't real.

 

[Pipes]

Hi,yeah I will try and put some up...I forgot to add that this build is a ground up build as in frame and all the parts attached to it which will use many parts not seen on a standard XS and in some cases will be second hand or to keep within budget.I have always wanted to build my own frame as I have had bikes with big and/or tuned engines,uprated suspension or paintwork etc but they have always used their original frame...so for this build I started with an '81 frame and engine in a box from the USA.The frame was to be used for the frame jig/mock up only as I wanted to keep things simple and this way I have all the dimensions for engine mounts,headstock size,length etc....I know I could build a completely one off frame however I liked but I wanted some guarantee that this will be rideable once I have finished.If I kept to somewhere close to stock then I may be going the right way..Like I said,this is the first time from scratch.
At this point in time I have a near completed frame and swingarm,forks temporarily fitted,rear single shock and linkage temporarily fitted,seat unit and one off tank.The engine had been fitted during some of the build but it is has just been removed and stripped down to its component parts ready for vapour blasting and then rebuilding.Here,hopefully,is a few pics,I apologise if they are not in any particular order and it will be slow as my laptop has less computing power than the first Atari!!!

 

[GLJ]

OK it's real!
Looking good.

 

[Downeaster]

I'm intrigued. I'll be watching this one!

 

[YamadudeXS650C]

Welcome.
I'll tune in, too.

 

[Pipes]

It going to be a little while before it gets anywhere near finished but I will keep chipping away as and when I can..I did say to the wife I would sell my other bike I built (a Suzuki GSX1135 EFE) which could help toward funding this one but I'm sure you understand how hard that can be and I am still in two minds.
Wheels are my next thing to plan for and then at least I will have a rolling chassis.

 

[Superjet]

Love that tank

 

[timbeck]

 

[Pipes]

Thank you superjet...I was in two minds whether it works or not but decided to persever with it and I think it will look ok...It is the third tank I have played with.The first was from a Honda XR but needed too much work once I started getting into it,the second was loosely based on flat track tank I saw on the web but the end result wasn't close enough.
Then one day this chap came into work with a Yamaha TY 250 aluminium tank that needed a weld repair and just for a giggle I laid it on my frame and instantly it spoke to me (metaphorically of course) and both my work mates liked it.The trouble is the TY tank held very little fuel and was a little too slim to suit the seat so I took some rough sizes and sort of enlarged them so I could carry more fuel and this is what I came up with.If I had,and could use,an english wheel then it may have looked even better but hey ho,...I have two Norton taps I am going to use which look good as I am trying to go for a modern vintage look if that makes sense

 

[Superjet]

I like the square edges of it. You dont see many made like that which makes it different in my mind. It compliments the engine cover and frame at both ends of the tank. Well done! JC

 

[gggGary]

Wow great fab skill skills there!
Can you describe how that monoshock is going to work?

 

[Mailman]

Wow great fab skill skills there!
Can you describe how that monoshock is going to work?

Yes yes, what he said! I would also love to know some details. Are you bending the frame tubing yourself? Are you the welder? Those welds look very professional. Oh and I know you are used to that Suzuki GS, but prepare yourself for that mighty XS650....it’ll yank your arms right outa their sockets!
Great work so far, keep up the updates, and photos man photos!

 

[MaxPete]

Welcome Pipes from Canada’s sunny southern coast in Windsor, Ontario!

I like your project - very impressive indeed! I noticed that the forward down tube ends at the front engine mount. Will you use the XS650 engine as a stressed member or do you plan to carry the tube down under the engine to join up with the frame below the rear mount?

I looking forward to seeing more coming along and in the meantime, I will rate this project as:


Pete

 

[Pipes]

Thanks guys,
Ok,I will try not to drivvle on lol...

Yes I am a welder although not as professional as some like you see on Instagram but I get by What you see is seamless cro-moly tubing for the all but the swingarm which is plain carbon steel TIG welded with appropriate wire and then capped with bronze just for asthetics as I plan to clear laquer the frame.

The rear mono shock uses a Yamaha R6 shock.The spring rate may be a head scratcher when it comes to it but as long as I give a supplier the approriate details they should be able to fix me up with a workable solution.I did think about twin shocks initially but I wanted to do something not necessarily more complex but more outside of the box.I purchased a YZ400F alloy swingarm with plans to use that but the more I saw it in the tubular frame the more I thought it would look out of place.I ended up fabricating a steel tube arm.Then the suspension.This came in the form of a monoshock either mounted as you see it or under the engine like a Buell,afterall if I was going to build something from the ground up then go all out...Then it dawned on me that the extent of the Buell idea would require some very clever engineering to make it look neat and still work efficiently and I got cold feet.Keep It Simple Stupid was in the back of my mind and while I could have mono shocked it from the swingarm straight to the frames backbone,cantilever style, I thought this idea a bit of a cop-out so I ended up with what you see.
The R6 shock is compressed with a linkage just as it is on the Superbike all be it with slightly different dimensions.I do have a short video I took somewhere of the shock (spring removed) being compressed by the linkage and in theory it should work fine.I still have room for adjustment with multiple mounting points for the linkage rods and other alloy linkage plates with differing hole spacings to change the ratio of lift etc...To be honest I spent hours on the net looking at animated shock linkage diagrams to get my head around how they work before I fabricated anything.I always like to do homework as I hate wasting money.The drawback this brings is the squeeze to get it all in there without extending the wheelbase too much.In fact I have gained about 50mm in length if I have my calculations right!!!
Lastly,you are correct in thinking MaxPete that I am using the engine as a stressed member.I am using all the engines mounts to hang it.One of the big conditions was to make the lovely looking engine a focal point....

 

[MaxPete]

Lastly,you are correct in thinking MaxPete that I am using the engine as a stressed member.I am using all the engines mounts to hang it.One of the big conditions was to make the lovely looking engine a focal point...

Very cool idea - I’m not sure that anyone else has done that with the xs650 engine. May I suggest that you reef up all of the mounting bolts good and tight so that the mounts can’t shift under load and....well, I sure hope the engine cases are up to it.
Cheers,
Pete

 

[Pipes]

Not sure if the photos are clear enough but the frame does cradle the engine just past the lower mounts which means the frame is simply missing the two spars from here to the front downtube..I think it will be fine but I could always fit a couple of tubes if necessary

 

[Pipes]

Hi guys..its been a while.This year has been a funny one to say the least.Work has been busy and my project has been slow going but mainly due to finances having to go elsewhere and seeing as the XS is more of a luxury it has also had to take a back seat when bills and things need paying...It's not for wanting mind you,

Ok,so September comes round and my son reaches 17,I end up buying him a Yamaha YZF125R (fantastic little bike) and his mate buys his Aprilia RS50 (a royal pain in the arse) so I thought I would use the money from the Aprilia and buy me some wheels then at least I will be nearer a rolling chassis.I went for a set of 19" polished SM Pro Flat track wheels as I had always decided to but something special in that department after all I am trying to save money everywhere else.I don't have a pic of the ones I bought as they are wrapped up in the shed waiting on tyres but I do have an image to keep you in the loop.

Next I bought some oil seals for the engine so I can start putting the bottom end back together over the xmas break,or that was the plan but I got itchy fingers and had a play today while my wife was at work.The cases have recently come back from the vapour blasters so it would be rude not hey?....

So at the end of play today I have a bottom end back together,sort of,as I have not committed to sealing them up yet as I am waiting on the timing chain although I guess I could seal the cases and feed the new chain through the tunnel unless that is you guys can tell pros and cons of doing it this way.Mind you,as I am typing this I am thinking that had I wanted to replace the chain during a routine 'service' I would have to do it with the engine built up already would I not??...

Anyway, I have some random pics of the work so far of the newly cleaned cases including starter delete and gearbox build.

Lets hope the next instalment isn't so far away...

 

[MaxPete]

Those wheels are very pretty indeed!

 

[Pipes]

That's why they are still wrapped up MaxPete .As soon as I get the tyres I will try them on the chassis and then we will see how the whole thing sits and see if my oddball calculations have worked out!!..

Out of curiosity has anyone ever weighed,or know the weight of the assembled engine,give or take a couple of kilo's??

(no starter,'81 model,)