Restoration-Mini

Technical Forums => Maintenance and Modifications => Topic started by: MiniDave on September 12, 2015, 04:00:19 PM

Title: New Rotors
Post by: MiniDave on September 12, 2015, 04:00:19 PM
Today I installed new front rotors, mine weren't worn badly at all, but had huge pits and rust spots - it looks like they sat out in the rain in a junkyard before someone bought them and installed them on Buzz.

They're not hard to change, it only took about 20 min a side, but while I was in there I decided to raise the ride height a bit - the left front tire had been rubbing the flare on certain turns, once I got in there I found out why, the threaded knuckle adjuster on that side was bent!

I may have a spare in my used parts if the thread is the same, if not I'll be ordering a couple from across the pond on Monday. I suppose I could try to straighten it in the press, but I don't know as I'd trust it since it bent once.
Title: Re: New Rotors
Post by: 94touring on September 12, 2015, 04:04:03 PM
Nice looking.  Yeah I'd just get a new threaded section.
Title: Re: New Rotors
Post by: Willie_B on September 12, 2015, 04:32:37 PM
Those are some big rust craters.
Title: Re: New Rotors
Post by: MiniDave on September 12, 2015, 04:55:35 PM
I know, right? Yet they didn't pulsate or make noise.....I found some on sale at Moss for $39 each, so I bought a pair.

I'm hoping the threaded knuckles for all hi-lo's are all the same thread, if not I'll have to buy some from England from the guys I bought the spring kit from.
Title: Re: New Rotors
Post by: MPlayle on September 12, 2015, 07:51:17 PM
Is the bent part the smooth shaft of the knuckle that inserts into the threaded part of the hi-lo, or the actual threaded part of the hi-lo?  I don't think the threaded part of the hi-lo is available separately.

I have seen sets of just two hi-los available, such as for doing just the fronts.  You may have to get one of those sets in order to get a replacement threaded portion.  That would also give you another as a spare along with a couple of spare trumpet portions.

Title: Re: New Rotors
Post by: MiniDave on September 13, 2015, 12:23:13 PM
I'll post up a pic later today if/when I find I have the right part.

Here's what I saw when I went in to adjust the height....

I still had the old hi-los that came with the rubbers and they actually fit, so I installed one of them in place of the bent one - the thread size was slightly smaller on the hi-los that came with the spring set, and the shaft size of the knuckle was smaller too, so I dug thru my old parts and found an old knuckle that was in perfect shape and used those.

I'll take it up to school and set the final ride height on the alignment rack.

Title: Re: New Rotors
Post by: 94touring on September 13, 2015, 02:48:07 PM
At least you found a replacement that will work.  Aside from that about all you could do is weld a matching size threaded bolt to the existing base. 
Title: Re: New Rotors
Post by: MiniDave on September 13, 2015, 03:13:31 PM
Steel bolt, aluminum base, so no welding there. I might be able to straighten the bolt in my press, but I've already sent an email to the supplier in England to see about getting a pair of new bolts, so I'll have a spare in case it happens again.

If he can't supply them I will try to straighten it just in case, but I doubt I'd use it, rather I'd just leave the other hi-lo in there - it fits fine. They told me when I bought the spring set that the hi-lows for rubbers wouldn't work with springs, but mine worked perfectly.
Title: Re: New Rotors
Post by: 94touring on September 13, 2015, 03:23:53 PM
Ah bummer!
Title: Re: New Rotors
Post by: MtyMous on September 13, 2015, 07:37:36 PM
One of mine did the same thing... I have no idea why. I wish I could source a stronger bolt.
Title: Re: New Rotors
Post by: John Gervais on September 14, 2015, 06:33:33 AM
Yikes!

Not intending to be rude here, but now's the time to invest in 'proper' homologated HiLo's.  You'll be able to use standard knuckle joints and they're a robust construction.
Title: Re: New Rotors
Post by: MiniDave on September 14, 2015, 07:42:19 AM
Yes, I contacted one of the suppliers this morning because Huddersfield says they can't supply the adjuster bolt separately, but they'll be happy to sell me another set of front hi-los for only £25 plus shipping......

I have a set of hi-los from Mini Sport for rubbers, but they tell me they're not strong enough for springs - I don't understand why not, they seem fine to my eye.
Title: Re: New Rotors
Post by: Merlin on September 14, 2015, 10:05:37 AM
I know that my rear hi-lo is sitting on the bench, Ill see if my hardware supplier can source a grade 8 version of that when I get back.
Title: Re: New Rotors
Post by: MiniDave on September 14, 2015, 11:05:56 AM
The bolt is 20mm X 2.5 X 70mm long, I found them in grade 10.9 at Mcmaster Carr.

Right now I have a Mini Sport Adjusta-Ride in there instead, they (Mini Sport) say they aren't designed for coil spring applications, only rubber springs but I think they look as strong or stronger as what came with the coils.

The Mini Sport is on the left in this pic....note the bolt in the Adjusta Ride is 22mm, and the shaft on the knuckle is 14mm vs 13mm on the ones for the coils....
Title: Re: New Rotors
Post by: MiniDave on September 17, 2015, 12:16:00 PM
A couple of interesting things, the adjusting bolts on the Mini Sport Hi-Los are hollow all the way thru, the bolts on the spring style hi-los are drilled only far enough to accept the knuckle, and where it bent is right at the end of that drilled part. Also, the hole in the rubber hi-los are 14mm, the ones in the spring style are 13mm

They always say tubing is stronger than a solid bar.....but I think the real answer is they used a "soft" bolt, probably on purpose so that would be the weakest link. I also don't think the aluminum part is made very well, it looks pretty and it seems well machined but the bolt doesn't fit the threaded part well, it's loose in the threads - that also could be due to using a hardware grade bolt instead of a proper hardened bolt......of course it's tightened up by the lock nut.

At any rate, I've decided to just use the Mini Sport hi-los, at least in the front, the rears are made differently so I'm not worried about them......