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  1. #1
    steep fast and loose :)
    Reputation: The_Lecht_Rocks's Avatar
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    Helius AM/FR Owners - Go measure your Bottom Bracket height

    please ?

    my AM comes in at 14" (355mm) with 2009 Fox 36 TALAS and standard stack Chris King headset and shock (200mm i2i) mounted in the top hole.

    I suspect now I've correctly measured the BB height that the Air shock is causing the mid-stroke blow through, hence pedal strike...

    Now go and measure up for me !!!!!!!

  2. #2
    from 0 - sideways 3.2 sec
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    13 3/4", medium frame, king steelset, fox float 36s, 57mm stroke RP23.
    Visit - www.gravity-sports.co.uk - Exclusive high end MTB Products

  3. #3
    steep fast and loose :)
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    stroke makes no difference derekr - the i2i is the important issue.......your BB is 1/4" lower than mine FFS ! ? ! even more prone to pedal strike !

  4. #4
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    On my 2008 FR (size L) with Fox Van and 200mm DHX mounted in bottom hole, it's 335 mm.

  5. #5
    steep fast and loose :)
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    bottom hole gives you how much travel boozzz ? 335mm is VERY LOW !

  6. #6
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    TLR will the tyre size and wear will also affect the reading by up to 30mm ?

    Hey i wish i could measure mine .... my bike

  7. #7
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    Simon. What exactly are you measuring? ground to underside of BB or ground to centre of BB. I assume the latter?

    My FR with 66's is 340 and 370 respectively(give or take a couple mm)

    Boozzz FR(as with all 08 FR's) gives full travel(167mm?) in both top and bottom holes. Top is for 50mm stroke. bottom for 57mm stroke

    I'm now running 40% sag on my ccdb and still not geting pedal strike(loads of LSC and LSR). Off to pitfichie today to give it a good work out

  8. #8
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    Yeah 167mm with a 57mm stroke shock. I measured to the underside of the BB, not the centre.

  9. #9
    steep fast and loose :)
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    to the centre - Dipper - Yours is about the same as mine on your 66's and Big Betty's c/f to mine on 36's and Nics.
    Thereby further proving the lack of mid stroke control attainable with the Monarch

  10. #10
    steep fast and loose :)
    Reputation: The_Lecht_Rocks's Avatar
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    boozzz - sorry - any pedal strike ?

  11. #11
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    Reputation: Boozzz's Avatar
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    Quote Originally Posted by The_Lecht_Rocks
    boozzz - sorry - any pedal strike ?
    No, never an issue. Could also be due to the fact I've always used bikes with low BB's.

  12. #12
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    Hi! I'm looking into a Nicolai Helius AM and I'm abit worried about the BB height being too High!

    Can it really rail corners while going downhill? Isn't 14 " a little too high to be really enjoyable? I don't give a damn about pedal strikes as long as I can corner confidently.

    Thankful for any input! / Mike

  13. #13
    steep fast and loose :)
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    it rails corners - get a test ride and be blown away by it's handling.
    pedal strike disappears with lower profile spd's (shimano)...

  14. #14
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    TLR: You've posted a BB measure of 355mm.

    That is with a 545 mm fork and a CK headset, but what tires were you running?

    The fact that pedal strikes disappears sounds a bit alarming.

    If I get a go on buying one I sure will get my ass to Nicolai and testride one, but numbers and measure is what I can compare with now.

    Does anyone know how the Helius AM acts compared to Transition's new Covert?

    Best regards / Mike

  15. #15
    steep fast and loose :)
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    tyres were probably Nobby Nic 2.4"'s. posssibly a NN 2.25" on the rear.
    awesome machine, other than the low BB on techy climbs.
    not an issue anywhere else now i'm getting used to it.

  16. #16
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    What about head angle for the helius am? 67.7 is 0.7 degrees steeper than most competitors.

    Can anyone please tell me about how it feels. Is it too unstable in the downhills?

  17. #17
    steep fast and loose :)
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    aye - 0.7 degree of difference makes it very very skittish downhill.

  18. #18
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    Guys
    I'm new to the world of full suss (and don't understand all the shock technicalities). I've had my AM for a couple of months and I'm plagued by pedal strikes so any advice gratefully recieved. I'm running a Fox DHX air shock with correct sag (according to the Fox manual) and pretty fast rebound on the 160mm hole. My BB height is 350mm. I'm using Easton Flatboys which are big pedals but I'm sure the problem shouldn't be this acute.
    Help please!
    Last edited by Surrey Hills Rider; 07-21-2009 at 07:45 AM.

  19. #19
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    SHR: Take the pedal slams as a blessing Not having them equals in a too high bb and/or too little travel.

    TLR: 0.7 degrees is alot considering that a total of 10 degrees cover mor or less the entire spectra from dh bikes to xc bikes.

    Gimme something constructive and relieving so that I can buy the AM without any worries.

  20. #20
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    personally, i think ~66-66.5 degree HT angle and ~13.75" bb is ideal for AM riding.

    on my rebuild of my helius FR, i was shooting for this. i think the HT angle came on-target, but i think the bb may have been closer to 14" than i preferred. i need to go back and measure now that the build is complete.

    still rides good, but a 14" bb is noticeably higher on-trail than something 13.5-13.75.

    bb height should be measured from the ground to the center of the bb (usually easiest to determine the center of the crank bolt).

  21. #21
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    I'm with you tetonrider2, your suggested angle and bb height sounds exactly like an Intense Uzzi. Don't know about build quality of those Intenses though.

  22. #22
    steep fast and loose :)
    Reputation: The_Lecht_Rocks's Avatar
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    SHR - the AM is 'fashionably' low in BB height and long in the top tube, allowing a shorter stem [i run a thomson 50mm 0 deg rise] and 160mm fork to be used without developing too twitchy handling that a higher BB and shorter TT would ensue.
    0.7 degree of HA can be eradicated via sag setting...
    my AM runs at 355mm (13.9") BB height, but i was struggling with mid stroke blow through and running too much sag on the CCDB..
    by realising the lower BB and adapting my pedal style to suit, the pedal strike can be ridden around but never allieviated - it's a symptom of the frame design and increased handling capabilities.

    if you ride lots of technical rocky climbs, then the AM will strike pedals all too frequently - it's less noticeable on descents and groomers.

    i can't yet say if pedal strike -v- increased handling is worth it for me - i need more time on the AM to decide if i want to continue with it or go elsewhere, possibly custom, for an increased BB height......

    my 6 pack had a higher BB and didn't lose out on handling.......that was horst link too, but 10mm less travel and a similar leverage ratio....

    you must test ride one before you buy....only by riding it on trails where you ride frequently can you compare it's performance advantage over other test bikes / rides.

  23. #23
    steep fast and loose :)
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    regarding quality of construction, i doubt you'll find a FS frameset better constructed anywhere else.


    and with all the options, nicolai are truly unique. just be careful with custom geometry as there are pitfalls if you design your own ride [reduced travel being one major issue] !

  24. #24
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    TLR thanks for the reply. As I mentioned I'm a novice when it comes to shock settings...so "0.7 degree of HA can be eradicated via sag setting..." Is this done by setting less sag than recommended or more?
    .

  25. #25
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    it is done by setting more sag which will lower the rear end in comparsion to the front. The result will be a slacker head angle

  26. #26
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    SHR it will also result in a lower BB height and more pedal strikes, I bought my AM with a DHX Air and never suffered to much with the pedal strikes albeit using small clipped pedals when I changed to a pair of flats I suffered a bit of pedal stike. Then I changed the shock to a Stoy and realised that I had been running the DHX far too firm; to stop it blowing through its mid travel and with the new shock had a far more plush feel and less pedal strike, due to what I believe is caused by better mid stroke compression damping.
    DHX Air now resides on my Helius CC (commuting bike).

  27. #27
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    Quote Originally Posted by The_Lecht_Rocks
    0.7 degree of HA can be eradicated via sag setting...
    not really. i know what you are saying, but the reality is that while sag affects HA, the standard way to measure HA is un-sagged.

    the reason is that one must compare apples to apples. if we all start measuring our bikes sagged, then there is no way to account for the fact that you might like 35% sag while i prefer less sage.

    further, sag is designed to dial in the shock's performance, not to correct geometry. if one dials in their sag but then must increase it to reduce HA, they will no longer have "perfect" sag.

    for that matter, one could adjust HA by getting a longer-travel fork, or by letting all the air out of only the rear tire, but you know where that's going....

  28. #28
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    measured my 2004 helius FR @ 13.85" bb height and 66.5 HA with 160mm travel fork and 200mm eye-to-eye shock.

  29. #29
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    more sag results in a slacker HA. however -- be careful about this.

    you should find your optimal sag independent of HA. sag is not meant to change geometry of a bike.

    HA is always measured without sag.

    we're talking, for instance, about bike with a HA of 67 degrees. you cannot turn it into a bike that has a HA of 66 degrees by increasing sag, as the bike with 66 degree HA (unsagged) has an even steeper HA with sag.

    again, be careful.

  30. #30
    steep fast and loose :)
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    more sag (if you have enough to spare) + less rebound damping can sharpen up handling on a slack front end.

  31. #31
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    Quote Originally Posted by The_Lecht_Rocks
    more sag (if you have enough to spare) + less rebound damping can sharpen up handling on a slack front end.
    more sag would make the bike feel even slacker and take up more of the travel, no?

    it technically doesn't affect HA as that is measured without a load on the bike.

    since the original question was about bb height and HAs, i want to be clear that sag has no effect on the geometry of the bike, but it can affect ride handling in ways that not everyone understands. (i.e., one can make an adjustment such as increasing sag to make their front end feel more slack, but it will also reduce travel.)

    i'm happy for folks to play around with this, but they should know there is no free lunch.

  32. #32
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    2p

    Sag is dynamic. How you set the sag when your playing about with rulers and tape measures in the level environment of your man-cave will bear little resemblance to what will happen when you point and pedal the thing up or down a steep hill. Front and rear suspension set-ups effect this and whether your weight is transfered to the front or the back of the bike at any given time will effect the sag much more than what you do in the shed.

    Seriosly - the thing to do is to get a decent shock (and fork) that won't blow through the mid travel (Like most air shocks) or pack off and spend all it's time at the end of it's travel (like any shock with pro pedal that I have used). Ideally a decent shock with high and low speed compression and rebound that you can play with yourself (CCDB) or entrust to a decent tuner. The better the info you give the tuner the better the set up can be. It takes time to get the settings right and may even take a few trips to the tuner or even a few shocks if your fussy.

    I would say a head angle of 66.8 degrees in the brochure is a guide to what it will be on the bike - the eventual number will depend on fork length, tyre sizes and headset stack-up....


    and this is before you consider spring wt (air pressure), stem length, seatpost layback, and the mass of the fat bas*&^% in the saddle with his full face helmet and rucksack... or the severity of the terrain ridden (or walked ).

    Make sure you get the best shock you can, geometry tweaks will be worthless if your shocks performance is rubbish. IMHO

  33. #33
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    Quote Originally Posted by thepimpmessiah
    2p

    Sag is dynamic. How you set the sag when your playing about with rulers and tape measures in the level environment of your man-cave will bear little resemblance to what will happen when you point and pedal the thing up or down a steep hill. Front and rear suspension set-ups effect this and whether your weight is transfered to the front or the back of the bike at any given time will effect the sag much more than what you do in the shed.

    Seriosly - the thing to do is to get a decent shock (and fork) that won't blow through the mid travel (Like most air shocks) or pack off and spend all it's time at the end of it's travel (like any shock with pro pedal that I have used). Ideally a decent shock with high and low speed compression and rebound that you can play with yourself (CCDB) or entrust to a decent tuner. The better the info you give the tuner the better the set up can be. It takes time to get the settings right and may even take a few trips to the tuner or even a few shocks if your fussy.

    I would say a head angle of 66.8 degrees in the brochure is a guide to what it will be on the bike - the eventual number will depend on fork length, tyre sizes and headset stack-up....


    and this is before you consider spring wt (air pressure), stem length, seatpost layback, and the mass of the fat bas*&^% in the saddle with his full face helmet and rucksack... or the severity of the terrain ridden (or walked ).

    Make sure you get the best shock you can, geometry tweaks will be worthless if your shocks performance is rubbish. IMHO
    all good advice. thanks for chiming in.

    i agree that it's all about performance on the trail. that said, the only apples-to-apples measurements that are worth anything are those done statically.

    if one attempts to use sag to increase HA or other geometry of the bike, they're just further limiting the ability to adjust sag for performance.

    also, you raise a good point: the stock height of the headset (below the headtube) can affect bb height and HA without affecting sag.

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