Jump to content
Slate Blackcurrant Watermelon Strawberry Orange Banana Apple Emerald Chocolate Marble
Slate Blackcurrant Watermelon Strawberry Orange Banana Apple Emerald Chocolate Marble

Archived

This topic is now archived and is closed to further replies.

purple_haze

what size bearings are my skates?

Recommended Posts

First Post..... Hi guys im new here and i need help with something. i have a pair of mission d limited and i think i probably need new bearings for the skates and i was wondering, if someone could help me with the size of my bearings. All i know is it uses a 8mm hexagonal axle

much help would be appreciated,

dave

Share this post


Link to post
Share on other sites

Pretty sure my DLimiteds came with standard 608 bearings. The micros are 688mm and you will notice the size difference.

Basically, look at the bearing. Is it small? About the size of a dime? If so = micro. If large, bout the size of a quarter = 608 standard.

Axel size does not depend on bearing size. Bearings have the same diameter. The axel size usually indicates whether a chassis set up is single (one bolt that locks into the other side of the chassis) or double (two interlocking bolts that meet up in the center of the bearing/wheel setup). I'm pretty sure the smaller axels, or 6mm to my knowledge, are for double axels, and the larger axles are for single systems. But don't quote me on that. I might have my MM sizes wrong.

Share this post


Link to post
Share on other sites

688's, or "mini bearings" have a width of 5 mm, a diameter of 16 mm, and a bore of 8 mm..unrelated to the number assigned to the bearing.

608's have a width(thickness) of 7 mm, a diameter of 22 mm, and also a bore of 8 mm...again the number does not relate to bearing dimenions.

A 608 bearing will have about 2.33 times the static load capacity of a 688 "mini" bearing...so that is why there seem to be "durability" issues often with the "mini" bearings as compared to the 608 bearing. As time and corrosion goes on, mini's will tend to fail much more rapidly than 608's.

When placed in the wheel hub, the mini's being narrower bearings will tend to have a spacer with a wider shoulder width than the 608 bearings..hence the problem swapping wheels and bearing sizes...you will need to have new spacers too, when shifting from wheels that accept mini bearings to wheels that accept 608's.

I have never seen a wheel/skate/chassis manufacturer that use the same spacers for either bearing set up, because the need for the outside of the bearings to have the same overall width between the frame bosses means that the thinner (5mm vs 7 mm) mini bearing will need a wider spacer to fit between the bearings...whichever axle system is used..

"Mini bearings" were designed to provide less "rotating mass" for speed skaters who could easily gain a few extra "ergs' over a 20 km race, to have a little more energy at the end of the race...However as when these "mini's" first appeared..those using them were often sponsored, and would change bearings for each race..at no cost to the skater....The reduced "drag" afforded by these bearings is soon offset by the relatively increased concentration of dust particles inside the smaller bearing in a hockey application...unless you are cleaning them after each use..hence any gains from the use of mini's are short lived for most people and almost unnoticable when they are present.

However in the Great Weight Race...the search for "lighter weight skates" to help beat their competitors, any weight that could be removed (even if only a few grams) was done so by the skate manufacturer..Hence mini's again became popular..not so much for their gains in performance but in how they helped reduce the overall weight of the skates.

Share this post


Link to post
Share on other sites

×
×
  • Create New...