MGB Rebound Straps - The Bad and the Ugly

[UPDATED 2012-04-03; scroll down to view]

 

We replaced the drivers side MGB Rebound Strap (aka Stop Strap) before the first race in 2011 - and here is a pic of it today, almost split through:

  

Yikes.

Could be worse though; below is the passenger side rebound strap that we could not remove due to a rusty bolt. Gnarley! But notice it's still hanging in there, probably due to the OEM high quality strap that has thread / rope embedded in the rubber of the strap. 

An attempt at a close up; it's fuzzy not because it out of focus, it fuzzy because IT'S DAMN FUZZY!

Someone should probably do something about that...


[UPDATE 2012-03-24] Turns out the "new strap" in the first pic is split all the way through in the bottom eyelet. This was the cause of Randy's Clunk described (and then subsequently ignored) in the Charlotte 2011 race report. When we replaced the strap last winter, the old bushing (which goes inside the rubber strap eyelet) was rusted tight to the holding pin / bolt - we could not get it off, so we left it and put the new strap right on it. Which then proceeded to sand through the new strap to weaken it enough to break when the very old and very cheap and very tired tube shocks let the axle fall too fast. Sigh. Updates later, as the tragety unfolds (the rusted pin / bolt is no longer available for sale - must step lightly here with only 3 weeks till next race!)


[UPDATE 2012-03-25] As expected, the passenger side bolt immediately sheared off when I tried to loosen it. %$#%#% oh well. As Forrest Gump sagely said: "That's good; one less thing to worry about."


[UPDATE 2012-03-30]

That split shown up in picture 1? It was all the way through:

3 Races old :-(

Time to order new straps... but how to stop them from splitting again? StrappingLad in the USA makes very nice replacement straps out of webbing that won't split; I emailed a question (my suspensions been lowered, do I need shorter straps?) but time has expired on a response, since I have a race in 2 weeks. 

I also didn't like the zero-stretch attribute of the webbing-based straps. "Step Functions" are a bad thing in most engineering practices, and this sudden jarring stop is probably no different. i wanted a little give first (as the original straps were designed) but then a final solid measurable maximum stopping length (like StrappingLads has).

So I talked my pit crew into sewing up two double straps that are about a half inch longer than the rubber based original-but-new replacement rebound straps:

MG Minions

The final result. Top is the $3 FRAKTA strap from Ikea that we hacked up and sewed (I have NO frakta idea what it was intended to be used for), middle is the strap on it's side, bottom is the strap around one of the rubber rebound straps:

 

 Encased MGB rebound strap installed, drivers side:
 

Encased MGB rebound strap installed, Guinness cooler side; note use of cotter pin and washer to hold lower strap on luckily when the rusted bolt snapped off it left enough threads to drill - since the strap takes no side-to-side force, it's just meant to stop it from slipping off.

 

The lower attach post with broken off thread, cleaned up with dremel and coated liberally with rubber-friendly silicone lube:

 

Note: DO NOT DO WHAT IS PICTURED BELOW:

Bad idea #2352

After a raucous discussion on the email list about rebound straps I somehow retained the misconception that the lower strap eye has a metal bushing just like the upper strap eye (you can see the bushing in the lower left of the FRAKTA pic above). Leading me to the conclusion that is was rusted on the post, and a few on the list agreed with me (they probably thought I was talking about the upper post). Long story short, I tried to dremel off the rusted-bushing-that-never-was and of course cut into the post itself... which is welded to the axle and very hard to replace, if you can even find them for sale.I stopped after about 1/16th of an inch when my dimly lit Lucas light bulb finally flickered on over my head. DUH. Sigh. So... repeat... don't do that.

LINKS:


Some great links, until I clean up this page:

• Really great documentation of the same problem I am fighting: http://www.mgb-stuff.org.uk/axletext.htm#reboundstraps and in-depth bigger pics: http://www.mgb-stuff.org.uk/rr.htm#3
• Non-rubberband straps: if he doesn't answer my email in 2 days I will make my own eh: https://sites.google.com/site/strappingladshop/mgb-axle-straps