Ground Clearance / Ride Height
Discussion
Apologies if this has been discussed many times in the past. I did try the search and read as far as page 20 of 180 but decided to ask.
I am planning on getting a Caterham later this year and the roadsport 150 seems to fit my use (for now I guess). However we have some speed bumps on our road, different types, some are the squares in the middle of the lane, others are the full width raised road type.
I have read about various ride height settings, e.g. the manual talks about 150mm measured by the wishbone, others mention the sump is at ~80mm.
If I go for the standard Roadsport 15 inch wheels and ZV3 tyres with standard suspension :
1. What would be the sump clearance,
2. What would be the height from the ground to the bottom of a lowered floor,
3. What would be the exhaust clearance,
4. What would be the height from the ground to the lowest part of the chasis in the middle of the front and back wheels.
I have already learnt so much from this forum and so thank you for that but also if you are able to answer the above.
I am planning on getting a Caterham later this year and the roadsport 150 seems to fit my use (for now I guess). However we have some speed bumps on our road, different types, some are the squares in the middle of the lane, others are the full width raised road type.
I have read about various ride height settings, e.g. the manual talks about 150mm measured by the wishbone, others mention the sump is at ~80mm.
If I go for the standard Roadsport 15 inch wheels and ZV3 tyres with standard suspension :
1. What would be the sump clearance,
2. What would be the height from the ground to the bottom of a lowered floor,
3. What would be the exhaust clearance,
4. What would be the height from the ground to the lowest part of the chasis in the middle of the front and back wheels.
I have already learnt so much from this forum and so thank you for that but also if you are able to answer the above.
Hi, sorry I can't give you specific figures but in general speed humps aren't a problem, as long as you take them slowly.
The cushions are best taken by driving between them with a wheel on each hump and the sump in the gap between them.
Raised platforms aren't usually a problem if you approach and depart slowly.
The worst ones in my experience are the hard rubber strips, simply because they are quite sharp, and when coming off them the suspension compresses and the sump scrapes a bit - best to approach at an angle very slowly.
Ride heights can vary a lot depending on suspension settings (adjustable platforms allows you to easily raise it if it becomes a problem), wheel/tyre combination, etc.
Whatever else you do, I would urge you in the strongest possible terms to order the car with A021/Toyo888/CR500 tyres, in fact ANYTHING except the ZV3's; they are ok in the wet, but really hopeless in the dry or cold.
The only other advice is join the lotus seven club and get along to your local meeting, before your order/build gets too far, to get some experienced advice and views, and look at a few cars as well. The membership fee of £45.50 really isn't much given the value of the advice you'll get, and the money that could potentially save you! (plus you get to post questions on Blatchat where there is a lot of experience).
The cushions are best taken by driving between them with a wheel on each hump and the sump in the gap between them.
Raised platforms aren't usually a problem if you approach and depart slowly.
The worst ones in my experience are the hard rubber strips, simply because they are quite sharp, and when coming off them the suspension compresses and the sump scrapes a bit - best to approach at an angle very slowly.
Ride heights can vary a lot depending on suspension settings (adjustable platforms allows you to easily raise it if it becomes a problem), wheel/tyre combination, etc.
Whatever else you do, I would urge you in the strongest possible terms to order the car with A021/Toyo888/CR500 tyres, in fact ANYTHING except the ZV3's; they are ok in the wet, but really hopeless in the dry or cold.
The only other advice is join the lotus seven club and get along to your local meeting, before your order/build gets too far, to get some experienced advice and views, and look at a few cars as well. The membership fee of £45.50 really isn't much given the value of the advice you'll get, and the money that could potentially save you! (plus you get to post questions on Blatchat where there is a lot of experience).
Hi,
Regarding ground clearance; usually the sump clearaance is the measurement that matters the most. I run at 65 mm and straddle the square type and don't have too much problem with the full width ones. The key is to go slowly over them and keep your eyes peeled.
The plastic or pub car park short ones are the most problems.
If you are thinking of the roadpsort 150 with the zetec ford engine that may well be in the 80 to 100 mm sump clearance so would be even better.
If the sump gets over the rest of the car is usually fine.
Enjoy the car.
Rob
Regarding ground clearance; usually the sump clearaance is the measurement that matters the most. I run at 65 mm and straddle the square type and don't have too much problem with the full width ones. The key is to go slowly over them and keep your eyes peeled.
The plastic or pub car park short ones are the most problems.
If you are thinking of the roadpsort 150 with the zetec ford engine that may well be in the 80 to 100 mm sump clearance so would be even better.
If the sump gets over the rest of the car is usually fine.
Enjoy the car.
Rob
Thank you for all the comments. It is very useful. I don't plan to track the car so not worried about having a really low ride height and 13" wheels although reading through here it seems that the track is where I will end up 
I had been told the ride height in the middle of the car could be quite low even with a ride height set up at the wheel of 150mm. So that got me worried as when I measured the speed bump it is 130mm at the high point. I had this vision that I was going to be beached just getting to the main road. It seems from all the side on pictures I have seen that the chasis and lowered floor is always higher than the sump.
Once again many thanks.
I had been told the ride height in the middle of the car could be quite low even with a ride height set up at the wheel of 150mm. So that got me worried as when I measured the speed bump it is 130mm at the high point. I had this vision that I was going to be beached just getting to the main road. It seems from all the side on pictures I have seen that the chasis and lowered floor is always higher than the sump.
Once again many thanks.
Get the car with a dry sump and you save yourself quite a few mm of exposure on the bottom. If you have your car with a lowered floor you'll have about 2cm lower just before the rear wheels, but if you hit there, then you've likely gone over the obstacle way too fast.
As already pointed out, fixed objects on the floor are you biggest worry -- we look at them coming up to them, and worst case do them at a 45 degree angle, seems to make it easier to clear with no 4rseache
As already pointed out, fixed objects on the floor are you biggest worry -- we look at them coming up to them, and worst case do them at a 45 degree angle, seems to make it easier to clear with no 4rseache
as posted.. 13" + A021Rs.. 185/70 R13 are 62ukp a corner inc vat and a pretty good (of not the best) all rounder tyr.
Very good in the wet, and pretty good int eh dry/cold... only realy failing is they can over heat and grain on a hot track day..
70's are usually reccomended for Live axles Caterhams, and lower profiles for DDion, the 60's and 55's are a little more each, but on a DDion chassis you wont notice a major difference between them on the road.
Very good in the wet, and pretty good int eh dry/cold... only realy failing is they can over heat and grain on a hot track day..
70's are usually reccomended for Live axles Caterhams, and lower profiles for DDion, the 60's and 55's are a little more each, but on a DDion chassis you wont notice a major difference between them on the road.
rammylad said:
I measured the speed bump it is 130mm at the high point
I have to assume you're referring to the big square traffic control bumbs! These aren't an issue - the sump passes to the side and you'll find that the size of the square is big (long) enough that the rear wheel is rising onto the hump before the front wheel has dropped back to road level. I've never had issues with any highways authority bumps, only with the full width short sharp things that you sometimes find in pub carparks. My sump clearance is 70mm.I have a Roadsport 140 on 15's and most speed bumps are fine.
In fact, the only time I've had trouble is with the rubber square type where there's only one in the middle of the road. In which case you have to go over them with one wheel on the floor and the other in the top. The sump seems fine, but the lowered floors (possibly just the seat bolts) do catch them slightly.
So long as there's two of them you can go over between them and you're fine.
In fact, the only time I've had trouble is with the rubber square type where there's only one in the middle of the road. In which case you have to go over them with one wheel on the floor and the other in the top. The sump seems fine, but the lowered floors (possibly just the seat bolts) do catch them slightly.
So long as there's two of them you can go over between them and you're fine.
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