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
Burman Box Again
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="Martyn Goodwin" data-source="post: 114519" data-attributes="member: 2433"><p>I will confess to be a slow but persistent learner - I <em>think </em>I have finally understood how to control main shaft end float in a Burman BAP gearbox.</p><p></p><p>Up front be clear that the ONLY time that I think you can get a true measure of main shaft end float is with the mainshaft with the 3rd gear on it, fitted into the inner cover and the k/s assembly in place and tight on the other side of the inner cover.</p><p></p><p>On the mainshaft at the k/s end there is a threaded portion that nut 70X fits onto and there is a shoulder there - when tightening 70X it is (should) be tightened up against that shoulder. Starting at the outer k/s end of the mainshaft between the tightened 70X nut face and the outer face of the small bearing firstly there is the Driven Ratchet PR50-41BA and then the Ratchet Pinion Bush PR50-39BA (this bush is installed with its top hat flange against the small bearing inner race). Slip fit over the Pinion Bush is Ratchet Pinion PR50-38BA and the spring PR50-40BA. Essentially this assembly makes a spacer between the nut 70X and the top hat part of the Pinion Bush. Let's call this assembly the Float Control (<em>ok I made that name up!</em>)</p><p></p><p>Now on the other (inner) side of the small bearing is the 3rd gear that is a slip fit on the mainshaft, with (hopefully) end float between the inner race of the small bearing and the shoulder on the mainshaft. It is the stepped face of the 3rd gear that abuts the small bearing and the mainshaft shoulder on the other side of it that becomes the partner to the Float Control. So we are looking at an assembly that can slide on the mainshaft between the mainshaft shoulder that abuts the 3rd gear and the nut 70X.</p><p></p><p>I have not been able to locate any <s>reliable </s>Burman works documentation that tells what the main shaft end float should be however the suggestions received suggest that around 0.010" end float should be adequate. Richardson states that main shaft end float should not exceed 0.030".</p><p></p><p>So if we are to control the end float of the mainshaft then it can only be done in one of two ways. </p><p></p><p>If there is <strong>excessive end float</strong> to reduce it we can fit a shim between the Ratchet Pinion Bush and the Small Bearing. Standard Vincent metric wheel bearing shims available from the Spares Company are ideal for this use - Order H17M/set. Thanks to Greg Brillus for this insight.</p><p></p><p>If there is <strong>insufficient end float</strong> then as Mr Bore correctly suggested we can reduce the length of the Ratchet Pinion Bush.</p><p></p><p>M</p></blockquote><p></p>
[QUOTE="Martyn Goodwin, post: 114519, member: 2433"] I will confess to be a slow but persistent learner - I [I]think [/I]I have finally understood how to control main shaft end float in a Burman BAP gearbox. Up front be clear that the ONLY time that I think you can get a true measure of main shaft end float is with the mainshaft with the 3rd gear on it, fitted into the inner cover and the k/s assembly in place and tight on the other side of the inner cover. On the mainshaft at the k/s end there is a threaded portion that nut 70X fits onto and there is a shoulder there - when tightening 70X it is (should) be tightened up against that shoulder. Starting at the outer k/s end of the mainshaft between the tightened 70X nut face and the outer face of the small bearing firstly there is the Driven Ratchet PR50-41BA and then the Ratchet Pinion Bush PR50-39BA (this bush is installed with its top hat flange against the small bearing inner race). Slip fit over the Pinion Bush is Ratchet Pinion PR50-38BA and the spring PR50-40BA. Essentially this assembly makes a spacer between the nut 70X and the top hat part of the Pinion Bush. Let's call this assembly the Float Control ([I]ok I made that name up![/I]) Now on the other (inner) side of the small bearing is the 3rd gear that is a slip fit on the mainshaft, with (hopefully) end float between the inner race of the small bearing and the shoulder on the mainshaft. It is the stepped face of the 3rd gear that abuts the small bearing and the mainshaft shoulder on the other side of it that becomes the partner to the Float Control. So we are looking at an assembly that can slide on the mainshaft between the mainshaft shoulder that abuts the 3rd gear and the nut 70X. I have not been able to locate any [S]reliable [/S]Burman works documentation that tells what the main shaft end float should be however the suggestions received suggest that around 0.010" end float should be adequate. Richardson states that main shaft end float should not exceed 0.030". So if we are to control the end float of the mainshaft then it can only be done in one of two ways. If there is [B]excessive end float[/B] to reduce it we can fit a shim between the Ratchet Pinion Bush and the Small Bearing. Standard Vincent metric wheel bearing shims available from the Spares Company are ideal for this use - Order H17M/set. Thanks to Greg Brillus for this insight. If there is [B]insufficient end float[/B] then as Mr Bore correctly suggested we can reduce the length of the Ratchet Pinion Bush. M [/QUOTE]
Insert quotes…
Verification
What was Mr Vincent's Christian Name?
Post reply
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Burman Box Again
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