The amount of used gears sets for the ford 9" with full spools are plentyful!! Trying to find stock carriers to install the mini spool is time consuming.imo
ive know 2 guys that have broke mini spools in their 7 1/2 metric rear ends...when i ran a metric i just had the spiders welded with no problems.....went to a 9 inch last year since we were allowed
When I first started racing I ran demo derby's as well. We welded the rear ends only to have them break all the time, no matter how or who welded it. We then switched to another idea where we welded (filled up the space between each tooth) between the spider gears just enough that we still could get them in. When they tried to spin they jammed into the side gears that the axles slide through and the rear end was locked. Sounds hackish but it never has failed. Also I have never had a mini spool fail, and until I read this thread have never heard of one failing. Point is we really didn't need spools, but if we are going to ford 9" we might as well have one due to the large amount of used gears and spools from retired late model rear ends.
Mine never failed, just getting rid of that 15lbs of spinning junk whipping up the oil and probably way out of balance sounds like a smart way to improve performance for an extra $100 over a mini spool.
jwo, don't get me wrong, I understand the 100 bucks, lighter more efficent. We've been 100, 200, 500 dollared for these little improvements that end up with us all eventually back on the same playing field we started with, just out the cash. These SS are at the limit of the technology for the stock equipment.
I only ask the question to understand why the change is needed. Few have had any (if at all) problems with mini's and you haven't had problem with your welding. Why the change? (remember extra speed makes no nevermind if we are all the same.)
The spool issue is an old one because it was added last year, so the question was about the process.
Making changes because some one asked for it, because it'll make the cars faster or because the advantage is just perceived, doesn't seem to be a good reason for change.
The tech guys down in the garage did a good job this year of protecting the racers and some of the things clairified and stated in the 2010 rules seems to further that.