Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Yamaha Tech
Boing boing: fork springs? Boing boing: fork springs?
Register FAQ Calendar Today's Posts
Yamaha Tech Originally the Yamaha XT600 Tech Forum, due to demand it now includes all Yamaha's technical / mechanical / repair / preparation questions.
Photo by Marc Gibaud, Clouds on Tres Cerros and Mount Fitzroy, Argentinian Patagonia

25 years of HU Events


Destination ANYWHERE...
Adventure EVERYWHERE!




Photo by Marc Gibaud,
Clouds on Tres Cerros and
Mount Fitzroy, Argentinian Patagonia



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 25 Aug 2010
Registered Users
HUBB regular
  
Join Date: Aug 2007
Location: Nice, France
Posts: 85
It felt the same on the last set of tyres (Michelin Desert) as well as the new Siracs that are on there now. Its true there aren't any balancing weights on the wheel, though. I'll pull it off and check the balance.
Reply With Quote
  #2  
Old 25 Aug 2010
Registered Users
Veteran HUBBer
  
Join Date: Apr 2003
Location: Manchester UK
Posts: 235
This is not a spring issue. An out of balance wheel would have a much higher frequency at the speeds you indicate. Firstly I would look at the teflon ring on your damper rod and the inner surface of the stanchion for wear. In fact just replace the ring regardless. Next step would be to increace the fork spring oil wt to the next level. i.e. if the bike has 10wt oil in, try 15 wt. This will increace the damping properties.
Reply With Quote
  #3  
Old 25 Aug 2010
Registered Users
HUBB regular
  
Join Date: Aug 2007
Location: Nice, France
Posts: 85
Quote:
Next step would be to increace the fork spring oil wt to the next level. i.e. if the bike has 10wt oil in, try 15 wt. This will increace the damping properties.
Yep - I tried exactly that when I changed the fork oil (motivated mostly by wanting to beef up the handling a bit for my largely on-road existence these days): no difference. Didn't think to look at the teflon ring though, damn. Time to get mucky again, then ...
Reply With Quote
  #4  
Old 25 Aug 2010
Registered Users
Veteran HUBBer
  
Join Date: Apr 2003
Location: Manchester UK
Posts: 235
When stripping look for evidence that the oil hasn't been foaming. (i.e. cloudy) If it is it may be indicative that service parts are wearing down.


It might be worthwhile to note here incase this is a new aquisition of yours that the more leggy of the XT's do get a bit like a ship at sea when at high speeds on a motorway. My Tenere would do 85 mph over single track bumpy minor backroads and be solid as a rock while sports bikers were having their martini shaken and not stirred at half that speed. 85 mph on the motorway and every little bit of turbulance or miniscule undulation in the road and I'd start feeling distinctly naseus and wishing I had bicycle clips on to hide the evidence that I was bricking it.
Reply With Quote
  #5  
Old 25 Aug 2010
Registered Users
HUBB regular
  
Join Date: Aug 2007
Location: Nice, France
Posts: 85
Uh oh, special tools ...
Thanks for the input, Bruken, sounds like you know of what you type :-)

Quote:
When stripping look for evidence that the oil hasn't been foaming.
Oh yes, it was super foamy when I changed it. Rats.

Quote:
incase this is a new aquisition of yours
Umm, I've had this bike for 20 years! It's one of those niggles that gradually creeps up on you as things wear out. There's only 85,000km on the bike, but they were all hard, loaded-up, off-road African km!

Lots of questions now!

A squint at the manual reveals "special tools" for taking fork legs apart:

"Hold the inner tube with the front fork cylinder holder (special tool P/N 90890-01328) and T-handle (90890-013101). Pull the inner fork tube from the outer fork tube"

Can I bodge this without special tools?

There's 2 candidates for the "teflon ring" you mention on my explodificated diagram - there's a "Slide bush" (on the bottom of the inner fork leg) and a "Guide bush" (damper rod).

Obviously I'd replace the fork seals at the same time. Anything else while I'm at it? Looks a fairly simple assembly otherwise.
Reply With Quote
  #6  
Old 25 Aug 2010
Registered Users
Veteran HUBBer
  
Join Date: Apr 2003
Location: Manchester UK
Posts: 235
On the damper rod itself which with a bit of imagination looks like a piston. On the top there is a teflon ring. Sometimes it is referred to as a bush but mostly as the Damper Rod Piston Ring. Inside the slider there is an oil seal that looks a bit like a flattenned O-ring right near the top. It is referred to as an oil seal (but not THE oil seal and dust seal that embraces the stanchion / fork tube.

When she is apart check the damper rod and fork tubes / stanchion isn't bent. Check the damper rod oil vent holes are clear and haven't worn.

The speacial tool can be made from a 32mm or 36mm (I can't remember which) bolt insert upside down and held in place with a vice grip. You only need to hold the damper rod in place (stop it rotating) while you undo the bolt on the outside bottom of the slider (model dependant). Sometimes it is not neccessary and sometimes if you compress the forks while still on the bike you can preloosen the bolt before removing the forks (tricky to do by yourself)
Reply With Quote
  #7  
Old 25 Aug 2010
Registered Users
Veteran HUBBer
  
Join Date: Aug 2001
Location: sunny England
Posts: 790
are you sure its just not the geometry of the bike? my xt front end goes very light and flighty when approaching 70/80, and my varadero does it too (but at a lot higher speed, its much heavier bike)

which xt model is it, air forks or just springers?

im assuming plain springers or you wouldve mentioned pumping up the preload by now. if you want to do it with the springs just slug the tops, i did mine about 1.5" and it makes a big difference to roadholding (mines been supermoto'd though, offroaders should keep soft suspension)
__________________
dave
Reply With Quote
Reply

« Previous Thread | Next Thread »

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
AT fork springs kevinhancock750 Honda Tech 6 11 Mar 2008 06:20
Fork Oil and Rear Springs crturboguy Yamaha Tech 2 4 Feb 2007 05:09
About to fit my new fork springs..!! (anyone know some germa Donmanolo BMW Tech 5 5 Dec 2005 21:38
R100GS FORK SPRINGS merlin BMW Tech 0 30 Aug 2002 23:55
R100GS fork springs merlin BMW Tech 1 22 Feb 2002 20:55

 
 

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

25 years of HU Events
Be sure to join us for this huge milestone!

ALL Dates subject to change.

2025 Confirmed Events:

Virginia: April 24-27
Queensland is back! May 2-5
Germany Summer: May 29-June 1
Ecuador June 13-15
Bulgaria Mini: June 27-29
CanWest: July 10-13
Switzerland: Aug 14-17
Romania: Aug 22-24
Austria: Sept. 11-14
California: September 18-21
France: September 19-21
New York: October 9-12 NEW!
Germany Autumn: Oct 30-Nov 2

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.

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 Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers and travel is covered on motorcycles of all sizes.
(ONLY US RESIDENTS and currently has a limit of 60 days.)

Ripcord Evacuation Insurance is available for ALL nationalities.


 

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!

Every book a diary
Every chapter a day
Every day a journey
Refreshingly honest and compelling tales: the hights and lows of a life on the road. Solo, unsupported, budget journeys of discovery.
Authentic, engaging and evocative travel memoirs, overland, around the world and through life.
All 8 books available from the author or as eBooks and audio books



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

Your ad could be here, on EVERY page of the HUBB, or the whole website, or as many as you like!

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 08:31.

Contact Us - Horizons Unlimited Motorcycle Travellers Website - Archive - Privacy Statement - Top