View Full Version : BMW kneeler

26.07.2018, 10:00 AM
Seeing as it is quiet at the moment Ill throw this to the lions.

I picked up a new project a couple of months ago to use on my anual Moidart/ Kinlochleven run,its a BMW R75 kneeler. This was being built by a guy to race but fell ill and it lay for some 10yrs then a friend of his put it up for sale. Having discusions with the MOT chappie on what is required to make this road legal then a trip to VOSA to have it sorted out. On closer inspection there are not two wheels in the correct position so I'lll have to clear the jig and rectify.
First is to remove the scooter chair wheel, I have purchased a 10" minilight along with a road legal Avon advan tyre. New hub aquired and my ex passenger is machining a new spindle as I type.
Motor has been stripped and measured bead blasted and thoroughly cleaned ready for assembly.
The motor consists of balanced crank, high comp Omega pistons not knowing the history of the con rods they were sent off to a metal improving company and have just arrived back from being shot peened to relieve stress which also increases the strength by aprox 30%.
The cylinder heads have been machined to create what is called a splayed head giving a more direct flow of fuel into the cylinders fed by a race cam, Kibblewhite valves and Dellorto carbs, the head has also been twin plugged. Stroll on April. :)

26.07.2018, 10:54 AM
That will be good fun but do you not think that a kneeler on the road could be a bit dangerous? It will be so low vehicles in front won't know it's there. You could always fit a flag to it :D

26.07.2018, 11:28 AM
It will be bright and LOUD , a friend had mentioned a flag but I could see that taking out pedestrians when cornering. I shall also have daytime led running lights.

26.07.2018, 11:58 AM
... a friend had mentioned a flag but I could see that taking out pedestrians when cornering...
:flash: Even more fun :flash: :D :D

28.07.2018, 08:17 AM
:flash: Even more fun :flash: :D :D

Here's me thinking you were a retired chilled out hippy ! :lol2:

02.09.2018, 08:30 AM
I achieved a little bit of kitchen engineering yesterday. I needed to up the main spine for the chair hub from 1 1/4 to 2" so machined a plug to fit the inside dia of the tube bored the centre then used a 2" hole saw boring each intersection then removing the tube to the next one. Life can be much simpler when the science has been removed, all done within the hour.

25.09.2018, 04:30 PM
Chair wheel mounted and in the correct place, camber and tow set. Minilight wheel instead of the scooter wheel keeping it within period, also added another 5 inches into the width extending the distance from centre of the drive wheel to centre of the chair wheel. Getting a wee buzz doing this one!! :D

25.09.2018, 10:01 PM
That looks fantastic but what's under the cover :flash::)

26.09.2018, 05:09 AM
Empty bottles ! Got in there before the supermarkets !!:lol2:

26.09.2018, 08:03 AM
That looks fantastic but what's under the cover :flash::)

It's another classic a Ducati TT2 with a 600 SL motor. I do small bits to it now and again but other projects keep on coming along that gain more interest :)

28.10.2018, 11:31 AM
More progress, I found a nice slim seat unit that complimented what I was aiming to achieve but this involved removing more tubes.
Hopefully this is the last I have to alter and I can now start joining the dots. I also discovered that the front end was leading and not trailing so made a new set of forks using oval tube, still in keeping with the CRMC regs.


Scott 888
05.11.2018, 07:38 PM
Just needs some bra broon pipes now Sam:)

05.11.2018, 08:26 PM
Cylinder heads modified,Just ordered Kibblewhite springs and caps for the high lift cam, bores rebored engine built,check valve clearence for the high comp pistons and adjust squish, just recieved my oval tube for the new forks , seat rails finished, master cylinders mounted, petrol tank fabricated, fairings mounted then painted then broon pipes and finally wiring done, stripped down powder coated and rebuilt. Getting there though.


26.11.2018, 02:56 PM
I was working in Newcastle the other week so I took the opportunity to save on a journey and drop the sidecar off at the fibreglass chappie in Darlington and have my seat unit and chair arch modified professionally.
I had to make a new subframe beforehand to suit the seat unit.
My Kibblewhite valve springs also arrived this afternoon to suit the higher lift cam and I have also just ordered the Pulse-jet ignition http://www.pulse-jetignition.co.uk/ I purchased a gearbox from a friend of the guy that invented this so decided to get in touch with him to find out more.
Using the twin plug head I have been informed that the noticable advantage will be over the 5k rev range,but a much wider benefit on the single plug head, it may not be of any use for road use on the BMW.
I shall stick it on the dyno and log the results before and after then try out on the TT2 Pantah as I have been sent adaptors to suit the shorter length 14mm plug as well. https://www.facebook.com/PulseJetIgnition/ pics are not uploading today for some reason.

26.11.2018, 03:53 PM
Pulse jet! (https://en.wikipedia.org/wiki/Pulsejet) For a moment I thought you had incorporated a V1 rocket! :D

26.11.2018, 04:00 PM
Just doodling around!:)

27.11.2018, 09:06 AM
That PJI looks really interesting. I used to run a series of Alfas and used Lodge multipoint plugs that a) avoided hot spots and be contributed to multi ignition points (usesless if you didn't drive the cars hard though) This concept looks like it uses similar base principles but making use of the lean burn advantages of a preigintion chamber.

Thanks again Sam, I have a call to make :)

27.11.2018, 03:29 PM
It was the 10% power increase that caught my attention, an economical tuning gain. It does show more of an increase in powere on the dyno readout with the BMW outfit 980 motor.

28.11.2018, 07:55 AM
Managed to get pics uploaded today, who needs a race transporter when you have a sturdy roof rack?
Does anyone know how to remove pics from the file manager as I am running out of storage space.


28.11.2018, 08:35 AM
I think the file manager automatically deletes the oldest files when there are too many. I've never deleted files from it since DuN started and it currently shows 26 files with room for another 4. I presume the older ones have been binned :dunno:

02.12.2018, 10:12 AM
I had a visit from Dove on here ( my ex sidecar passenger) to give me a hand taking up slack on the jibs of the mill ( I watched) so we decided to give the mill a test run and machine the cylinder heads to straighten out the inlet track and make stubs to suit the Dellorto carbs. Don't fret the carb is 180 deg out!



19.12.2018, 08:31 AM
I headed down to Darlington yesterday to pick my outfit up from the fibreglass works, here is one reason why not to use a propane heater in your workshop, the chassis is covered in rust.:ohwell: Just as well he did a good job altering the seat and arch.

19.12.2018, 11:31 AM
You should have given it a coat of primer first ;) I wouldn't think that propane heaters and fibreglass resin fumes would be a good mixture either - a potential to go BOOM :eek:

05.01.2019, 01:58 PM
The chassis shall be blasted and powder coated after a complete dry build so hopefully all the rust maggets shall be removed. No time spent on the bike over the holidays due to being in Ireland at the outlaws, I managed a couple of hours this afternoon though. Inlet track machined and new stub to take a Dellorto carb welded in place, having to use a short bell mouth as the right hand cylinder sits further to the rear.

31.01.2019, 06:33 AM
Still on the dry build before paint, i put together a dummy motor over the weekend and mounted the exhaust that came with the bike but it looks as if it will be a little hot under the kneeler.
On measuring the header lengths they are not in the same post code so have ordered a 180 deg bend and I shall make up a nice stainless 2 into 1 system which will give more room under the seat.

14.02.2019, 04:36 PM
I had a couple of hours free this afternoon so started on the leading link, I have made the from calipers floating and need to get this sorted before mounting the shocks.

14.02.2019, 04:47 PM
Your pictures are a' sideways Sam, they're gein' me a sair neck. An that left hand disc is affa roosty.
Good progress though :thumbs:

14.02.2019, 04:57 PM
Pics were taken in portrait, when I transfer they go skew whiff ! Why no have a wee dram it may ease yer neck off. Time is running away fast, trying to get ready and tested for the anual Moidart run on May 2nd.

18.02.2019, 06:47 AM
A little bit more progress on the front end, I have made the trail adjustable by slotting the pivot point and welding blocks either side.
I have made plates to fit inbetween the blocks with holes at different spacing enabling me to draw the pivot point further in giving more trail .

05.03.2019, 06:55 PM
Front end nearing completion with adjustable ride height. I looked at getting a piece of AS 516 plate to machine up a disc but this was prooving to be too much of a pain and was priced 120 for a laser cut blank. I managed to find a couple of Citreon discs new delivered to the door for 12. A half hour on the lathe to bore out the centre then take down the dia, lastly onto the mill to bore the mounting holes, hey presto a nice new spanking disc at 6 each.:thumbs:

20.03.2019, 11:53 AM
I have been speaking to a few folk about the oil delivery and found that the early engines were prone to cavitation. To make the best out of the oil supply issues so I can rev to 8k plus the scavange has been opened out to 12.5mm the main oil feed from the cam shaft bush housing to the back of the main bearing housing was also opened out to 8mm .
The oil pump rotors were slimmed down by 4mm to reduce the flow rate a new pump end plate was machined (cheers Dove) with a 4mm spigot on the rear to take up what was removed this all helps increasing the pumping efficiency. Sump baffle made also as this is in a sidecar and not a solo.
I Had top make a spring compressor as well, I have to fit restrictors to reduce the damper stroke and being 30mm long there was no way I ould have forced the spring down that far to get the buggers in. Kinlochleven wont happen for me this year work has got in the way and have finally run out of time.

21.03.2019, 02:15 PM
Finally recieved my seal and gasket set for my Dellortos after a 4 week wait all to save 7.00 :ohwell: rebuilt with the correct jets and anti surge washers on the main jet holder, float needle valves, short bellmouths and lever choke. I stopped short of new needles and slides as it was fast approaching on a new set of carbs

21.03.2019, 02:53 PM
I got my Dellorto rebuild kit from Ducati Paddy in about 2 days.

21.03.2019, 03:01 PM
They were in stock when I ordered them but had also ordered a Brembo (style) mastercylinder which was on a seven day delivery from order. Stupidly I said just send them all together to save them on postage. You learn !!

22.03.2019, 02:24 PM
One for the gadget folks! the digital multifunction guage arrived for the outfit along with the drive. This is connected into the gearbox revcounter drive then calibrated to wheel size. A much better solution than picking up a magnet on the front hub as there is too much happening on that front end.:thumbs: All that I can find on the drive at the moment as I did not receive any litrature for the drive. https://www.schweizerschrauber.ch/mot/ps-a.en.html

07.04.2019, 07:13 AM
One step forward three back, Snowball affect yet again.
I could not find a starter for the Bike as this was from an early model and had only 9 teeth compared to the later which has 12. These are modified Toyota units as BMW no longer make them.
One source was wanting 300 which I was not willing to pay but eventually found a new one for 78. When I was doing the dry build I found that the starter was touching the top tube or within a mm. Moving the motor inboard was what I though would be a solution but this caused problems with the drive even although it had a uv joint. The other problem was it was impossible to remove the oil filter withought tilting the motor. Last Saturday morning I attacked the back end with a grinder so new position for the motor and a better looking swing arm mount in order.

07.04.2019, 09:01 AM
Sam, your workshop will soon be known as "Hackett & Weld Motors" :D

07.04.2019, 09:23 AM
I've been called a lot worse!! ;)