Replacing Giant Defy 4 2013 Freehub

Question

Hi what is the correct freehub replacement part for Giant Defy 4 2013?

The bike is all original, 8s pg-850 cassette

thank you,

Answer 1

In my opinion, the act of replacing a freehub body on any given wheel--especially from older, generically branded hubs--is a ridiculous exercise in frustration. Knowing the brand or maker of the rear hub can go a long way to determining what's needed. The problem there is that many OEM hubs found on the vast majority of low to midrange priced bikes have zero identification markings on them. One cannot go by the brand of rim necessarily because any rim of appropriate size can be laced to a compatible hub. Said compatibility may simply be the correct number of spoke holes to match the holes in the rim.

While that would seem a bit of a tirade to the industry (it is) a larger point is that removing the current freehub is beneficial in a search for a replacement. This is due to the fact that what makes (for example) HG freehub bodies different and possibly incompatible is the method used to connect the body to the hub, the number and location of the pawls and their method of engagement (spring, magnetic, do they come from the hub and engage the body?, or do they come from the body and engage the hub?). There are also considerations as to the type of bearings (loose ball vs. cartridge) and axle size the hub is equipped to use (thru axle vs. solid axle vs. QR). These latter considerations can be determined with the freehub body still in place, but the meat of the information still lies hidden in the interface of the body to the hub and removal of the body is necessary to be certain what you're then looking for in a replacement.

How then does one remove the body? Well, that depends on the hub maker and their chosen design. (Are you feeling the frustration of the multitude of DIYers?) Take heart, we never give up that easy. A freehub body is secured by a right hand threaded bolt. This fixing bolt may be part of the hub or may be part of the freehub body or can be a separate, loose bolt that engages threads are either in the body or sometimes within the hub. Finally, many of today's freehubs are removable by hand when the end cap (end of a thru axle system) is removed by hand (where the thread engagement of the tru axle holds all together) or sometimes is threaded onto the inner axle and secures the hardware of the hub.

Removing the freehub body from your wheel will take a 10 or 12 millimeter hex wrench. The hex aspect should be long enough to engage the fixing bolt. It may be accessed by the hex wrench approaching the bolt from the right, drive side of the freehub. If you find you can't even begin to insert the 10 or 12mm hex from the right side, then access to the bolt is from the left, non-drive side. Either way the threads fixing the freehub body may be very tight. One trick would be to mount the hex wrench in a vise, then put the wheel on to the wrench and turn the rim around the wrench. Much more leverage. One caveat: you're dealing with a right hand threaded system (righty tightly, lefty loosey). The direction you turn the wrench to loosen the bolt is dependent on the direction you approached it from. If it's from the left, non drive side, you'll turn the wrench right, which from the hub body perspective is turning the threads left, loose.

Here's the most relevant aspect to your question. Thanks for listening. The Defy 4 from 2013 is specced with SLR-2 rims and has an 8 speed cassette on an 8,9, 10 speed HG (common, Shimano-style) freehub body. Utilizing a web-based tool from a Giant spares website one can muddle through the options to find either a direct replacement (for 8-10 speed road cassette OR a compatible--see above--11 speed freehub body if you want to be upgradeable. The 11s freehub body will work for your 8 speeds with the addition of a spacer which is typically provided with an 11s body). This freehub body is the one I would expect to be a direct replacement.

Again, I cannot emphasize enough that having the current body removed so it can be compared to a replacement option will save a headache later on. All this too is dependent on your bike still having the original, specced components, namely the SLR-2 rear wheel. The punt, of course is to take the entire rim to the shop and let them handle it.