Betor fork mods.

[sixdazed]

Here's the short version of the article-just the facts ma'am!
   To keep oil contained in the piston area requires a simple modification.Take a piece of tubing the same o.d. as the damper rod.The added piece of tubing should be 1 inch (approx.)long.Weld one end completely shut.Next,carefully weld the finished "cap" onto the top of the damper assy.(above piston).Heliarc works best for this.Grind off any excess weld because this cap has to fit up inside the fork spring.After welding,drill four 1/4" holes in the sides of the cap (above the weld) at 90 degree intervals.This mod. keeps oil always available to the damper piston to minimize topping and bottoming out.
    Another problem inherent in betor forks is oil leaking out the breather holes in the fork caps.The fork mod. previously described will also cure this problem.
     Fork Filling-#1-Remove fork caps and pull out the springs.#2-Drain out the old oil.#3-Clean out excess oil gathered inside fork tubes and sliders by replacing drain plugs,then fill each tube with solvent (gas can be ued but solvent is better)Let solvent sit for 5-10 minutes.#4-Drain solvent blow out excess with air gun.#5-Clean excess oil off fork springs.#6- replace drain plugs.#7-Leave front wheel off,but slide axle thru to keep forks even.#8-Rock bike forward on stand so bottom of forks touch the ground.(In this position the forks are nearly vertical and can be filled more accurately.)#9-Pour in oil(do NOT use std. capacity!)#10-Use a flashlite to sight down each tube.Fill each tube until oil just covers the flat above the piston (the spring sits on this flat).#11-Place your foot on the axle,grab the handlebars and gently pump the forks up and downThis will displace all the trapped air in the damping system and cause the oil level to drop slightly.#12-Keep your foot on the axle and pull the forks up as far as they will go.Make sure you can feel the damping rod bumping against the topping spring,then repeat step #10...#13-Repeat steps #11 and #12.Continue to repeat until the oil level remains constant after pumping.Final oil level should be as described in step #10-(covers the flat just above the piston)#14-Tip the bike back up level on its stand and slip the springs into place,insert the caps and you've got it-matched forks.one last suggestion-you can keep the fork caps operating(breathing)better by injecting a squirt of wd-40 in the breather hole each time you change your fork oil.Before re-assembling let the caps sit for a while so the excess wd40 will drain off.
    OK-THATS IT!Keep in mind this is a period modification taken out of a 1975 magazine so don't expect cartridge fork performance from your 7" travel Betors.And for safety reasons always use the factory service manual for disassebly/assembly,replace any worn parts,and if you don't feel confident performing this,have a qualified technician do it for you.Have a good welder do that part of the mods. too,if you have doubts about your welding skills.I condensed this article to save space but believe i've included all important steps-if you have doubts email me and i'll go over it(the article) with you.Legal waiver -do this at your own risk!I'm not responsible if you screw up the procedure and your forks come apart over the big Double!!!!!!!Hope this helps some of you Betor guys dial in their forks...
                                       Ric

ric emmal

[Merlin]

Merlin
Advanced Member



83 Posts
 Posted - 08/09/2007 :  11:48:29 PM          
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..........I know this sounds insignificant but plugging the topend of 7" travel rods and putting the oil out the sides works wonders.........