Buying new brakes + new tyres - advice ??

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2cy
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Buying new brakes + new tyres - advice ??

Post by 2cy »

I need to buy new brakes & tyres for the Ami Super. Several questions to ask if I may ..

A. 135 or 145 tyres.? rolling resistance is probably just a little less and the steering may be a little lighter with the 135 section. But what's your opinion.?
B. Citroens were designed to run on Michelin tyres. That then would be the obvious first choice (but for their expense). However Michelin tyres have (I hope) moved on since the early 1970's, so which spec of tyre currently available is better for the 1015cc GS / Ami super. (nB. the Ami is 85kg less than the GS, performance is similar). Or has anyone found a better (quietness is good) tyre to fit ??

C. Brake Pads. Do the handbrake pads wear out ? I'm not near my car to see if they need these, but buying now may save me money rather than having to buy what's available at the time.
D. Brake pads. What brand and spec of driving brake pad should I go for ? ..I was looking at Mintex on e-bay, as this is the only brand-name I've heard of, but then I've seen three different specs, and have otherwise read on other forums that Mintex tend to squeal and/or are very dusty. In short many opinions tend to dicard Mintex in favour of Ferodo. Again what's your experience please ..

Thanks, Peter

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Mothman
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Re: Buying new brakes + new tyres - advice ??

Post by Mothman »

Hi, a simple and quick answer to all of your questions may probly be answered in 1 fell swoop if you contact Rob Moss at the Chevronic Centre in Hitchin, number 0-1-4-6-2 4-5-5-28-0. He has just fully restored an Ami for himself so should be able to answer all your questions.
However, ime sure other members of this forum will be able to help but ime sure Rob will be able to give you a quick answer.

Andy

sandybx
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Re: Buying new brakes + new tyres - advice ??

Post by sandybx »

Dear Peter :)
There is a set way to fit and adjust the handbrake pads :wink: It is too long winded to explain tonight Peter :wink:
I will be back on tomorrow evening to explain :)
Vince :wink:

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2cy
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Re: Buying new brakes + new tyres - advice ??

Post by 2cy »

Thanks Andy and Vince,

I will indeed be contacting Rob Moss at the Chevronic Centre, but before I do so.., I'd like to gather opinions and experience from others, so that I might be better informed when talking to him. I'm sure he is a busy man :)

I have bought an Autobook workshop manual on the GS and also a Peter Russek glove-pocket book on the Ami-Super, but I'd be very glad for any any advice you feel might be clarified further. Thank you. ;-)

Of course, if these questions have already been answered then I'd be glad to be redirected to appropriate topics.

Pete

sandybx
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Re: Buying new brakes + new tyres - advice ??

Post by sandybx »

Dear Peter.
Firstly, you need to undo both lock nuts on the threaded parts of both handbrake cables. Then you need to remove both handbrake cables from their respective handbrake lever.
Once you have the cables removed from the calipers you need to undo all 4 bolts that hold on the handbrake levers to the calipers.
Then you need to remove all 4 eccentric cams and parts washer the levers and the eccentric cams and dry them and lightly clean the eccentric cams and their holes in the levers with a little fine emery paper.
Then you need use a small screwdriver to prize out the old handbrake pads.
The new pads should be copper greased on all 4 edges and their backs before being refitted to the front calipers.
Then you need to copper grease the eccentric cams and their holes, before refitting the handbrake levers back onto the calipers using the long bolts.
Adjusting the handbrake cables is an art. All 4 eccentric cams have screwdriver slots in. each pair of calipers need to adjusted correctly. The rh lever the eccentric cam needs to rotated from 3 o clock up to 12 o clock. And the lh eccentric cam needs to be rotated from 9 o clock up towards 12 o clock. And the same procedures for the other caliper.
When you have completed both adjustments on both calipers, you then need set them up correctly ( still with NO cables attached yet ) each lever should have just a little bit of free play, to ensure that there is no bindng on the handbrake pads.
Ensure that all 4 handbrake levers are at their highest point to the calipers.
Refit cables and lock nuts handbrake lever on dash should be 3 clicks on a tight 4.
The handbrakes are MOT able so following this procedure will enable a straight pull up as opposed pulling to one side which is a fail.
Cheap front brake pads tend to squeal, go for the Ferodo
I hope this helps Peter.
Vince.

macplaxton
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Re: Buying new brakes + new tyres - advice ??

Post by macplaxton »

A) For a Ami Super, just go for what it had originally for size 135SR15s.

B) For manufacturer, I'd go with Michelin ZX, but there are other options (in no particular order):

Camac BN313
Firestone F560
Maxxis AP2
Maxxis MA701
Meteor Cruiser IS12
Nankang CX668
Toyo 310
Vee Rubber V329

Loads of choice in that size.

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2cy
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Re: Buying new brakes + new tyres - advice ??

Post by 2cy »

Great..

Thank you Vince, I'll print that out and read it before and again as I do the job. For now I plan to clean and reuse the existing handbrake pads.. which may be original. I have new callipers.

Spoken to Rob at Chevronics and he's suggested Textar rather than Ferodo for the main brake pads. And I've ordered Hazell Quinton shoes for the rear drums, not least because I could phone through to QH-direct., and check their width. Most sellers specify the 180mm diameter but neglect to say whether the width is 30 or 34 mm. The narrower width is used on the 2cv.

I've also ordered new rear-brake-cylinders from Germany today. These are another oddball ..being 19mm dia pistons. Most cylinders being offered for the 'Ami-Super' are again 2cv / Dyane ones, which appear to come in either 16, 17, or 17.5mm diameters. It's taken me flippin' ages to go through and reject all but the one seller.

Thank you Mac.. I'll stick to 135's then.. I've been told, by the friend who help me buy the car, that he's recently met a chap who can get both new and used Michelin tyres (he's in Slovenia where the car is) so when I go down next month I'll meet up with him and see what he's got. Any idea how to decipher the dating codes on them ??

My long-term experience with my front-wheel-drive Chrysler Voyagers is that my rear tyres perish before I wear them out, so if this chap has half decent used Michelins then I'll put them on the rears and for the spare.., so then (for now) I'll just need to buy two new ones for the front wheels. ;-)

Pete

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Stonehopper
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Re: Buying new brakes + new tyres - advice ??

Post by Stonehopper »


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2cy
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Re: Buying new brakes + new tyres - advice ??

Post by 2cy »

Interesting video re fitting new tyres on the rear.

Like most front wheel drive cars, with engine forward, two persons on board, and spare wheel mounted under the bonnet, the weight distribution of the Ami-Super is heavily bias towards the front. Therefore centrifugal forces (working against tyre adhesion) through a bend is greater on the front.

Furthermore, aside from road surface and conditions.. any changes in acceleration, braking, steering, and body roll all contribute to a tyre loosing adhesion. With perhaps the exception of the latter - each of these variables are greater on the front wheels of a FWD car.

As the rear tyres tend (pending the curvature of one's route) to follow the front (even though the rear track on the Ami is a little narrower) - so water (or loose debris ) laying on the road is shed aside ...before the rear tyre gets there.

I suggest that the argument presented in the video is unduly limited to a particular situation (powering through a flooded bend), and certain cars.. I'd go on to suggest ; the most crucial factor is the tyre load distribution (both front / rear AND nearside / offside) and that varies enormously on whether its front or rear wheel drive, and particularly in the case of French cars.. the amount of body roll (effecting the tyre/road contact patch). :rofl2:

In the event of emergency braking.. a very much more common occurrence than hydroplaning, then again I'd argue for grip being most needed on the front tyres :- This car's front disc brakes are twice as powerful (if not more so) than the rear drums, so max front tyre grip is needed to effect retardation. The more powerful the brake - the greater the loading on the tyre. And with the transfer of weight distribution under heavy braking (ie. the tail goes up, while the nose dives) then the rears all but loose road contact anyway. One needs grip - where there is road contact.., which is again at the front end. And on a corner - that may be pretty much through just one tyre.! :shock:

Rear end skipping sideways or even a rear end spin is to me far more preferable than my loosing steering and braking on the front. With control through the drive and steering I have a chance of correcting a slide. When the front is lost... what can I do ? The additional traction of better tyre tread and a slightly more supple compound is also likely to regain lost grip, and therefore control, sooner. In the event of a 4-wheel drift - I'd like the fronts to steer. The same factors are in effect when driving in snow or on loose gravel. For soft conditions the newer tyre is likely to be more supple than a tyre with olde rubber. ...Traction Avante !

So.., although I accept that tyres (with less tread and less weight on them) tend to hydroplane more easily, my desire to have, maintain &/or most quickly regain control over the vehicle - still leads me to put new tyres on the front. Of course the rears should always have a decent depth of tread to bite as best possible.

As for punctures.. logic suggests ; a deeper treaded tyre is less likely to get a puncture than one with a shallow tread. And again, given the choice - I'd prefer not to have a puncture in 'the control tyres'.

But.., I'll gladly listen to counter arguments, ..and even to be persuaded to change my mind.! Perhaps, my reasoning is overly influenced by my experience as a motorcyclist . [-o<

Thanks, Pete

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Stonehopper
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Re: Buying new brakes + new tyres - advice ??

Post by Stonehopper »

It is hard to accept that with more weight on the front new tyres should go to the rear. It almost defies logic. But it doesn't defy science. The practical experiments as seen in the videos (there are many) shows that more control is lost with new tyres to the front - and this applies to front wheel driven cars as well as rear wheel driven.

There is an argument that states the good tyres on the front in wet weather 'dry' the road for the rears. If there is breakaway on a bend, the rears take a different path - one that has not been 'dried' to any extent, and so aquaplaning increases and blows that argument away.

If the front begins to slide in understeer, coming off the throttle is the most natural reaction, and will allow grip to be restored.
If the rear end goes first, it takes a more accomplished driver to counter steer and maintain control. Of course, if you are experiencing either, then you are driving too fast for the conditions.

On bikes, things happen differently, and a lot of things can affect stability other than the rate of tyre wear. Any 'offs' that I have had have been when the front has lost grip through fuel spillage, wet manhole covers, ice or snow.

Overall it's a subject that is hotly debated amongst those who believe the good tyres should go onto the driven wheels - front or back. But throughout the trade - and tyre manufacturers also - any pair of new tyres should go on the back, regardless of where the drive or weight bias is.

The only time I had the 2cv breaking traction was a deliberate action to scare my passenger - and old mate. Hammered into this empty narrow bend and got the front to slide onward, then it gripped and the rear began to slide - understeer to oversteer - but it lasted but a split second and we got round just fine - dry road too. Brown trousered passenger. Good fun.

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2cy
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Re: Buying new brakes + new tyres - advice ??

Post by 2cy »

Had to take my Chrysler Grand Voyager into the shop today as recently the car developed a steering wobble and was pulling to the right. The wobble was odd because it started around about 25mph, quite noticeable at 30, peaked in wobbleness around 40, and then lessened to almost nothing above 50mph.

I had taken the car to another garage, asking them to check a front link arm that I'd had fitted last year, or whatever else it might be and to check the tracking. They adjusted the tracking very slightly but could find nothing else wrong. Today's garage they found the steering rack link arm (what one mechanic called the dumbbell) was worn / loose. This could be felt at the rim. Nothing could be done about that today, but while at it he swapped wheels front to rear. The more worn front tyres (still legal) are now on the back. Wobbles gone, as has the pull to the right. :-) I'll replace the two more-worn tyres as something was obviously amiss.

...while there I asked about putting new tyres on the back.. Both (experienced) mechanics said that's not something they'd do on a front wheel drive car. They couldn't understand the reason to do so, aside perhaps to bed the new tyres in for the first hundred or so miles. They added that their practice is to put the new tyres on the front - because the backs wear so slowly. Otherwise (as most owners don't seem to rotate tyres) new tyres on the back would get get old before they were worn out. Old tyres are dangerous. I must admit, on the Voyager, its rear tyres had to be changed last time simply because they were perished. Even full blown winter tyres (bought in Slovenia) - being used year round don't seem to wear out on the back of this vehicle.

When I had an A-series Falcon Kit-car (652cc motor, mildly tuned, with twin carbs) I repeatedly took it around Donnington flat out. Flat out down the straight (no windscreen), and at the very last second, before the hairpin, I'd jab the brakes and throw it into the bend. Then it was foot flat down - hard on the throttle to pull it around the corner. The marshals dived for cover were amazed at this spidery little kit-car kicking Caterham arse around this bend, as the corner scrubbed the speed off and the front wheel drive dragged it around.. Not a hint of the back end spinning out. The Caterham on the other hand.., once power-steered around the bend, re-overtook and then simply disappeared through the more mildly curved the esses.. :mrgreen:

Aside from occassions when deliberately induced.. I've had several 4-wheel drifts over the years and have always steered out of them. I've spun (rear end lost) rear-wheel-drive cars twice (powerful Fords both times), and I've spun a fwd mini-clubman - as it was flying through the air !.. but otherwise I've not yet lost a fwd's tail ..not least as dramatically as in the video. [-X ..I'd recommend they lessen their rear tyre pressures a tad. :roll:

Raul
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Re: Buying new brakes + new tyres - advice ??

Post by Raul »

2cy wrote:
A. 135 or 145 tyres.? rolling resistance is probably just a little less and the steering may be a little lighter with the 135 section. But what's your opinion.?
Rolling resistance is actually a little bit less with 145. Wider tires deform a little less than narrower tires therefore the rolling resistance is less. The contact patch size is the same.

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Stonehopper
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Re: Buying new brakes + new tyres - advice ??

Post by Stonehopper »

Interesting that 2cy has had steering linkage issues - my last MOT tester mentioned (though not an advisory) that there was a slight wheel bearing play in the front right. I checked for play with wheel clear of the ground and could detect no play whatsoever in the top/bottom apsect (12/6 o'clock), but definitely some in the 9/3 o'clock. Wheel spun perfectly with no undue noises and none when cornering. The culprit was the right hand ball joint that connects the tie rod to the rack.

Two new joints arrived super quick from Chevronics, along with new rubber gaiters. All fitted today, now I'll have to re-check the tracking. New tyres needed at the front too - might just go for a pair of Nankangs if I can find the link!