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 Daniel Rintz, Himba children, Namibia

The only impossible journey
is the one
you never begin

Photo by Daniel Rintz,
Himba children, Namibia



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 2 Apr 2009
Registered Users
HUBB regular
 
Join Date: Jan 2008
Location: On the road, u.k - Australia
Posts: 43
Tyre pressures for a FULLY loaded R100gs?

Could anyone let me know what tyre pressures I should be looking to have on my '88 R100gs. Its carrying a pillion, two full 35ltr aluminium boxes, a few tools, tent etc. Not sure of weight exactly but quite a lot! Haynes manual only gives pressures with a pillion (36front 42rear) it doesn't say what to do if you are carrying the equivalent of three or four!
Leave my house tomorrow, leave country in two weeks. Finally!
Reply With Quote
  #2  
Old 2 Apr 2009
Registered Users
Veteran HUBBer
 
Join Date: May 2008
Location: SW France
Posts: 304
What tyres? I should stick with what BMW suggest and see how the bike feels
Reply With Quote
  #3  
Old 2 Apr 2009
John Ferris's Avatar
Gold Member
Veteran HUBBer
 
Join Date: Feb 2001
Location: Reno,NV,USA
Posts: 560
On the side of the tire they have the max load and pressure.
I would not go over that.
In most tires I see that is 42.
Reply With Quote
  #4  
Old 2 Apr 2009
Jake's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Mar 2005
Location: Northumberland, uk
Posts: 761
My r80gs with two up, two large tech panniers stuffed to the max (my missus likes stuff) and a full HPN tank 43 lts we both weigh in total with gear on about 23 stone and I ride front at 36 psi and rear at 42 max I would drop that a bit once on crap roads 32/36 max no real problems so far, I reckon you really need to make sure your rear shock is set up right though. seems to make a huge difference to the handling when loaded up.
Reply With Quote
  #5  
Old 2 Apr 2009
Registered Users
HUBB regular
 
Join Date: Jan 2008
Location: On the road, u.k - Australia
Posts: 43
thanks for responses, I've got Metzler Tourance on. Think I'll stick with what is says for pillion and see how i get along.
Reply With Quote
  #6  
Old 2 Apr 2009
Registered Users
Veteran HUBBer
 
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 317
My R80-100RT weighs about 270kg at summer and 285-290kg something at winter.
I do not carry a passenger (with very few exceptions).

Front 1.9-2.1kg
Rear 2.3-2.4kg I would need to go up to 2.6-2.7kg if I have a 50-60kg passenger and 2.7-2.9 if I have a 90-100kg passenger.

You need to have someone who can read tire-looks under load to check the apperance of the tires under load...
Or - you do as we were taught at driving-school - put the hand on the tire directly after a ride; cold = too high pressure, warm/hot = too low pressure. Should be "handwarm" - 35-45'C or so if I understood it correctly.

It is better that you run with a bit too high than a bit too low pressure!
BMW manual is -not- correct concerning asphalt surface... they state graveroad pressures(!).
Which brings your question to - you will need to adjust the pressure in accordance to the surface you will be running on and the ambient temprature.

Too low pressure => very sensitive to uneven road surface; the bike uses a full lane or more...

Comparison to my VW Type 4.
Supposed to have 2.2kg... must be an aprils fools joke! I use 3.5-3.7 front and 3.3-3.5 rear. Friend of mine had 3.8-4.0kg front and 3.6-3.8 rear when he drove his T4 as a taxi.
It is the same thing with bike tires - you will have to raise the pressure significantly above factory specs.

The pressure affects, damping, tracking, grip, braking power, wear, and mileage. Too cold or too hot => more wear on highway; off road is a compleatly different issue.
__________________
Drive Safely,
Albert
Reply With Quote
  #7  
Old 3 Apr 2009
maria41's Avatar
The franglais-riders
Veteran HUBBer
 
Join Date: Jul 2005
Location: UK
Posts: 1,175
maybe more than recommended by BMW

My old BMW F650GS recommended 31 / 34 when 2 up. Fully loaded (me alone and my panniers) it felt like having flat tyres.

When I replaced my rear shock (in preparation for my trip to south america), I was asked by the workshop to come fully loaded. The mechanic there recommended me to pump up the pressure to 34 / 44. At that pressure the bike felt real good at speed.

You should experiment to see how the bike feel but you with pillion and luggag eyou should give a go beyond BMW recommended pressure.

Cheers,
__________________
Maria

www.franglais-riders.com
Reply With Quote
  #8  
Old 3 Apr 2009
AliBaba's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Apr 2001
Location: Norway
Posts: 1,379
I run 37.5 PSI front and rear all the time unless I will cover long distances in soft sand.
Reply With Quote
  #9  
Old 3 Apr 2009
Contributing Member
Veteran HUBBer
 
Join Date: Aug 2005
Posts: 839
Psi

how much do you runn in soft sand and with wich tires.

Hendi
Reply With Quote
  #10  
Old 4 Apr 2009
AliBaba's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Apr 2001
Location: Norway
Posts: 1,379
Quote:
Originally Posted by HendiKaf View Post
how much do you runn in soft sand and with wich tires.
I’m not a big fan of dropping the pressure so I don’t do it before I get stuck a few times. The pressure is dropped multiple times until it works, I don’t use any gauges for this but I don’t like it when the pressure is below approx 7.5 PSI. 3 PSI has also worked…


Mostly I use Michelin T63 or Pirelli MT21.
Reply With Quote
  #11  
Old 4 Apr 2009
Registered Users
Veteran HUBBer
 
Join Date: May 2008
Location: SW France
Posts: 304
Quote:
Originally Posted by AliBaba View Post
I run 37.5 PSI front and rear all the time unless I will cover long distances in soft sand.
37.5psi (2.5bar) seems very high for an MT21 front tyre. I would have thought that sort of pressure would make the front feel a bit skittish.

The Tourance would probably work better on the road with higher pressures and it will heat up less and therefore wear less but reducing the pressures for off road won't make much difference
Reply With Quote
  #12  
Old 4 Apr 2009
Registered Users
Veteran HUBBer
 
Join Date: Apr 2006
Location: Tallinn, Estonia
Posts: 1,048
Given that my sidecar weighs a lot more than most bikes that might run narrower off road tyres I was looking into all this stuff a while back, to try and widen my choice of tyres with some metric options.

That and the fact that I, too, ran a BMW two up and heavily loaded, athough this was the lardier 1150GS, led to me posting this, so I hope it helps:

I can't comment on the pressure of the tyres regarding the upper limit of normal, other than what is written on the side of the tyre as previously pointed out. However, I will say that, because I did not check my pressures as muh as I should, the weight did make the knobbles on my TKC start to split at their base when the pressure was too low.

The one thing that I will comment on, though, is the weight limit of the tyre, rated by a numerical value. If your bike is as heavy as you claim, I would ride it down to a workshop with scales and measure the whole weight and that over the individual tyres, to be sure that these do not exceed the weight rating of your particular tyre brand.

See what I mean here: in the right hand column.

To give you an idea my rear tyre was supporting about 350kg when we were both on board and fully loaded.
__________________
Adventure: it's an experience, not a style!
(so ride what you like, but ride it somewhere new!)
Reply With Quote
  #13  
Old 4 Apr 2009
AliBaba's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Apr 2001
Location: Norway
Posts: 1,379
Quote:
Originally Posted by Magnon View Post
37.5psi (2.5bar) seems very high for an MT21 front tyre. I would have thought that sort of pressure would make the front feel a bit skittish.
In my experience 2.5 bar is the best pressure for general use and the tire will work well in most conditions.

The problem with MT21 (at least for me) is that the knobs next to the center wears out, this increase with lowered pressure. This is mostly a problem if you brake aggressively (typical driving high speed on forest roads) but for desert and touring use it’s the best tire I’ve used.
MT63 doesn’t have that problem but it lacks a bit of grip, it’s also quieter at high speeds.
Reply With Quote
  #14  
Old 5 Apr 2009
Registered Users
HUBB regular
 
Join Date: Jan 2008
Location: On the road, u.k - Australia
Posts: 43
The weight of the bike unladen is 220kg, we then have a fair bit of luggage (45kg) and two people (140kg) so a total of 405kg. It doesn't look all that bad, not compared to some I've seen, but it does feel heavy and the front can feel a bit skittish. Is this heavy?
Reply With Quote
  #15  
Old 5 Apr 2009
electric_monk's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Aug 2001
Location: Waterford, Ireland
Posts: 309
See if the tyre manufacturer has a website and whether it lists recommended pressures. I know Metezler do.
Bear in mind they are probably the only people who can be sued for misinformation as anyone elses opinion is just that, an opinion. That's not to disparage anyones opinion.
__________________
The electric monk always has faith.
Reply With Quote
Reply


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

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
For Sale: Nissan Patrol fully loaded 8000 euro Bobus Equipping the Overland Vehicle 0 2 Oct 2006 11:42
Fully kitted fully loaded Toyota Land Cruiser HZJ 75 expedition vehicle for sale bnoij Equipping the Overland Vehicle 0 25 Sep 2006 00:33
Tyre pressures Mark Yamaha Tech 9 13 Jun 2005 18:58
Fully loaded Landy 110 for sale in Holland bnoij Equipping the Overland Vehicle 0 17 Sep 2003 05:09

 
 

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

HU Event and other updates on the HUBB Forum "Traveller's Advisories" thread.
ALL Dates subject to change.

2024:

Add yourself to the Updates List for each event!

Questions about an event? Ask here

HUBBUK: info

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...

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 14:55.