I ve a Race Face Diabolus crank set that keeps slackening its self off , ,what I'd like to know is will Locktite red engineering strength cure the problem and is it a common thing for race face products to do

Personally I'd go with blue or green as red might be a more "permanent" solution

Just remember to degrease thoroughly beforehand as the loctite won't work if it's greay

thanks ,only got the red , might have to grow some muscles when the time comes to change the bottom brackets

Using red locktite seems bonkers to me.

Loctite 222 for a low strength or 243 for medium. With 243 you still are able to disassemble with hand tools.

use loctite 'bearing fit' This is Loctite product 241. This is sometimes card up for the public at places like halfords as 'stud n bearing fit'

it is designed for assembled parts such as cranks onto a spline etc rather than fasterners so is more appropriate as it can deal with bigger gaps.

It is also the ideal product to retain cartridge bearings in their housings (bearing fit! see) and other little bits and bobs – even if the housing has become a little oversize.

the other product that works well if you put it under the heads of fasteners (ie not on the treads) is loctite 638 with is a retainer rather than a thread lock – I use well it high temp brother 648) to secure conrod bolts in engines.

with all engineering fasteners always clean component before application – use acetone or something.

And all loctite products work best if you use them for what they are intended..