Chaps
when referring to a "cutt down axle" in Clubman - to what extent are we talking? How much do you take off the axle from 1030mm say - and do different people vary it i.e. personal preference?
I presume a cut down axle will flex less and provide more grip - so would this place a cut down medium in between a standard medium and a standard hard?
cheers
Dave
when referring to a "cutt down axle" in Clubman - to what extent are we talking? How much do you take off the axle from 1030mm say - and do different people vary it i.e. personal preference?
I presume a cut down axle will flex less and provide more grip - so would this place a cut down medium in between a standard medium and a standard hard?
cheers
Dave
Views: 2007
Comments12
As far as cut down axles dave, im not sure as to which give grip and what not, however as a rule of thumb alot of people cut the axle down to maybe 1mm / .5 mm to the edge of the keyway, or at the edge of the keyway.
Cheers Fongy!
I'm sure theres some NASA type explanation of what it does - makes it come on quicker / go off sooner / more grip / less feel / more jacking / less bite!
As far as I have been told dave(I only EVER ran the m1 cutdown) it does make it shoot off the corner, as far as feel and all that, i'm not really sure, as we hardly ever changed it. The only day that we did do it, go from a medium, to a medium cut down is that it came off the corner half a tenth quicker....(add those half tenths up over a series of corners, and u'd be pleasantly surprised)...
Gary, I have nothing to hide, so there is nothing secret squirel about this.
I just pulled out the old setup sheets, and it did confirm that at most tracks that the comments I had written down was that it did confirm that the best times were achieved with a cut down axle, and that it felt a little bitter off the corner. It doesn't feel like a great amount off the corner, however the time sheets(data) showed that half a tenth of the corner, and over a series of corners added up to a great deal off time!
I love these topics as these are questions i asked my self and answered my self with a huge amount of data to back it up!
So here we go IMO ! Take a med axle at 1040mm and set some times you will feel the kart will have good entry to apex and feels good off every turn! now massage it down to a 1020 ( most common and practical length) you will now notice that the kart is more nimble and changes direction quicker, the only trade off is fast flowing corners your wheel work is more as the rear continually moves around. So theories say that it reduces the bind through the corner as it allows for a different ( rate of lift ) (nice terminoligally Col) hope you dont mind that i used it. causing the chassis to feel free off of every turn.
My Mychron data revealed that out of the tighter turns we benefited to the tune of 180 - 230 more rpm on a more consistent basis and the flowing corners was a massive 300rpm! time wise and this has been tested twice is 2 /10ths at my local track. I could go on for hours and give example to what it did for hp increase on the logger but all you need to know is it is worth a try .
Now try it with a Hard axle!
Bloody good answer David - cheers! so 1020mm is about the length to aim for....
As stated David it is the most practical length! i have seen axles under a metre! but it requires a cnc to cut new key ways.
Get chopping, lol
David Plumb said:Bloody good answer David - cheers! so 1020mm is about the length to aim for....
or none of the above and is just another karting folklore/red herring secret squirrel tips :)
Alright, so you've probably all gathered by now that I HATE it when people "pass on" setup "secrets" that they've not tested, nor have any way of knowing whether they're fact or fiction. And the great thing is, we've had great replies in this thread from two people who HAVE TESTED IT!!
I love it!
Okay, so if Dave and Fongster can confirm for us that there's definitely a change in the behaviour of the kart, let's have an educated guess at the physics of it...
1. We know from using longer and shorter hubs, that changing the flex characteristics of the kart between the bearing hanger and the tyre definitely changes the feel of the kart.
2. If you cut down the axle, but run the SAME rear track, then more of the hub is now "hanging off" the end of the axle. This allows a hub of the same length, to behave as though it were softer.
3. Going softer in this area will give you a SOFTER roll stiffness, and a FASTER rate of lift (in almost all conditions). The great thing is, it's a very predictable change, so you can use it to your advantage.
Real world example:
Matt "Mutt" Hayes and Andrew "Merx" Mercuri both racing the same kart in Clubman Light at the 2005 SA Open, at Bolivar (possibly the grippiest meeting I've ever attended). All throughout practice, they are doing very similar times, and running very similar setups. Come qualifying, Merx runs a short hard (1015mm) axle, Mutt takes a risk, banks on the the track getting grippier and requiring a SLOWER rate of lift, and goes the full length hard (1050mm).
Result?
Merx gripped up something fierce on the sweeper coming onto the straight by lap three, Mutt did his fastest lap on the last lap and qualified pretty well... With exactly the same setup - other than the axle length.
Finally Mr Plumb, 1015-1020 is the usual length for my cut-down DPE axles, although the 1000mm Tony Kart "N" is a lovely option for Clubman Light as well...
Also, if you want to run a shorter axle than the current keyways, and don't have a milling machine, you can just drop a spot of weld at the "open" end of the keyway (to stop the key from falling out), and use a shorter key.
Col
I'm testing and Racing this weekend and hence just do not have the time to do your reply justice! It would take me the weekend to follow it!
As ever mate - Brilliant help and precisely why this site is becoming an essential part of a new Karters source knowledge
Thanks mate and bloody well done on the site / KRacer and the great Vid's
Cheers
Dave
hello,
some one got it right....
i cut them to the key way when i run them, or you can buy them in a short version.....
Col Fink said:or none of the above and is just another karting folklore/red herring secret squirrel tips :)Alright, so you've probably all gathered by now that I HATE it when people "pass on" setup "secrets" that they've not tested, nor have any way of knowing whether they're fact or fiction. And the great thing is, we've had great replies in this thread from two people who HAVE TESTED IT!!I love it!Okay, so if Dave and Fongster can confirm for us that there's definitely a change in the behaviour of the kart, let's have an educated guess at the physics of it...1. We know from using longer and shorter hubs, that changing the flex characteristics of the kart between the bearing hanger and the tyre definitely changes the feel of the kart.2. If you cut down the axle, but run the SAME rear track, then more of the hub is now "hanging off" the end of the axle. This allows a hub of the same length, to behave as though it were softer.3. Going softer in this area will give you a SOFTER roll stiffness, and a FASTER rate of lift (in almost all conditions). The great thing is, it's a very predictable change, so you can use it to your advantage.Real world example:Matt "Mutt" Hayes and Andrew "Merx" Mercuri both racing the same kart in Clubman Light at the 2005 SA Open, at Bolivar (possibly the grippiest meeting I've ever attended). All throughout practice, they are doing very similar times, and running very similar setups. Come qualifying, Merx runs a short hard (1015mm) axle, Mutt takes a risk, banks on the the track getting grippier and requiring a SLOWER rate of lift, and goes the full length hard (1050mm).Result?Merx gripped up something fierce on the sweeper coming onto the straight by lap three, Mutt did his fastest lap on the last lap and qualified pretty well... With exactly the same setup - other than the axle length.Finally Mr Plumb, 1015-1020 is the usual length for my cut-down DPE axles, although the 1000mm Tony Kart "N" is a lovely option for Clubman Light as well...Also, if you want to run a shorter axle than the current keyways, and don't have a milling machine, you can just drop a spot of weld at the "open" end of the keyway (to stop the key from falling out), and use a shorter key.
Wow, this is a completely new idea to me. So you are cutting down axles, but keeping the same rear track? Wouldn't that have approximately the same effect as using shorter hubs while keeping the same rear track?
And if you make the track narrower when cutting the axle, then what's the point of cutting down the axle? I don't see how cutting off the part of the axle that normally would stick out of the hub inside the wheel would make a big difference to handling.
I am really NOT the person to answer this mate - but I think its all about Flex? and tyre usage....?