commando front forks
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http://lansdowne-engineering.co.uk/
buy and install a set of Lansdowne cartridges and your front end problems will be over
buy and install a set of Lansdowne cartridges and your front end problems will be over
Nater_Potater
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rwalker28 said:
end-the-road-t23240.html
'Not looking good for John. Our prayers go out to him.
Nathan
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Many of you will probably consider this blasphemous, but has anyone heard of someone successfully grafting a 35mm twin disc Sportster front end onto a Commando? I'm guessing that the stem between the top and bottom yokes would have to be custom made, any issues other than that?
I've got the front end off my 75 Interstate and figured now would be the time to ask. A Sporty front end can be sourced on Ebay for less than $400.
I have some machining experience so likely could cobble up spacers to take the place of the front wheel speedo drive.
Any info appreciated.
Mike in Mass
I've got the front end off my 75 Interstate and figured now would be the time to ask. A Sporty front end can be sourced on Ebay for less than $400.
I have some machining experience so likely could cobble up spacers to take the place of the front wheel speedo drive.
Any info appreciated.
Mike in Mass
Nater_Potater
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Why limit yourself to Harley? A quick search on fleabay brings up all sorts of late-model sport bike front ends. With some careful measurements, plus the ability to create the proper spacers, you could have a killer set of forks for a (relatively) low cost. Just take a look at GranPaul's bike: gallery/image.php?album_id=20&image_id=143 Yes, it can be done!Mike In Mass said:
Okay, now I'm thinking of finding myself a basket case and going crazy...
Nathan
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When I first bought my Norton I found the front forks to be rather stiff. The Norton shop I went to sold me a set of progressively wound springs made by Progressive Suspension. I found them to work pretty well. Some people don't seem to like them, but it is a personal preference.
You said you tried everything to figure out the rattling, so I assume that you have checked all of the hardware, headlight mounts and everything attached to the front end for secureness. If so, possibly the tach or speedometer cable are rattling against the fender when the forks are compressed.
Also if your bike is equipped with the Norton disc brake system the brake pucks could be rattling in the brake caliper. On my bike they do. I don't notice it unless I am shaking the front end while the bike is on the stand. Sometimes I hear the noise when I hit a certain frequency of bumps which doesn't happen very often. Seeing how the brake pucks don't have any anti rattle clips I don't see that there is much you can do to stop that.
If you are referring to the forks topping out which Norton forks commonly do, I tried to stop it on my bike by purchasing a pair of RGM Extended Fork Bushings http://www.rgmnorton.co.uk/buy/fork-top-bottom-bush-oil-seal-kit-with-extended-bushes_2295.htm
With these bushings installed I still experienced my forks topping out when hoisting the bike on the center stand. Most disappointing! After riding my bike this way for awhile I took my forks apart to determine why this was happening. On inspection I found that the extended bushings only covered the large holes in the fork tubes still leaving the two 1/8 inch holes exposed. So what I thought I would do is plug one of those 1/8 inch holes on each of the fork tubes with a NAS1097 AD4-4 flush rivet. When I reassembled the forks the forks still topped out when I hoisted the bike onto the center stand! I was just getting ready to plug the remaining 1/8 inch holes but instead I decided to try installing two 1/16 inch washers between the damper jamb nut and the top cap bolt. Doing this allows the forks to extend 1/8 inch more so that the RGM extended bushing would cover over the 1/8 inch holes. Success!! No more topping out. I finally ended up using only one 1/16 inch washer between the cap bolt and the jamb nut; and instead of using just one, I used two p/n 067514 damper tube fiber washers for each fork leg. This allows the fork leg to extend an additional 1/16 inch for a total of 1/8 inch extension. Now I can ride my bike as hard as I can across a railroad crossing (gaining air time) without hearing topping out of my forks.
The fork tube with one of the 1/8 inch holes counter sunk before riveting
The fork tube with the flush rivet installed
Peter Joe
You said you tried everything to figure out the rattling, so I assume that you have checked all of the hardware, headlight mounts and everything attached to the front end for secureness. If so, possibly the tach or speedometer cable are rattling against the fender when the forks are compressed.
Also if your bike is equipped with the Norton disc brake system the brake pucks could be rattling in the brake caliper. On my bike they do. I don't notice it unless I am shaking the front end while the bike is on the stand. Sometimes I hear the noise when I hit a certain frequency of bumps which doesn't happen very often. Seeing how the brake pucks don't have any anti rattle clips I don't see that there is much you can do to stop that.
If you are referring to the forks topping out which Norton forks commonly do, I tried to stop it on my bike by purchasing a pair of RGM Extended Fork Bushings http://www.rgmnorton.co.uk/buy/fork-top-bottom-bush-oil-seal-kit-with-extended-bushes_2295.htm
With these bushings installed I still experienced my forks topping out when hoisting the bike on the center stand. Most disappointing! After riding my bike this way for awhile I took my forks apart to determine why this was happening. On inspection I found that the extended bushings only covered the large holes in the fork tubes still leaving the two 1/8 inch holes exposed. So what I thought I would do is plug one of those 1/8 inch holes on each of the fork tubes with a NAS1097 AD4-4 flush rivet. When I reassembled the forks the forks still topped out when I hoisted the bike onto the center stand! I was just getting ready to plug the remaining 1/8 inch holes but instead I decided to try installing two 1/16 inch washers between the damper jamb nut and the top cap bolt. Doing this allows the forks to extend 1/8 inch more so that the RGM extended bushing would cover over the 1/8 inch holes. Success!! No more topping out. I finally ended up using only one 1/16 inch washer between the cap bolt and the jamb nut; and instead of using just one, I used two p/n 067514 damper tube fiber washers for each fork leg. This allows the fork leg to extend an additional 1/16 inch for a total of 1/8 inch extension. Now I can ride my bike as hard as I can across a railroad crossing (gaining air time) without hearing topping out of my forks.
The fork tube with one of the 1/8 inch holes counter sunk before riveting
The fork tube with the flush rivet installed
Peter Joe
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PeterJoe said:When I first bought my Norton I found the front forks to be rather stiff. The Norton shop I went to sold me a set of progressively wound springs made by Progressive Suspension. I found them to work pretty well. Some people don't seem to like them, but it is a personal preference.
You said you tried everything to figure out the rattling, so I assume that you have checked all of the hardware, headlight mounts and everything attached to the front end for secureness. If so, possibly the tach or speedometer cable are rattling against the fender when the forks are compressed.
Also if your bike is equipped with the Norton disc brake system the brake pucks could be rattling in the brake caliper. On my bike they do. I don't notice it unless I am shaking the front end while the bike is on the stand. Sometimes I hear the noise when I hit a certain frequency of bumps which doesn't happen very often. Seeing how the brake pucks don't have any anti rattle clips I don't see that there is much you can do to stop that.
If you are referring to the forks topping out which Norton forks commonly do, I tried to stop it on my bike by purchasing a pair of RGM Extended Fork Bushings http://www.rgmnorton.co.uk/buy/fork-top-bottom-bush-oil-seal-kit-with-extended-bushes_2295.htm
With these bushings installed I still experienced my forks topping out when hoisting the bike on the center stand. Most disappointing! After riding my bike this way for awhile I took my forks apart to determine why this was happening. On inspection I found that the extended bushings only covered the large holes in the fork tubes still leaving the two 1/8 inch holes exposed. So what I thought I would do is plug one of those 1/8 inch holes on each of the fork tubes with a NAS1097 AD4-4 flush rivet. When I reassembled the forks the forks still topped out when I hoisted the bike onto the center stand! I was just getting ready to plug the remaining 1/8 inch holes but instead I decided to try installing two 1/16 inch washers between the damper jamb nut and the top cap bolt. Doing this allows the forks to extend 1/8 inch more so that the RGM extended bushing would cover over the 1/8 inch holes. Success!! No more topping out. I finally ended up using only one 1/16 inch washer between the cap bolt and the jamb nut; and instead of using just one, I used two p/n 067514 damper tube fiber washers for each fork leg. This allows the fork leg to extend an additional 1/16 inch for a total of 1/8 inch extension. Now I can ride my bike as hard as I can across a railroad crossing (gaining air time) without hearing topping out of my forks.
The fork tube with one of the 1/8 inch holes counter sunk before riveting
The fork tube with the flush rivet installed
Peter Joe
This sounds as though you are adding preload to the springs or adjusting sag. I've replaced numerous forks springs over the years and rarely have I ever installed an equal length (~ to the stock spring removed) replacement spring. I've always has to add spacers such as small lengths of pipe or have added shims beneath the fork cap to achieve a similar result. Sounds as though when you "topped out" you literal ran out of spring tension, especially if adding preload compensated for this.
I'm very fortunate I ordered a set of Lansdowne cartridges from John last year, I'm still sorting my growing pains with my mk3 before I install them. I want to see the difference and experience the "OEM" ride
. I do think if your not opposed to some Non-oringal bits them there are a lot of very cool options, some only limited by money, tools and talent. I think there are some good low dollar options too. My goal was to stay with only stock parts unless I could hide the tech, hence Johns kit. I did pull the trigger on some Hagons aft to balance it out. I really like the Works kit but looks to modern and well 600 and up didn't seem to be worth it for a street only ride. I've seen a bunch of Japanese front ends used with nice disc front ends and heck some mag wheels too! I would love to run some mags!
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Yes is the answer. However a few weeks ago a friend had a customer bring in a Norton with similar problems.....I received damn nigh daily updates as time progressed and more faults were found. The problems I heard about were.....
1. The fork legs(main tubes) were oversize . Never assume new main tubes have been CORRECTLY manufactured. I doubt any dealer checks them as they receive them from the manufacturer... I once checked a batch coming into a friends shop...rthey were ALL 0.002 inch under the minimum size quoted in the workshop manual....the dealer sold them all and apart from the two pairs I took and had hard chromed /ground back to correct size only one customer returned a pair as incorrect and he was a German customer.....which proved that the average British bike owner does not check the bits they buy!!
2. At the bottom of the main tubes they are machined tro take the steel fork tube bush......the IDIOTS who manufactured the legs had machined this area 0.007 inch NON concentric to the rest of the leg resulting in the forks sticking / jamming as they extended.
3. The machined finish of the legs was not very good which did not help matters as they slid through the bronze bush. They should have a ground finish.
Over the decades I have even seen Commando forks assembled with Dommy length damper tubes which not only restrict fork movement but means that as the forks extend the mechanical end stop takes place in the damper tube. If you check the full movement within the damper tube and then the movement of the main tube within the fork bottom you will find there is more movement in the damper tube so that when correctly set up on the damper rod in the fork tube top not then with the forks on either full extension or compression the damper assembly NEVEr becomes the mechanical end stop. From memory there is approx 1/8 inch more travel in the damper assembly.
Are your fork yokes bent??
I wonder which dealer supplied the fork legs??? I must remember to ask but I bet my guess will be correct!!
1. The fork legs(main tubes) were oversize . Never assume new main tubes have been CORRECTLY manufactured. I doubt any dealer checks them as they receive them from the manufacturer... I once checked a batch coming into a friends shop...rthey were ALL 0.002 inch under the minimum size quoted in the workshop manual....the dealer sold them all and apart from the two pairs I took and had hard chromed /ground back to correct size only one customer returned a pair as incorrect and he was a German customer.....which proved that the average British bike owner does not check the bits they buy!!
2. At the bottom of the main tubes they are machined tro take the steel fork tube bush......the IDIOTS who manufactured the legs had machined this area 0.007 inch NON concentric to the rest of the leg resulting in the forks sticking / jamming as they extended.
3. The machined finish of the legs was not very good which did not help matters as they slid through the bronze bush. They should have a ground finish.
Over the decades I have even seen Commando forks assembled with Dommy length damper tubes which not only restrict fork movement but means that as the forks extend the mechanical end stop takes place in the damper tube. If you check the full movement within the damper tube and then the movement of the main tube within the fork bottom you will find there is more movement in the damper tube so that when correctly set up on the damper rod in the fork tube top not then with the forks on either full extension or compression the damper assembly NEVEr becomes the mechanical end stop. From memory there is approx 1/8 inch more travel in the damper assembly.
Are your fork yokes bent??
I wonder which dealer supplied the fork legs??? I must remember to ask but I bet my guess will be correct!!
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J. M. Leadbeater said:
That's not correct, the damper tubes and rods always act as the extension stops in standard Commando forks.
http://atlanticgreen.com/forks.htm
http://www.nocnsw.org.au/technical/norton-roadholders
http://www.britbike.com/ubb/bin/ultimat ... tml#000008
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John Roberts kit provides improved dampening but the early version (pre 2010) still had the top out clunk. The later versions of his excellent kit produced after 2010 should slow down the top out jolt depending on how it is adjusted. I'm not sure if there is a top out dampening provision or if it is the heavier improved dampening that lessens the top out.
For quiet top out you can use the rivet method described in the post above or plug it up with a small set screw (below the fork tube surface) as described below (these are instructions).
WARNING – you must plug the 1/8” diameter oil escape hole in the bottom of the fork tube (just above the lower bushing) or you will not get the necessary oil cushion to prevent “top out”. Thread the 1/8” hole with a 6-32 tap and use the provided set screws (coat the threads with JB weld epoxy (best) or red loctite to keep them in place). Make sure the set screws are not proud of the surface or installed too deeply. Smooth any leftover burrs off with fine abrasive. Failure to plug the 1/8” holes could result in damage to the Turkite fork bushings because of harsh topout. Use 20 wt fork oil for stock dampers.
You need aluminum sleeves that press into the alum fork legs so that the holes near the lower fork bushing will be covered by the sleeves when the forks reach pull extension. You can make your own from tubing. They must not be loose in the fork legs or the oil escape hole will be covered all the time and you don't want that - you only want them covered at full extension. The sleeves don't do their job unless the 1/8" holes are plugged as described in the above paragraph.
Place the upper sleeves between the upper and lower fork bushings as in left photo. Place the slit in the aluminum slider so it is located opposite the large hole near the bottom of the steel fork tube. When assembling the forks you will have to pinch the upper sleeve slightly to get it started into the aluminum fork slider. If the sleeve is too loose to stay located at the top of the aluminum fork slider – open the gap slightly.
[Note that if you have slit sleeves that press in under tension - the slit must be only 1/32" wide when installed in the fork leg or you will lose the necessary dampening action. I use a thin jeweler saw to cut the slit.]
The early Commandos had a bottom out clunk problem. This was prevented with later models. To prevent the bottom out clunk with stock dampeners see below.
For early fork dampers with holes below the conical section, place lower sleeve at bottom of damper tube to cover the holes (so it abuts against cone) as in photo above right. Use sealer, JB epoxy or loctite to hold them in place. If there are no holes in the conical section or just above it, drill two ¼” holes just above the conical section as in the photo above right. If there are no holes below the conical section to cover up but there are holes in the upper/central conical section or just above it as in the photo, then you have late model forks and do not need the bottom aluminum sleeves. See below.
For quiet top out you can use the rivet method described in the post above or plug it up with a small set screw (below the fork tube surface) as described below (these are instructions).
WARNING – you must plug the 1/8” diameter oil escape hole in the bottom of the fork tube (just above the lower bushing) or you will not get the necessary oil cushion to prevent “top out”. Thread the 1/8” hole with a 6-32 tap and use the provided set screws (coat the threads with JB weld epoxy (best) or red loctite to keep them in place). Make sure the set screws are not proud of the surface or installed too deeply. Smooth any leftover burrs off with fine abrasive. Failure to plug the 1/8” holes could result in damage to the Turkite fork bushings because of harsh topout. Use 20 wt fork oil for stock dampers.
You need aluminum sleeves that press into the alum fork legs so that the holes near the lower fork bushing will be covered by the sleeves when the forks reach pull extension. You can make your own from tubing. They must not be loose in the fork legs or the oil escape hole will be covered all the time and you don't want that - you only want them covered at full extension. The sleeves don't do their job unless the 1/8" holes are plugged as described in the above paragraph.
Place the upper sleeves between the upper and lower fork bushings as in left photo. Place the slit in the aluminum slider so it is located opposite the large hole near the bottom of the steel fork tube. When assembling the forks you will have to pinch the upper sleeve slightly to get it started into the aluminum fork slider. If the sleeve is too loose to stay located at the top of the aluminum fork slider – open the gap slightly.
[Note that if you have slit sleeves that press in under tension - the slit must be only 1/32" wide when installed in the fork leg or you will lose the necessary dampening action. I use a thin jeweler saw to cut the slit.]
The early Commandos had a bottom out clunk problem. This was prevented with later models. To prevent the bottom out clunk with stock dampeners see below.
For early fork dampers with holes below the conical section, place lower sleeve at bottom of damper tube to cover the holes (so it abuts against cone) as in photo above right. Use sealer, JB epoxy or loctite to hold them in place. If there are no holes in the conical section or just above it, drill two ¼” holes just above the conical section as in the photo above right. If there are no holes below the conical section to cover up but there are holes in the upper/central conical section or just above it as in the photo, then you have late model forks and do not need the bottom aluminum sleeves. See below.
Craig
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All true and very detailed explanation .... thanks for that ... but never heard a fork rattle from topping out or bottoming .... usually it was the head light ears that rattled or some other loose component .... that was part of the question ... and yes my fork kit is post 2010 ... thanks again ...
Craig
Craig
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