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midlife

240 head mod

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 I was going to powder coat the frame on my 240 and have moved the footrests and thought I might steepen the fork rake how much do you steepen the forks or is it not worth it.

I there any one with pics to show where to cut.

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Leave headstock alone. Buy some new yokes. They are out there. Try Audit CNC. (Ad in Classic Dirt Bike)

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Cutting the headstock can be one method to alter the steering head angle, however you need to have  a good knowledge of what you are doing and the correct methods to employ. Welding back to the frame needs to be done by a competent operator. Quickening the steering is the reason for this mod and I would doubt its needed when you can as pjw123 suggests replace the yokes, this gives you the option to return the bike to standard. There are lots of people cutting their frames and altering this and that but it looks to me like it’s a fad thing as you don’t see these people getting any better results maybe a confidence booster in some cases. Another way to quicken the steering without massive metalworking is to just fit slightly longer rear damper/spring units or move the locating points ( a bit more complicated then it seems. Road bike riders often raise the forks at the front end ..actually sounds daft but the forks are raised up through the yokes by x amount of mm. As you are an advanced member you might already know some of this, but you have a very good handling bike as it is, assuming it’s in fine fettle and may just benefit from reappraising the initial set up and your riding....no disrespect intended here...? Over to the ‘head mods’ dept.?

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5 hours ago, b40rt said:

If anything needs a head mod its you ?

Is there not any footage off what a 240 Fantic could manage "back in the day"  these bikes were brilliant and with modern tyres it would be a scary we bike.

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17 hours ago, breagh said:

Is there not any footage off what a 240 Fantic could manage "back in the day"  these bikes were brilliant and with modern tyres it would be a scary we bike.

Heck, I saw what a 240 could do at the Mosteller Cup this year.  Young gun Nigel Parker rode one in the morning doing flick turns, hopping both wheels, and generally riding it like no 240 was ever designed to be ridden.  He went on to ride his Sherco in the afternoon, earning an Ironman.  The 240 was neither restored nor restomodded, it was an original survivor.  :thumbup:

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A weak point on 240 frames is the head stock braces. They will flex and crack and inevitably the steering angle will increase, not what you want at all. As most have suffered this they and need to be pulled in and the braces strengthened or replaced. Many owners decide while they're at it a steeper would be a worth while. To check yours put the bike on a stand measure from the front spindle to the swingarm pivot, it should be 890mm center to center. My 240 is 5mm over and due some work. I have measured some modified bikes and 870mm is common so subtle tweak but given the damage it's quite an improvement. I had a one once that measured about 900mm! 

An unmodified original 240 is perfectly usable without modification so if yours isn't damaged the choice is yours but worth while if it needs adjusting.

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Just for peoples info, I recently replaced the triple clamps (yokes) on my 300 with some lovely steepened alloy jobs from Gerry Minshall. The standard front axle to swingarm pivot measurement was near identical to that of the 240 being 893mm and that measurement would obviously vary slightly depending on where one runs his fork tubes in the clamps.

With the new alloy clamps the front axle to swingarm measurement is now 875mm so my wheelbase is now nearly 20mm shorter, my angle finder tells me approx 1.5 degrees steeper now.  I haven't had it out for a ride in the bush yet so cannot make any comment on the changes. Pic below is how it looks with new clamps.

 

003.jpg

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Interesting stuff fourex. I was recently discussing this modification with some classic trials friends and the unknown factor was how will this effect the feel of the steering especially on full lock. Will it tend to tuck under? Be interested to hear how you find it rides.

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3 hours ago, fantic240motor said:

Interesting stuff fourex. I was recently discussing this modification with some classic trials friends and the unknown factor was how will this effect the feel of the steering especially on full lock. Will it tend to tuck under? Be interested to hear how you find it rides.

Yeah, don't hold your breath though as our Trials season is over.  It's stinking hot at this time of year in Australia, last couple of days mid 30's in Brisbane and it doesn't get much better for a while.  I know this sounds like an excuse which it is, but I will probably not ride it in a Comp Trial until Feb/March 2019 which will be the best test. I do hope to have a practice/ play session or two before then so will happily keep you up to date when that happens. 

Definitely no reason to modify a frame as 'midlife' originally thought when triple clamps might give the desired outcome provided the frame isn't already stretched as you have thoughtfully pointed out.

Edited by fourex
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22 hours ago, fantic240motor said:

Interesting stuff fourex. I was recently discussing this modification with some classic trials friends and the unknown factor was how will this effect the feel of the steering especially on full lock. Will it tend to tuck under? Be interested to hear how you find it rides.

I'm also curious whether the back of the front mudguard might foul on the exhaust on full compression, time will tell. At least I can revert back to original clamps if it doesn't work out (expensive exercise however), a frame cut and shut cannot be so easily reversed.

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2 hours ago, fourex said:

I'm also curious whether the back of the front mudguard might foul on the exhaust on full compression, time will tell. At least I can revert back to original clamps if it doesn't work out (expensive exercise however), a frame cut and shut cannot be so easily reversed.

Quote

During your hot spell take the chance to remove the springs and find out if the mudguard catches on the pipe.  Better than discovering in a more dramatic fashion.

 

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On 11/30/2018 at 6:29 PM, 2stroke4stroke said:

 

Now that you have me thinking on a Friday arvo after a few 'xxxx' bitter ales, no need really to pull internals , just loosen clamps, remove bars and drop forks through. This will tell me if anything is going to snag, hey?  But as others have said, it's unlikely to be a problem because otherwise it wouldn't be an aftermarket option.  " fantic240motor" your input is good.

Edited by fourex
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On ‎11‎/‎28‎/‎2018 at 5:40 AM, brewtus said:

Heck, I saw what a 240 could do at the Mosteller Cup this year.  Young gun Nigel Parker rode one in the morning doing flick turns, hopping both wheels, and generally riding it like no 240 was ever designed to be ridden.  He went on to ride his Sherco in the afternoon, earning an Ironman.  The 240 was neither restored nor restomodded, it was an original survivor.  :thumbup:

I've ridden with Nigel a couple of times, His dads fantic I think , You should see Ryan Young on My 240 ! he knows how the gravity switch works ; I haven't figured that part out yet

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On 11/30/2018 at 8:18 PM, fourex said:

Now that you have me thinking on a Friday arvo after a few 'xxxx' bitter ales, no need really to pull internals , just loosen clamps, remove bars and drop forks through. This will tell me if anything is going to snag, hey?  But as others have said, it's unlikely to be a problem because otherwise it wouldn't be an aftermarket option.  " fantic240motor" your input is good, no need to delete.

For anyone interested, I dropped the forks all the way through the clamps and as below slight fouling, but in reality they would never be this compressed. The second pic is closer to the real world, bye the way it's only 35 degrees at the moment and this is down stairs in our garage/workshop which is all brick and concrete being the coolest place to be.

 

001.jpg

003_(2).jpg

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