Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > BMW Tech
BMW Tech BMW Tech Forum - For Questions specific and of interest to BMW riders only.
Photo by Andy Miller, UK, Taking a rest, Jokulsarlon, Iceland

I haven't been everywhere...
but it's on my list!


Photo by Andy Miller, UK,
Taking a rest,
Jokulsarlon, Iceland



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 31 Jul 2004
Contributing Member
Veteran HUBBer
 
Join Date: Aug 2001
Location: B.C. Canada
Posts: 209
Front brake Options for 1983 R80G/S

Has anyone fitted late model 4piston sportbike brakes (nissin,tokico,etc) to the front of an 81-84 r80g/s...

Prices start at $900 U.S. and up for new caliper and rotor that still have to be machined to fit...seems a bit much. Thought some used sportbike brakes might be more practical. Cheers, Peter
Reply With Quote
  #2  
Old 31 Jul 2004
Grant Johnson's Avatar
HU Founder
Veteran HUBBer
 
Join Date: Dec 1997
Location: BC Canada
Posts: 7,313
Cameron, Timo and I were just looking at sport bike calipers for our R100GS front ends, and the R80G/S is actually easier to mount a sport bike caliper on. Basically find something that looks about right, get a big disk off a sportbike, machine an adapter for the disk to wheel, and make a plate to mount the caliper on.

I had a 4 piston Performance Machine caliper on my G/S forks, worked well. Easy install.

You will have to change the master cylinder as well. 14 mm works perfectly on my 6 piston caliper, probably good on most 4 piston as well.

I just happen to have a Tokico six piston laying around...

Note that it's 81-87 G/S then GS and a different front end.

------------------
Grant Johnson

Seek, and ye shall find.

------------------------

One world, Two wheels.
www.HorizonsUnlimited.com
__________________
Grant Johnson
Seek, and ye shall find.

------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com
Reply With Quote
  #3  
Old 31 Jul 2004
Grant Johnson's Avatar
HU Founder
Veteran HUBBer
 
Join Date: Dec 1997
Location: BC Canada
Posts: 7,313
btw, I have a spare 15mm master cylinder which I had on the PM 4 piston brake you're welcome to borrow to try.

------------------
Grant Johnson

Seek, and ye shall find.

------------------------

One world, Two wheels.
www.HorizonsUnlimited.com
__________________
Grant Johnson
Seek, and ye shall find.

------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com
Reply With Quote
  #4  
Old 31 Jul 2004
Mr. Ron's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Oct 2003
Location: Vancouver, BC, for now...
Posts: 792
Hello.
This topic has been brought-up a few times now and there's some great info in the hub. I thought i might mention, if you go with a sport-bike type calliper, you will most likely need the left one. This may sound odd at first, but remember the calipers on sport-bikes are mounted behind the fork. Yours will be mounted ahead of the fork. If you take the left caliper and swing it 180 degrees you can easily mount it on the right side ahead of your fork. i purchased a left front caliper from a 2001 Yamaha R1 and will be mounting it in the near future. Do a search and you'll come up with some great info
Good luck!!
Reply With Quote
  #5  
Old 31 Jul 2004
Grant Johnson's Avatar
HU Founder
Veteran HUBBer
 
Join Date: Dec 1997
Location: BC Canada
Posts: 7,313
Sorry Ron - on the G/S - the caliper is behind the leg, so Cameron needs a regular right hand caliper.

The G/S has a completely different front end to the GS.

Note on yours, (a GS with no /) if the pistons are different in size front to rear (called a differential caliper) then you will be running the differential backwards and you will get significant uneven pad wear - depending on how much difference there is in the bore size of the pistons.

The purpose of the differential is to even out pad wear - if you mount it backwards...

------------------
Grant Johnson

Seek, and ye shall find.

------------------------

One world, Two wheels.
www.HorizonsUnlimited.com


[This message has been edited by Grant Johnson (edited 31 July 2004).]
__________________
Grant Johnson
Seek, and ye shall find.

------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com
Reply With Quote
  #6  
Old 1 Aug 2004
Mr. Ron's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Oct 2003
Location: Vancouver, BC, for now...
Posts: 792
OOPS!
Thanx for pointing that out Grant. I'll have to do more research before offering advice. I see your point with the diferential caliper, fortunately my pistons are all the same size so this shouldn't be a problem.
Thanx and good luck!
Reply With Quote
  #7  
Old 2 Aug 2004
Gold Member
Veteran HUBBer
 
Join Date: Mar 2001
Location: British Columbia
Posts: 246
Mr Ron,

Are you certain that your R1 caliper is evenly sized? I have looked at quite a few and all the 4 piston calipers that I have seen are differential. You have to measure the pistons carefully, as often the outside housing is the same size, but bored to different diameter inside (i.e. 32mm/34mm). I was planning the same thing, but have gone back to the stock 48mm twin piston Brembo for lack of options (modern convention is to mount behind the legs, making our R100 forks unique). I think perhaps that the answer is to be found in a larger rotor and perhaps more aggressive pads.

Interesting to note, when I was looking into the various sizes of calipers (measuring piston surface area only) the 48mm was larger then the 4 piston Nissin, which was larger then the 6 piston Tokico! Of course, the pad length and surface area was greater for the muli-piston calipers, but mechanical leverage was similar.

Hopefully done the mounting tomorrow - I'll let you know how it works in a few weeks when the new Master cylinder arrives.
Reply With Quote
  #8  
Old 2 Aug 2004
Contributing Member
Veteran HUBBer
 
Join Date: Aug 2001
Location: B.C. Canada
Posts: 209
Thanks Guys, I knew Grant had a few different brake setups on his bike. Those PM calipers are very nice and also expensive...
Thanks also for the info about differential brakes, I did not reailize that the pots could be different sizes.
I would like to try a 4 piston caliper first, for size and weight reasons.
Have also been told that the old Harley guys used to cut the mounting flanges off the fork leg and tig weld them back on where needed to fit different calipers...

The next step is to get to the wreckers and see what might fit...Cheers, Peter
Reply With Quote
  #9  
Old 2 Aug 2004
Grant Johnson's Avatar
HU Founder
Veteran HUBBer
 
Join Date: Dec 1997
Location: BC Canada
Posts: 7,313
Cutting and rewelding the mounting was probably ok on the old Harleys - in the days when the fork leg was a half inch thick, perhaps even steel - on modern super thin alloy legs a rock hit can total the leg. I'd expect severe problems with welding to a modern leg (even ones as relatively non- modern as the R100GS)

Feel free to try and let me know how it goes.

------------------
Grant Johnson

Seek, and ye shall find.

------------------------

One world, Two wheels.
www.HorizonsUnlimited.com
__________________
Grant Johnson
Seek, and ye shall find.

------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com
Reply With Quote
  #10  
Old 3 Aug 2004
nb nb is offline
Registered Users
HUBB regular
 
Join Date: Apr 2004
Location: Rosario. Santa Fe, Argentina
Posts: 19
Hi Ron,

An interesting alternative is to put a left caliper with a new/usable disk. I used a left Brembo caliper from a 1981 police R80 bike with a R60/7 disk. I've to put a suplement in the wheel hub, because the disk worked with an old Brembo or ATE caliper (I can't remember).
The twins disks works perfectly, real cheaper modification and a real noticiable brake power increase.

Saludos desde Argentina.
Nicolas.
Reply With Quote
  #11  
Old 3 Aug 2004
nb nb is offline
Registered Users
HUBB regular
 
Join Date: Apr 2004
Location: Rosario. Santa Fe, Argentina
Posts: 19
sorry, I forgot one thing: I change the master cilinder to 16mm.

saludos.
nicolas
Reply With Quote
  #12  
Old 22 Sep 2004
Gold Member
Veteran HUBBer
 
Join Date: Mar 2001
Location: British Columbia
Posts: 246
Having just completed attaching a 320mm GSXR rotor onto my R100GS forks, I would say that the stock caliper is just fine in this configuration - no need to also mount a 4 or 6 piston caliper. I think it is easier to achieve better braking with a larger rotor then with more pad area. At first glance, it seems easy to just bolt on a different caliper. However, what you gain in length, you will lose some in width of the pad anyway as most multi-piston calipers as designed for a narrower running surface.

The 48mm brembo caliper I have on my GS front end is cutting into the rotor stems almost to the bobbins, as it was designed for a larger rotor surface area. Going the other way (say - 6 piston caliper on stock rotor) will likely mean you are not using all of the surface area of the rotor.

Lots to measure and think about!

[This message has been edited by Timo (edited 21 September 2004).]
Reply With Quote
  #13  
Old 26 Sep 2004
Mr. Ron's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Oct 2003
Location: Vancouver, BC, for now...
Posts: 792
Hello. I've noticed on E-Bay Tokico 6-piston Calipers from GSX-R 1000-1300 bikes are selling cheap! The last one, a lefty, for $68USD. I'm not sure but they apear to NOT be diferential calipers, unlike the R-1 caliper i purchased earlier Anyone out there know for sure?
Reply With Quote
  #14  
Old 27 Sep 2004
Gold Member
Veteran HUBBer
 
Join Date: Mar 2001
Location: British Columbia
Posts: 246
A quick phone call/ visit to your local Japanese parts house should reveal the answer to that one. Inquire about a caliper rebuild kit for the bike in question, and it should note different piston sizes. I'd be very surprised if it is not differential, but hey, you don't know til you research. I think stock parts off of modern sportbikes tend to be cheap, as lots of owners are 'upgrading' to keep their bike current in the performance world.
Reply With Quote
  #15  
Old 27 Sep 2004
Mr. Ron's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Oct 2003
Location: Vancouver, BC, for now...
Posts: 792
Hello. Good point...these types of bikes also have a very high crash rate compared to others, lots of parts available. So Timo, could you explain how you mated the GSX-R rotor to the carrier. Maybe a photo, could save a lot of typing. Your idea seems like the most logical aproach, after all i'm guessing in most places it would be easier to find parts from a modern Japanese racebike than an old airhead GS!
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now
, and add your information if we didn't find you.

Next HU Eventscalendar

ALL Dates subject to change.

2025 Confirmed Events:

  • Virginia: April 24-27 2025
  • Queensland is back! May 2-4 2025
  • Germany Summer: May 29-June 1 2025
  • CanWest: July 10-13 2025
  • Switzerland: Date TBC
  • Ecuador: Date TBC
  • Romania: Date TBC
  • Austria: Sept. 11-14
  • California: September 18-21
  • France: September 19-21 2025
  • Germany Autumn: Oct 30-Nov 2 2025

Add yourself to the Updates List for each event!

Questions about an event? Ask here

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

Adventurous Bikers – We've got all your Hygiene & Protection needs SORTED! Powdered Hair & Body Wash, Moisturising Cream Insect Repellent, and Moisturising Cream Sunscreen SPF50. ESSENTIAL | CONVENIENT | FUNCTIONAL.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook

"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.




All times are GMT +1. The time now is 12:36.