New project: XS1100 endurance racer

[HobbyMan]

Uhhhh.... Speechless

[MeatTooth]

Fantastic build!

[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.

[GARTHXS]

awesome

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

[jwhughes3]

Wow!

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

[Mathh]

december 6th 2009

Here it is, ready for final welding ...



Then it 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. We then 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 more 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...

[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...

Added both tubes from the top of the headstock:



Another pic from the rear:



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:



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


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



november 30th 2009

Here we are again.. Added the two front tubes from the headstock down.. Looks great..



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..

november 30th

Here's a pic from the problem area as described yesterday, will need another exhaust because i want the RC exhaust in one piece:



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:


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..

december 3rd 2009

Back on line .. 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.

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, approx. 33 feet of tube went into the build already.

[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:



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:



first picture of the mockup...



november 20th 2009
Second 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.added



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. Alsointhe upperpicture 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..





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 to cut again 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.

november 26th

Well, frame was too wide. So cut up and made new, it is now 29cm


.
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.
A 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.

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.

:

I Don't like the looks of that either, so I asked 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 ft to right nor for removing the outer spark plugs he went back to the drawing board. Another friend stepped in with a 3D drawing in order to help: This is the first try,based on his own bike ( a Moto Martin framed ZX750).


I like the look of that but cannot imagine how the rest will look when added. so ...........second try after an hour ... all based on the first pics of the GG and Motoplast frames..


Now we all could visualize everything alot better and In order to achieve my request he altered the way the tube runs along the side, a lot higher now.
Way better!



And from the rear..



Now this is definitely going in the right direction.

november 26th 2009

Q said he needs info on the shock as this happens without one hahaha



Great program!

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

november 27th

He is busy early ..





That's better!