hmmmnz

bmw R80 scrambler project

33 posts in this topic

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

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

IMAG1050Medium_zps7f468747.jpg

IMAG1048Medium_zps3782fefe.jpg

 

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

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)

 

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

143A_1-1975-Honda-CL360.jpg

or 2-1 like this

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

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

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 :(   :D

 

 

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Sharp looking bike mate !!!

Ticks all the boxes !!

Looking forward to the changes

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Nice bike man.

Single sided swing arms never seem to be used off road. I wonder if there are strength issues.

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Im sure they be alright. Alot of the Rseries dual sports are single side.

I think the shear weight of a boxer bmw would slow you down enough so you couldnt get close to pushing the strength of the swingarm

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Yeah can confirm that the newer bmw single swing arm bikes at least can be hammered off road. They even make 'adventure' models with extended tanks and such for such bashing.

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That black one looks amazing aye. Just needs a sump guard. I wish I could convince the wife that I need a bike

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you do need a bike, every one needs one, for cheap commuter duties if nothing else,

 

mono lever swing arms are probably the strongest of all the single sided swing arms that bmw have used,

quite often guys with the newer paralever  swing arms will change them out for the mono's , also the monos are filled with oil, where the paralevers are dry, so you tend to fuck shafts every 40k miles or so, essentially they are consumable parts on the paralever bikes,

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ok a bit of a pictureless update,

well got the wheel machined,  sweet i think,....

nope, just because its been done before doesnt mean its the best way  :D

basically the hub fits perfectly, but the side effect to that is that the rim hits the swingarm,

what i didnt read is that the rim has to be laced with an off set, and there is basically only 1 place in the world that is willing to and has success of doing this with bmw cross laced rims,  woodys wheel works in the states, which would mean sending the wheel over

50 quid,  getting them to do the work 250 quid,  new spokes 50 quid, postage back 50 quid,  and if i wanted a 18" rim on instead of te 17" thats another 100 quid

so 500 quid total!!!!   hmmmm thats almost the price i paid for the bike, so just isnt going to happen,

 

my new plan is space the shoes out and make a filler for the gap, 

im not sure why this hasnt been done before,??

i cant really see a problem with it,   i guess people just follow some one elses example and go from there,

im just pissed that i machined the hub, with out fully thinking things through,   atleast i can machine a spacer to bring it back to standard so not all is lost

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Whats the difference betwen BMW and other motorcycle rims?

 

Having an offset hub is fairly normal on pushbike rims so is not exactly a special art.

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Dude, just use a spoke length calculator and you will be sweet. Just make sure you use one that does offsets.

 

Nice project BTW.

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bmw uses cross laced rims,  basically the spokes go to the outside of the rim, not the center like a traditional rim, is so you can have a tubeless tire on,

bmw x lace rims

xlacediagram.jpgGS%20spoke%20wheel.jpg

traditionaly laced rim

0000-Drag-Specialties-Twisted-Chrome-Spo

 

the bmw rims are notoriously hard to even lace as standard, let alone with an off set,  no one in the uk was willing to try it, and i only found 2 guys who would lace a bmw xlace rim

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Surely you could do it yourself? a couple of nights fucking around to get the spoke lengths right has got to be worth it, especially seeings as the alternative is 500 squids....

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ive tryed before just to re-lace one, and failed badly, they just dont lace the same, even got a couple of bike shops in taupo to try and they couldnt do it, ended sending it over to a guy in the uk to do, (bmw dont fix, they try and get you to buy a new complete wheel)

ive tryed to get him to do this rim, but he won't do it with an off set,

 

best option/cheapest, is just to get the hub back to standard, and then make a spacer for the brake shoes to fit the hub and then fill the 20mm gap that it will leave,

shouldnt be too hard,

and if i ever dent or fuck the rim, i wont have to pay again for it to be laced offset

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Fair enough, it sounds like you have done enough research to know you aren't getting tupped.

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My next question is why use a BMW rim? why not lace it to a std style motorcycle rim?

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its been done before as well, but the problem being is the angle of the spokes from the hub, when you lace them to the center it ends up bending the spokes, because the amount of spoke that is set into the hub part,

 

ill drop off my hub to be "un-machined" which will impress my machinist no end :D

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right long time no reply,

well havn't done a huge amount,

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

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:

IMAG1298Medium_zps4403082a.jpg

IMAG1299Medium_zpsc9c5c967.jpg

IMAG1300Medium_zps016a9718.jpg

 

 

 

video

 

 

yeah, thats all for now, front end next

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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 :D (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

IMAG1303Medium_zps88c4405f.jpg

IMAG1304Medium_zpsb17a6481.jpg

IMAG1305Medium_zps457f70d5.jpg

IMAG1306Medium_zpse05cb272.jpg

my headlight brackets are just 2 exhaust clamps per side and a steel plate
IMAG1307Medium_zps7c0dd0df.jpg

clocks, almost the same outlook :D
IMAG1308Medium_zpsb11e9279.jpg


next is either seat and rear subframe or rear wheel
 

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ok been a while,

finally got my seat and subframe done and fitted

IMG_20140704_215357Medium_zps1674e79d.jp

 

IMG_20140704_215405Medium_zps1db63af6.jp

like the copper cable exhaust hanger :D

IMG_20140704_215440Medium_zps28e982eb.jp

the subframe goes inside the shock instead of around the out side

IMG_20140704_215423Medium_zpsf682382e.jp

 

tail light is still original, untill the new one turns up

exhaust needs to be re-done

new gel battery needs to be fitted in a hidden location

33/11 ratio bevel box needs to be found so i can fit the 17" rear spoked rim,

longer rear shock needed

 

of all the bikes i have, its my commuter weapon of choice :D  got a 6 week euro trip planned as well, so the beemer will be doing that as well,

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update, for shits and giggles,
after fitting a new subframe and seat,

i decided to rub 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



excuse my niece and nephew.

10592746_10152256609241606_7384337456128

umm since that pic, 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

10606207_571245656321181_758009000527680

10628025_10152629222781224_8929361546526

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,

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