Sometimes you get a large jolt, other times you don't, has anyone narrowed it down to maybe some trains or certain seats or if the weather or time of the day (Morning or afternoon) makes any difference?

Sometimes you get a large jolt, other times you don't, has anyone narrowed it down to maybe some trains or certain seats or if the weather or time of the day (Morning or afternoon) makes any difference?

It might be worse depending on where you sit, but I've definitely felt the large jolt on pretty much every ride I've ever had on it.

I tend to sit on the right hand side and don't notice the jolt, but when I sit on the left its always worse. Where possible I try to sit at the front, but when sitting on the back left this for me and this may be different for others but is one way to get whiplash

I tend to find that there is one car that jolts more than others, on that car the front left is always the worst, must be the bearing or wheel.

Mad Coaster Man has a point; When you look at the drop base, it looks fine, but if the jolt was caused by the wheel, it'll mean you're constantly getting that jolt for the whole ride, unless it IS part of the drop base that causes the wheel to jolt, causing the train to jolt with it.

However, BigBobJones mentioned it could depend on where you sit; When I went to Thorpe two days ago, I went on SAW and didnt seem to feel a jolt at the base of the drop, but there are still a few jolts during the remainder of the ride, meaning the wheels could have something to do with it. Am I right?

every year during the closed season don't they take all the cars apart for there annual safety check and repairs etc? surely the same dodgy car would have been replaced by now?

Who's implying it's dodgy? Thorpe and Gerstleur obviously don't see it that way.

With regards to the 'jolt', this was posted shortly after Saw opened:

Finally worked out Saws bump.Well basically its a change in radius. That makes it look like it has a flat spot. There is a sudden drop by litrally centermeters. I've used circles to make it stand out more, if you couldn't see it before. Basically it does this:Should be roughly like this green line:Hope some Thorpeys take a look at this next winter... I don't really like my neck cracking.

So basically, just a change in curvature of the track. This then led to higher laterally Gs at the base of the drop than, which creates the jolt so many people experience. At an educated guess, I think this could be down to the drop - it was originally meant to be a 97 degree drop, like most Eurofighters, but was instead changed to the 100 degree drop for the record, which could explain the change in curvature of the track (as the Immelmann loop was kept exactly the same, so was designed to follow a 97 degree drop, not a 100 degree one).

I can't say I've ever noticed this change - it's always going too fast for me to notice!

I don't mean to go off-topic, but here's Colossus' loop viewed side-on:

Now is it me or is it a play on the eyes? It looks like it has a change of curvature, yet I've watched it side-on manier times and it doesn't slow up as it goes upside down through the loop. Nor does it feel like it slows when you ride it.

So does it have a change of curvature? Same question with both Nemesis'.

A-kid got it exactly right, and that's why it's so uncomfortable there.

Colossus, Inferno and Nemesis loops are perfecto.

The only way you 'notice' the change is the jolt (and by eye if you closely examine it for long enough; which is what I assume A-Kid did originally).

As for Colossus' loop (and any vertical loop for that matter), it's not a perfect circle, so it has a change in radius (change in curvature I'm not too sure, but if it does, it's not in a bad way). Technical name for it is a clothoid loop.

Basically, as you get nearer the 'top' of the loop, the radius increases, which in turn decreases the force on the riders. So, as Fred says, all those loops are fine!

So Saw has been shut loads this year because of the cold. Minimum operational temperature 2 degrees I think? Out of interest anyone know why this is and also why when building it they couldnt construct it in a way that would allow it to work in colder temps? For a new ride its slightly surprising (sorry if this has been posted somewhere else).

It can depend on stuff like type of metal etc how it operates mechanically that means it's hard to get around.

The thing I don't get is in the past Stealth has failed to open in temepratures as low as what we've had lately. So far, it seems to have run better than Colossus and Saw.

I was starting to think it was down to the ride manufacturer, but I don't think that's case.

The thing I don't get is in the past Stealth has failed to open in temepratures as low as what we've had lately. So far, it seems to have run better than Colossus and Saw.

I was starting to think it was down to the ride manufacturer, but I don't think that's case.

Many possibilities. Colossus struggles to make it around the final corner in low temperatures, and in temperatures as low as we're seeing it's got a too high likelihood of it valleying for it to open. Stealth doesn't have this problem, as it only has to launch it's way around a 13 second circuit to the brakes. Of course it still has the risk of rolling back, but this seems to happen less frequently nowadays, and when it does it's considerably easier to recover than Colossus. Other reasons could be that they're different ages and different types of rides, for example maybe Colossus's lift motor has problems in low temperatures just like Saw's does. Stealth again wouldn't have the same problem as they use different systems which might be able to deal with the cold weather.

As for it failing to open in years gone by, we can only really make assumptions. Maybe as Intamin have developed, they've replaced older parts with newer ones more able to withstand colder temperatures? Maybe it just gets better maintenance now than it did before?

Of course it still has the risk of rolling back, but this seems to happen less frequently nowadays, and when it does it's considerably easier to recover than Colossus.

Really, resetting Stealth is easier?!

Really, resetting Stealth is easier?!

Yes, once the brakes stop the train after a roll back, they release and allow the train to naturally roll back into the station, as can be seen as 2:24 here...

Colossus on the other hand would have to be pulled externally over the turnaround and into the brake run.

Ah them days were the best, everyone got so excited!

Stealth, the only ride people cheer at when it shuts down

I still haven't experienced a rollback

I want a Roll back

I've come within 2 trains of being on a rollback - beat that!

And Dan, yes I did know about the natural rollback after the brakes release!

I didn't realise before that there is an obvious slow down of the train each time before hand, so I guess the ride staff can sort of tell a rollback is coming up?

I dont think there always is, back in 2010 rollbacks were pretty frequent and if you look in the console there are engineers in there and they are watching it go over each time so it seems like they were expecting it to happen eventually!

Really, resetting Stealth is easier?!

Are you deliberately being silly here? Stealth is designed with rollbacks in mind hence why the magnetic fins come up as the train passes through the launch section. A hasty reset can occur and the train can go back into the station to be relaunched. If a Colossus train decides not to make it around the final turn around, it will rest between the inlines and the corner that goes over the pathways. Instead of it rolling back into the station (which would be impossible for Colossus to do), a crane is needed to hoist the train over the turnaround.

I want a Roll back

Me too! It is really unlikely to get one though...