NO MORE! - Tyres Rubbing the Arches

[Cali_bay]

Right....Just adjusted my coilovers to the highest setting, dropped the bus down and went for a quick spin. I only have one rub, when I drove down a speed hump at a higher speed than I would usually. So an improvement, but only me in the front, so need to test with a passenger. I measure the arch to tyre before and it was 2.25” and after 2.5”, so gained 0.25” (12.7mm).

Looking at tyres:-

Original bus tyres on steels:- 185 x 14 - 652 mm diameter

Current tyre size 185/65 15 (91) - 621mm minus 4.75% on diameter over std. = ~15mm increase in clearance over standard tyre.

So if I changed to 175/55 15 - 574mm minus 11.96% over std. but can’t find any greater than 77 load rating which is 412kg/tyre = ~ 25mm over my current tyre.

Found a 185/55 15 with a load rating of 86 which is 530kg, which I’m fairly sure would do. :idea: :?:

So going if I went for the tyre change option and having set the coil on max I would gain nearly 40mm of travel. This would certainly help, but at the expense of making the speedo further out than it already is. :|

So not sure which way to go at the moment, but there’s options open.

Whilst chatting to Steve (lhu128l) today, we may have a cunning plan………… :idea:

 

[Dirty Harry]

I'm running some 165/60/14s at the minute and rubbing has been pretty rare so far. Seem to get a bit when on full lock but I haven't had any whilst driving along for a while now. Didn't put a great deal of thought into the load rating on them, the tyre fitters didn't seem to think it would be a problem. I guess it could cause issues, I might have to look into it more. Surprised that the front axle weight is that high!

I run the wagenswest spindles too and i'm running 195x75x14 on them and with no real problems, just a occasional minor rub, but this is only when i drive it pretty fast over the speed bumps.

 

[r73]

I'm running some 165/60/14s at the minute and rubbing has been pretty rare so far. Seem to get a bit when on full lock but I haven't had any whilst driving along for a while now. Didn't put a great deal of thought into the load rating on them, the tyre fitters didn't seem to think it would be a problem. I guess it could cause issues, I might have to look into it more. Surprised that the front axle weight is that high!

I run the wagenswest spindles too and i'm running 195x75x14 on them and with no real problems, just a occasional minor rub, but this is only when i drive it pretty fast over the speed bumps.

Blimey, shows how much lower you go on flipped spindles over WW ones, with those size tyres mine wouldnt even come off the jack :shock:
195/75/14 - about 15mm higher than stock
i was working all the sizes out but then found this! http://www.1010tires.com/TireSizeCalculator.asp?action=submit" onclick="window.open(this.href);return false;

 

[Geeze]

The stock suspension has about four inches of travel before it starts to run out of movement. Almost twice the clearance you've got ( :shock: hence the rubbing!)

This is sort of verified by the folk on 'slam tyres' and dropped spindles saying that they get no rubbing (on the tyres :msn4: ) - the 60+mm of clearance you have plus another nearly 40 from the smaller tyres (though most then dial out some of that clearance on beam adjusters but that doesn't alter the travel limits).

Does your bus still have the bumpstops in place?

Dropping down to a 185/55 may just about bring the bumpstop into play, as I'm fairly sure there's about three inches of movement before they start to compress. So 55 profile might just about buy you enough room to stop the worst by taking some of the hit on the bumpstop before the tyre tubs out. I'd guess you'll probably find it's still not enough on big hits but it should help? On the up side, you can get 185/55 in an 86 load rating which should be ok for the front axle weight (1050kg from memory :?: - 86 load is about 530 so it squeaks by!).

Random aside, but in the spirit of the thread, this is the problem with such dramatic lowering on the spindles. The stock suspension is soft and long travel and the dropped spindles retain all of it. For a lowered car with less clearance you really want stiffer springs (so less movement for the same force) but that's hard to do on torsion bars.
The bugpack coilovers help because they increase the springrate, which reduces the travel for a given amount of 'bump'.
Airshocks would do the same thing. The other option would be to go for stiffer dampers to help control the compression movement.

When you lower a bus on the beam (cut and turned or adjusters), the arms go into an angle, which increases the effective spring rate which in turn is what causes the stiff ride when you lower it heavily on the beam (that and everything just plain old running out of movement!). I reckon the ideal would be to mix and match - two inches on the beam (effectively stiffening the spring rate) and another two on the spindles (so that the beam isn't at full travel)......

 

[Wensbry]

Si, you could always go back to Stock Height mate !!!! :shock:

 

[Graham L]

My tyres are 185/65 15's.

Thats the problem. I have 175/55 x 15 on mine. It still rubs occasionally :lol:

I agree with Clem and I run the same tyres although mines a stock beam no adjusters, have to say though I'm not exactly small and dont get any rubbing now in Monty running dropped spindles even with 2 in the front. Tyre size is critical.

The point with dropped spindles is that you get get full suspension travel as you haven't restricted it by fitting adjusters so when you move the pivot point 3.5 inches up into the wheelarch, sooner or later its going to foul. The coilover dampers help and I think give a good ride but as most of you are aware push the bus back up by an inch if you run them on the highest setting.

I think a lot seems to rely on how worn your springs are within your beam in the first place as measurements on another post showed significant differences in beam height to the ground.

Not a plug but still working on a set of adjustable coilovers that will give a good ride but stop the fouling, should get the new test set onto Monty tomorrow, other work permitting

 

[67westy]

Not a plug but still working on a set of adjustable coilovers that will give a good ride but stop the fouling, should get the new test set onto Monty tomorrow, other work permitting

Graham, will you be at Stanford hall with these? Wouldn't mind having a look if you are....

 

[Graham L]

Hi Adam

Hope to be but not sure which bus we are going to be in, chances are it will be Arnie and not Monty as we are camping overnight and currently no bed in Monty, unless we take 2 buses!!

I know the load ratings are there for safety but a lot of people run 175/55/15 on the front with no issues, I run these tyres on both of my current buses and ran them on the westy I used to own as well. Even running 185/65/15's doesn't get you to the recommendation of 25% above the gross weight of the vehicle which on a 1970 Westy Campmobile is 2165Kg with an unladen weight of 1307Kg but I do wonder how many people actually run their buses at full capacity with 850kg of luggage and bodies, thats a lot of weight. Not saying this is right or wrong as safety is hugely important, running 175/55/15s on the front and 185/65/15's on the rear gives you an overall load rating of 1944kg approx 90% of the Gross Permissible Weight of the vehicle. Microbuses get an extra bit of margin by about 30kg but the gross weight remains the same.

I personally would not run anything less than a 175/55/15 on the front, running slam tyres which usually have a max rating of 72 loses you another 114kg of the Gross weight so down to approx 85% of the Gross Permissible weight.

 

[67westy]

Hope to be but not sure which bus we are going to be in, chances are it will be Arnie and not Monty as we are camping overnight and currently no bed in Monty, unless we take 2 buses!!

I might have to try and get over to your open day then. Would like to get back to the 175's I have if your shocks would solve my rubbing problems, not too happy on the smaller tyres as the rating is only 387kg :shock:

 

[moler]

I don't get any rubbing during normal everyday driving (bumpy roads, speed bumps, and all), and up until very recently it was the daily covering over 13,000 mile with this setup...unfortunately it's on a split, but I will be using exactly the same setup on the crewcab too, so thought I'd add it into the mix.

Obviously a spilt king & link pin beam of standard width, dropped spindles, adjuster, all quite normal. The tyres on the front are 165/55x15. CSP disc's that reduce the track by about 16mm overall. The front wheels are little special though, 5 1/2" x 15" but with on offset somewhere in the region of 75mm, so they have a tucked look.

To start with this setup rubbed alot with spongy shocks I had fitted for the MOT, the cure was a set of adjustable Spax from CE matched to my ride height, I use them on the 4th from lowest dampening rate setting.

 

[r73]

Hi Adam

Hope to be but not sure which bus we are going to be in, chances are it will be Arnie and not Monty as we are camping overnight and currently no bed in Monty, unless we take 2 buses!!

I know the load ratings are there for safety but a lot of people run 175/55/15 on the front with no issues, I run these tyres on both of my current buses and ran them on the westy I used to own as well. Even running 185/65/15's doesn't get you to the recommendation of 25% above the gross weight of the vehicle which on a 1970 Westy Campmobile is 2165Kg with an unladen weight of 1307Kg but I do wonder how many people actually run their buses at full capacity with 850kg of luggage and bodies, thats a lot of weight. Not saying this is right or wrong as safety is hugely important, running 175/55/15s on the front and 185/65/15's on the rear gives you an overall load rating of 1944kg approx 90% of the Gross Permissible Weight of the vehicle. Microbuses get an extra bit of margin by about 30kg but the gross weight remains the same.

I personally would not run anything less than a 175/55/15 on the front, running slam tyres which usually have a max rating of 72 loses you another 114kg of the Gross weight so down to approx 85% of the Gross Permissible weight.

175/55/15 do seem the best non std option for balance between height and load. Or 185/60/14 with a higher load index of 82. These are the 2 choices T2D reccomend. But neither of them are heavy duty enough for a heavy bus really. I'm not really sure you can average the vehicle weight and use the back tyres in the equation. The tyres' load index is axle rated (front and rear) and as far as full capacity load, 2 adults sitting in the front of a westy poptop kind of is the max load? Thing is tyres are made to a much higher std these days and i'm sure theres a fair safety margin, so it is so unlikely to be dangerous, maybe more likely is the old bill or insurance implications?

 

[r73]

The stock suspension has about four inches of travel before it starts to run out of movement. Almost twice the clearance you've got ( :shock: hence the rubbing!)

This is sort of verified by the folk on 'slam tyres' and dropped spindles saying that they get no rubbing (on the tyres :msn4: ) - the 60+mm of clearance you have plus another nearly 40 from the smaller tyres (though most then dial out some of that clearance on beam adjusters but that doesn't alter the travel limits).

Does your bus still have the bumpstops in place?

Dropping down to a 185/55 may just about bring the bumpstop into play, as I'm fairly sure there's about three inches of movement before they start to compress. So 55 profile might just about buy you enough room to stop the worst by taking some of the hit on the bumpstop before the tyre tubs out. I'd guess you'll probably find it's still not enough on big hits but it should help? On the up side, you can get 185/55 in an 86 load rating which should be ok for the front axle weight (1050kg from memory :?: - 86 load is about 530 so it squeaks by!).

Random aside, but in the spirit of the thread, this is the problem with such dramatic lowering on the spindles. The stock suspension is soft and long travel and the dropped spindles retain all of it. For a lowered car with less clearance you really want stiffer springs (so less movement for the same force) but that's hard to do on torsion bars.
The bugpack coilovers help because they increase the springrate, which reduces the travel for a given amount of 'bump'.
Airshocks would do the same thing. The other option would be to go for stiffer dampers to help control the compression movement.

When you lower a bus on the beam (cut and turned or adjusters), the arms go into an angle, which increases the effective spring rate which in turn is what causes the stiff ride when you lower it heavily on the beam (that and everything just plain old running out of movement!). I reckon the ideal would be to mix and match - two inches on the beam (effectively stiffening the spring rate) and another two on the spindles (so that the beam isn't at full travel)......

good summary I think

 

[dubdubz]

I run 175/65 r14 86T xl, these are 6ply as opposed to 8 - I think they are 58.31cm wide instead of 57.16cm for the 180/60, but the difference in the sidewall strength was noticeable

there was/is a thread on tyres and ratings

 

[Cali_bay]

Thanks for all your replies, I think I'm going to give some new front tyres a go.

Going to keep an eye on Graham's coilover development as this could improve things further, as the T2d coils are now maxed out.

The stock suspension has about four inches of travel before it starts to run out of movement. Almost twice the clearance you've got ( :shock: hence the rubbing!)

This is sort of verified by the folk on 'slam tyres' and dropped spindles saying that they get no rubbing (on the tyres :msn4: ) - the 60+mm of clearance you have plus another nearly 40 from the smaller tyres (though most then dial out some of that clearance on beam adjusters but that doesn't alter the travel limits).

Does your bus still have the bumpstops in place?

Dropping down to a 185/55 may just about bring the bumpstop into play, as I'm fairly sure there's about three inches of movement before they start to compress. So 55 profile might just about buy you enough room to stop the worst by taking some of the hit on the bumpstop before the tyre tubs out. I'd guess you'll probably find it's still not enough on big hits but it should help? On the up side, you can get 185/55 in an 86 load rating which should be ok for the front axle weight (1050kg from memory :?: - 86 load is about 530 so it squeaks by!).

Random aside, but in the spirit of the thread, this is the problem with such dramatic lowering on the spindles. The stock suspension is soft and long travel and the dropped spindles retain all of it. For a lowered car with less clearance you really want stiffer springs (so less movement for the same force) but that's hard to do on torsion bars.
The bugpack coilovers help because they increase the springrate, which reduces the travel for a given amount of 'bump'.
Airshocks would do the same thing. The other option would be to go for stiffer dampers to help control the compression movement.

When you lower a bus on the beam (cut and turned or adjusters), the arms go into an angle, which increases the effective spring rate which in turn is what causes the stiff ride when you lower it heavily on the beam (that and everything just plain old running out of movement!). I reckon the ideal would be to mix and match - two inches on the beam (effectively stiffening the spring rate) and another two on the spindles (so that the beam isn't at full travel)......

good summary I think

Great info , yes I still have my bump stops, so hopefully I can bring them into play.

 

[Cali_bay]

Had the bus out today 8) 8) with a full load and no rubbing issues

So the combination of coil overs on highest setting, new tyres and a bump stop mod, seems to have fixed the issues and the other half is not feeling so self conscious of her weight :lol: :msn4:

 

[r73]

Had the bus out today 8) 8) with a full load and no rubbing issues

So the combination of coil overs on highest setting, new tyres and a bump stop mod, seems to have fixed the issues and the other half is not feeling so self conscious of her weight :lol: :msn4:

Nice one! what tyres have changed to? and whats the bump stop mod?? ta Rob

 

[Cali_bay]

Had the bus out today 8) 8) with a full load and no rubbing issues

So the combination of coil overs on highest setting, new tyres and a bump stop mod, seems to have fixed the issues and the other half is not feeling so self conscious of her weight :lol: :msn4:

Nice one! what tyres have changed to? and whats the bump stop mod?? ta Rob

I changed to 185/55 15 as they were reinforced with a load rating of 86 which is 530kg. The bump stop mod is a bit prototype I am working on with a mate from work. It basically allows the bump stop to come into play before the tyre rubs the arches. Going to give it a bit more testing before I sort out the final version.

 

[r73]

ah ok - something else i'll wait to see with eager anticipation!! that and Grahams Coil overs
glad you got it sorted tho. those tyres sound like a good move - given the load rating, thats got to improve the ride in itself.

 

[Geeze]

Had the bus out today 8) 8) with a full load and no rubbing issues

So the combination of coil overs on highest setting, new tyres and a bump stop mod, seems to have fixed the issues and the other half is not feeling so self conscious of her weight :lol: :msn4:

Glad to hear you got it sorted
Am also intrigued to see the bumpstop mod.... spaced to sit lower? :?:

 

[Geeze]

ps.
as this is turning (justifiably given all the threads on dropped spindles!) into a one stop shop on how to make them work, here's the SP at the other end of the beam:

shows stock beam / stock spindles with torsion bars removed and then lowered to point of balljoint bind (ie. limit of travel).
Tyres are 195/45R15 (so smidge taller than slam tyres).

Definitely doesn't look like 3.5" spare under that beam lip for the drop on the spindles.
Something else to worry about when I finally get around to getting mine fitted up :roll:

Cali-bay, have you caught the beam yet? Or all good on that front with the taller 185/55s and bumpstop mod?