[Rob]

Hello:

A standard strut boot has such a bumper as the top
part to limit the travel of the strut rod.


Would it make sense to use a longer bumper to limit the
rod travel even more in the following cases:

1. lowered car

2. bigger wheels,

in both cases to prevent tops of the tires rubbing the fender?

Are different lengths of such bumpers available?



Thank you,




Rob.

 

[Beaverboy]

When you lower, you either want to leave the bumpstop alone, or chop some of it off to increase the length of your suspension travel. If you want to limit the amount the wheel can rise, then get some blocks fabricated to fit between the strut mount and the strut tower to effectively raise the height of the car. This way you keep your suspension travel stock, but reduce the tendancy of the oversized wheels and tires from hitting the fender. Your other option is to cut the fenders and add some flares :twisted: The bumpstops are designed as a last resort to keep the struts from bottoming out and breaking, not to keep the wheel from hitting the fender.

(Rob, I know you've heard this from me before, I'm stating this for Xiph0id)

As for bigger wheels. Whenever you install bigger wheels, you install tires on them that are no larger in diameter than the stock tires. Bigger wheels means shorter sidewalls and the same overall diameter. (I believe Rob is being unconventional about this for his own purposes)

205 width tires are the widest you're going to fit underneath without running into any real trouble, and you can increase the overall diameter of the tires by about 15mm before you start getting too close to the underside of the spring perch.

The fronts pose no threats to 205 width tires, but the rears might. Have your rear fenders rolled (have the lip turned up out of the way) and you won't have any clearance issues in the rear.

 

[Rob]

Hello:

Beaverboy thank you for the detail response.

The reason I asked that question was as follows.
I purchased 205/55/15 tires and 15x6.5 40mm rota wheels.
Once installed I noticed the front wheel sticks out too much such that it
would touch the front fender lip if the suspension compressed some
distance.

Of course I am going to roll the rear fender lip but this is
not the end of the story.

The problem with wider wheels is that you actually decrease
the shortest distance to the fender because
the fender is not square shaped
but rather arch shaped.

The stock fenders were designed to accommodate 175cm stock tires
given a certain spring load and rate.

Now if you put 205 wheels your suspension can not travel the same
distance. This means you actually decrease the maximum load
your car can handle without rubbing the fenders.

So in my opinion if you go to 205 wheels you should
either limit the spring travel or get higher rate springs.


In other words if you used to drive your wagon on 175 wheels
with 3 passengers plus some load in the trunk then you did not have
any problems with rubbing.

Now can you carry the same load on your 205 16x7 40mm wheels?




Thank you,



Rob.

 

[Beaverboy]

Well, with MacPherson struts, the front wheels aren't going to travel straight up and down. They follow the angle of the struts.. which are angled inward. Usually as they compress the control arm pushes the bottom out, tipping the top of the wheel even further in (creating more negative camber). It's slight, but it seems to be enough to avoid any rubbing.

When I first installed my wheels (the 16" Rotas) it was on the original (180k mi) front struts, and I'm pretty sure I used up all of the suspension travel at some point or another (braking hard on grippy tires over bumps). The rear fender was the only one that ever gave me any trouble.

Oh, and Ford designed the fenders for 175cm stock tires w/ tire chains. That's the main reason American compact cars have so much more fender gap than, say, Hondas. Hondas aren't designed with chain clearance in mind.

What style Rotas did you go for? Were they lightweight or what? :wink: What kind of tires did you spring for?

 

[Rob]

Hello:

I purchased Rota Slipstream 15x6.5 and
Continental Extreme Contact 205/55/15.

So far I have not driven the car because I am
also overhauling brakes and suspension.
I switched to 10.25" rotors/calipers and put
energy suspension bushings for the front control arm
and the stabilizer bars.

The hardest part was to replace the control arm
bushings because they sit really tight and
you have to use a puller/ c-clamp to move them.

Beaverboy said:

Well, with MacPherson struts, the front wheels aren't going to travel straight up and down. They follow the angle of the struts.. which are angled inward. Usually as they compress the control arm pushes the bottom out, tipping the top of the wheel even further in (creating more negative camber). It's slight, but it seems to be enough to avoid any rubbing.

You are right that would solve the problem. I wish it would be enough.

Just in case to be 100% sure I am going to conduct the following experiment.

I will remove the front/ rear spring and use the stock jack
to raise the front/rear wheel to limits to see the whole range of
the suspension travel.

I will post results once I am done.

I found the following link, which thoroughly/technically explains
the rubbing issues.
I think everybody who wants to switch to wider tires might find
this link extremely useful. Our forum is missing such a thorough
treatment of this problem.

http://forum.teamzx2.com/viewtopic.php?t=3040

Thank you,

Rob.

 

[Beaverboy]

Hello:

I purchased Rota Slipstream 15x6.5 and
Continental Extreme Contact 205/55/15.

So far I have not driven the car because I am
also overhauling brakes and suspension.
I switched to 10.25" rotors/calipers and put
energy suspension bushings for the front control arm
and the stabilizer bars.

The hardest part was to replace the control arm
bushings because they sit really tight and
you have to use a puller/ c-clamp to move them.

I had to use a puller to get mine out too.. The urethane slid in with smooth hand pressure after a good greasing though.

Brake upgrade.. niiiice :wink:

If you can, please post some pics of your new setup when you finish. I bet those look really good in 15".

I'm curious to see how your experiment will turn out.

Good link over to TeamZX2.com Those guys have their stuff together.

Thanks, Rob.