Results 1 to 11 of 11
  1. #1
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    311

    weight savings? new drivetrain on heavy bike

    hi guys.

    i have a bike that i love, but it's sinfully heavy. i can't afford the ultimate new bike so i'd rather keep this one going and put money into it to make it better. it's an AM 29er that is 32+ depending on tires. i'm having a new wheelset built up and this will have a big impact. i can change tires and will try tubeless and this always has an impact.

    the drivetrain is a combo of SLX shifters and some sub SLX shimano cranks/cogs/chain. i've got new SLX brakes and they are just fine, despite weight.

    i like my LBS's, but dam the internet, with it's great pricing. looks like i can put together a combo XT/XTR or RF Turbine crankset for reasonable money- around $600 or so.

    i know that shifting would improve substantially, what i don't know is if weight will drop much if at all. i have to assume it will, but weight figures on the net are always subject and i don't know the weight of my components.

    any armchair guesses from the guys in the know? am i hoping for at least a pound and a half for that kind of coin, but may be kidding myself.

    thanks for your input.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Nov 2009
    Posts
    187
    You need to post the exact spec. of your bike in order to get good recomendations.

    Chris.

  3. #3
    mtbr member
    Reputation: moefosho's Avatar
    Join Date
    Apr 2013
    Posts
    1,695
    It depends on what model SLX components they are? Or what year and Model of the reign X you have. Then we can get some accurate weights.
    Going to a 1x10 setup is a quick way to drop weight because you eliminate a shifter, a derailleur, and a couple of chain rings. You also get to put a smaller RD on since you are only running 1 front ring. Try doing the rides that you normally ride while only using the middle chainring. Never switch to the big or small ring. If you can pull it off then think about switching.

    Otherwise SLX are all good parts for an AM bike. Normally I just tell my buddies to upgrade when parts wear out.

    If you really want to spend money then I would watch Ebay for full XT or XTR groupsets. You can find good deals on new take offs or slightly used.

  4. #4
    ups and downs
    Reputation: rockyuphill's Avatar
    Join Date
    Nov 2004
    Posts
    13,810
    There wasn't a huge weight difference between XT and SLX, maybe 5-8% on most pieces. For example Shimano XTR M970 triple cranks were 786gms, XT M770 triple cranks were 856gms and the SLX M660 triple cranks were 886gms. That's a pretty typical of weight gap percentage for the current 10 speed components. There's a sizable and pricey gap between the weight of XTR and XT or SLX.
    I'm a member of NSMBA and IMBA Canada

  5. #5
    mtbr member
    Reputation:
    Join Date
    Nov 2009
    Posts
    501
    Quote Originally Posted by cunningstunts View Post
    i know that shifting would improve substantially, what i don't know is if weight will drop much if at all. i have to assume it will, but weight figures on the net are always subject and i don't know the weight of my components.
    am i hoping for at least a pound and a half for that kind of coin, but may be kidding myself.
    It's possible you could save a pound and a half but your current stuff would have to be hilarious. I know race face used to make some hilariously heavy cranks for instance. Just take your stuff off your bike and weigh it. It's the best way to find out what you stand to lose.

    It's pretty easy to get pretty accurate weights on things before you buy them. Either go to the LBS and weigh stuff or look it up online. You can usually find pictures of parts on scales. Recently places like bikeradar and bikerumor have taken to actually weighing things themselves and posting it.

    I don't agree that going from SLX to XTR is going to make shifting better. I went from XT to XTR, my friend has SLX. Does XTR shift better than XT? Maybe but I wouldn't say its a big enough difference to really matter. Does 2x10 shift better than 3x10? I think so, I think it's a lot better in the front but I think the rear shifts pretty much the same. Multirelease on the downshift? I lived without it for a long time...if it poofed off my bike I would get over it pretty quick. I'm often suffering too much to care. Damn the front shifts way better than my 3x10 xt or my friend's 3x10 xtr (which I have over 100 miles on).

    That race face crankset is what, 80g heavier than XTR? Why? Don't make the mistake of thinking you need something burlier than you actually do. Maybe you need it maybe you don't, maybe it's heavier and weaker too. Who knows? Don't assume that just because it's heavier it's stronger.

    Excel is your friend.

  6. #6
    ups and downs
    Reputation: rockyuphill's Avatar
    Join Date
    Nov 2004
    Posts
    13,810
    In your profile it mentions you have a Reign X Coil, is that a coil rear shock and a coil fork? If so there's an extra 2 pounds over air fork and shock, on a frame that is likely about 7.5-8.0 pounds.
    I'm a member of NSMBA and IMBA Canada

  7. #7
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    311
    the bike in question is a 2011 norco shinobi. in it's first year it was a stand alone offering, with basic build. the following year it was so well received they made shinobi's 1-3 with 1 being a pretty sweet bike for around 5500, with fox 34 fork. mine is much like the 2 version. it would seem like the rf turbine crankset is fairly light, xtr chain and xt rear cogset. this is the last frontier on my bike, the lev seat post sure ain't going anywhere, nor is the stem and bar set up. this is the exact bike other than my cockpit changes. the new rims will be the light bicycle to a hope front and hadley rear hub. run tubeless eventually.
    Norco Shinobi 29'er - Tested - Pinkbike

  8. #8
    mtbr member
    Reputation: moefosho's Avatar
    Join Date
    Apr 2013
    Posts
    1,695
    Looking at that spec sheet, the place where obvious weight can be lost is the wheelset, tires, crankset, handlebar, stem, and possibly saddle.

    Other than that it wont be very beneficial.

    Like I said before, you can easily drop a pound by going 1x10 and that wont cost anything. You can also look into getting a lightweight crankset (possibly carbon) or XTR.

    Why do you want to keep the current cockpit? Usually you can drop quite a bit of weight by replacing OEM parts from Norco like the bars, stem and even grips.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    311
    only because i already have. my bars/stem, post and saddle are all aftermarket selected for fit and comfort. also, living in BC i have a lot of steep climbs, often long and steep, 1x works for only the strongest and lightest guys around here. my knees wouldn't fare well winching my 29er around these mountains...

  10. #10
    mtbr member
    Reputation: moefosho's Avatar
    Join Date
    Apr 2013
    Posts
    1,695
    I see...
    Most of your drivetrain parts wont give you much weight savings if you upgrade. Your crankset is low end though.

    You could go with a crankset upgrade go to 2x10
    Shimano XTR M985 10SPD Double Crankset > Components > Drivetrain > Cranksets | Jenson USA Online Bike Shop

    Your current crankset and bottom bracket weigh approx 990g
    This XTR crankset and BB is about 700g. thats 2/3 of a lb right there. All you would need to do is adjust the FD. Or you could buy a new one of those as well.

    That, wheels and tires. can drop you a decent amount.

    Hope this helps man!

  11. #11
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    311
    it does, many thanks. yes i was coming to the same conclusion, it's going to be mostly in the crankset and then i would have to go XTR or some carbon stuff like RF Sixc to really make a diff. all the rest of the bits would maybe be a half pound in total. i guess the saying 1000/pound is about right eh?

Similar Threads

  1. XX1 weight savings versus XT
    By trenchDiggr in forum Ibis
    Replies: 11
    Last Post: 03-12-2013, 03:04 PM
  2. 29er weight savings
    By coling in forum Wheels and Tires
    Replies: 2
    Last Post: 01-11-2013, 06:55 AM
  3. Weight savings and Terrain
    By bank5 in forum Weight Weenies
    Replies: 3
    Last Post: 01-24-2012, 01:38 PM
  4. Ti spring weight savings?
    By macming in forum Shocks and Suspension
    Replies: 3
    Last Post: 11-05-2011, 06:44 PM
  5. Weight Savings
    By Singlespeed McGee in forum Wheels and Tires
    Replies: 6
    Last Post: 01-22-2011, 08:15 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •