hsea17

Allow me to ask if anyone knows if a Giant D-Fuse Carbon seatpost can be fitted and used on a Giant SCR 2 2020.
The Giant SCR is, as many know, an affordable aluminum bike, but what I see as most important is that it fit me and with improved wheels and tires and relatively light pedals, my bike still weighs no more than 9.15 kg which I think is good for a bike which hardly cost me US 500,-
Thanks & Regards
hsea17

base2 

D-fuse is D-fuse. It's proprietary to Giant. A D-fuse post can only go in a D-fuse hole. So your answer is: "Yes." Aluminum, carbon, as long as it's the D-fuse shape, it's interchangeable.

Cool news if you ever wanted a "not" proprietary seat post & your frame uses the wedge-style expander: Some new Giant gravel bikes come with a D-fuse post & a different optional seat wedge clamp to allow the frame to accommodate round posts. Giant did this because dropper posts are round.

If this is the case, check your local Giant dealer or LBS that sells Giant for the round post clamp wedge. The mechanics may have one or a few in the top of their toolbox if a customer bought a bike but forgot the accessory packet. Happens.

Edit for general info:
If the frame previously had an aluminum post, clean out any grease that may be present. Use copious amount of friction paste on any surface contacting the post & (if appropriate) grease in the most sparing way possible inside the inner faces of the wedge, wedge bolt threads. The wedge expander design leaves ample room for water intrusion & begs for corrosion.

hsea17

Posting a picture of similar bike and yes my current seatpost is formed as D and so is the "Hole" Thanks, hsea17

veganbikes

If it is a D-Fuse post sure you can swap it but I wouldn't put a ton of money into that bike. Save for the bike you want. The problem with D-Fuse is it is only used on Giant bikes so that expensive proprietary post will only be good on their bikes until they discontinue it and move on to a different proprietary model or decide to be smart and use a standard round post.

Crankycrank

I'll add that if your current post is still good changing to a little bit lighter carbon model will be hardly noticeable. I would save that money for something else.

hsea17

Thanks for replying. In principle, I agree with you, but the difference is maybe that I have the last years intentionally downgraded from everything from Carbon frames and Dura Ace to aluminum and Claris due to age and less motivation. By the way, according to the bike dealer, the Claris is now a completely different thing than it was just 3-4 years ago, and I can confirm that myself "knock on wood", because I havent had any problems with the gears or the brakes the bike is equipped with at all.
With a slight price reduction, I was able to purchase the D-
Fuse Composite zero offset seatpost for US 50-, so while that obviously doesn't change anything with my lost motivation and age, I think it's worth it.
hsea17

veganbikes

Claris hasn't really changed (aside from no more externally routed cables but those went the dodo for Shimano a while back) a new bike will generally shift decently for a bit. The dealer is either getting too high at work or doesn't work on many bikes. It is Claris it is one notch up from Tourney. If I was looking for a good budget groupset 105 all the way or maybe if really lower budget Tiagra. I couldn't go from Dura Ace to Claris that would be a rough transition unless my stuff had been so worn out or unmaintained that most anything would shift better.

Though for my money Ultegra is the best it is pretty much Dura Ace performance at a little more weight and cost which as someone who isn't competitive and wants things to last for a long time is perfect for me.

Aluminum or Carbon, nah I will take my steel or titanium lasts a long time so I don't have to worry about those things.

50 bucks for a carbon post isn't bad hopefully it doesn't mean they are discontinuing it or something.

70sSanO

Claris shifters are fine. I've set up the external cable routing ones with older Deore and XT RD's and the shifting is good, a long throw, but shifts are fine.

If someone wants an 8 speed setup, there is not a lot of choice out there. It is either Claris, Microshift, or maybe NOS R500's.

John

hsea17

Thanks for the reply. Do you with "friction paste" mean "carbon Paste"? If so I find conflicting information online about using carbon paste! Some say go "dry" when others say "use" so I'm a bit unsure if this is necessary even though the frame is aluminum and the seat post carbon! Unfortunately I don't remember today about the bikes I've had in the past where the frames have been both aluminum and some in carbon if the seat post necessarily were in the same material as the frame!
hsea17

base2 

The paste, by any name it is called locally, has rough bits in it intended to grip the two parts. Carbon can be so hard & so smooth it can be difficult to get enough friction with the surface to make the component stay put. Giant includes a little packet of the stuff with every new bike with a carbon seat post. It is clear they intend for the packet to be used with the seat post as there really aren't a lot of models with other OEM carbon components.

Carbon & aluminum tend not to play well together in the same way aluminum & steel don't play well together. So, in this case, in addition to making sure the parts stay where they are supposed to, it helps to prevent electrolysis. It's not uncommon for aluminum steer tube spacers or aluminum nipples in carbon rims to be the sacrificial anode.

Some extremely premium components ( Extralite stems, for example) may say not to use friction paste because the manufacturing tolerances are so high there isn't room in the interface for the tiny glass beads to fit. If so, follow that manufacturers instructions.

As a general rule though, all part interfaces on a bicycle get grease, anti-seize, or carbon/friction paste depending on the interface. If not for preventing corrosion, then for consistency of torque value applied, preventing galling of the threads, seizure of the bolt or some other reason I can't think of at the moment.

On your bike, Giant intends friction paste to be used in the d-fuse interface & the greased bolts to be torqued evenly & sequentially to no more than 5nm.

hsea17

Thanks. The bike dealer says grease when the frame is aluminium. I have the "shimano" grease in my small bike tool box and I have seen "Parktool" carbon paste available on some online websites in this region so should be able to get that to but think I try with some grease as a starter.
hsea17

icemilkcoffee 

no- just listen to what the others were saying- you need carbon paste to increase the friction and grip. If you put grease on there you will decrease the friction and grip. Not good.

hsea17

Thanks for the reply. Have ordered this SAC-2 SuperGrip™ Carbon and Alloy Assembly Compound | Park Tool but when thinking about grease or any paste I have a tendency to think of vaseline which totally goes against any logic (IMO) when it comes to getting something to stick.
hsea17

hsea17

Hmm... maybe switching from an aluminum seat post to a straight carbon seat post wasn't as smart as I hoped.... On the plus side, it's 200 grams lighter and takes away a bit more shock/vibration when I'm riding. But something I didn't think much about was that my position on the bike changes even with the seat at the same height from the BB and distance from the middle of stem/handlebar. Anyone have a solution other than switching back to my old seat post?
Happy Holidays
hsea17