50mm BB drop on 2020 Norco Bigfoot- dealbreaker?- Mtbr.com
Results 1 to 18 of 18
  1. #1
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054

    50mm BB drop on 2020 Norco Bigfoot- dealbreaker?

    Was really liking the look of the new 2020 Norco Bigfoot, then noticed it only has 50mm bottom bracket drop. 60mm seems to be pretty standard, and the Farley has 65.

    My Fuse hardtail (built around 29x2.6" tires) has 60, so it seems like that would be the minimum I'd want for 26x5" tires (or possibly 27.5x4" or 29x3" if I added a second wheelset). I understand fat tires at low pressure will have a smaller effective diameter, but I don't have any issues with the 60mm drop on my Moonlander with 4.8's, and don't like the idea raising my bike's COG an extra ~1/2".

    So my question is twofold:
    -Why would Norco go significantly higher on the BB (even their Ithaqua carbon frame has 60mm drop)
    -Is there some sort of move towards higher BB's on fat bikes I'm not aware of? The Bigfoot was just redesigned and seems pretty modern in all other respects.
    ''It seems like a bit of a trend, everyone trying to make things longer over the last couple of years" Sam Hill

  2. #2
    Rocking on a Rocky
    Reputation: RockyJo1's Avatar
    Join Date
    Jul 2012
    Posts
    1,573
    With the 1/2 a degree difference in head angle keep it about the same height?
    :thumbsup:It doesn't matter what I ride as long as I ride it Rubber Side Down●~●.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Dec 2014
    Posts
    1,989
    You're bikes COG is not at the bottom bracket. Its around your butt and waistline approximately 4 feet off the ground and that 1/2" means diddly squat since you can get off the seat and move around as necessary.

    You're overthinking this. Just buy it and ride it if it feels good to you on a test ride.

  4. #4
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by RockyJo1 View Post
    With the 1/2 a degree difference in head angle keep it about the same height?
    Don't think I quite follow what you're suggesting. On a rigid bike, the BB height is what it is, given the spec'ed head tube angle. And if anything, on a bike with a suspension fork a slacker HTA should keep the BB higher as the fork compresses, as less of the travel will be in the vertical plane.

    If you altered the HTA on a given bike (say with an angleset) it would effect BB height. However, comparing two completely different bikes, the only way I see how it might come into play is if the slacker HTA is supposed to bring back some of the stability that the higher BB takes away. Mountain bikes generally have gone the opposite way in recent years though, going both lower and slacker.

  5. #5
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by prj71 View Post
    You're bikes COG is not at the bottom bracket. Its around your butt and waistline approximately 4 feet off the ground and that 1/2" means diddly squat since you can get off the seat and move around as necessary.
    You're getting a lot wrong here. For starters, it should be "Your bike's", not "You're bikes".

    Secondly, I did not say that the bike's COG is the bottom bracket, but rather that raising the BB raises the COG. Everything on a bike is based off of distance to the BB, so raising/lowering the BB inevitably raises/lowers everything else, and in turn the bike's COG.

    Finally, I said "bike's COG", not "bike + rider's COG". I do understand there's a difference, but it's also pretty ignorant to suggest the first does not effect the second. By your own admission, when you are in the saddle your COG will be effected.

    And why do you think DH and Enduro riders, who spend a disproportionate amount of time out of the saddle, have such a strong preference for low BB's? It's because body positioning should be determined by terrain, not overcoming poor geometry.

    You're overthinking this. Just buy it and ride it if it feels good to you on a test ride.
    You are right that a test ride would go a long way towards either confirming or rebutting my concerns, but that's not an option right now- hence my question.

    It's possible I'm overthinking this, but having owned dozens of mountain bikes I definitely prefer a lowish BB. I absolutely love the way my Fuse handles, and it currently has 2.3 tires on it so a ~12.2" BB. I could see going a little higher on a fat bike, but pretty sure I would find a ~13" BB off putting.

    Could I live with it? Maybe, but at this point it seems like an unforced error on Norco's part. The only explanation I can think of is that it helps keep the CS short for a given amount of tire clearance (the less BB drop, the easier for the seat tube to clear the tire).
    ''It seems like a bit of a trend, everyone trying to make things longer over the last couple of years" Sam Hill

  6. #6
    mtbr member
    Reputation:
    Join Date
    Dec 2014
    Posts
    1,989
    Again... You're over thinking this. 1/2" is about the width of your pinky finger. It's not going to making any tangible difference.

  7. #7
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by prj71 View Post
    1/2" is about the width of your pinky finger. It's not going to making any tangible difference.
    Out of curiosity, at what point would you concede that a higher BB does make a difference? 1" higher? 2"? Never?

  8. #8
    mtbr member
    Reputation: serious's Avatar
    Join Date
    Jan 2005
    Posts
    3,377
    Low BBs are great until you ride in rocky areas and constantly risk pedals strikes and even hitting the chain ring when riding over obstacles. The suspension corrected setup does not help either if you stick to rigid.

    I cannot see stability and handling being an issue on a fat bike with a slightly higher BB. I wish my BB was a little higher.


    Sent from my iPhone using Tapatalk
    My rides:
    Lynskey Ti Pro29 SS
    RM Suzi Q 90 RSL
    KHS Team 29
    S-Works Roubaix
    KHS CX 550 cyclocross

  9. #9
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by serious View Post
    Low BBs are great until you ride in rocky areas and constantly risk pedals strikes and even hitting the chain ring when riding over obstacles. The suspension corrected setup does not help either if you stick to rigid.
    I'm pretty well versed in rocky areas (New England), and would agree that there is definitely a trade off for going lower. I can even see an argument for going slightly higher on a fat bike since: a) your speed is generally lower, so harder to carry momentum through choppy stuff, and b) you can't always tell if it's rocks or just lumpy snow you're pedaling through in lighter snow cover.

    It's funny you mention suspension corrected setup, as I would probably run a 100mm Mastodon on either bike (Bigfoot or Farley). Neither company lists what fork length the bikes are designed around, but backing into the numbers it appears the Bigfoot is based around a ~20mm longer fork (I suppose this would be confirmed by the BF being specced with a 100mm Mastadon, and the Farley an 80). So a good chunk of that 15mm lower BB on the Farley gets eaten up if you ran the same length fork.

    I cannot see stability and handling being an issue on a fat bike with a slightly higher BB. I wish my BB was a little higher.
    Good food for thought, thanks.
    ''It seems like a bit of a trend, everyone trying to make things longer over the last couple of years" Sam Hill

  10. #10
    mtbr member
    Reputation:
    Join Date
    Dec 2017
    Posts
    105
    Quote Originally Posted by miles e View Post
    Neither company lists what fork length the bikes are designed around
    Below the geometry specs on the Bigfoot's page, there's a downloadable PDF listed as "Service Parts Reference" which has a lot of specs including "Fork Length (MAX)/offset... Maybe that'll help.

    eric/fresno, ca

  11. #11
    mtbr member
    Reputation:
    Join Date
    Dec 2014
    Posts
    1,989
    Quote Originally Posted by miles e View Post
    Out of curiosity, at what point would you concede that a higher BB does make a difference? 1" higher? 2"? Never?
    It makes a difference in pedal strikes or no pedal strikes if you are riding this bike on summer trails. The difference in BB height of 1/2"-3/4" among all of bikes available means diddly squat for handling. It's all marketing fluff generated by the bike companies to make you think you are getting a better handling bike.

  12. #12
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by ericzamora View Post
    Below the geometry specs on the Bigfoot's page, there's a downloadable PDF listed as "Service Parts Reference" which has a lot of specs including "Fork Length (MAX)/offset... Maybe that'll help.
    It does, thanks. Lists 511mm A2C, which would equate to a Mastodon EXT 100 @ 20% sag.

  13. #13
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by prj71 View Post
    The difference in BB height of 1/2"-3/4" among all of bikes available means diddly squat for handling. It's all marketing fluff generated by the bike companies to make you think you are getting a better handling bike.
    So 1" then? Would you say a 1" difference in BB height is where it starts to make a difference in handling? In my experience 1" would be the difference between a good bike and one that is borderline unrideable. For me, 1/4" is noticeable, 1/2" from my preferred height (for a given bike/application) starts to be a deal breaker.

    As much as I disagree with where you draw the line between a good bottom bracket height and one that is too high, I'm actually somewhat sympathetic to your cause. I think super steep seat tube angles are a stupid fad, and the downsides they present are typically glossed over or ignored completely.

    Everything about bike geometry is a tradeoff/compromise- not to mention personal preference based on a rider's size/ability/terrain. I just think don't it's as simple as saying "bottom brackets should alll be 1/2" lower/higher" or "seat tube angles should all be 3 or 4 degrees steeper than they were a few years ago". Any significant deviation in a bike's geometry will introduce potential drawbacks, the trick is for each rider to figure out if the benefits outweigh them.
    ''It seems like a bit of a trend, everyone trying to make things longer over the last couple of years" Sam Hill

  14. #14
    mtbr member
    Reputation:
    Join Date
    Dec 2014
    Posts
    1,989
    Quote Originally Posted by miles e View Post
    So 1" then? Would you say a 1" difference in BB height is where it starts to make a difference in handling? In my experience 1" would be the difference between a good bike and one that is borderline unrideable. For me, 1/4" is noticeable, 1/2" from my preferred height (for a given bike/application) starts to be a deal breaker.
    You're throwing hypotheticals out there as I don't believe there is a 1" difference in BB heights between any of the bike manufacturers. And 1/4" isn't noticeable nor does it make the bike more stable or unstable.

    Dave Moulton's Blog - Dave Moulton's Bike Blog - Bottom Bracket¬*Height

    https://www.daveypushbikes.com/blog/...tood-dimension

    Pedal strikes are reason to obsess over BB height. Not bike handling.

  15. #15
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by prj71 View Post
    You're throwing hypotheticals out there as I don't believe there is a 1" difference in BB heights between any of the bike manufacturers.
    It's called a thought experiment, to see where your line of reasoning takes you. I don't care to do a survey of current MTB's, but in the not too distant past it was not unheard of to have BB heights of similar travel frames vary by an inch. To the extent they don't any more (even while BB heights have gotten lower across the board), that would be testament to the fact that manufacturers have figured out there is an upper limit on BB height for a given bike to handle well.

    And 1/4" isn't noticeable nor does it make the bike more stable or unstable.
    The fact that you keep repeating this does not make it true. You may not be able to detect 1/4" difference, that has no bearing whatsoever on if others can.

    The first blog appears to be a retired road frame builder, and prominently features racing tricycles. Don't mind if I pay it little attention.

    The second one is interesting, but did you notice the part at the bottom where he talks about his custom 650b bike with 70mm BB drop and a 290mm BB height? I don't think the article is making the point you think it does.
    ''It seems like a bit of a trend, everyone trying to make things longer over the last couple of years" Sam Hill

  16. #16
    This place needs an enema
    Reputation: mikesee's Avatar
    Join Date
    Aug 2003
    Posts
    14,693
    Quote Originally Posted by miles e View Post
    ...COG will be effected.


    I'm not usually one to pick nits with spelling or grammar used by strangers on the innertubez, but since you've felt it necessary to do that here, I think it's acceptable to point out that 'affected' was likely what you meant above.



    I have a Farley with a 100mm Mastodon. It's not my deep snow fatbike. It's my everything BUT deep snow fatbike. Mixed snow/ice/rock rides for ~5 months of the year, backcountry/bikepacking epics the other 7.

    I have 170mm cranks on it and I wish it had at least 1/4" less BB drop.

  17. #17
    mtbr member
    Reputation: miles e's Avatar
    Join Date
    Jan 2004
    Posts
    3,054
    Quote Originally Posted by mikesee View Post
    I'm not usually one to pick nits with spelling or grammar used by strangers on the innertubez, but since you've felt it necessary to do that here, I think it's acceptable to point out that 'affected' was likely what you meant above.
    Dammit, you're right. I even thought about it at the time, but remembered the rule wrong. Probably been making that mistake for awhile, so thanks.

    I have a Farley with a 100mm Mastodon. It's not my deep snow fatbike. It's my everything BUT deep snow fatbike. Mixed snow/ice/rock rides for ~5 months of the year, backcountry/bikepacking epics the other 7.

    I have 170mm cranks on it and I wish it had at least 1/4" less BB drop.
    More good info. I notice you didn't say "I wish it was 3/4" higher because BB height doesn't matter and is just an industry conspiracy to sell more bikes".

    Really, I'd be surprised if everyone did approve of a particular bike's BB height, which is why I wasn't expecting most fat bikes to be so close to, if not right at 60mm BB drop when I started comparing.

    To (hopefully) provide some closure here, I did settle on a bike with...60mm BB drop. It wasn't a determining factor by any means, but I knew it would not be a drawback for me (based on my experience with my Moonlander).
    ''It seems like a bit of a trend, everyone trying to make things longer over the last couple of years" Sam Hill

  18. #18
    mtbr member
    Reputation: serious's Avatar
    Join Date
    Jan 2005
    Posts
    3,377
    Just to give you more data on my perspective: the Suzi Q has a crazy 70mm BB drop. I cannot understand why they would do that to a fat bike. Their XC race bike (the Rocky Mountain Vertex) has 60mm BB drop).

    I will never put CF cranks on this bike because pedal strikes are literally unavoidable, especially in the rocky area I ride. I got really good at avoid strikes, but occasionally, when I have to keep hammering up a rocky climb, hits will happen. Very frustrating!
    My rides:
    Lynskey Ti Pro29 SS
    RM Suzi Q 90 RSL
    KHS Team 29
    S-Works Roubaix
    KHS CX 550 cyclocross

Similar Threads

  1. 2020 Hightower 2 vs 2020 Tallboy 4
    By Doug in forum Santa Cruz
    Replies: 84
    Last Post: 03-20-2020, 11:46 PM
  2. 2016 Norco Bigfoot 6.3 vs 2017 Norco Bigfoot 6.3
    By vectrose in forum Fat bikes
    Replies: 4
    Last Post: 06-18-2017, 04:49 PM
  3. Replies: 19
    Last Post: 04-18-2011, 05:12 PM
  4. Dealbreaker - Input requested
    By bikeninja13 in forum Yeti
    Replies: 9
    Last Post: 08-19-2007, 06:29 PM
  5. Thomson 50mm or azonic shorty 50mm
    By bullcrew in forum Downhill - Freeride
    Replies: 6
    Last Post: 01-23-2005, 12:49 AM

Members who have read this thread: 102

Posting Permissions

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

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.