bmw scrambler project (a slow build)

[hmmmnz]

ok, not long ago i bought an 1989 r80rt monolever beemer,

i was actually looking for an older r80/100 gs-pd or older g/s air cooled for a scrambler project

the reason was they had the wire wheels, and i detest the cast wheels on these old beemers,

but they were going for stupid money here in the uk, and then this old rt came up for about 1/3 my budget of what i was willing to pay for the gs model, so i thought fuck it, i can some how make it spoked,

i was going to change the front end of the gs any way, so that would only leave the rear wheel that would need some thinking about,

so anyway, collection, i had to drive down into england to pick up a bath room for the old merc camper, and this bike was kind of on the way, in so much as it was south of scotland

met up with the guy, paid him the money and would return in the after noon to collect after getting the bath room,

all was good did that and rode back to edinburgh with no issues,

the rt models when they came out looked like this

https://www.bmbikes.co.uk/photos/photophotos/R80RT%20Mono%20644.JPG

whoa, super ugly fairing massive screens etc, perfect tourers, but one of the ugliest beemers ever

mine didnt come with the fairings (previously crashed) which suited me just fine

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/IMAG1050Medium_zps7f468747.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/IMAG1048Medium_zps3782fefe.jpg

also the guy changed the rocker covers from the flat newer style to the older skool ones

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/IMAG1054Medium_zps75159353.jpg

no really fussed either way,

i had already ditched the tail section and gave it to a mate, as ill be completly changing the back end

any way the plan,

1 change the rear wheel to a r100gs wheel, i bought that already and as we speak its being machined down to fit the monolever hub (there is no straight replacement wheel, but the gs wheel is close enough, and just requires 21.25mm (in my case) to be machined down inside the wheel itself)

https://www.stephenbottcher.net/BMW/misc/rearhubconv/2wheels.jpg

so no biggie

after that will be the front end or exhaust

ill be using a usd front end of un-known manufacture as a replacement to the stock beemer forks wheels, triples, etc, probably a drz or crf may be some white powers, price will determine that,

the exhaust will be a high level custom made running high from the start either 2-2 all the way through like a cl360

https://www.midamericaauctions.com/wp-content/uploads/2012/04/143A_1-1975-Honda-CL360.jpg

or 2-1 like this

https://cars-database.com/data_images/gallery/02/triumph-scrambler/triumph-scrambler-07.jpg

unsure yet

i will also raise /drop the swing arm and probably move the mount onto the steel part of the swing arm

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/IMAG1051Medium_zps60e2ab10.jpg

and possibly lengthen the swingarm to gain a bit of extra travel

im going to try and get it look a bit like this

https://www.boxerschmiede.de/fotos-projekte/bmw-scrambler-classic.jpg

but obviously a monolever, with exhaust on 1 side only, and usd forks

yeah, so, this will be a long-ish project, im a bit low on funds after bumming around europe in the campervan for the summer, and skiing all last winter, really should start looking for a job
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[stevo as b4]

That will be some cool mofo of a street scrambler when it's done. I guess a BMW build isn't the cheapest bike to have a as project but the end result should be fairly awesome!

The one thing I think that would have made the scrambler in your thread look better is if it was dry sumped and had a bash plate under the engine. Loads of work and potential for un-reliability to do that, but for the looks it would be worth it!

[hmmmnz]

i was going to put a bash plate on, but never thought about converting to dry sump,
i suppose the old oil in the frame might be quite cool, but doing oil changes was always a pain in the arse on my rotax engine'd mz500

i can see where your coming from though, ill tuck the idea in the back of my mind for future mulling
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[hmmmnz]

right long time no reply,

well havn't done a huge amount,

rear wheel has been machined then un-machined, then left,

i'll get round to it at some stage,

i did the exhaust, im not entirely happy with it so will probably change it at some point to bring it closer to the frame, and have a more level run, but i am happy with the noise, its quiet at idle but makes an awesome noise at full whack,

any way pics:

https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1298Medium_zps4403082a.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1299Medium_zpsc9c5c967.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1300Medium_zps016a9718.jpg

video

https://www.youtube.com/watch?v=l_RQzLAegDE

yeah, thats all for now, front end next
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[trevor saxe-coburg-gotha]

Sounding pretty damn mean.
____________________
"Life is a sexually transmitted disease and the mortality rate is one hundred percent."

Mobylette Type 50 ---> Raleigh Grifter ---> Neval Minsk 125

[BTTD]

I like the old airheads, but I have to say (IMO) that is the ugliest exhaust I've ever seen on one. Does sound nice in that coarse bmw bark way though.

I guess it'll make more sense once the rest of the bike is done - look forward to seeing how it progresses.

[hmmmnz]

yeah as i said, im not particularly happy with the exhaust as yet,
i want it to run high like it does, but not to have the upwards angle,
it did look a bit better withe the exposed stainless pipes before i put the stainless guard on it, but it was too hot on my leg,

it'll get changed me thinks
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[hmmmnz]

right front end done,
surprisingly easy,
im using an aprilia pegaso 650 complete front end,
and using the bmw master for the breaks, and the aprilia head race bearings,
funnily enough i had all the bearings to hand (i have a pegaso as well)
which was part of the reason i went for this usd set up,
all the mods i had to do was shorten the stem on the pegaso triples,
make a new set of head lamp brackets, and widen the headrace bearing cover over to fit the pegaso bearings, and make a new mount for the clocks,
by far and away the easiest usd conversion ive done,

any way pics

https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1303Medium_zps88c4405f.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1304Medium_zpsb17a6481.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1305Medium_zps457f70d5.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1306Medium_zpse05cb272.jpg

my headlight brackets are just 2 exhaust clamps per side and a steel plate
https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1307Medium_zps7c0dd0df.jpg

clocks, almost the same outlook
https://i58.photobucket.com/albums/g257/hmmmnz/IMAG1308Medium_zpsb11e9279.jpg


next is either seat and rear subframe or rear wheel
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[hmmmnz]

update, for shits and giggles,
i have fitted a new subframe and seat,

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/IMG_20140704_215357Medium_zps1674e79d.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/IMG_20140704_215405Medium_zps1db63af6.jpg

umm since those pics, not that you can see it, the exhaust has been changed to run lower and closer to the engine and frame so it doesnt burn my fucken leg, and allows the boxes to be mounted as close as possible to the frame

excuse my niece and nephew.

i also rubbed off all the paint and am letting it rust a bit before chucking a clear over it, you know because all the kids are doing it,
so it must be cool, i thought about sticker bombing it, but came to the conclusion that im 35, not 17

https://i58.photobucket.com/albums/g257/hmmmnz/10592746_10152256609241606_7384337456128384276_n_zps2652d183.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/10606207_571245656321181_7580090005276805392_n_zps50414730.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/10628025_10152629222781224_8929361546526922805_n_zps9fa30a7d.jpg

the boxes are 20mm us army ammo boxes and come in at around 30 litres (29l) so are a fairly decent size without sticking out too far,
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[hmmmnz]

well thats the boxes done,

new/really old steel mudguard added as well, for extra awesome,

pics.

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/10643271_572412592871154_1697816881_n_zpsde47cd22.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/10653919_572412562871157_506105_n_zpse2f931a5.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/10592215_572412516204495_761650112_n_zpsf63569f5.jpg

from the back, the panniers/ammo boxes are just a touch wider than the heads, so thats good,

i could probably get them the same width with a bit of a design change, but that'll do me

ammo box/crash protection

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/10617506_572412649537815_1650299862_n_zpsbd08d8e7.jpg

https://i58.photobucket.com/albums/g257/hmmmnz/bmw%20scrambler%20project/10643232_572412622871151_807503907_n_zpsc0e87a71.jpg
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Robby]

Fuel tank needs to be smaller, with the lower edge of it finishing higher up so you can see more engine.

[BenR]

Looking good fella although not too sure on the rusty tank. Are you living in the UK now? I still owe you money dude.

[Carl_steveo]

I actually like the rusty tank. It's looking cool.
____________________
Current: Honda Nsr 125
Live: Sunderland
Luke "cant be arsed to read your post, but suck my balls anyway."

[hmmmnz]

[BigDan1190]

Looks fantastic man. Any more plans for it?

Would be cool if the tank had a finish of sorts. Still old school, a bit bad ass, just something more than bare rust lol.

[PT1989]

Looking good.
Quite keen on that seat, where from & how much?
____________________
Currently riding; 1991 Yamaha XJ900F

[beardface]

Looking good, should go for a slimmer front mudguard.

https://www.moto-verso.co.uk/wp-content/uploads/2012/12/image37-620x412.jpeg
____________________
www.soundcloud.com/bodren

[hmmmnz]

Id like to but since i have a usd front end its a bit harder to to than the conventional one that you posted,....
first i have a gearbox to rebuild,

Fucken thing shat itself at stormin the castle, and i had tobuy a new bike at the rally to take me on the euro trip,
bandit of course, just cant beat the reliability of the old oil cooled suzukis.

More as it happens
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[hmmmnz]

ok, well as some of you know, on my way to do my euro trip i blew the gearbox coming into stormin the castle, so i ditched the beemer and bought a bandit12 to do it on,
fast foward to a few weeks ago when i finally got round to picking up thebmw and dropping it off to a local guy who is an expert on air head boxes, he has dozens of them and they get sent to him from around europe to do, luckily he agreed to do mine as he had nothing on,
and didnt even want to get paid for the job,
just pay for parts,

so here is his write up on the job

I had a quick look at the bike after you had gone. That box sounds as though its got a really serious problem, I've never heard a noise like that before. It will be interesting to see what happened (I'll post pictures).

I was out with horses today and tomorrow I've got to sort out a neighbour's chainsaw before doing anything else but hopefully I'll make a start at getting the box out.

I'll report back on progress.
....



Just to remind you, this is what turned up:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3776_zps3yq6iwxz.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3779A_zpsvwzoxkmd.jpg


It was very difficult to push about as the box wasn't running free in Neutral, this was accompanied by horrible 'clunking' noises.

Pretty soon it was a sorry little Rat Bike :augie:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3836_zps2qvgtldq.jpg


Taking it apart wasn't difficult. The tank was held on by the single fuel pipe and the airbox only had one bolt - which was very loose. The seat was clinging on with two nuts that were just started on their threads .

The air filter is a scrapper :blast.

Anyway, the box was soon on the bench:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3797_zpsnpithxqo.jpg


The Output Flange nut came off OK, but the taper was very tight (a good sign).


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3812_zpspm4my0xv.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3815_zpsdc5slriu.jpg


The box was very dirty around the clutch end. The clutch lever was very stiff so I was expecting trouble there.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3799_zpsetsakjj5.jpg


The magnetic drain plug didn't look too bad - which surprised me as I was expecting more swarf than this:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3809_zpsqydusowf.jpg


Soon the box was apart to reveal . . Swarf everywhere .


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3827_zpsld8cl5xq.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3828_zpsn2osh3c3.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3829_zpsecivh7sn.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3831_zpskq42gcac.jpg


I can't show it in stills, but the rear bearing on the output shaft was the worst I've ever seen - its almost possible to remove the outer track from what's left of the balls and cage. The other bearings are shot as well - but are not as bad.

The output shaft has been pulled back from the front bearing. There shouldn't be any discernible space between the bearing and the fifth gear pinion. This is why we fit circlips to the front of the inner bearing :augie.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3833_zpsvhuk6vlb.jpg


The swarf has contaminated the oil and has worn the two bearing sleeves that the first and second gear pinions run on - The plain sleeve for First Gear:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3843_zpslef28hmv.jpg


The First Gear pinion has a plain thrust washer on each side. The inner one has been pressed into the Third Gear sliding pinion - its supposed to be flat . This has further damaged the bearing sleeve that did the damage to it.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3842_zpsidndzctd.jpg


The (expensive) roller Bearing on the front of the Input Shaft is usually OK, however, this one is jammed solid and the rollers won't turn so I guess its full of swarf :blast.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3853_zpsfinf9hh7.jpg


I think the box has run low on oil at some point in its life (there was oil in it when I drained it) as the Input and Output shafts have been 'blued' with heat where the bearings have been choked with swarf:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3845_zpsq5nigjg0.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3848_zps3jgn6ymz.jpg


I'm not intending to replace them as the bearing sleeves will be renewed. I can't see them going soft (or brittle) with the heat treatment.


Some of the retaining washers and circlips on the Output Shaft are damaged and will be replaced. One circlip has been reduced to almost half its circumference, yet I didn't find any broken pieces :nenau.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3839_zpsdg5ioq3x.jpg


The 'clunking' noise heard when the bike was being wheeled about came from the Drive shaft. The rear bearing on the Output Shaft was so worn that the Drive Flange was hitting the outer sleeve on the rear gearbox cover - where the 'boot' attaches. This movement allowed the Worm Drive on the Flange to chew-up the Speedometer Drive gear - you can see how the spline teeth are now tapered towards the lower end. I have ordered a 'Good used' one from Motorworks.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3821_zpsfv03fvye.jpg


Worse, the Drive Flange has cracked the rear cover. Its not critical and I'll put a touch of Epoxy adhesive on it. A 'Good Used' rear cover is £110 from Motorworks .


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3901_zpsmafya6le.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3906_zpsaieufr8r.jpg


The good news:

There is some. The selector forks are fine with just one tip showing signs of heat. They will go back in OK.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3858_zpsexcf478j.jpg


The complete Selector Mechanism is also A-OK. I'll replace the springs and Indexing Roller as a matter of course but this is actually better than some I've seen .


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3859_zpseepzgwja.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3863_zpstxiztope.jpg


The cam faces on the Input Shaft Shock Absorber are also very good.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3856_zps9bkpgseb.jpg


The Clutch:

The Clutch assembly looked well past its sell-by date and I wasn't very hopeful about saving all of it.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3804_zps6cdwtsqj.jpg


I removed the six 'hold down' bolts and expected the outer retaining ring to fall off and the Friction Plate to fall out . . . not a bit of it, the thing was welded together and nothing would shift it.

I soaked the three locating pegs in Penetrating Oil and left it for a couple of days - still no movement. So with a gas torch and a hammer and cold chisel (to use as a wedge) I eventually got the bits separated.

The Friction Plate is just down to the rivets and the rest is rusty and seized. I'll save what I can but I have ordered three new parts from Moto-Bins today.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3892_zpsdlnv968m.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3893_zps9rk5i3vy.jpg


The problem then was that all the components were contaminated with very fine metal swarf and I didn't want to put anything back in that state. Washing the Gear Pinions in Kerosene didn't remove the swarf so I dug out my 27 litre Ultrasonic Cleaner :clap.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3887_zps93ttfqbr.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3889_zpsoaqkqkme.jpg


"Hubble-Bubble" .


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3890_zpssicc6jwq.jpg


After two 20-minute sessions, the cleaning fluid was a dark brown colour.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3896_zpskdphzm8r.jpg


When the fluid was drained the bottom was coated in particles - mostly steel swarf. I cleaned the tank out with a large clump of paper towel which came out covered in sparkly bits.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3900_zpsd9vkfl6r.jpg


As the gear pinions and so on were now thoroughly de-greased I carefully re-oiled everything and set it aside ready for assembly.

I have a couple of (large) orders outstanding with Moto-Bins and Motorworks so assembly will have to wait until the shiny new bits have arrived.

To be continued....

.....


I fitted the centre track from a 6403 bearing onto the Output Shaft and then stuck it in the lathe.

Using a carbide strip ground down to a shade over 1mm thickness and given a cutting tip, I cut a circlip groove into the forward end.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3915_zpszjraklez.jpg


It doesn't take long and a new circlip fitted OK.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3919_zpsodrliax6.jpg


Then a van arrived . . Oooooh, shiny bits :bounce1.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3909_zpspwe3ffml.jpg


Hmmmm, doesn't look like £432-worth does it :confused:.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3911_zpslcgq1rlz.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3913_zps3ce3ztrg.jpg


It's not all for this bike as I'm re-stocking some of the small stuff .


New vs. Old.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3920_zpsfco4ytcy.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3923_zpsjsb9cceu.jpg


The second gear bearing sleeve was a nice tight fit on the shaft.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3925_zpsdpqw1vmj.jpg


Always ensure that these oil holes are lined up as there isn't an oil groove on the inside of the sleeve.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3927_zpsvdc8vomz.jpg


The new 'High Fifth' gear was fitted, along with fourth & Second gears, front bearing and the all-important circlip. Second gear is a lovely fit on that new sleeve - smooth without any hint of play :thumb.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3929_zps4yxl2tp4.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3932_zpscrfewuap.jpg


I then added the third and first gear pinions. First gear is also a nice smooth fit without shake on its new sleeve - quite unlike the way it was when it came off originally.

The 'Standard Fifth' gear is shown, there is no difference in diameter they just cunningly re-profile it to include fewer teeth :confused:.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3935_zpswxpcu0zo.jpg


I built up the Input and Intermediate shafts yesterday, but didn't take pictures (it involves spring compressors, various home-made steel 'dollies' and my floor press) all three shafts are now ready to go back in. The Gear Selector mechanism is also ready with new springs and Indexing Roller.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3937_zpsf2p61wxq.jpg


I may get the box assembled tomorrow but then there will be a short break as I'm off to "The Bristol Classic Bike Show" at Shepton Mallet on Friday/Saturday. I won't be on the 1150GSA this year as I don't fancy the M6 on a Friday with snow and ice - I'll be taking a large 4x4 . I must be getting old and soft :rob.

I put the gearbox casing through the Ultrasonic Cleaner yesterday. It is clean but the alloy is now dark and mottled. I'll see if I can clean it up with something before building it up.

To be continued . . . .


.....

More progress to report :thumb.

Having assembled the three shafts I heated the gearbox case with a Propane torch and fitted them along with the intermediate shaft selector fork that has to go in at the same time. There are two oil baffles in front of the Intermediate & Output shafts and the Input shaft's roller bearing has to go in before the others as all three bearings are an Interference fit. It entails a bit of juggling and one has to be quick.

A quick tap with a rubber mallet ensures that all bearings are seated before the case cools.

Then the Selector mechanism, Output Shaft Selector forks and shaft and main oil baffle are fitted.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3938_zpsbz68ljtd.jpg


When the case has cooled the gear lever if fitted and the gearchange is checked. It isn't great with the rear bearings unsupported but as long as all gears can be selected it will be OK when the rear cover is fitted.

Then the rear cover gasket goes on with a light smear of Blue Hylomar.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3944_zpspf0iigkm.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3945_zps4gnwjvul.jpg


And now for the technical bit - Shimming the end-float .

One needs a 'Shimming Plate' for this job:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3947_zps9v7hg4kc.jpg


I have drilled mine so that I can bolt it down on top of the gasket. I think that this gives me the most accurate measurements but people have different approaches and may just rest the plate on the case or put the gasket in after the measuring has been done - each to his own.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3949_zps1g4crc6g.jpg


I use a 'Outside Micrometer' and a 'Depth Micrometer' for this job.

First measure the thickness of the Shimming Plate:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3953_zpsdz7vynuy.jpg


Then measure the thickness of the oil baffle that goes on the rear of the Intermediate shaft:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3954_zps5h0mzujz.jpg


Using the Depth Micrometer, measure the height of each bearing above the plate - I take about six measurements around each bearing.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3955_zpsshxkwjbj.jpg


Then measure the depth of the bearing housings in the rear cover - again, I take about six per bearing.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3956_zpsny5tjjka.jpg


All of this is written down and then the shim thickness is calculated for each bearing:

The formula goes . .

(Depth in cover - 0.05mm clearance) - (height above plate + plate thickness + baffle thickness) = Shim thickness.


One then has to assemble a collection of shims to the right value. These come in four nominal sizes - 0.20mm / 0.28mm / 0.38mm / 0.50mm. However there is quite a variation and I spend time mixing & matching until I get the right result to within 0.02mm.

Here, I am looking for 0.95mm for the Output shaft and the shims measure 0.94 - good enough for me .



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3959_zps6jjno24g.jpg

The collection of shims are lightly greased and placed centrally on the bearings - you don't want them moving as the cover is fitted :blast.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3961_zpsh1wby3ef.jpg


I screw four 6mm studs into the back if the case as a guide for the cover. It will be hot and if fumbled causes mayhem with shims falling about the place .


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3965_zpsyoogcte0.jpg



A final check is made of the rear cover to ensure it is flat. If not it will cause problems.



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3963_zpswps0ktwu.jpg



And then the cover is heated with the Propane torch and carefully lowered onto the bearings. It is then tapped down with a rubber mallet and five of the nine set screws are fitted.



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3967_zpswqcbycb3.jpg


The studs are removed and all set screws fitted and torqued-down to 9 lbs/ft.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3969_zpsqtaqeoqm.jpg



When the box has cooled and I am happy that the clearances feel right I fit the three oil seals. First the input shaft splines are masked and the shaft given a light smear of grease.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3970_zps9p75prcr.jpg



I use a long socket of appropriate size to seat the oil seal into the case. The seal is given a light coat of Blue Hylomar to ensure its oil tight around the case.



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3972_zpskbkyyqfn.jpg


Surplus compound is wiped away and that's one done :thumb.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3973_zpsetqay0zg.jpg



Now remove the gear lever and repeat the process with the gear lever shaft oil seal. I used an 18mm socket to seat it.



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3974_zpsqtqrlqak.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3975_zpsf32hunxq.jpg



The gear lever shaft is given a light smear of grease and replaced.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3976_zpsfxgigtlw.jpg



The Output Shaft oil seal is given the same treatment. This is a Monolever bike so the oil seal lips face outwards to let the box breath into the leg (which has oil in it). Paralevers have a different oil seal that is faced inwards as the leg is dry. Paralever boxes breath through the hollow bolt that secures the speedometer cable and battery earth strap.

I use a flat steel disk I turned on the lathe with a 50mm 3/4" drive socket to seat the rear oil seal.



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3977_zpsofgkyfyz.jpg



The output Shaft drive flange is then given a light greasing and fitted to the taper shaft - the taper is kept dry. The nut is torqued down to 161 lbs/ft which is a bit of a heave. I use a long locking bar and a Certified 50-300 lbs/ft 3/4"-drive torque wrench for this.



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3978_zpszogg75kh.jpg



Almost finished now. The Neutral Switch is checked with a Multi-Meter and fitted with a new washer. The Drain Plug is also fitted with a new washer. I cleaned the swarf off the magnet with cloth and a high-pressure air line (don't try this at home kids :rob).



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3980_zpsquf31bmh.jpg



The replacement Speedometer Drive, a new collar and the breather bolt are then fitted (it doesn't strictly need a breather bolt as a plain one would do but it has one so it went back in).



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3982_zpsxen1lxoa.jpg


And that's it - the box is finished . . . .



https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3984_zpsjtzbbxkd.jpg



Now for the clutch . . . . .

......


so thats it, box is done clutch done, bike back together
and a massive parts bill to pay, almost to the price i paid for the bike a couple of years agio
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Just_James]

Nice work on this

That's an awesome ultrasonic cleaner too! Would love one of those!
____________________
Current Bikes / Projects: 1999 Rieju RS1 50
Previous bikes - 1986 DT125R (field bike), 1989 KX250, 1980 KX420 (with 500cc big bore), 1992 YZ250, 1988 KX500, 1989 XR250R, 1988 VFR400R NC24, 1999 Cagiva Mito 125, 2008 Rieju RS2 50 , 1993 Honda NSR 125

[hmmmnz]

Well, where was I . . Oh yes - the clutch.

All the new parts (plus one old one) were laid out:


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3988_zpshrwkrpxo.jpg


I then de-greased and washed the flywheel and housing as well as I could with Industrial cleaner and hot water (DOH, I should have set the camera 'white balance' to "Daylight" :blast).


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3989_zpsikdjzwz5.jpg


I used 'Optimol TA' on the splines and spring contact points before assembly to make sure that everything moves smoothly.

Its just like a car clutch and the friction plate needs to be centred before the cover plate is tightened down. I used a spare Input Shaft with the pushrod pushed through to the diaphragm spring to align everything before the 6 set screws are tightened down evenly to a final torque of 17 lbs/ft.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3991_zpskerh7z9x.jpg


The Input shaft is then withdrawn and the gearbox installed. I had removed the swing arm to make this easier.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3993_zpsmrwjjoqs.jpg


With the gearbox installed (the splines lined-up OK, thankfully) The airbox goes on - this is not a nice job as the two upper bolts are a fiddle. I should have ground a 6mm Allen Key down a bit but decided to just take my time over it.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3994_zpsy4xjhenk.jpg


Notice anything missing . . . Yup, I forgot to put the cross-over fuel pipe in so it all had to come apart . . Bummer :blast.


The clutch operating arm is then installed and set to the requisite 203mm clearance from the cable mounting lug (The BMW Club had long articles in their mag about this :augie ).


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN3995_zpskcgle67p.jpg


I thought I'd better put a new Air Filter in while I was at it :rolleyes:.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4000_zpsacalymqq.jpg


The rear brake stoplight switch looked a bit past its best - but it works :thumb.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4004_zpsv9k3vc2r.jpg


The swing Arm was installed, centred and torqued-down. A new Speedo Cable boot was fitted in place of the hard and cracked one and everything started coming together.

I remembered to fill the gearbox with oil and while I was at it checked and topped up the bevel drive and drive shaft. The engine oil was nice and clean so didn't need touching.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4006_zpsabpwowjj.jpg


Then the rear carrier, tank, seat and silencer (:confused:) were fitted. This involved bad language and a lack of photographs but finally here we are . . . .

The Rat Bike Lives :bounce1 :clap.


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4026_zpsfl4ypeiv.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4029_zpsr3e9gh9o.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4033_zpsemt0rmtp.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4035_zpsgswv40p0.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4034_zps5wt6xsnu.jpg


https://i227.photobucket.com/albums/dd167/Beemerbob/BMW%201987%20R80%20Rat%20Bike%20Gearbox%20Rebuild/DSCN4036_zpskmkgmypb.jpg



so thats it, got the bike back today,
ride home was interesting, would only fire on one except at idle or with the choke on, so i rode home on the choke still managed 65mph with the new higher 5th gear just on choke

clutch is super easy, easier than any of my other bikes in fact,

to do jobs are, unblock main jet, replace all the cables,
balance the carbs, do the valve clearances, tighten the rocker arm end play, replace the indicator relay with a led unit, then start the rear wheel spoked wheel
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[MarJay]

Rub down that tank and re-spray it. It looks awful as a rat, and it has the potential to look so nice.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Pete.]

Good write-up on the guy's rebuild job. I'm surprised that the cluster end-float clearance is just 2 thou. Seems unnecessarily tight to me but if the guy does so many I guess he must know what he's doing.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[chris-red]

Who is this gearbox magician that fixes them for free!?
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[Moxey]

Ah so yours was the exploding Beemer from Stormin a friend was nearby when that happened recall him telling me about it on the night, would never have guessed it was someone from on here.

As for the bike I think it would look a little better if the tank was painted either black or possibly this colour scheme
https://t1.gstatic.com/images?q=tbn:ANd9GcQhvkrQsk9dFYwCJ-u7-EtkXj_TUkd50Z21F-2-1VSVRCGbcrewVg
____________________
Current: 55 FZS 1000S, 02 FZS 1000, 77 CG 125, 04 XR 125 Some Bike Pics...
'I was too busy paying attention to pay attention'