Dibdib's giant Giant rebuild thread

[Dibdib]

(Thread topic was "Replacement rear shock - what do I need to know?")

Forgive the ignoramus question but I'm pretty clueless at bike tech at the best of times and doubly so with MTB bits.

The rear shock on my Giant full-susser is completely shot - one of the two chambers leaks air and the other pretty much won't hold any pressure at all. At this point I'm reluctant to even try sending it off for a rebuild as I expect it's probably beyond repair, and would just be throwing money away. So I'm resigned to buying a new one, but what do I need to know? I'm guessing travel length, and maybe some kind of sizing for the frame fitments - are these standardised?

[tiermat]

Eye diameter, eye to eye length (can't remember if it is at full extention or compression, so measure both) and weight rating (maybe). Travel usually refers to the distance the rear wheel moves, which varies depending on more than just the stroke length.

Model, size and year of bike might just get you all the info you need, though.

[Dibdib]

Cheers Tiermat. I'm hoping to scour fleabay as the MTB is definitely on a budget, but thanks for the starters - I'll have a proper look at the bike when I get home but it's a Giant NRS with some kind of RockShox shock on it.

ETA: Teh Googles tells me it's 6.5"x1.5" (165x38). From a quick glance at Chain Reaction... Ouch.

[PaulF]

I wouldn't write it off, it may just need a service. Haven't used either but both Mojo and TF Tuned have a good reputation on Singletrackworld my be worth dropping the a line. Can't help thinking that may end up cheaper than something second hand from eBay of dubious provenance.

 

[Dibdib]

I wouldn't write it off, it may just need a service. Haven't used either but both Mojo and TF Tuned have a good reputation on Singletrackworld my be worth dropping the a line. Can't help thinking that may end up cheaper than something second hand from eBay of dubious provenance.

Do you reckon? The positive air chamber seems to leak slowly and probably just needs a service; the negative chamber is supposed to hold 50psi but loses that in about 5-10 seconds - I can see the needle dropping to zero even with the shock pump still attached! I'd be happy to be told otherwise but to someone who knows nowt, that's so bad I can't help but assume it's screwed.

I'll give TF Tuned a call tomorrow, they're only based down the road... 

[Dibdib]

I'll give TF Tuned a call tomorrow, they're only based down the road... 

The Man With A Plan sez that not only does it sound dead, even if it wasn't, they can't get service kits for it any more anyway. New shock time!

[Dibdib]

Thread renamed, as it looks like I'm seriously considering a more thorough rebuild/upgrade of the Giant. Despite being old and a bit clunky, it doesn't owe me anything and I'm happy with the frame, wheelset and brakes it feels like it makes more sense to tidy it up than to scrap it and buy something brand new. So far, my to-do list is:

• Rear shock service New rear shock
• New headset
• New bottom bracket and chainset, maybe cassette groupset (10sp upgrade)
• New suspension fork?
• Service hubs and brakes

And so, on with the stupid questions. First of all, can I put a 10sp cassette on my existing Hope Pro II hub? Hope's website say it's not 11sp compatible (and neither is my wallet) but a 10sp upgrade might be a nice bit of futureproofing, as I'm replacing half of it ajnyway.

[Chris N]

Yes.  Shimano 11 speed MTB cassettes will also fit - it's just the 11 speed road cassettes that are wider.

[Dibdib]

Ooops. I guess I'm committed to it now. I'll get the LBS to take the BB out, I'm not putting another Octalink BB in there so I'm not wasting money on a tool. Then to start cleaning, assessing, and deciding how much gets binned.

One worry is the freehub - the cassette needed persuading off with a hammer, and while that was always getting replaced I was hoping to reuse the freehub. A replacement looks like £60 or so, so hopefully when it's cleaned up it won't be too chewed 



ETA: And it just got a bit more expensive

[Chris N]

File the burrs off, fit a cassette with an aluminium carrier for the bigger cogs.

[Dibdib]

The facepalming continues. This evening I spent a merry hour-anna-bit swearing extracting dirt and stones from inside the seatstays via the breather holes. Heaven knows how so much crap got in there, but I've got 99% of it out and vastly reduced the rattling. I'm almost tempted to just squirt some superglue in and shake it until it glues the remaining grit to the end of the tubes...

[PhilO]

A squirt of builders' expanding foam might be a better bet, as it'll stop stuff getting in in the future?

I see that it's an NRS. Getting a shock to fit shouldn't be too difficult, but bear in mind that the NRS was designed to run at zero sag, and I gather that the OE shock was designed around this requirement. A more modern shock will give more active suspension, and a slightly slacker static head angle. It shouldn't be an issue, per se, as I understand most owners prefered it that way, but it's something to be aware of if you weren't already.

[Dibdib]

A squirt of builders' expanding foam might be a better bet, as it'll stop stuff getting in in the future?

Yeah, I definitely want to do something to prevent it filling with mud again. I'd prefer something reversible though rather than builder's foam - maybe even just tape.

In other news, a big thanks to yacf'er bikenrrd for the Rockshox fork. I think I've sourced a cheap local rear shock too, and there's a new bb, chainset, cassette and chain slowly working their way through Royal FMail's system towards me.

I think the only big expense left will be getting the brakes and hubs serviced - after fifteen years of neglect, I think new fluids, seals and bearings is the order of the day. Thankfully Hope seem to have service kit available for pretty much everything they've ever made 

[Dibdib]

An update!

• With the frame suitably emptied of mud and grit  and given a wipe over with a cloth, it was the turn of all the suspension bushings and bearings to be stripped, cleaned, lubricated and remolished. I might replace the bearings altogether later on because they're a bit gritty, but I think they'll do for now.
• Frame and forks have been to the LBS today for a few bits I didn't have the tools for. The old Octalink bottom bracket is out and in the bin, along with the notchy old headset, and they've fitted a lovely new headset in its place.
• With that done, tonight I've been able to put the bars back on and put the lockout switch on them, and also fit the new HT2 bottom bracket and Deore chainset. I briefly considered 1x10 but that's expensive and I'm bad at hills as it is. Pedals are on too, just some cheap nylon DMR V6s so I can see what flats feel like (and put off cleaning the SPDs in the bits box.)
• Front and rear mechs still aren't back on the frame, but are at least clean now and sat in a shoebox waiting to be refitted.
• Sadly I've broken my first thing of the project - although it wasn't entirely my fault. I opened up one of the shifter top plates to give it a clean and it turns out the existing damage wasn't just cosmetic. Some of the innards were broken and I couldn't immediately figure out how to bodge them back in, so new shifters time!
• I also still need to buy a shock, and maybe a saddle and seatpost - there's nothing wrong with the old ones, they're just a bit naff (and not GOTHBLACK.)

It's finally starting to look a bit like a bike again, maybe it'll be finished before winter. I didn't say which winter though.