The Ultimate Hub for Direct Sprocket Bolt Up

Andyinchville1 · #11 (**permalink**) 06-03-2008, 10:36 PM

HI Goat Herder....

Interesting idea about making the sprocket a slip on fit.....I may take a trip to the bike shop this weekend and look into that idea....Good thinking "out of the box"!

Andrew

Andyinchville1 · #12 (**permalink**) 06-03-2008, 10:40 PM

HI Roman415,

You are correct....Our sprockets come pre drilled to mount in place of the disc brake as well as being able to use the standard HD 9 hole mounts....Some bikes may have chain line issues when using the disc mount option (can sometimes be overcome by re dishing the rear wheel or using spacers etc...) but the 9 hole mount is always an option....
Hope this helps you.
Andrew

cityevader · #13 (**permalink**) 06-03-2008, 11:05 PM

Quote:

Originally Posted by roman415

Just would like to give this a bump. I am a newcomer to the forums and am planning to install one of Dax's 70cc kits on my Rock Hopper mountain bike.

The Rock Hopper has disc brakes, and I was curious if any has gotten this to work.

It looks like I will have to ditch the rear disc brake if I go with the traditional spoke hub install (the brake itself doesnt look like it would clear the new sprocket)

For some reason (correct me if I'm wrong) I get the impression that you would be able to mount the sprocket to the actual rear disc, rendering it useless but providing a solid mount for the new sprocket. Does that make any sense?

I have another set of non-disc brakes that I was going to slap on in the rear but keep the front disc.

Thanks is advance

Funny, I've got a Rockhopper too... about, oh, 10 years old (My goodness, has it been that long?!?) With Sun Rhynolite rims and Shimano XT disc hub with 9 speed cassette. The engine's driven sprocket's inner hole was smaller than the wheel's hub body. I grinded off about a 1/8 inch off the sprocket's inner radius to slip it over the hub and up against the disc rotor mounting lugs, but when the wheel was mounted, that put the sprocket hard against the frame...so I ground off the hub's disc mounts altogether to spoke-mount the driven sprocket, and it cleared fine.

If possibly you've got an old 7 speed arrangement, the wheel's dish might be reduced enough to move the sprocket closer to the "center"....but then again, I don't recall disc brakes readily available when the 7 speeds were around, but possible when 8 speeds were popular.

Note: My Rockhopper frame was right when they changed things around in 1997-ish, when I snapped the frame. It had a short one inch headset for threaded fork, but when warranty-replaced, was sent taller headtube updated to 1-1/8 for threadless forks....where was I going with this??????
I guess just reminiscing about the good old days when I used to pedal instead of motor around!

roman415 · #14 (**permalink**) 06-04-2008, 11:30 AM

Thanks for the responses!

I am still waiting on my kit to show up (hopefully today or tomorrow *fingers crossed*.) I will post pictures and let you know about clearance.

I mistakenly said i have a rockhopper, what I really meant was Hardrock (I got half of the name right :P)

I actually have 2 hardrocks, one has a smaller frame (my bro's,) so i do have the luxury to pick out the one that will work best with the kit.

Will keep you guys posted.

Andyinchville1 · #15 (**permalink**) 06-26-2008, 10:07 PM

HI Guys....

Because of the amount of interest in mounting our drive sprockets in place of the disc brake on a disc brake hub....I decided to build an adapter that will offset the sprocket closer to the spokes (places the sprocket in generally the same position that the original 9 hole mount would have placed the sprocket)....The reason for this is because some frame and sprocket combinations did not work for some people (chain rubbing the rear stays or too extreme a chain angle)....for most the solution was as simple as redishing the wheel and / or spacing the rear wheel......Tho functional....this is not optimal since it can compromise rear wheel strength...the adapter takes care of all this without need to redish or respace (Basically the sprocket (with enlarged center) is bolted to the adapter and the adapter is bolted to the 6 holes of the disc brake mount)...If I shave some of the adapter behind the 6 bolts there may be enough room for the disc caliper?...Will the disc on the disc brake still work if I space it out 1/8 inch?....I will post pics soon....

PS - I can possibly make the adapter so that the sprocket and disc brake disc can be used BUT since I do not own a bike with a disc brake I'll have to take a trip to a bike store to check them out.....

goat herder · #16 (**permalink**) 07-03-2008, 10:06 PM

Hey one more idea for your slip on sprocket after mounting it use a tig welder spot weld the sprocket to the octagon hub shape making it truly out of the spokes.

goat herder · #17 (**permalink**) 07-03-2008, 10:07 PM

Hey one more idea for your slip on sprocket after mounting it use a tig welder spot weld the sprocket to the octagon hub shape making it truly out of the spokes.