Well, that went well.

barbagris

Mad Scientist
Joined
Aug 1, 2010
Messages
12,988
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On the verge of insanity
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1979 Guzzi V1000G5 - 2018 KTM 790 Duke
I determined a while ago that my upgraded forks were a wee bit soft as every so often they would "just" bottom out. Maxton advised a lesser air gap - i.e. more oil.

So this morning after a short "lie in" - I descended into the dungeon and stripped the front end - and raced (as fast as one can in a 22 year old diesel Land-Rover) over to my local suspension place.

They dismantled and re-filled to 120mm air gap (as opposed to Maxtons original 170mm and revised 140mm-130mm) according to their bespoke tables. The program actually said 117.6mm. This was surprisingly done FREE.

Returned home and reassembled with no issues. Checked headstock - no movement.

Off to the pool to cool off. Road test tomorrow, after I re-examine all nuts/bolts etc.

:)
 
I determined a while ago that my upgraded forks were a wee bit soft as every so often they would "just" bottom out. Maxton advised a lesser air gap - i.e. more oil.

So this morning after a short "lie in" - I descended into the dungeon and stripped the front end - and raced (as fast as one can in a 22 year old diesel Land-Rover) over to my local suspension place.

They dismantled and re-filled to 120mm air gap (as opposed to Maxtons original 170mm and revised 140mm-130mm) according to their bespoke tables. The program actually said 117.6mm. This was surprisingly done FREE.

Returned home and reassembled with no issues. Checked headstock - no movement.

Off to the pool to cool off. Road test tomorrow, after I re-examine all nuts/bolts etc.

:)
so you spent all that money on Maxtons and they werent perfect !my god
 
I determined a while ago that my upgraded forks were a wee bit soft as every so often they would "just" bottom out. Maxton advised a lesser air gap - i.e. more oil.

So this morning after a short "lie in" - I descended into the dungeon and stripped the front end - and raced (as fast as one can in a 22 year old diesel Land-Rover) over to my local suspension place.

They dismantled and re-filled to 120mm air gap (as opposed to Maxtons original 170mm and revised 140mm-130mm) according to their bespoke tables. The program actually said 117.6mm. This was surprisingly done FREE.

Returned home and reassembled with no issues. Checked headstock - no movement.

Off to the pool to cool off. Road test tomorrow, after I re-examine all nuts/bolts etc.

:)
That's quite an increase in air gap over stock , any idea how much oil is in each leg ?
 
the air gap is for the oil to have a place to go.
so when u hit the brakes if u have to much oil it will blow out the seals.
when i first got my bike with 6000 miles i hit the brakes hard and the oil blew out the left fork seal.
if it was mine i would not increase amount of oil.
 
That's quite an increase in air gap over stock , any idea how much oil is in each leg ?
Nope - Maxton sent the units specifying fill to AIRGAP 170 and that's what DMX did for me. Maxton did not fit them.

On the whole the ride is SPOT ON - I had to back out the rebound adjusters a bit when I fitted higher bars and took my weight off the forks but the ride is excellent. They are VERY sensitive to any change in the adjustment. Only had them bottom out a max of 10 times since fitted in Sept - And all but 2 of those on one particularly aggressive and badly placed "sleeping policeman" (speed bump) on our estate. But nonetheless it's been a niggling thing that has had me backing off the throttle in the tight twisties. Today was simply "the day" to do it. Just woke up and thought - forks.

When I contacted Maxton a couple of months back they advised they had revised the air gap to 130/140. A substantial DECREASE in air gap. And also suggested this rather than up the springs. Called DMX as well and they advised the same - more oil.

Damian at DMX knows how much disassembly is involved on my R3 - and today he said " Do you want me to put the air gap at the minimum?". When he said only 10mm less than Maxtons revised level - seemed reasonable. All this should really do is reduce nose diving. Though I suspect a bit of a stiffer spring effect. This will suit my riding style.

Worth mentioning that the smaller front tyre 150/70 and bigger rear 240/55 means the weight transfer rear-front is more pronounced due to axle height changes and Maxton probably do not know this. It was @1olbull who made me aware of this detail. Not something I had even considered before. A stock R3 notably does not dive much - but I had attributed this to the weak OEM springs and thus reduced real suspension travel. There's more to it.
 
the air gap is for the oil to have a place to go.
so when u hit the brakes if u have to much oil it will blow out the seals.
when i first got my bike with 6000 miles i hit the brakes hard and the oil blew out the left fork seal.
if it was mine i would not increase amount of oil.
Given that DMX are suspension guys and only that - if they say they fit refurbish and service USD Kayaba 43mm with a minimum 120mm air gap - I trust them implicitly.

And the air gap usually ime is measured at full compression so it's really an air spring not somewhere for oil to go. Most folk don't measure air gap - they just tip "x" oil in.

Too much oil will blow out a seal - but so will weak seals. Usually though you will hit an almost hydraulic lock before that happens. ime. Mine have over spec'd Ohlins seals in.
 
Given that DMX are suspension guys and only that - if they say they fit refurbish and service USD Kayaba 43mm with a minimum 120mm air gap - I trust them implicitly.

And the air gap usually ime is measured at full compression so it's really an air spring not somewhere for oil to go. Most folk don't measure air gap - they just tip "x" oil in.

Too much oil will blow out a seal - but so will weak seals. Usually though you will hit an almost hydraulic lock before that happens. ime. Mine have over spec'd Ohlins seals in.
Yes I guess air gap is all that can be adjusted unless one goes for custom springs .
Does anyone do them for the R3 ?
 
Yes I guess air gap is all that can be adjusted unless one goes for custom springs .
Does anyone do them for the R3 ?
Pretty much all the cartridge mfrs (both side of Atlantic) seem to recommend about 1kg/mm. With about 30mm preload.
Maxton have 1.1kg/mm springs but advised against it for my weight - fatties :p may need them.
The US place I looked at for @Joesmoe had 1.2kg/mm too. You'd need to get the spacers made up so Static and Dynamic Sag matched.If Maxton had said bigger springs I would have done so. But tbh the ride is perfect - it's just the excess of travel and the pneumatic bump-stop is now substantially stiffer.

Pretty much any spring mfr can make custom springs and if you decide to do so - they should be just that - custom.
I have done this in the past for bikes when adding big frame mount fairings etc. Used to use a place next door to Rickman Bros.
Simply pre-loading more often leads to springs binding before full travel is reached.
Especially tricky with dual rated or progressive rated springs.

tbh - I wanted to convert the forks to Pneumatic springing to match the Fournales rears.
Kayaba do MX forks with air springs. But Fournales did not want to get involved (fair enough) and DMX indicated that the price would be a little prohibitive.
So like all of us I rune spring/air hibrids. I did look at converting the stock forks to Air Adjusted forks - but ran out of ingenuity at a key moment.
 
Pretty much all the cartridge mfrs (both side of Atlantic) seem to recommend about 1kg/mm. With about 30mm preload.
Maxton have 1.1kg/mm springs but advised against it for my weight - fatties :p may need them.
The US place I looked at for @Joesmoe had 1.2kg/mm too. You'd need to get the spacers made up so Static and Dynamic Sag matched.If Maxton had said bigger springs I would have done so. But tbh the ride is perfect - it's just the excess of travel and the pneumatic bump-stop is now substantially stiffer.

Pretty much any spring mfr can make custom springs and if you decide to do so - they should be just that - custom.
I have done this in the past for bikes when adding big frame mount fairings etc. Used to use a place next door to Rickman Bros.
Simply pre-loading more often leads to springs binding before full travel is reached.
Especially tricky with dual rated or progressive rated springs.

tbh - I wanted to convert the forks to Pneumatic springing to match the Fournales rears.
Kayaba do MX forks with air springs. But Fournales did not want to get involved (fair enough) and DMX indicated that the price would be a little prohibitive.
So like all of us I rune spring/air hibrids. I did look at converting the stock forks to Air Adjusted forks - but ran out of ingenuity at a key moment.
Surely not ? :p
 
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