My R80 Custom Adventure Bike
 

I will be starting my R80 custom adventure bike soon. I will be posting pictures of my progress and ideas that I have. I hoping to get some tips and feedback along the way. Here is a picture of my frame. It is a monolever frame. It was made in August of 1986 http://s3.amazonaws.com/advrider/icon10.gif. It has a title. Hopefully it is straight!?! $210 Shipped.

I have rented a 10,000 square foot warehouse. It might be a bit overkill for this project but here is where I will be building it.

Warehouse

Alex,
I'll definitely pitch in to help you with this in Philly...maybe we can stick a classic K-bike motor on there!

edde

That's an interesting start you've made and quite a novel idea by attaching a large fan to the bottom of the frame . Will you get enough lift from that to get it to hover and what are you thinking about for forward propulsion ? :thumbup1:

Bike accesories
 

That's a air conditioner for riding in hot climates. It keeps the chocolates from melting.

Here's a few sugestions. Start by tossing the rear sub-frame and build one out of Chro-mo, be sure to gusset and triangulate properly to the main frame. Look closely at how BMW welds attachment points to the tubing and copy it. Re-enforce the frame Ala HPN.Good time to start thinking about a new tripple clamp and some real forks. KTM stuff is a good option. WP 4860 forks are an excellent fork, found on E-Bay sometimes for cheap and easy to customise. Marazzocci 50mm Extreme is also a good bet, but not as plentiful. Make sure you use parts that are common and easy to find. Wish i were there!

Don't screw around, if you plan on spending good money send the damn frame to HPN and have it reinforced. They will provide mounting points for the 43L tank, larger fairings etc. and the sub frame will be redone with new gussets and extra reinforcing. While you do this let them also add the pannier frame kit. I will also consider the option of fitting the long travel forks with lengthened swing arm. All and all you would need about $9500 for this lot that should include the frame mods, WP 48mm forks to fit your G/S front wheel, rear shock and the longer drive shaft. This will also include a new crash bar set modified with longer side stand and the small carrier frame for single seat use.
The only downside to this is that you will have to find something else to do for the next one and a half years as this is how long you will have to wait for them to get your job done.
But time flies and before you know it you will be ready to start assembly of one of the greatest machines ever built

Getting it done by HPN would be awesome but I dont really want to pay the euro. I love working on my bike at every level too. The hardest thing hpn does is change the angle of the headtube. Sending a frame across the seas and to get powercoated and welded and for it to take a long time isnt practical. I think the US has a lot fabricators that can do what I need done. I am still debating whether or not to get all of these upgrades. I need to decide soon so I can continue with my project.

I agree. As awesome as HPN is, what they do is not rocket science. Any good fabricator who is skilled with motorcycles can do the same job for much less. Alex, are you a fabricator, or will you be farming most of the work out?

Do you happen to know what HPN does with the frame? The reinforcement is just a small part of the work.
I seriously doubt that any good fabricator could do the same work for around 1000 Euro, but they can probably make copies of the reinforcement.
Up here all I can get for 1000 euro is that I can rent a welder for less then two days, will he manage to get me a frame with the same quality? I don’t think so; he will probably need at least a week just to build the jigs, after he has figured out how they should be.


Most fabricators will also have problems with tasks like:
-Extend monolever and driveshaft
-Produce extended paralevers
-Hub-production
-How to fit a 140” tire on a monolever and paralever
-Increase power with 50 percent and still have a durable engine
-Design titanium conrods
-Design cranks
-Design camshafts
-Make the smoothest boxer-engines ever produced
….. the list goes on and on.

BTW: it is all tüv-approved.


Most good fabricators will know how to make parts if you give them a drawing or a part they can copy but only a few are able to design something from scratch.
IMHO HPNs advantage is that they have a lot of experience and they have good designers. They have build aprox 700 bikes and sold a lot of parts.
Most companies (even Gletter) that builds airhead-adventure bikes use some HPN-parts


I’m not saying that HPN is the only ones who can modify bikes, and modifying a bike can be really funny (this also goes for a HPN-project).
I have spent a lot of time modifying my own bikes for many years and it has given me much pleasure and I have learned a lot. It’s a nice hobby!

I think a simple head tube reinforcement and a reinforced subrame should do the trick. Most driveshaft shops can extend a driveshaft. I dont know how hardcore i need to get with titanium connector rods. I dont want to build a race bike.

I would like to most of my self. I do lack a lot of tools though. If I get my hands on a welder, i would like to do the reinforcements. There are a few things I i might get farmed out elsewhere like the triple clamps that work with bigger forks. There is someone in Virginia that machines them, and they wont mess around with the tank. Its stuff like that, I dont want to dropping money on R&D.

Hi Alex
The only part of the red and white bike that has been assembled or worked on by HPN was the frame. The rest of the work I have done myself. HPN have supplied most of the parts but then a lot of what was done to this bike is great but not necessary for a traveling bike.
GS frames do crack and brake and from the rally experience HPN accumulated a wealth of knowledge to reinforce the frames at the areas where the are most likely to brake. Besides, after welding the frame is all twisted from the heat and need to be straighten again. HPN uses a special jig for this and it can take an experienced operator some time to get the frame true again.
The money spend on the frame including the shipping is peanuts in comparison with what you are going to spend on this bike, so don't be wise about this. Besides you are playing with your own life because a frame collapsing at 120km/h will not be fun and can cost you more than the approx. $ 4000.00 for the basic adventure frame with no crash bars and pannier frame including shipping from the US and back. (no powder coating as they will send you the frame as is after the changes are made.)

BMW mods
 

Hi guys ,
I did some extensive trip with my old Bemmer and I was curiouos to know if you guys are really sure about spenting that much money on a used bike is wise and well worth it. I always upgraded my bike and easily spent few $1000 dollars doing it but $10000+ on frame work.. is that such a huge diffence?, I am not criticising I am just curious. Regarding using a regular welder to work on transforming your frame ,I will think that may be difficult to find a guys with enough experience and real knowledge to do it right, anyone can weld but I saw pro welder doing HD and I will not trust them on something so different to thier regular work.I once design my own luggage rack and it took me a lot of time and reseach to get the right guy to do the job.

I modified my own ´89 PD for about $7k, plus $4k for the bike. I stripped and re-enforced the frame. Built a Chrome-moly sub-frame and designed a simple but solit pannier system. I also built a custom tripple-clamp for WP 4860 forks, which i had shortened and re-sprung by a pro. I have a 215-21 front whel with oversize spokes built for Ralley laced onto a billet Eagle hub. The bike uses a KTM Hardparts 310mm rotor and a Berringer 4-piston caliper. With a 12mm master cylinder, only 2 fingers will lock up the front wheel! Motor has re-built heads with dual plugs, 32mm carbs. The bike is rock solid and has been tested two-up, easily burns any fuel you put into it and is super re-liable. Compared to my recently purchased, over complicated 12oo gs, this is a better travel bike hands down, which is why i´ve decided to keep it :)
You can see it here: web.mac.com/adventman .
I won´t argue with the quality of HPN, their stuff makes me drool! But i also feel that it may not be necesary for just a travel bike. Depends on your expectations, really.
Just a note: I work as a Special Effects Fabricator in the Vancouver film industry. The stuff i build usually puts the well being of everyone involved into my hands. Failure is never an option! I´m fortunate to have both the tools and the skills to build my own bikes. I don´t mean to say in my previous post that these mods can be done by just anyone. I apolagise for any mis-understanding.
HPN is without a doubt the master in building off-road airheads and should be considered if someone plans on going to the extreme that these bikes are built for. That being said, i read about a guy who recently rode around the world on some kind of scooter thing...to each their own.

You can use a KTM tripple clamp from a 950, you only need a new pin machined to fit the bearings in your headstock. This also makes life much easier, all front-end components become plug and play KTM parts, which are very good IMHO.
...But! I just remembered, you MAY have clearence issues with the fuel tank. This is the problem with the ´89 PD, requiring a custom clamp.. Maybe GS Workshop knows?? Maybe placement of the tank ot the tank itself can be adjusted?

So, true....

Looks like you have a nice bike!

I think the difference is huge, and I think it’s worth it!

Before I did my rebuild I spend a lot of time thinking, I was not sure at all. My bike was really tired and I had to do some serious work, or I could buy a new one… I was not able to find a new bike which I really liked. The closest mach was HP2 but it required a lot of modifications to be a travel bike that suited my needs.

I have friends who weld and talked a lot with them, one of them has made a lot of strange bikes and he could do the job for me.
When I took a closer look on the bike I found that what was really beaten up where parts from different companies (Jesse, Overland solutions ++), the BMW-stuff was pretty good. I was afraid that this job could end up in the same way – rubbish in a few years.

So I started to look for a company that was as good, or better, then BMW and I only found one..

For me the result is stunning. I have performance not far from the HP2, but on a touring bike with a sturdy frame, long range tank, a fairing and it’s even more reliable then the HP2!
It was also a lot cheaper…
What more could I expect?



A few years before the rebuild:
http://www.actiontouring.com/AliBaba_1.jpg


Edit: I did not spend “$10000+ on frame work”

I think it would be very important to not increase the turning radius of the bike. I am wondering if these fork upgrades will do this. The big forks look badass but I dont know how practical they are for everyday riding.

You are right, most forkupgrades increase the turning radius of the bike but I will not say that it affects my daily riding. Being an old trial-rider this was a bit irritating, now I don’t notice it anymore and the way the suspension works makes it worth it – for me.

For example I would like to be able to move my bike in to a tight hostel courtyard or navigating tight single track paths. Maneuverability it at slow speeds. This is going to take some research.

I would say there are better bikes for courtyards but tight paths are not a problem. In fact it is much easier because the bike handles better.

If you are willing to reduce the tanksize then it gets better, and maybe use something like Marzochhi Magnum and not USD.
The HP2 has solved this in a nice way, see how it's done there (shorter tank, moved backwards).

+1 on the Marzzocci Magnums! They are a very stiff fork (50mm) but in the standard configuration. More room around the tank, less to worry about on the bottom. I just wish they were more available :( Say, does the 50mm fork have a 12mm or 22mm axel?? I think this is important to know.
When i built my bike i maintained the stock BMW geometry, including suspention travell. I find it adequate for off road, loaded and even two-up. I would like to build a 12" suspended bike in the future though :)

As far as I know they are not produced anymore but if you can get one parts are still available. The axel is not standard BMW and you have to make an adapter for the brakes. It comes with a variety of triple clamps which likely have to be modified (or you can get a new one).

A friend of mine got two Magnums a few years ago and installed one on a K75 (pics here: http://www.horizonsunlimited.com/hub...0-1200-a-29697 )and one on a G/S. I think he shortened both:
http://www.actiontouring.com/pic/vidargs.jpg

For around $10 000.00 You can modify the frame and add a full HPN pannier set, reinforced with gussets at weak points and a new set of crash bars and side stand modified for the longer forks + WP USD 48mm forks to fit the standard GS front wheel, the rear shock, WP as well and the lengthened drive shaft. and it will include the cost of shipping.
HPN is not so expensive: it is rather the vast amount of good modification available that accumulate to spending lots. If you leave your bike standard and only do the frame and suspension it will provide a solid platform for you to change and renew the rest of the bike over time.
And you should not need to spend more than $ 10 000.00 to do this.
Keep in mind that no other touring bike including the KTM Adventurer is supplied with a suspension that provide 285mm of fork travel.
Examples of costs compared to BMW parts is the front brake disc to fit BMW caliper. HPN - cast steel, mounted floating with new set of pads is about Euro220.00 where as the BMW part in slippery stainless steel without pads is about Euro300.00. Not only is the HPN part cheaper it is also greatly improved.
A new standard fuel tank from BMW will cost almost double the amount of the HPN 43L tank.
A Baja front fender from HPN is about one quarter the price of the BMW front fender in black where you will have to spend more money to have it painted as well.
A Behr front rim in heavy duty for off road racing is 88Euro compared to about 200Euro for the weak BMW Akront rim.
Just some examples to make you think.

Well I dont have a nice front wheel or nice brakes. So would it be better to go with the entire front end that goes with those forks(brakes, wheel, and triple clamps)?

Just using KTM stuff, like 4860's makes things easy, plug and play. If you need to build a new clamp, make sure the fork spacing is identical to the KTM clamp. This saves you the need of Adapters and the sort. Contact Woody's Wheelworks: http://www.woodyswheelworks.com/index.shtml about a wheel. I beleive he may be building Tubeless spoke wheels similar to the BMW stuff for KTM hubs.

Here are some picstures and ideas on what I did to my G/S:

www.nohorizons.net

If you have questions, ask.

Kevin

Cool, I like your exhaust guard. You are the first person I have seen install the enduralast. How is it holding up? Is that the stock electric ignition below it. I have never seen that before.

Well, to continue the project, Someone from brooklyn delivered a bmw r80/7 to me in philly for $840. It was delivered in pieces. It came with a perfect seat, perfect exhaust, perfect front end, new mezlers. I have been cleaning it for a few days. It had terrible compression 90psi in one cylinder and 60 in the other. I dont know why I cant upload large photographs. its 2007, bandwidth shouldnt be an issue anymore, but anyways here is a link to the photographs. Picasa Web Albums - Alexander - Building a BM...

This thread got very interesting. I wonder whether anyone used WP front fork which is called Extreme to modify front end of their airhead. It seems to be very similar to Marzocchi Magnum and it's easier to get. I even have a feeling that I saw an airhead with this fork and KTM triple clamps. Alex, good luck with your project.

I have cleaned the whole engine, there really isnt much more to clean. I think it is about time to open the wallet and start burning the c-notes. I think I am gonna start out with the enduralast alternator and the omega ignition. I like the double redundancy there. I think that is very important in an adventure bike. I think having 2 coils would be nice too.

A friend of mine will probably do this conversion during the winter, he has some leftovers from his KTM-days.. I’m not sure if he will shorten the Extreme or not. He also got the KTM rim but it is crap so I’m not sure if he will fit the BMW-rim.

I talked to John Rayski yesterday and he seems to be very responsive on his emails. He even hooked me up with a person who put an omega ignition on it.

I dont really have a good bmw wheel, it would be nice to find an aftermarket 21" wheel for something else.

If you have hubs, send them to Woody's Wheel works. He did my wheels .. check my site. Best wheels you can get. Not cheap though.

I would just need to get the rim, I know how to wire wheels. I dont know if there needs to be a minimum mass for a hub on certain size rims, I will have to look in to that.

21 inch front Sun rim, 18 inch rear Sun rim .... Works like a charm.

I am in the market for a rear monolever hub also. Anyone have one? I am also looking for a swingarm.

AliBaba, could you please PM me whether KTM triple clamps fit the BMW frame and how this conversion works if your friend decides to do it. I'm really interested in this modification. My main concern is a different offset and steering angle.

no need to pm. I am also very interested in this. I want to start a list of all candidate forks and try to get the plus and minuses for each.

The steering geometry depends on a lot of variables. If you machine the fork so it gets standard BMW-length you will get the same steering angle but the offset depends on the triple clamp and the fork (how/where the rim is mounted).

I will post info if he does the conversion!

OK, wasn't sure if it would fit this thread.

You may find it helpful to look here Welcome to Boxerworks.com

They have a wealth of technical knowhow. also tere are several sources of parts off from it. I have found Motobins to be good. Bt I am extremely lucky, not two miles from me a a BMW guru with a huge workshop and acres of parts.

Forks
 

I've been thinking how to improve the front end of my bike for some time. First I should mention that I intend to rise the hight of the bike. If I didn't want to change the hight I would probably keep the stock R80/100 GS fork and would experiment with springs and internals and oil.
The forks which I was considering in the past were forks off Honda AT or Suzuki DR800Big. But the only advantage of these forks would be their length. I may be wrong though.
The forks I'm thinking about now are Marzocchi Magnum and WP Extreme. They are adjustable, longer and stiffer compared with BMW fork. The thing I'd like to know is whether these forks would work with KTM triple clamps and BMW frame. Apparently they are both the same diameter. Also, would BMW wheel fit?

Okay, the KTM axel will fit through the front hubb of a R100 GS, but a bushing needs to be machined...it can get complacated. Then, if you are using a KTM tripple-clamp, you will have clearance issues with the brake rotor. I went through all this and in the end had a custom wheel built and built a tripple clamp myelf. It was a lot of work. I would sugest using a complete front end and forget about te BMW wheel. Besides, it's worth a lot of money an helps offset the cost of new stuff if you sell it.

I am in favor of a complete new front end. The question is, what triple clamp is the best to adapt to the bmw.

To fit the triple-clamp is the easy part. It’s “only”to adapt the stem and get bearings (and covers) that fits. If you don’t want to do this you can buy bolt-on clamps for the most common forks.

Example, bolt on 50mm from Gletter (original wheel fits):
http://www.gletter.de/usdgobkl.jpg



In my opinion more important factors are.
* Brakes, is it room for the setup you want? (As Mr Ron says)
* Front wheel
* Geometry (esp if you increase the height)
* Can the frame handle it?
* Increased turn radius

I would not underestimate the stress on the frame when you use a longer fork. Personally I think that a straight and solid frame is very important:
http://www.gletter.de/rabruch4.jpg



I think the BMW cross spoked wheels are a good option. They also leave more room for the brakes.
The Brembo-hub used for the GS-models (don’t know for the G/S) is a very stable unit with huge bearings. My bearings were as new after 180kkm. The KTM (and many others) wear out much faster. Most KTM rims are not sturdy enough for a big powerful GS.

The geometry is harder to solve. Some people prefer to fit a longer fork and see what kind of modifications that has to be done to make it work. Other people calculate everything before they start. Both groups have failed and both groups have made nice bikes. Maybe it depends on the type of skills you have.
There are numerous started projects that never got finished. :crying:

After all the front is the easy part, it’s harder to make the rear end match :devil:

http://www.gletter.de/rabruch4.jpg

I have seen this picture around the internet. It looks like the rider hit something head on with this frame.

I don't think so. It looks more like the forces have tryed to rip of the front in forward direction. It could be after a bad wheelie or a jump - with a longer fork.

Edit: You notice that the frame is upside down?

Thanks for that explanation - so the opening of the cracks is initiated from the bottom edges of the frame members; I agree, it looks like the force applied has "rotated" the frame members upward & around the headstock - a big, overweight rider maybe? :rolleyes2: :rolleyes2: :rolleyes2:

ha, no i did not notice that.

Wow! Excellent guys! Lots to learn on this thread.

Does anybody know what the advantage of a r100gs and r80gs swingarm over a regular swing arm, The regular swing arm mounts on the final drive.

I am still looking in to the forks. I think I am gonna go with the honda cr500 fork. Is there any other USD forks out there that I should consider?

Also, anybody know how to compress the spring in the driveshaft to take it apart?

If the bike was an original G/S you will not be able to fit the Paralever swing arm of the R100 80GS. You can do the other way round.
The main advantage of the Paralever is that it prevents the rising of the rear when accelerating and dipping as you brake.
The main advantage of the fixed arm is it's simplicity and durability.

To undo the spring I use a bearing puller and extent the bolts by replacing them with threaded rod cut to the right length.
An interesting fact about the HPN extended swing arm and shaft is that they use the older 70's shaft extended by 100mm with a piece added by friction welding. This shaft does not have a spring and the splined knuckle on the rear fit direct to the shaft( less parts to wear and possibly brake.) and the extended swing arm is machined on the inside to be large enough for the shaft to fit through the swing arm without having to disassemble the shaft.

Well my project is coming along, I sold most of the extra parts from my bike. I just picked up a new brand new r80 4 bolt monolever finaldrive, I will be machining a r100gs hub to use with it, i will be using a tubed rim. I also got the gasket kit to rebuild the engine. I got the enduralast alternator. Should be fun to install. I got a subframe, tank, seat, new oilfilter and k&n airfilter. Should have some pics soon. Oh yeah, just picked up a pair of KTM WP 4860 suspension from a 450sx, hopefully i wont have to tinker with the springs or valving to much. Pics to come soon. I am traveling in europe right now and I still cant get away from my little project I have going.

I want to use the ktm front end, are you mentioning the ktm rims from the smaller bikes or all of them? The 990 seems to be a big bike, i think that wheel should be fine on a bmw. what do you guys think?

r-dub over at adv rider recently had a number of custom triple clamps machined to adapt KTM USD (and conventional) forks to R80G/S's... you might ping him or search for his threads in the "old school" forum that tracks his developement. One thing that hasn't been mentioned (unless I missed it) was the huge difference in offset from BMW to KTM, I believe my R100GS has 36mm's and the largest you can find for a KTM is 20mm.

Great Project!

I think I am going to go with the 20mm offset. I have some pics, I need to upload em though. I am trying to figure out the spacing between the ktm bikes, like how interchangeable are all the wheels?

20mm offset sounds about right, I can check tomorrow...

http://lh3.google.com/Alexander.Rosc...JPG?imgmax=512

http://lh5.google.com/Alexander.Rosc...JPG?imgmax=512

http://lh6.google.com/Alexander.Rosc...JPG?imgmax=512

http://lh4.google.com/Alexander.Rosc...JPG?imgmax=512

http://lh6.google.com/Alexander.Rosc...JPG?imgmax=512

http://lh4.google.com/Alexander.Rosc...JPG?imgmax=512

http://lh5.google.com/Alexander.Rosc...JPG?imgmax=512

DR Forks
 

I've seen you and Solo on ADVrider. Here's my solution to the front forks. It has gone very smoothly. All I have left to do is rig up some steering stops and smooth sailing from then on. Last night we milled the spacer, and everything fits great. No changes whatsoever in the bike's geometry.

An Unholy Union: DR forks on a G/S - ADVrider


I'd appreciate any suggestions you might have as well.

Good luck on your project. Looks like a lot of fun!

Here are some picstures and ideas on what I did to my G/S:

If you have questions, ask away

What ever happened to this project?

A buddy of mine is looking at adventurizing his R80 and I was going to send him some links.

Cheers