Narrow Air Cleaner (2019)

marshg246 · Oct 24, 2019

I've written K&N again. Their E-3410 special order filter might work. It's a good height, and only a little smaller than desired diameter. 8.125" diameter is correct, the E-3410 is 7.75". If it is flexible enough, this it might work out.

I've spent way to much money ordering ridiculously expensive filters to try that ended up not working.

maylar · Oct 24, 2019

johnm said:
Only slightly off topic. This is the shortened air cleaner we made for use with the CNW starter. I preferred to retain as much of the classic look as possible. Uses a standard air cleaner but just cut, shortened and reglued.

The side bolts moved up, shortened and slim plates added to clear the frame tubes at this point

Now I have seen the slimmer one I wonder if it would have worked too. I shall check when I get the bike assembled. Just picked up the refurbished engine this morning.

Where did you get that made? I'm also using a CnW starter and would be very interested in losing the tiny K&N.

marshg246 · Oct 24, 2019

marshg246 said:
I've written K&N again. Their E-3410 special order filter might work. It's a good height, and only a little smaller than desired diameter. 8.125" diameter is correct, the E-3410 is 7.75". If it is flexible enough, this it might work out.

I've spent way to much money ordering ridiculously expensive filters to try that ended up not working.

They wrote me back and said that it is flexible. The height is better than the RGM filer. It is 7.75" diameter (approximately 8.125 is stock and the RGM is 8.25") and 2.063 (52mm) high (approximately 2.9" is stock). The RGM is 1.9" high - slightly higher will be fine and will make the hoses work better. I hope this works or I've thrown away another $45!

johnm · Oct 24, 2019

maylar said:
Where did you get that made? I'm also using a CnW starter and would be very interested in losing the tiny K&N.

It was made by a friend in Wellington New Zealand. I bought a spare set of original air box parts and we made a wooden former to shape the shortened front piece. It was then welded and ground smooth. The grill was easy just cut rebent and tack welded. The air cleaner is standard just shortened and reglued. The air cleaner area should be ok however I have not tested it yet. The tank breather outlet will require a new home.

you can see in the photos that the finish is not perfect yet but I’ll sort that once I have tested it out.

Tornado · Oct 24, 2019

marshg246 said:
They wrote me back and said that it is flexible. The height is better than the RGM filer. It is 7.75" diameter (approximately 8.125 is stock and the RGM is 8.25") and 2.063 (52mm) high (approximately 2.9" is stock). The RGM is 1.9" high - slightly higher will be fine and will make the hoses work better. I hope this works or I've thrown away another $45!

That's great hear. Can we get a part number for future reference?

Seems that's a great solution for a do it yourself kit as the stock commando grill can be cut back and some shorter bolts fitted no need for future filter replacements.

Steves · Oct 24, 2019

I used to struggle changing the airfilter and thought about changing to the thinner version. Then I thought it's just more money for something that probably is not required.
I now change an airfilter with little effort in about 20 mins. I unscrew the carbs at the cylinder head, pull them out the way, change filter then reverse back. Bit fiddly with the 2 inside bolts, use lock washers!

johnm · Oct 24, 2019

Steves said:
I used to struggle changing the airfilter and thought about changing to the thinner version. Then I thought it's just more money for something that probably is not required.
I now change an airfilter with little effort in about 20 mins. I unscrew the carbs at the cylinder head, pull them out the way, change filter then reverse back. Bit fiddly with the 2 inside bolts, use lock washers!

I agree. With a ball ended Allen key of the right length it’s easy to unscrew the inner screws and move the carbs

cyclegeezer · Oct 24, 2019

maylar said:
Where did you get that made? I'm also using a CnW starter and would be very interested in losing the tiny K&N.

Matt claims to be working on one for CNW. Email him and get notified when they're made.

marshg246 · Oct 24, 2019

Tornado said:
That's great hear. Can we get a part number for future reference?

Seems that's a great solution for a do it yourself kit as the stock commando grill can be cut back and some shorter bolts fitted no need for future filter replacements.

Sorry, said it earlier but didn't think about the number again, it's E-3410. I'll report back when it arrives. Like all K&N filters - silly expensive but if it really is the last filter needed then maybe OK.

marshg246 · Oct 24, 2019

Steves said:
I used to struggle changing the airfilter and thought about changing to the thinner version. Then I thought it's just more money for something that probably is not required.
I now change an airfilter with little effort in about 20 mins. I unscrew the carbs at the cylinder head, pull them out the way, change filter then reverse back. Bit fiddly with the 2 inside bolts, use lock washers!

Yes, that's how I've been doing it. I have three stubby ball-end Allen wrenches that help get it done - they are identical except that I twisted two of them so I have different ball angles. Still, it's a little ridiculous to remove a carb to change an air filter.

I don't like cussing bikes and old engineers that cannot defend themselves.
I don't like having to remove the air cleaner and front cover just to change the Amal banjo filters.
I don't like not being able to use 5/16" fuel lines like I do an every other British bike I own.
I don't like removing a carb to get the air filter and front plate off to manually sync the carbs, then putting it all back together.

rvich · Oct 24, 2019

Maybe a bit late to the party as I see a filter has been ordered, but K&N have two filters of interest that I found. The E-2570 which is 8.188 outside diameter, 1.875 in height listed as flexible. The E-2600 is 8.188 X 2.188, flexible.

I suppose these may be the ones you have already tried. Its hard to tell from the photos on the web site whether they could be shaped to the ham can.

marshg246 · Oct 24, 2019

rvich said:
Maybe a bit late to the party as I see a filter has been ordered, but K&N have two filters of interest that I found. The E-2570 which is 8.188 outside diameter, 1.875 in height listed as flexible. The E-2600 is 8.188 X 2.188, flexible.

The E-2570 is not flexible nor is the Wix version of it - already wasted that money. K&N support tells me that E-2600 is not flexible enough either. I sent them an exact, full size drawing of the gauze and the desired diameter range and height range - they said that they had nothing flexible enough to go in it at the sizes needed.

The E-3410 is a little smaller diameter and they told me today that is it flexible enough. It appears to be made like their full-sized OEM-type filter - I certainly hope so!

Steves · Oct 25, 2019

marshg246 said:
Yes, that's how I've been doing it. I have three stubby ball-end Allen wrenches that help get it done - they are identical except that I twisted two of them so I have different ball angles. Still, it's a little ridiculous to remove a carb to change an air filter.

I don't like cussing bikes and old engineers that cannot defend themselves.

I don't like having to remove the air cleaner and front cover just to change the Amal banjo filters.

I don't like not being able to use 5/16" fuel lines like I do an every other British bike I own.

I don't like removing a carb to get the air filter and front plate off to manually sync the carbs, then putting it all back together.

Agree with point one. Not sure about 2, if I decide to clean the filters (rare) I can do it in situ. It is a right pain getting the second one started screwing in because of the fuel balance pipe being (probably) like 1mm too short, there is a technique though which can be a struggle to remember from the last time. Not sure what size fuel lines I have, they are crimped. Carbs seem to stay in sync when removed. I pull the slides out protect and tie off top of the frame. I sync the carbs without the engine running except for the pilot circuit and a final check with manometer.
Absolutely it's ridiculous to take the carbs off to change the air filter, but for me it's just easier. I think the thinner ham can is a good idea, I just didn't want to spend the money.

Tornado · Oct 25, 2019

I've been using a micro ratchet to get at the Allen head mani bolts insitu. Seems to work ok though might cut down the hex bit to make it just a little shorter so overall length can clear things better as bolt winds out.

cliffa · Oct 25, 2019

I've just found an old thread on this very subject ..

https://www.accessnorton.com/Norton...filter-smaller-has-anybody.13641/#post-193232

Tornado · Oct 25, 2019

Any recommendations on how to cut down the steel oem grill for those with limited tooling at hand? A band saw seems best but that ain't gonna be possible for me. I have a spare oem grill that I got when buying the K&N oem filter....guy wanted $75 for just the filter or $50 total for filter & complete HamCan with new rubbers ;-)

Tornado · Oct 25, 2019

marshg246 said:
The E-2570 is not flexible nor is the Wix version of it - already wasted that money. K&N support tells me that E-2600 is not flexible enough either. I sent them an exact, full size drawing of the gauze and the desired diameter range and height range - they said that they had nothing flexible enough to go in it at the sizes needed.

The E-3410 is a little smaller diameter and they told me today that is it flexible enough. It appears to be made like their full-sized OEM-type filter - I certainly hope so!

Seems a user in the thread Cliffa linked to states that E-2570 worked for him:

"Re: making the commando stock air filter smaller, has anybod

K&N Norton spec'd Filter:

K&N NO-0100
Height = 2.875"
Inner Diameter = 6.875"
Outer Diameter = 8.125"

What I used with the shortend assembly:

K&N E-2570
Height = 1.875"
Inner Diametr = 6.25"
Outer Diameter = 8.188"

Where I ordered it from:

http://www.summitracing.com/parts/knn-e-2570

Can flow all the CFM the engine can use and then some. No problems with restriction (unless you have the ultimate flowed, ported, cc'd overbored race engine)
Fine for my stock 850 with the FCR's and more CFM that the individual filters that are supplied with the FCR kit."

https://www.accessnorton.com/Norton...filter-smaller-has-anybody.13641/#post-193230

When you say it's not flexible how is it made rigid, can it not be forced?

cliffa · Oct 25, 2019

OK, dumb question I know, but being a relatively new Commando owner of only 3 years, may I ask why the narrower air cleaner is wanted anyway?

Cheers,

cliffa.

maylar · Oct 25, 2019

Easier to get on and off the bike. As some have noted, it's actually quicker and easier to remove the carbs and manifolds first. A royal PITA.

cliffa · Oct 25, 2019

I haven't tried it myself, but what is the tough bit - the boots going back on, or just finagling the filter element out and back in?

For folks such as me who have the Madass140 single pull setup, it's not as easy to remove the carbs as they only come off as a pair without quite a bit more dismantling.

Narrow Air Cleaner (2019)

Similar threads