The Spares Company
Club Shop/Regalia
Parent Website
Contact Officials
Machine Registrar
Club Secretary
Membership Secretaries
MPH Editor and Forum Administrator.
Section Newsletters
Technical Databases
Photos
Home
What's new
Latest activity
Forums
New posts
What's new
New posts
Latest activity
Information
Bike Modifications
Machine Data Services
Manufacturers Manuals
Spare Parts Listings
Technical Diagrams
Whitakerpedia (Vincent Wiki)
The Club
MPH Material Archive
Flogger's Corner
Obituaries
VOC Sections
Local Sections
Local Section Newsletters
Miscellaneous
Club Assets
Club History
Club Rules
Machine Data Services
Meeting Documents
Miscellaneous
Essential Reading
Magazine/Newspaper Articles/Letters
Adverts and Sales Brochures
The Mighty Garage Videos
Bikes For Sale (Spares Company)
Log in
Register
What's new
New posts
Menu
Log in
Register
Install the app
Install
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Modified Steering Stem
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="hadronuk" data-source="post: 98160" data-attributes="member: 1866"><p>If I might intrude here, I think progressive springs are a very bad idea for standard geometry Girdraulics and questionable for modified forks. The inevitable increase in spring preload with progressive springs exacerbates the existing tendency for the standard forks to "jack" to full extension in some circumstances. This may have been a factor in Surtees '98 Goodwood tankslapper, as he had fitted progressive springs.</p><p>With the modified steering stem, because the links are now near parallel, any vertical force generated in one link is largely cancelled out by an opposite force from the other link. (It is not advisable to only consider the lower link, because under braking, tension forces in the top link are about 80% of the compression forces in the lower link.) </p><p>The benefits of the near parallel links may be sufficient to offset a largish spring preload, but I think there would be considerable problems in arriving at a suitable specification and source for progressive springs. Given the number of extra variables, think of the linear spring selection difficulties and then multiply a few times. A quick/cheap route might be to find an existing progressive spring S/H and hopefully chop bits off one end or the other. Springs for Triumphs might suit, but they are a bit small in diameter and around £80 a pop when new.</p></blockquote><p></p>
[QUOTE="hadronuk, post: 98160, member: 1866"] If I might intrude here, I think progressive springs are a very bad idea for standard geometry Girdraulics and questionable for modified forks. The inevitable increase in spring preload with progressive springs exacerbates the existing tendency for the standard forks to "jack" to full extension in some circumstances. This may have been a factor in Surtees '98 Goodwood tankslapper, as he had fitted progressive springs. With the modified steering stem, because the links are now near parallel, any vertical force generated in one link is largely cancelled out by an opposite force from the other link. (It is not advisable to only consider the lower link, because under braking, tension forces in the top link are about 80% of the compression forces in the lower link.) The benefits of the near parallel links may be sufficient to offset a largish spring preload, but I think there would be considerable problems in arriving at a suitable specification and source for progressive springs. Given the number of extra variables, think of the linear spring selection difficulties and then multiply a few times. A quick/cheap route might be to find an existing progressive spring S/H and hopefully chop bits off one end or the other. Springs for Triumphs might suit, but they are a bit small in diameter and around £80 a pop when new. [/QUOTE]
Insert quotes…
Verification
What was Mr Irving's Christian Name?
Post reply
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Modified Steering Stem
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top