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Old 07-07-2008, 10:28 AM   #1
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Default The Spool Shimmy

No, its not the latest craze sweeping the nation's dancehalls - it is a little handling trait I have noticed - and I wondered whether other people had too.

When you run a front spool, quite often you can get a wiggle from the rear end when you put the power down hard out of a corner.

On flowing grippy tracks this phenomenon isn't a problem, but I raced over the weekend at a tight carpet track that started off "green", and with rubber tyres the car could be quite a handful, pitching off-line so much at times that I hit the track markers at certain places.

Switched to the diff and the car was a lot more settled, a lot more consistent and a lot faster as a result.

Technically I imagine it is something to do with inside front wheel being over-driven compared to the rear, or the forces from the spool trying to straighten out the steering too suddenly.

Is this something that other people have experienced too? If so, how did you tune it out, or do you just learn to deal with it?
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Old 07-07-2008, 01:50 PM   #2
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I think you fixed your problem by ditching it. You can't be dead set on having 1 setup work everywhere. You found a track layout that made you not like the spool, so you switched to a diff and the car was faster. I personally don't like a spool, and will honestly never run one because of how it felt. Time-wise I'm faster with the diff, so who cares what the next guy does.
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Old 07-07-2008, 02:06 PM   #3
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thats fine but a spool is still normaly faster on pretty much every race track just look at the world class drivers andy moore marc rehinard mike blackstock etc and they all run spools most of the time yes you got the car working well with the diff but a setup alteration i think would make a spool that much faster then you would be twice as fast as you was in the first place
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Old 07-07-2008, 05:38 PM   #4
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Quote:
Originally Posted by sosidge View Post
No, its not the latest craze sweeping the nation's dancehalls - it is a little handling trait I have noticed - and I wondered whether other people had too.

When you run a front spool, quite often you can get a wiggle from the rear end when you put the power down hard out of a corner.

On flowing grippy tracks this phenomenon isn't a problem, but I raced over the weekend at a tight carpet track that started off "green", and with rubber tyres the car could be quite a handful, pitching off-line so much at times that I hit the track markers at certain places.

Switched to the diff and the car was a lot more settled, a lot more consistent and a lot faster as a result.

Technically I imagine it is something to do with inside front wheel being over-driven compared to the rear, or the forces from the spool trying to straighten out the steering too suddenly.

Is this something that other people have experienced too? If so, how did you tune it out, or do you just learn to deal with it?
Actually, I agree with you completely, I've noticed the same at my local carpet track, with a spool, it's like the car's trying to screw itself into the ground, & I have to really hang on to it, but a diff will calm, it down(though at the cost of some steering response). But that's where the one-way comes into its own, here that seems the best way to get the amount of steering we want without overdriving any wheels & creating that instability....
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Old 07-07-2008, 07:19 PM   #5
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Spool is never a good idea on carpet. As you already found out it makes the car very inconsistant. You either run a diff or a oneway. Spool is mainly for asphalt.
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Old 07-07-2008, 11:03 PM   #6
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Originally Posted by Yeti35 View Post
Spool is never a good idea on carpet. As you already found out it makes the car very inconsistant. You either run a diff or a oneway. Spool is mainly for asphalt.
Mod rubber on carpet sees a lot of spool usage.

I've noticed the shimmy as well. The car seems like it's fighting itself around the sweeping turns, especially if you try and power out of them.
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Old 07-08-2008, 01:24 AM   #7
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I have seen on a very small,tight/technical carpet track (10x15m) a diff with foams and a stock motor is just as capable as a 13.5 with rubber (with a spool I think). The smaller and more technical track the more low speed steering you need.

With the right foams I could put down as much power as I wanted to and the back end stuck, if you are just as fast as the guy next to you it doesnt matter how the car is set up I guess.

When space is limited there is only so much power you can put down, but maybe now i'm on the verge of being off topic,lol.
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Old 07-08-2008, 02:56 AM   #8
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I too have noticed the shimmy you mention.
I just figured this was from wheels fighting for which direction to pull the car and I learnt to deal with it.

On carpet I found a diff much better.
On asphalt, I am running a spool and I am liking it more than the diff atm.

That being said, traction levels and track layout call for different setups. On a less technical carpet track I might try a spool. On a more technical asphalt track I might opt for a diff.

But in the end, I'll use whatever gives me the best results

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Old 07-08-2008, 03:40 AM   #9
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When i ran foam tyres on asphalt with the spool i found the "shimmy" to be irratating thinking its was tweek or something else.
I went slightly smaller on front tyres and it helped tame it down a lot.
Maybe it just needs some overdrive to help it pull out of the corners a bit better.
Outdoors on asphalt with rubber there is no signs of the "shimmy"
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Old 07-08-2008, 11:28 AM   #10
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Spool is never a good idea on carpet. As you already found out it makes the car very inconsistant. You either run a diff or a oneway. Spool is mainly for asphalt.
your carpet must be diffrent from ours in the uk we race on the biggest indoor carpet events in the uk over the winter (carpet wars) im pretty sure tht the top ten of every class ran a spool. mod included andy moore ( world champion) chris grainger (natinal champion) marc fisher (corally's number 1) ollie jefries etc in 19t my self stu rand (2x carpet wars champion and 2007 corally stcc champion) kevin brunsed and lots more now we all cant be wrong.

ive ran a spool on many indoor carpet tracks and it has always been faster and more consistance
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Old 07-08-2008, 11:49 AM   #11
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I have found on smaller technical tracks running 10.5 with rubber tires the spool actually works better especially layouts that have tight turns with short bursts of speed. This made it easier to get off the corners quicker and more importantly drive it deeper into the corners and avoid being rear ended running in a tight pack. The only thing that was required was to change the setup slightly to allow the car to rotate better at the lower speeds.
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Old 07-08-2008, 12:39 PM   #12
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your carpet must be diffrent from ours in the uk we race on the biggest indoor carpet events in the uk over the winter (carpet wars) im pretty sure tht the top ten of every class ran a spool. mod included andy moore ( world champion) chris grainger (natinal champion) marc fisher (corally's number 1) ollie jefries etc in 19t my self stu rand (2x carpet wars champion and 2007 corally stcc champion) kevin brunsed and lots more now we all cant be wrong.

ive ran a spool on many indoor carpet tracks and it has always been faster and more consistance
I don't have a carpet track anywhere near me but tried running a spool at IIC a couple different times and the car was more consistant with a oneway. I had others that run carpet way more then I and told me the spool is not good for carpet and it proved true for me at least. So I guess it is going to be a personal preference thing. I run a spool all the time on asphalt and would run nothing else.
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Old 07-08-2008, 12:50 PM   #13
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thats fair enough but i certanly wouldn't write them off
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Old 07-08-2008, 01:14 PM   #14
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The TRF team won pretty much every significant carpet race so far this year with a spool. It seems like a lot of people go that route in mod carpet, but stick with a one-way for stock & 19T.
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Old 07-08-2008, 01:33 PM   #15
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I had this problem, then a wise dog suggested using less traction compound on the front tyres.

I run spools on carpet with no sauce up front and this is the fastest set up I've run.............................................

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