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Roadholder Forks overhaul

Submitted by robert_tuck on Mon, 16/01/2023
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Heavy Twins

My 99 forks have been in action  for at least 25 years since I last gave them any attention apart from oil changes.  They appear to operate normally but have always crashed a bit at the extremes of travel. The  fork oil always  comes out looking in poor shape full of alloy deposits. 

A couple of years back I received a Christmas pressent of progressive springs, long bushes, damper caps  and covenant  bits , they have been lurking under the bench. Now is the moment. Had some trouble stopping the Damper turning but a tip from PH (a thin screwdriver through the drain hole) worked. Removing the springs was only made  possible by molewrenching the damper caps off.  They show plenty of wear from contact with the rods . The damper top threads ( 3/4 cycle?)  are of different lengths so a die will be needed (anyone?) to correct . Probably one of the reasons the wheel spindle is reluctant to enter .The longer bushes snag on minor bruising of the staunchions ,and the new damper caps snag on similar marks at the top of the rods. A bit of fetling with emery sorts it. The old steel bottom bushes exhibit no wear at all .

The Covenant kit is no use at all  as its designed for Commando dampers ,so Have to think of something else to block the damper holes. I hear that fully synth oil is far better for not wearing the sliders out so I will be trying some 10/40  Yamalube (free issue!) , probably be a bit thin ,but worth a try. May remove the head bearings ( taper) as they have been in for the same time and have been excelent , even though not sealed in any way, but regularly treated to spray grease.  I may go mad and take the  thing down to Motoliner to get the twist out of the frame ,although they say my measurements dont show enough error for them to worry about (3 mm out of line tyre contact patch).

Submitted by david_cooper on Mon, 16/01/2023

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Robert..mysterious USA sites often discuss issues with Commando fork behaviour, but it doesn't often seem to crop up in the UK  does it?  And although the USA had a lot more Commandos than Dommies (and Atlas etc), the articles I've read never seem to mention the earlier bikes.

Was it only a Commando issue? And why is it mentioned more often here? Especially about Dommies?

Submitted by don_anson on Mon, 16/01/2023

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Hi Robert, 

I did the Covenant mod to my 1968 Atlas a few years ago and it transformed the fork action out of sight! I can't believe the factory with all the engineering support and race experience didn't come up with this simple mod!

If my memory serves me correctly I cut about an inch, maybe a bit more off an aluminium tv antenna mast and slipped it over the bottom of the stanchion to cover the lower bleed hole. It fitted perfectly as it was very thin walled tube.

My Atlas spent most of its life in a museum in South Australia before I got it and as such the fork internals were in very good shape and easy to disassemble. 

Don Anson

Melbourne 

Submitted by robert_tuck on Tue, 17/01/2023

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Hi Don,  I have already had a scout round to look for a sleeve. Needs to be around 1 mm thick . Last time I had a TV mast  in my hands was when balancing on the roof ridge 40ft up screwing it to the chimney. Now I stick to totally safe stuff like bikes.!. If it all works as planned our 68 Atlas will be next. Not allowed out or even in the garage for now as i have been poorly for a couple of weeks with what i think is a new form of unrecognised  covid . I have been here before having cought covid  off some Chinese at the end of 2019 , well before the official first cases registered. I have to wait till "nurse" goes out to do anything.  

Submitted by dan_field on Tue, 17/01/2023

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RGM sell improved dampers if you give up looking for a sleeve! I’ve got improved commando dampers in both my sets of long road holders and am pleased with how they work. Interestingly using the commando springs makes them not much better than a rigid, so i still have the external springs, which makes fitting the fork legs and retrieving keeping the damper rods up a bit of a tussle! - telescopic magnets help in that respect!

Dan

Submitted by robert_tuck on Tue, 07/02/2023

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A bit of progress,   I had to make 8 plugs for the damper holes ,  could not use the Covenant plugs . Cleaned up all the threads with taps and dies to aid assembly. Cleaned up slight bruising on staunchions and rods ,took several cleans to get all ancient grot out of sliders and dampers.. Made several stupid errors in assembly including forgetting paper washers , and doing things in wrong order. Borrowed aftermarket leg puller collides with top of damper rod so had to dismantle sliders yet  again . Perhaps i should read the manual ?, oh no it says reassembly is the reverse of dismantling,  can't remember that far back !, After all the stupidity going to have to drain and refill forks yet again as some oil lost in the faffing about. Each time I go into workshop i get sick and spend another week indoors  coughing up yuk . Any thoughts of going further with steering jobs long gone. Roll on spring, and warm weather. I will give my riding impressions of new damping and springs.

Hi David , could be. I have had to clean out the bathroom mould and then found some white mould on my van seat that has been unused for a month . Taking anti biotics .  I know now why my parents spent half the years in Portugal 

 

Submitted by dan_field on Tue, 07/02/2023

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The cough doing the rounds is evil, I couldn’t shake it off until I had antibiotics - still feeling run down now and I had it over Christmas - I hope you get better soon.

Dan

Submitted by robert_tuck on Wed, 08/02/2023

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Got my fork legs assembled and on the bike only to find they are so  stiff  (even with top nuts removed ) that its another stripdown . Perhaps the staunchions are not true , or the yokes ,but i cant  spot it .(yet!!) .  Bugger ,   IF IT AINT BROKE DONT FIX IT.      First rule.

Submitted by dan_field on Thu, 09/02/2023

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I assume the forks were in your bike when you tested? Roadholders seem very sensitive to any side pressure, so in hindsight it may worth checking each leg separately before you put the wheel or mudguard bracket on, if they both move smoothly then you know its the mudguard or wheel spindle thats pulling them in or out slightly.

If your forks are still in, then it might be worth loosening everything off then bouncing the forks up and down to settle everything in before tightening up again - unless you’ve already tried that!

Dan 

Submitted by barry_carson1 on Thu, 09/02/2023

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Hello,

when i fitted some new fork bushes to my roadholders they use to jam /stick and not a smooth operation . i tried everything . i eventually changed the new bushes for another set and tried the forks they worked ok. on compareing the two sets of bushes it seemed if the bottom bush hasnt got a radius where indicated on number one in the photo. then they tend to stick like a stiction effect. number two type in the photo were the ones with sticky operation.

 

 

Barry

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Hi lads,  no I haven’t got that far yet , no wheel or guard , just pushing the sliders up and down ( with the top nuts off ) should be easy , the new ( longer) top bushes we’re not too tight and the bottom steel bushes are orriginal 1960 that measured the same as the new ones ( gone into my stock) , I am wondering if i swapped the staunchions over !! , going to try rotating the tubes to find a happy place . Never been crashed since I built it but the yokes had to be straightened ( 25 years ago)  perhaps new clearances are pointing up an old issue .

Submitted by robert_tuck on Sat, 18/02/2023

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Forks on and working , One leg needed a 1/8" washer between damper rod top nut  and top yoke nut to get the axle ends to line up , Don't know why or what the effect will be on fork action.  Mudguard has decided it wont fit now (was allright!)   so taking out the bridge for some re-shaping to avoid clash with fork shrouds  and loading up the sliders.  The only way to properly fit the mudguard is to remove the bridge studs ,  I can feel another fork removal comming on.

 



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