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="timetraveller" data-source="post: 103345" data-attributes="member: 456"><p>First a reply to Chris. One of the first things I suggested was to remove one spring and see what happened with one 30 lbs/inch spring. I was worried about damper and fork bearing friction. See below.</p><p></p><p>Greg; my first thought was that either the damper or the fork spindles were not set up properly so I suggested that he removed the wheel, damper and spring boxes to make sure that the forks dropped readily under just gravity. They did and he sent me a video to show the tests. He then sent me some more measurements of damper and spring box movement and I became suspicious that he was not using the long eyebolts. He was not and he then replace those with the long ones. He is using a standard Vincent damper, which has a slightly different length to an AVO but only by a few millimetres and at that stage I was trying to ensure that the angle of the lower link was correct, not just the spring rate. Perhaps I should say that the chap is in Italy so I cannot just pop round and have a look for myself. At the moment he is back to trying something else and will let me know what happens.</p><p></p><p>One thing that occurred to me during our correspondence when he was weighing the bike's front end was that it is possible that one should remove the value of the unsprung weight before doing the sums for the springs. For example the bike weighs 73 kg at the front and 105 with him on board. Later today I am going to weigh a wheel and stripped down front forks to see exactly what they weigh but is going to be a significant fraction of those amounts. So the springs are having to support the weight of the bike plus rider minus the unsprung weight. The damper is having to control the inertia of all of that.</p><p></p><p>Vibrac also had problems with the 30 lbs/inch springs on his latest creation for road use, hence my comment that he should find the results of the Italian tests useful.</p><p>Thanks for all ideas and feedback.</p></blockquote><p></p>
[QUOTE="timetraveller, post: 103345, member: 456"] First a reply to Chris. One of the first things I suggested was to remove one spring and see what happened with one 30 lbs/inch spring. I was worried about damper and fork bearing friction. See below. Greg; my first thought was that either the damper or the fork spindles were not set up properly so I suggested that he removed the wheel, damper and spring boxes to make sure that the forks dropped readily under just gravity. They did and he sent me a video to show the tests. He then sent me some more measurements of damper and spring box movement and I became suspicious that he was not using the long eyebolts. He was not and he then replace those with the long ones. He is using a standard Vincent damper, which has a slightly different length to an AVO but only by a few millimetres and at that stage I was trying to ensure that the angle of the lower link was correct, not just the spring rate. Perhaps I should say that the chap is in Italy so I cannot just pop round and have a look for myself. At the moment he is back to trying something else and will let me know what happens. One thing that occurred to me during our correspondence when he was weighing the bike's front end was that it is possible that one should remove the value of the unsprung weight before doing the sums for the springs. For example the bike weighs 73 kg at the front and 105 with him on board. Later today I am going to weigh a wheel and stripped down front forks to see exactly what they weigh but is going to be a significant fraction of those amounts. So the springs are having to support the weight of the bike plus rider minus the unsprung weight. The damper is having to control the inertia of all of that. Vibrac also had problems with the 30 lbs/inch springs on his latest creation for road use, hence my comment that he should find the results of the Italian tests useful. Thanks for all ideas and feedback. [/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