Ultimate Hub for Direct Sprocket Bolt Up

Discussion in 'Performance Mods' started by andyinchville1, Sep 23, 2007.

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  1. HI All,

    In reading all the posts that expressed a concern over the current 9 hole mounting system for the sprocket (mainly addressing the issue of spoke breakage and /or obtaining a precision alignment of the sprocket itself), I was wondering why nobody makes a high quality hub that a sprocket can directly bolt up to....

    I do realize that Grubee (I think) sells a hub that this can be done BUT it is really not suitable for a multi speed rear casette / freewheel and it probably isn't of real high quality anyways (like a true high end bike part...Say for instance Shimano Dura Ace...etc...).

    I was wondering if it would be worthwhile to take a hub designed for a disc brake and mount our sprocket onto it in place of the disc...This would not only provide a good spoke free mounting area for our sprockets BUT also give us a high quality, readily available, hub with multi speed capability and perfect sprocket centering / alignment (not necessarily chain line alignment but the sprocket would have no wobble or be out of true.. .chain line alignment can be handled by a sprocket offset (sprockets would not be a problem since they can be custom made / drilled for this type application).....

    Any thoughts or ideas on this?....Is the mounting area of a disc brake set up strong enough? ( I think the bolt holes are smaller and fewer but maybe high strength grade 8 could be used?)...Any experimenters out there? ;-)


  2. Papasaun

    Papasaun Guest

  3. Wow, Now that's A bike!...Thanks for the link Papa....And to think I would have been happy to do away with the disc to swap in a sprocket....Didn't even enter my mind that you could have both!
  4. alesterfeind

    alesterfeind Guest

    I bought this axle with the hub for a disc brake to try this out for a direct bolt on:


    Andy, could you custom a 36T sprocket for this, and if so, what would you need from me? I could mail you a stencil drawing of the hole pattern so you could go by that. I was told that this type of hub is used by others, but I assume they are drilling out their own sprockets since I don't see any for sale that would fit due to the hole pattern.

    Let me know what you think.
  5. 5-7HEAVEN

    5-7HEAVEN Guest

    :cool:I have a STATON hub on my rack mount. quite pricey, but gets the job done. 7-speed cassette plus 16t freewheel sprocket on left side.

    i spoke with Dave Staton, regarding a 36 freewheel sprocket for left-side. he knows of none available, but said that his 16t could be drilled to bolt the 36t on to.

    i also ordered a HD hub from bicycle-engines.com. they referred me to their sub, who will drill a 36t sprocket to mount onto a freewheel hub.

  6. HI Johnny,

    Yes, I could make a sprocket for that disc brake hub (actually, I've been dying to try that but my normal work has been quite crazy lately)....To make things as precise as possible I would need the actual hub so that I could get the precise measurements needed...unfortunately stencil drawings or "rubbings" are not precise enough when setting up the milling machines (of course I would send the hub back when I am done with it)...I wonder if all disc brake bolt patterns are the same?

  7. Oops....further reading of the ad for the hub indicates that yes all discs have standard spacings if they meet the same 6 bolt IS standard...That is good news!...Finally the possibility of a real quality hub with a direct bolt on sprocket!

  8. Klox

    Klox Guest

    The conversion Philcred did must be one of the best i have seen thus far. Only time will tell if it will withstand the forces applied..... Good on you Philcred!!!!

    My personal choice would be a hub like this Shimano hub: http://www.universalcycles.com/shopping/product_details.php?id=19064&category=740
    It is splined and therefore more suitable for an application where high torque could be an issue.
    Or maybe one of these beefier ones like this one: http://www.universalcycles.com/shopping/product_details.php?id=9621&category=83

    The machining of an adaptor for the Shimano hub would cost a bit of money, but it's only a once off expense...
  9. alesterfeind

    alesterfeind Guest

    Klox, those do look nice, especially the chrome, but that price is what I would pay for an entire motor. I was hoping to stick under $50, and come up with a solution that others in here would feel is affordable. However, I have not tried the Shimano that I mentioned above, so it will be a test hub. It may be that a pricier, larger model will be better. We will see.
  10. alesterfeind

    alesterfeind Guest

    Andy, I will PM you on the details so we can try this out. Thanks!
  11. Klox

    Klox Guest

    Hi Johnny! Point taken. I know that some guys work to a budget. If finances was no problem i would go for a toy like this: http://www.fxbikes.com/fxproducts.html
    (yes, i know it's not a true motored bicycle).
    No matter which option you choose, i'm very curious to see the outcome!
    Cheers, Klox
  12. mickey

    mickey Guest

    Davesmotors sells 6 bolt pocketbike sprockets that will exactly fit the bolt pattern in the M525 hub. gg997(42t) and gg998(33t). I ordered them to try as they were only $5 each. They are aluminum rather than steel and turned out to be too thick for the 415 chain. I've debated whether they could be ground down at the teeth to fit but I worry that they would lose too much strength. I may just grind the teeth off entirely and use it as an adapter to a regular steel sprocket.
  13. vyzhion

    vyzhion Guest

    Ya know... the NuVinci hub has disc brake holes on it. I know it is really pricey but I have heard nothing but good things about it. If I can find someone that can machine a 6 hole bolt pattern into a 36 tooth sprocket I could put the NuVinci on and use it with a rack mounted gx50 with Staton's lifetime guarantee gear box. That would be a sweet ride I think. Or maybe even dax's new titan once they are available. Or the spookytooth 4 stroke when they start selling them. Or even the whopper stopper skyhawk 2. The possibilities seem endless muahahahahahaha! O yea why didn't someone think of this before?
  14. 5-7HEAVEN

    5-7HEAVEN Guest

    :cool:Vy, that MIGHT be a brilliant idea, if you don't mind a fixed sprocket instead of freewheel. you'll have to install a freewheel drive sprocket on the box, because the STATON gearbox isn't used to spinning full time. unsure if the drive sprocket's shaft is long enough for a freewheel sprocket, since the shaft has a snap ring holding its drive sprocket.(the STATON drive sprocket has a machined face on the inside, which leads me to believe that it was shaved to fit the shaft and circlip precisely.)

    Now are you POSITIVE that you'll be able to DRIVE the NuVinci gearing on the left side?

    and don't forget the 10"-11" width of engine and gearbox.

    Vy, if the driven sprocket on the left side of the NuVinci's disc hub can utilize its advertised gearing features, you can be credited with offering all happy time engine followers the NuVinci gearing possibilities!(of course, that's after they find/adjust to their optimum gearing.

    and that is a HUGE benefit!

    Last edited by a moderator: Oct 27, 2007
  15. vyzhion

    vyzhion Guest

    The sprocket would bolt up to the nuvinci hub (or any disc hub for that matter) the same as it would to spokes with the traditional mounting hardware. Would it not be the same as clamping the sprocket onto the spokes? Is the staton gear box any bigger than the figure 8 one that comes with the JL Hoot kit? I was figuring that it is about the same. When I hooked my drive chain up to my crappy Chinese gear box it ran full time (at least whenever the back wheel moved). Would the staton box be any different? Staton sells that gear box with a freewheel in one of their kits so there has to be a way to affix it. In this thought process I am assuming that the staton box is just a really high quality replacement for the lousy gear box that comes with the 4 stroke kits. If I can make it freewheel too then I'm extra happy. I am not really sure of anything, just bouncing ideas around.
    Last edited by a moderator: Oct 27, 2007
  16. 5-7HEAVEN

    5-7HEAVEN Guest

    :cool:The disc brake hub is an integral part of the the bicycle's rear hub. it has a machined surface, and studs or a bolt hole pattern to match the disc.

    happy time driven sprockets are bolted onto the everyday bicycle hub through spaces between the spokes.

    the main reason that STATON gearboxes last for thousands of miles is because the drive sprocket is not in motion for a large percentage of the bike ride. it seems logical that the longer the gears are in motion, the shorter the gearbox's lifespan, and vice versa.

    the STATON gearbox's drive sprocket is not freewheeling. it's the driven sprocket on the STATON rear hub that has the freewheeling capability.

    the STATON gearbox is 9 1/4" long, 5" high and 2 1/2" wide(3" at the clutch).

    i have a spare STATON drive sprocket and a STATON driven sprocket. the sprocket attached to the rear hub is 5/8" thick with a 1 3/8" threaded hole. the drive sprocket is 1/2" thick with 5/8" keyed hole. just as i'd thought, the drive sprocket was heavily machined/resurfaced, so much that you can barely see the threads where the setscrews would've been. :shock:

    because the setscrews' holes were machined away, the modified sprocket is retained by a snapring(circlip)on front of the shaft.

    of course these sprockets are not interchangeable. you could probably find a 5/8" 18t freewheelsprocket, but to machine it down to 1/2" width and still retain the freewheel intact is a machinist's guess.
    Last edited by a moderator: Oct 27, 2007
  17. vyzhion

    vyzhion Guest

    That gear box has a lifetime guarantee... I am willing to bet it will hold up under strain. It is made in the usa, after all. ;) Besides, as part of their NuVinci kits STATON sells the gear box with a frewheel... I am quoting here, "the inside drive gear box will come with a 18T 1/8 inch freewheel" There has got to be a way to attach it to the shaft. And the crappy Chinese gear box I have is 7 1/2" long, 5" high and 2 1/2" wide at the clutch. The STATON box is a bit longer but I had plenty of room front-to-back when I had this in my bike.
    Last edited by a moderator: Oct 27, 2007
  18. Ghost0

    Ghost0 Guest

    Came up with a pretty simple solution to the hub problem last night. Create a disc out of maybe 1/8" aluminum that goes where the sprocket currently sits. Make the OD the correct size to use 24" wheel spokes on your 26" wheel. Use the existing hubs spoke holes to mount the new plate using rivets or screws. Now you should have a nice sturdy surface to drill and mount your sprocket to. Just a thought and I am pretty sure it will work.
  19. vyzhion

    vyzhion Guest

    The more I think about using a Nuvinci with a left-side sprocket bolted to the disc brake holes, the more I think it won't work. Some others have convinced me that the left side mount probably won't utilize the multigearing capabilities of the NuVinci hub, just as a regular spoke mount doesn't use the multigear output of a standard cassette. It's too bad tho. At least we can use a cheaper- non-geared disc brake wheel to bolt up a true sprocket and not worry about broken spokes. Any ideas where I can get a 36 hole sprocket drilled for the 6 hole disc brake pattern?
    Last edited by a moderator: Oct 27, 2007
  20. 5-7HEAVEN

    5-7HEAVEN Guest

    :cool:Vy, you can buy the HD hub from bicyle-engines.com. their 6-hole sprocket bolts directly onto their hub.

    Orrr, they have a left-side freewheel attachment that their 44t-48t sprocket bolts onto.

    Didn't your kit include this hub?