New project: XS1100 endurance racer

[Mathh]

Here's a project I have been busy with (still am) and want to share with you. Lots of pics for the interested. It will be familiar to some of you guys as I copied most of it from the UK site, which I updated daily.
Last month a friend of mine, whose hobby is building frames, and myself have been busy in building a replica frame late 70's beginning of 80's endurance racer style. To do that i had to travel 200 miles to Friesland in the north of the Netherlands with in the back of the car: 1 engine, 1 xschop chaindrive, 1 rear wheel, 1 set of rsd front forks, 1 exhaust and a handfull of monoshocks...
A new one off frame + swingarm was to be made within a couple of weeks for my long dreamed of a classic endurance racer replica whatever..
What will it look like? Well it will be a mix of a 70's Godier Genoud Kawasaki endurance racer and a 80's Motoplast frame (Kwacker, Laverda). I love these racers as I have been visiting these endurance races in those days when it was still possible to walk through the pits. Lots of ingenious technical solutions coupled with gorgeous styling and big horsepower in comfotable frames. As Yamaha was not exactly overly busy in these days it will be a bike that Yamaha should have built (in my humble opinion). Still had that spare ex-turbo engine lying around so that worked out well.

For the people who don't know the above mentioned bikes: this is a GG kwacker from the 70's:



This is a Motoplast Laverda:



This is a GG frame (seat and tank are monocoque):



This is a Motoplast frame:



More GG pics:



Frametubes will be thicker though as I think they look tiny. They worked well however in those days. No tubing under the engine. I will definitely go for the monocoque construction, keeping the frame low and short. Looks nice and tidy. It will also get a one off swingarm: I am thinking of a GG lookalike but with a side mounted monoshock although it will be difficult to connect it to the back of the frame

september 24th 2009

ready for transport. Scruffy ex-turbo engine with shiny chaindrive:



november 20th 2009

First pic arrived today.. took a while because the guy just extended his garage to double size..



old wheelbase 1545mm, estimated new one 1440mm, steering head angle was 60,5 degrees, new 66 degrees from horizontal

november 22nd 2009

Tubing for the frame itself will be 32x2 mm (smaller than what he normally uses), for the swingarm 27x2mm. As the front wheel fitted in the end will be a 17" instead of the now fitted 18" , wheelbase will shrink another 20mm to 1420mm. Still looking for that wheel however..
Next pic show the RC Engineering collector fitted to check clearance.



This frame will not use the two lower front engine mounts (I don't like the looks) but only the upper front ones and the rear ones (solid ones, no rubber). Two extra engine mounts will be made and connected to the upper part of the rear of the engine: one bolted to the chain drive on the left, one bolted instead of the crankcase cover on the right. Here is the solid solution for the front engine mounting , this 30mm pipe has the same diameter as the inside of the engine mount and will be bolted to the frame and stays with the engine when lowered.



november 23rd 2009

Frame will be 31cm wide where the swingarm mounts, so a 200mm wide rear tire is a possibility.





Kickstarter is a must, so still waiting for an answer if the frame is not too wide at the right side..



november 25th 2009

Well, frame was too wide. So cut up and made new, it is now 29cm wide. Still possible to use a 200mm tire if necessary in the future. Communicating by email is a bit difficult as it turns out. His next step has to be cut up as well as it is too high. He already thought it would be too high as he is still thinking in streetfighter lines. I think the correct hight is the same as the intake ports, still good to mount the rear shock I think. I want it as low as possible. Have to wait though as he is asleep now after working last night. He is a proces operator.



In the meantime i'm having problems in the wheel department. As I cannot find a matching front wheel to the dymag 5-spoke in the pics I obtained two period Marvic Magnesium wheels. The rear wheel I bought in France ( a small regional "a vendre"site) for a ridiculous price. It is a 6x18" wheel. A 5.5x18" wheel would be better but it is a start.







This marvic front wheel was handed to me by a friend and it looks horrible. I had it checked and it turns out it has a crack in the rim and one of the spokes is oxidized completely. Aluminum oxidizes on the surface only, magnesium oxidizes within the material, unvisible to the eye. So this wheel is good for the bin.





Preferably Campagnolo's are the wheels I want most but they are rare as hen's teeth, they pop up once in a while as parts for Suzuki RG500's:





november 25th 2009

Next update. I asked him to lower the headstock in comparison to the rest of the frame. That way I can ride with clip ons on top of the upper plate. It also makes it easier to place the front frame tubes. He also lowered the rear portion of the frame to the height of the intake. Next are the tubes to the front:





Don't like the looks of that either, so I aked him to try and get the same look as on the GG and MP frame in front of the cylinderhead were all tubes come together. As there is no room for the horizontal tube from left to right he went back to the drawing board. Another friend stepped in with a 3D drawing in order to help: This is the first try:



In order to achieve my request he altered the way the tube runs along the side, a lot higher now.



I like the look of that but cannoty imagine how the rest will look when added. so I got this as an answer from our mutual friend:





Now this is definitely going in the right direction.
Just curious how this will develop as my welding friend is now busy welding and has not seen the last drawing yet...

november 26th 2009

A lot of pics will follow as the welders thoughts are still inclined towards building streetfighters. And communication is a bitch but now we swapped out mobile numbers.. I asked our 3D man to change the shock and he came up with this (and I said nahhh...):



Then he returned with this and said: "but we definitely need a shock!"



Great programme!

Because i want the frame tubes in front of the engine the same as the GG, conclusion was there is not enough room for the tubing AND the possibility to remove the valve cover. I suggested to make the first tube V-shaped, but it was not enough..



After that I suggested to change the wheelbase and the steering head angle to less extreme values. That helped a lot. He also tilted the engine a bit backwards. Now there was room for the extra tubing. Only remaing problem was that the sparkplugs could not be reached anymore. So the tube went upwards, meaning no longer a straight line from headstock via the front tube to the rear. I can live with that as the GG does not have that either.. This is the end result so far:



mmmmm, that's less than we had yesterday

[Mathh]

november 28th 2009

The project goes on and on. Despite the distance it's all going well and we're still having a laugh

Now then, these went in fine and look good. I wanted to lower the front tubes to horizontal but he needed the space available for his welds:





After the last picture I started worrying about the tubes that are going to pass between the downpipes. Our gimmick expert (we call him "Q") made a drawing to explain:



The GG frame has them running between the downpipes.
Turns out that with the RC exhaust these frame tubes need a bend. When I built an exhaust myself the frame tubes can be straight. I think I want them straight but then I need to make an exhaust...
mmmm... lots of extra work..

In the mean time Q came up with a comparison between my effort and his own Moto Martin frame (Q owns a Moto Martin GPZ750). The Martin frame looks not as stiff as our effort, especially behind the cylinder head. Our frame has 2 triangles at that point:



I remember the XS1100 Moto Martin has 2 extra frame members below the engine running from front to rear.
I asked Q if he could produce a drawing which shows the difference in stress between the two frames. He'll give it a try at work and this is a pic he did for his own swingarm:



This is a pic from late this afternoon: one pipe with three bends. Now he's making another one for the other side that has exactly the same bends:



november 29th 2009

Sunday and no time has been wasted. Got a phone call around noon to start up my laptop.

second tube ready:



matters were urgent as the two front downpipes interfere a little with the 2 outer exhaust pipes. He asked if he could cut up the exhaust to make room for 2 straight tubes: NOOOOO
So the exhaust will come off to make room for 2 straight tubes. More work for me:



pic from the rear:



3D sketch from the end result (in chrome!):



Then we had a big duscussion about strengtening the rear of the steering head. He wanted extra gusseting at the bottom and at the top. We already decided about one tube running from the bottom of the steering head to the V-shaped pipe:



But I definitely do not want one at the top, it will be too crowded, it is not necessary (most forces will be at the bottom) and i need the space for stuffing the coils etc. This is another pic from the side:



for extra strenght i suggested this solution he did earlier on a frame fot a V-Twin:



november 30th 2009

The tank is still undecided. My initial plan was a monocoque that could hinge on the front and bolted to the rear frame. However when hinged upwards it will spill petrol won't it.
So more thinking involved..

I will use on of these 2 fairings, preferably the one with the oil cooler opening. The one on the back is rare as hen's teeth, the one with the extra opening is as rare as hen's gold teeth....



november 30th

There we are again! the middle tube from front to rear in this pic has been deleted to get the strengthening from right to left as on the upper rails as in the V-Twin pic. This means less chance of distortion around the bearing area when welding:



Here's a pic from the problem area as described yesterday:



And here a pic from the finished front:



Soon we'll start with the swingarm and the right hand side monoshock. There is a choice between a 1998-2001 with a 80 kg spring and a 2008-09 fireblade with a 120 kg spring. Both are multiple adjustable and have a length of 30 cm, so we can switch if necessary. I have a R1 unit witha 90kg spring on the turbo and that works well (but it is an Öhlins unit). My preference for this bike is the Fireblade unit. Here is a pic:



Q made a calculator to determine optimal placing of the unit:



We'll go on tomorrow...

december 3rd 2009

Back on line now... first design flaw: frame cannot be removed from engine without removing frame lugs... So i called him an ass.... (in a nice way):





After a lot of discussion we chose almost the same solution as in the front..:





Don't like it 100% because I wanted the tube through the engine and the lower frametube combined, but in that case the frame would become too wide at that point. So instead I told him to weld a small ring in front of the frame lug on the right, so it looks the same as the left side.... (nagnagnag).

Okay, engine out of the frame. According to Q's calculations, he made this drawing below (little bit different as the frame) it should weigh, 12 kg 270 grams:



the real frame (welding not finished) weighs 11 kg 500 grams at this stage. When welded it will not exceed 12 kg's. Stock frame with lower yoke weighs 20.6 kilos.



The last two days there were several discussions about where to mount the shock , because not all measurements are known at this point. Q also called in some help to check his calculations as he was not sure of the effect of the spring preload. I'm sure it will turn out just fine..
Tomorrow the frame will be mounted in the welding jig.

Oh yeah, apprx\ox. 33 feet of tube went into the build already.

[Mathh]

december 6th 2009

Well, frame went into the jig:



and after three hours of adding heat and metal, voila:





And here after adding the engine. It fits like a glove, no distortion from the welding at all.







In the meantime we've had several discussions about wheelbase, trail, rake and so on. Pic below shows the frame waiting for the next step, carefully set up for a 1520mm wheelbase. That is still 25mm shorter than the standard XS.



As an example you can find some reference measurements from some modern bikes.



As the fork is a 41mm pre Exup one, offset is 35mm and expected trail will be around 95mm.



Then I changed wheelbase to 1500mm, because i am a bit scared the bike will get a bit too heavy on the front.



So, at this moment with a wheelbase of 1500mm , swingarm will be 455mm long (420mm standard) and i am awaiting some expert's comments...

[jwhughes3]

That is one incredible project. I can't wait to see your finished product. The design work alone is astounding.

Good luck!

John in San Antonio

[GARTHXS]

I wish I had the resources you have there , I always enjoy looking at the pics of your bikes

[Athedra]

I have seen several project bikes in the making, and the research and input you do is amazing. Keep it up, and would love to see more of your work.

[MeatTooth]

Fantastic build!

[HobbyMan]

Uhhhh.... Speechless

[lakecountrydave]

Wow! Very Impressive

[latexeses]

That frame really does look a good deal like the Laverda! This may be a silly question but are you going to do any heat treating to equalize any stresses in the metal from the welding?

It looks awesome so far. Would love to be able to watch the process in person. Quite an education.

[TajMan]

extremely extremely impressive
I'm jealous of such a custom build! nice job

[TomRodgers]

Yeah....i WISH i could have the resources......damn. Looks good so far!!!!

[Mathh]

Thanks for the compliments guys. I love doing projects like this... the story goes on..
december 9th 2009: next on the list is the swingarm. Previous days have been filled discussing several types of chain adjusters and tube size.
Very difficult if people don't listen. This is Q's first set up:



Well , I wanted a GG swingarm lookalike although with a fatter tube. First idea was two 35mm tubes welded on top of each other with a lower brace, bit like this:



Looks way too modern however.... Anyway, the adjusters were meant to look like these below. Second pic shows that the swingarm has to go inward from back to front, or there will be a large gap between the arm and the tire...





Then I decided to use a 38mm tube for the swingarm and a 32mm tube for the lower brace. This is the first result. .
Pic shows we moved the rear axle to the middle of the adjuster getting a final wheelbase of 1500mm. In this case I can vary the wheelbase from 1460mm to 1540mm (if necessary). Second pic shows nice gap between swingarm and rear tire, still plenty of room for a 200 tire though:





First attempt at the lower brace, way too deep...



At this stage Q came up with some suggestions and finally lost it... heheheh. I guess the swingarm in that final pic must weigh the same as the entire frame









december 10th 2009:
I suggested to move the lower brace upwards, this is the (still questionable) result :



And finally Q understood and produced this:



Comparing the shocks resulted in this, pic one is a 2009 Blade shock, pic two is a 2000 R1 unit. The blade solution looks too painful





Final shock position still has to be calculated though. I hope that happens before final welding.. These are pics from this afternoon before final welding.







When looking at the pics the swingarm still looks very massive, but that is because there is nothing else in the pic that draws attention. When tank and seat are in position it will look less big.
I love the way how the line form the lower frame tube pointing downwards is continued in the swingarm braces..

I also received another magnesium rear wheel, a 5,5x17. The other one is a 6x18. This way i can experiment with ride height as well:

[TomRodgers]

Methinks that when this is done, "Q" should be asked how much $$$$$ for a duplicate setup....

i myself have a two extra engine/trans/middle drive setups that would LOVE a cradle like that!!!!!

[Mathh]

This is the response from a guy on the UK forum:
"The really nice thing about this thread is how quickly we get to see the next stage."



Well, bad news then. After this episode the bike will come back to my place and speed will drop dramatically
However I will try to finish the bike before the next euro meeting.... :

Q finally picked up the pace, chromed everything and even managed to polish the front rim :



according to him the swingarm will weigh 6.0 kilos, the real thing weighs 5.5 kilos (I think Q's swingarm has the bearings installed):



And back together again:



And finally some outdoor shots:













Here's a pic from the first prototype with the shock still on the left...



And through a dutch forum which also covered the build i managed to finally find a supplier of the very rare fairing and seat:



I will pick the bike up in two weeks. So until then..