Roadholder short forks

Richard,

The long Roadholders have external springs whilst the short ones have internal springs, so the fork leg seals are different.  Also the oil dampers in the bottom of the fork legs are different. 

In the photo "A", "B" and "D" are long Roadholder legs and have the top machined for the lower fork shroud to fit onto and fixed in place with two small screws.  You can also see there are different positions for the mudguard fixing bracket.

"E" may be misleading as it seems to have an external spring place, I cannot remember why this there as I took the photo a couple of years ago.

Richard,

The photo that I copied into the text doesn't seem to been attached, so I'll try again.

Hi Richard,

   Except the bushes and seals, nearly all the parts are different, so you will be best looking for a full set of short Roadholders. You could then offset the cost by selling your long set. Check the yokes are correct for your year if you want originality as they changed over the years.

Did you say that your ES2 was a pre-featherbed type, a featherbed type or a post-featherbed type ?  The forks for all these models were "Roadholder" variations.   As Philip said the pre-featherded models were longer than the featherbed types but the later ES2 Mk2 (Matchless model) also had longer RH forks than the featherbed ones.  It seems as if you are suggesting that you have a feathered framed model with long RH fork legs and sliders ?  You are unlikely to have pre-featherbed long RH yokes on a featherbed frame because they don't fit without major surgery.  Does your front-end not point upwards indicating huge acceleration permanently ? If not they may have already been shortened - an easy task.... Also does your centre-stand touch the floor when required to ?   There are lots of possibilities to successfully modify your Bitsa but you probably need to take more images and define what you've actually got.  Chin up regards, howard

My long roadholders are approx 780mm from spindle to top of the yoke. My Short roadholders measure 700mm - both under their own weight. 

I’ll leave you to work out exactly what you’ve got but it doesn’t match my long or short roadholders!

The long and short roadholder sliders are pretty much the same as each other, the main difference between the long and short forks is in the length of the stanchions and the internals. 

You can fit later dampers into long roadholder  sliders although this is usually done using commando stanchions which are almost the same length (a couple of mm shorter) as the long roadholders but have a circlip holding the lower bush in place instead of the nut. This is what I have on my pre featherbed ES2.  

Assuming everything else is correct, if you want to lower the ride height at the front the easiest way may be to fit short roadholder stanchions, they are not particularly expensive but you may have to replace/shorten the damping rod that screws into the fork top nuts.

But I’d suggest you post a picture here so we can confirm exactly what you have!  

Dan 

I can recommend the 'Forks, Wheels & Brakes' DVD by Mick Hemmings, through the Club shop. It has lots of useful information for identifying various Roadholder forks.

Kevin

Richard our short road holders are the same length mine wasn’t measured at full stretch. However I can confirm the my stanchions came from Andover Norton. They are correct ! 
 

Without taking them apart I don’t think you are going to get to the bottom of your longer forks. Long road holders normally have external springs and just a damping tube in the bottom of the slider, I think they can only have an internal spring if the damper is replaced with the internals from short road holders or commando forks. If the damping rod is too short it may stop the forks extending fully, or you may have modified stanchions. Your forks do look like long road holders but you say you replaced all the internals, what exactly did you replace? Can you remember how the bush is attached to the bottom of the stanchion? 
 

The mystery continues! 

If you fit 30mm longer top bushes then your full extension will be reduced by 30mm. You will lose 30mm off your full fork movement so another alternative is to get 30mm machined off the top of your current stanchions, plus add back taper and fork top nut thread. This second alternative would reduce the full extension by 30mm but keep the full fork movement. 

Richard, if your stanchions have a circlip then they are definitely not long roadholder stanchions. 

If it were my bike, I’d drop out the front wheel, slide out one leg and take it apart and measure the stanchion, damper tubes and damper rod to see exactly what I had! If In the end you shorten the stanchion then yes the rod willl need to be shortened by the same amount, but that’s easy enough with a saw and a die! 

Did you replace the Springs?  On reflection undoing a cap and measuring a spring might give you an insight into what’s going on. 

Dan 

Richard, Just been in the shed doing some measurements. 

PreCommando short Roadholder staunchions are 21.8" long and long Roadholder stanchions are 23.3"  long.  Note Commando stanchions  are longer at 23.2" but look similar to the short Roadholders. 

Spring lengths are 11.8" for Long Roadholders,  18.7" for short Roadholders and 18.7" also for Commandos. 

Hopefully the photo from the 1956 parts book showing exploded diagrams of long and short Roadholders has attached to the message

I'll check the sliders tomorrow.  Nearly New Year's Day down here. 

Happy New Year to all members.

If you shorten the springs their spring rate will increase, exactly like a shortened plank. So before shortening the spring I would see if the preload/static sag is correct with the normal load including rider. That should be for front suspension 1/6 of the total travel so 5" total travel should have 7/8" preload/static sag.

Have you checked that the frame tubes where the stand 'stops' are still ok (no flats/holes) and that the holes in the stand and the pivot bushes aren't worn? Either of these will leave you with the 'both wheels on the ground' scenario. 

Regards,  George. 

WI’ve just done some more measuring too, I found my old stanchions,as you have found the Short roadholders are 550mm long the long roadholders are 592 mm long, giving a difference of 42mm. I also measured from the top of the stanchion to the top of the lower bush, that also has a difference of 42mm. So we all have the correct stanchions!

However you are getting an overall fork length of 740mm, your dominator and my Navigator are nearer 710 ( I’ve put blocks under the stand to make sure the forks are fully extended and can confirm the same measurement 710mm.   If you put your Dominator on wooden blocks and pull the forks down as far as possible can you get them to 740 mm? if you can’t then something else is enabling the other short roadholders  to extend further than normal. I thought that the bushes hit each other to top out, they do on long roadholders, but perhaps it’s the damper rod that creates the stop? If it does then longer damper tubes would perhaps allow the forks to extend too far? 

At least you know that your stanchions are the right size! 

Dan 

George's suggestion about the lower frame tubes is worth checking.  I have a 1969 Mercury and my stand didn't lift the wheels off the ground either.  In discussions with Phil Hannam he mentioned that the last featherbed frames (1969 'ish) were made of lighter weight tubes and that sometimes the tubes can rust and deform, so that the stand does lift the bike properly.

Simply run a straight edge along the bottom tube to check this.  My frame was OK so I ended up adding pads onto the feet of the stand, which worked fine.

Also, are your tyres the original profile?  On my ES2 I fitted some Mitas tyres and these are a deeper section and this resulted in both wheels touching the ground with no clearance.  New tyres will obviously have full tread, so will accentuate the problem with stands.

Philip

Hi Phillip

Unfortunately that wouldnt explain why Richard’s short roadholders appear to be 30mm longer than normal when fully extended. Can anyone else measure their’s to double check? 

Of course it may be a combination of issues! 

Dan 

It sounds to me that the damper has topped-out before the bottom bush reaches the top bush.  It is a known problem with the Short Roadholder forks.  It you get time to remove the top nut and then release the damper rod you will see that the forks can extend further until the bushes collide. You should first insert a length of locking wire around the retaining nut (3/8 inch) at the top of the damper rod so that the damper can be relocated later.  The rods should technically be longer so that all the front-end weight is not suspended on the two little scuttle-nuts that hit the alloy damper tops.  The issue came to light when buying parts for my Commando.  I wondered why the dampers were almost two inches longer and yet the sliders, bushes and seals were all the same dimensions. So there you are,  with standard components in Short Roadholders (on the featherbed models) the dampers top-out  before the bushes touch.  This can be a big problem going quick on bumpy terrain and an absolute 'no no' on a dune sled.  Many people fit Commando dampers tho' watch for the different thread forms. The Commando damper rods are too long of course.  Some people fit longer damper rods especially if the originals are alloy.  Care must be taken fitting longer damper rods and precise measuring is recommended so that the dampers don't bottom-out.  My measurements suggest that the internal spring gets coil-bound and acts as a stop before the scuttle crashes into the bottom of the damper.  However many people use external springs without making adjustments and they don't act as stops.   This has been an interesting thread.  Happy New Year to you all, howard 

Well there is your problem!  ..... you have commando damper tubes,  they are longer than the short roader ones. Commando dampers are 232mm and short roadholders are 194mm. That accounts for the 40mm extra length. 

https://www.rgmnorton.co.uk/buy/alloy-fork-damper-body-with-improved-damping-standard-commando-1_2282.htm

https://www.rgmnorton.co.uk/buy/alloy-fork-damper-body-cap-with-bolts-improved-damping-short-r-holder_2281.htm

The rod should be 503mm long

https://www.rgmnorton.co.uk/buy/steel-fork-damper-rod-26tpi-featherbed_4015.htm

According to RGM the rod and springs were the same length in the commando and short roadholder forks, the main difference being the length of the damper tube. 

So with a couple of new damper tubes you’ll be sitting pretty on your stand .... hopefully anyway! 

Dan 

Ps why is there a weld mark around your damper tube?

So Richard - If you've already got Commando dampers fitted at least you know that they won't top-out and as they're probably ten years newer than the older ones they should operate well.  You will also probably need to weld some 15mm blocks to your centre-stand.  You can ride to your heart's content safe in the knowledge that your forks are operating correctly and are not topping -out the dampers on our pot-holed highways........ regards, howard

Howard

If I understand you correctly you are advising Richard to run with forks 40mm longer than they should be.  Why would you recommend that? It upsets the handling and the stand as we know, as well as looking odd! All short road holders top out in the damping tube which is oil damped. Most owners with long road holders hate the clank on topping out you get when the two bushes hit, which is what Richard will get if he leaves the commando dampers in there. 
But I guess it’s Richards decision ! 
Dan 

No I am not advocating running longer forks.  Richard has already confirmed that the stanchion tubes are the correct length for a Dommie.  If his assertion that the only difference is the damper length then when the bike is on its wheels being ridden the only noticeable difference will be when the sliders drop to their full extent over bumps etc.  In such a case a Dommie damper can top-out depending on the damping rate and the persistence of the drop.   The bike will sit and ride correctly and the only obvious difference will be when he pops it on the stand the wheel will drop until the bushes collide instead of the whole mass of the wheel, sliders, mudguard etc resting on the two (or one in some cases) scuttle nuts encountering the damper top screw.  Fitting the Commando damper allows the forks to operate throughout the range afforded by the travel of the bushes in the slider.  When the damper rods screw into the top nut it can easily be the case that one damper will top-out before the other so beware.........Ride safe, howard   

We’ll have to agree to disagree Howard!! You are forgetting that by fitting longer dampers you will have the same preload as having standard damper tubes and a standard rod,  So the sag will be the same but they will be starting from a set of forks 40mm longer. 

While the landsdown mod is popular I have not heard anyone recommending fitting commando damping rods to short road holders.  Of course you could shorten the spring to compensate but by doing that you increase the spring rate!   
 

I would also guess that with shrouds fitted them may even show a gap fully extended? 

dan 

Dan - How can the forks be longer if the stanchion tubes are the same length , the sliders are the same and the bushes are the same ?  All that is different is the operating regime in which the damper scuttle moves within the damper tube.  If you look at a stanchion tube with the lower bush in place and insert this into the slider with the top bush in place,  you will see that there is a total movement of the top bush and slider of 155mm.  Now if you look at the total travel available for the scuttle to move in the damper tube you will measure 155mm.  So to get perfect operation of the forks the scuttle should be aligned to the respective position within the stanchion. Something went awry when the factory determined the overall length of the damper rod from the scuttle nut to the depth in the top nut.  It must have seen adequate to them that in normal operation with a fairly slow damping coefficient the fork damper would not top-out and when the bike is on the centre-stand the downward force exerted is applied fairly slowly as the stand rotates on the mounting pivot so the top-out then isn't so severe.  When Commandos were designed this feature was obviously considered and so even tho' the first models shared the same slider, bushes, wheel, seals, mudguard and mudguard bridge as my Mercury,  the damper is longer.  Moreover you should not compare the clunk of a long Roadholder fork topping-out as this is not a double-damped system. Je reste ma valise !!  Howard  

Hi Richard 

Cutting and tapping the damper tube will fix it.
 

A minor point but your assumption about a longer tube allowing the slider to drop until it’s stopped by the rod isn’t quite right. I think the longer commando damper tube is allowing the slider to travel until the bottom bush on the stanchion hits the top hat bush in the slider. This is how the long road holders stop. 

By all means send me a message I’m happy to call if you’d like to discuss anything! 

While you may not be bothered when you have everything in bits you could modify the dampers to improve damping, or RGM sell them ready done. It involves blocking the holes in the damper tube and drilling some new ones. Depends how you want to use the bike I guess! 

Dan 

Good news Richard, we got there in the end!

Just a point of interest the threads on the commando damper rod are also different and won’t fit into the pre commando fork top nuts. 

All the best

dan