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 24 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2002
Location: Wessex, UK
Posts: 2,136
Higher 5th gear for airhead gearbox

I am thinking about fitting a higher 5th gear in my R80GS, does anybody have experience of this, who makes them and anything to avoid when buying and fitting?
Reply With Quote
  #2  
Old 24 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Jan 2009
Location: Bassett, Nebraska
Posts: 276
It has been years since I rebuilt my own transmissions on older airheads. So I was curious to see if Motobins was still in business and found this post:

Motobins parts quality - ADVrider

I am too cheap to pay for a higher 5th or lower 1st, and limited my rebuilding to new bearings and seals, shifter pawl springs and Kbike metal shifter roller wheel to replace the plastic one used in airheads. However reading the above post, I would use the Kaiser 5th with superior heat treating since it sounds like a superior part. Not sure I could bring myself to open up a perfectly good transmission just to replace 5th if there is nothing on the magnetic drain plug indicating imminent bearing failure though. But that's just me.

Labor is the main cost of rebuilding a transmission which is why I did the work myself and spent my money on parts. I ordered from Motobins and had good luck. It's not rocket science and there is plenty of useful information on the internet to aid the home mechanic.

Cheers,
John Downs
__________________
South America and back on a 250 Super Sherpa Minimalist Adventure http://advrider.com/forums/showthread.php?t=831076
Reply With Quote
  #3  
Old 24 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2002
Location: Wessex, UK
Posts: 2,136
Thanks for that John, it sounds like the Kaiser is the gear to go for and I have no problem with paying extra for quality, has anybody fitted one of these and done a lot, as in 50,000 plus miles?
My dilemma is I am planning a trip across central Asia next year with a gearbox which is working fine but has done 160,000 miles without being touched. I know the rule if it ain't broke don't fix it but think it must be running on borrowed time now and rebuilding it at home will be easier than in the middle of Kazakhstan, alternatively I could just fit the gearbox from my G/S which has only done 40,000 miles since a rebuild.
Reply With Quote
  #4  
Old 24 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Jan 2009
Location: Bassett, Nebraska
Posts: 276
Or just take the G/S and avoid high mileage GS trans and paralever potential problems. Not sure why you feel the need for higher 5th traveling through the Stans. Unless you have chronic airhead syndrome and love fettling. :-) I know I used to have it pretty bad. There is no cure.

But in all seriousness, 160K miles is very good for a paralever GS trans. I am a little jealous. I agree with you, better to rebuild at home with new bearings and seals and higher 5th. I was able to borrow trans tools from mates. Mainly flange puller and measuring plate for determining bearing shims. I have more time than money and like puzzles so it was satisfying work.

Cheers,
John Downs
__________________
South America and back on a 250 Super Sherpa Minimalist Adventure http://advrider.com/forums/showthread.php?t=831076
Reply With Quote
  #5  
Old 24 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2002
Location: Wessex, UK
Posts: 2,136
Quote:
Originally Posted by John Downs View Post
Or just take the G/S and avoid high mileage GS trans and paralever potential problems. Not sure why you feel the need for higher 5th traveling through the Stans. Unless you have chronic airhead syndrome and love fettling. :-) I know I used to have it pretty bad. There is no cure.
I have used both for travelling and prefer the GS with its longer, more comfortable seat and better front end. The G/S is even higher mileage and needs money spent on it before embarking on a longer trip with it.

Your diagnosis is correct with the syndrome and it is not just for the Stans but for everyday use I would prefer slightly higher gearing for more relaxed cruising and a couple more mpg.
Reply With Quote
  #6  
Old 24 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Jan 2009
Location: Bassett, Nebraska
Posts: 276
Okay then. I never like to sink money into a high mileage bike I am taking on a long journey other than the usual tires, battery, tune up, grease bearings, new clutch cable and throttle cables that sort of thing. I would probably put the G/S trans in and spend my money on gas and kebabs. Rebuild the GS trans with taller 5th if you make it back without getting run over by a crazy Kazak. But that's just me.

Please note: justifying spending big bucks on higher 5th for a GS to get better fuel mileage and slightly higher cruising speed is a sign you have the chronic syndrome in it's advanced stages. There is no hope for you my friend. Just kidding.

Safe travels.

Kindest regards,
John Downs
__________________
South America and back on a 250 Super Sherpa Minimalist Adventure http://advrider.com/forums/showthread.php?t=831076
Reply With Quote
  #7  
Old 25 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2006
Posts: 1,598
I lowered the gearing on my Enfield, the PO had fitted a 19 tooth sprocket in place of the original 18. It felt like I was going uphill all the time and I spent a lot of time changing gear and in fourth. when I fitted the 18 tooth sprocket the bike was much more tractable and will now accelerate ( within reason) up inclines whereas before it always involved a gear change. better than that I now make faster times over the ground and the MPG remained at 95. So unless you spend a lot of time on motorways think carefully before raising the gearing.
Reply With Quote
  #8  
Old 25 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: May 2008
Location: SW France
Posts: 304
Quote:
Originally Posted by oldbmw View Post
I lowered the gearing on my Enfield, the PO had fitted a 19 tooth sprocket in place of the original 18. It felt like I was going uphill all the time and I spent a lot of time changing gear and in fourth. when I fitted the 18 tooth sprocket the bike was much more tractable and will now accelerate ( within reason) up inclines whereas before it always involved a gear change. better than that I now make faster times over the ground and the MPG remained at 95. So unless you spend a lot of time on motorways think carefully before raising the gearing.
The airhead does have the advantage of one more gear which can be treated as a cruising gear and may not come into use at all when using back roads. Airheads are a bit thirsty and upping 5th gear for those longer stretches on good roads will certainly help the fuel economy.

I agree with the other point that taking a box apart just to fit the tall gear is perhaps tempting fate but then setting off with a box with with 160k on it is unlikely to end well.

Depending on how experienced you are with the GS gearbox (and if you have the special tools) I would either rebuild it and fit the higher gear or get it done professionally.
Reply With Quote
  #9  
Old 25 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2002
Location: Wessex, UK
Posts: 2,136
Quote:
Originally Posted by oldbmw View Post
I lowered the gearing on my Enfield, the PO had fitted a 19 tooth sprocket in place of the original 18. It felt like I was going uphill all the time and I spent a lot of time changing gear and in fourth. when I fitted the 18 tooth sprocket the bike was much more tractable and will now accelerate ( within reason) up inclines whereas before it always involved a gear change. better than that I now make faster times over the ground and the MPG remained at 95. So unless you spend a lot of time on motorways think carefully before raising the gearing.
The airhead GS is already lower geared than the G/S which is lower geared than the standard R80 so there is little risk of overgearing. In the end it might just come down to cost, I would prefer to spend my money on petrol and visas rather than parts for the bike and might just settle for a new set of bearings and seals, something I would do myself having rebuilt one in the past.
Reply With Quote
  #10  
Old 26 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2006
Posts: 1,598
Quote:
Originally Posted by Magnon View Post
The airhead does have the advantage of one more gear which can be treated as a cruising gear and may not come into use at all when using back roads. Airheads are a bit thirsty and upping 5th gear for those longer stretches on good roads will certainly help the fuel economy.

I agree with the other point that taking a box apart just to fit the tall gear is perhaps tempting fate but then setting off with a box with with 160k on it is unlikely to end well.

Depending on how experienced you are with the GS gearbox (and if you have the special tools) I would either rebuild it and fit the higher gear or get it done professionally.
My Enfield has five gears same as my old bmw.
Reply With Quote
  #11  
Old 26 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: May 2008
Location: SW France
Posts: 304
Quote:
Originally Posted by oldbmw View Post
My Enfield has five gears same as my old bmw.
There you go, what do I know and I should have read your comment properly.

That said, neither my R80G/S or R100GS are overgeared in 5th but I can only guess at how they would pull a higher gear. The 80 might struggle at motorway speed into a headwind.
Reply With Quote
  #12  
Old 27 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2006
Posts: 1,598
Quote:
Originally Posted by Magnon View Post
There you go, what do I know and I should have read your comment properly.

That said, neither my R80G/S or R100GS are overgeared in 5th but I can only guess at how they would pull a higher gear. The 80 might struggle at motorway speed into a headwind.
I know it is not what you might first expect, but despite the Enfields cruising speed being reduced by 3% with one tooth less. I make significantly faster times over the ground. Partly because it will climb slopes easily now and forge against headwinds without the need for gear changing. It has not reduced my MPG at all. After all mpg is mostly a result of cylinder pressure versus the gearing and resistance. If you raise the gearing you will need to raise the throttle openings.
However the BMW motor I had changed mpg significantly with throttle openings and revs. for instance twice when I managed well in excess of 57mpg, once was following a friend on a diesel Enfield, the other was poodling about all day in the pyrenean mountains ( a surprise) because of being on the over run coming down the mountains.
normally it hovered around 50mpg. The Enfield does over 95
Reply With Quote
  #13  
Old 27 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: May 2008
Location: SW France
Posts: 304
I agree that upping 5th gear on an unfaired 80 could result in worse fuel consumption due to larger throttle openings required to maintain crusing speed into headwinds or incline.

I think it would be an improvement on a 100 which has a much flatter torque spread - you don't have to rev the nuts off it to make progress!
Reply With Quote
  #14  
Old 28 Sep 2012
Registered Users
Veteran HUBBer
 
Join Date: Feb 2006
Posts: 1,598
My bmw was a 1985 R80RT.

bike was ok, but not for me. just too awkward, too heavy and too tall. and the gearchange was on the wrong side
Reply With Quote
  #15  
Old 30 Sep 2012
Registered Users
New on the HUBB
 
Join Date: Sep 2012
Posts: 2
I have a higher 5th and lower 1st fitted to my R100GS & R100GSPD, both very useful, widely available from most aftermarket BMW parts dealers. Had both boxes rebuilt at the time of fitting.
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
XT 600 Gearbox new or old version? 2499 Yamaha Tech 5 3 Sep 2012 23:46

 
 

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 22:16.