recumpence said:
I'm sorry, but once you use disc brakes, you never go back. I have no clue why he is against them.
Anyway, the only issue I am struggling with on my mountain bike build (have not started it yet) is rear disc brake with a sprocket big enough to achieve the drive ratio I am looking for.
I may have to mod my Avid cailper and make a "Sproder" (rear sprocket/brake rotor). Either that, or put a small custom rotor on the drive jackshaft. Neither option seems apealing to me, though.
So, how much clearance do you have between the tire and seat post at full suspenison travel?
Matt
Everyone,
I'm very near the end of my semester at Uni and am extremely preoccupied trying to get all my end of session assignments and presentations organised. Then I'll have a few days off before final exams begin. In short I'm trying to minimise the time I spend on ebike planning and building for the next month but will then have 3 months off for the summer break. Even so, I can't keep ebike thoughts out of my head! I may check in and see what you guys are up to every once in a while till then.
I'll try to catch up with the other posts later tonight. Thanks for everyone checking in and offering suggestions.
Matt,
The brake/sprocket combined "sproder" is something I've thought about and have seen before. The issue I see is that disc brakes are happy when dry and chain drives are happy when lubricated. The combo is probably not a great compromise but does yield a cool look on choppers.
The only way I can think of to have a decent sized disc brake and a big rear sprocket (or toothed pulley) would be to have a sprocket with quite a complex shape that bolts first to the 6 hole disc mount then kicks back towards the spokes (like the top hat adapter does) and then comes BACK over the whole disc and caliper. Such a sprocket could be machined out of a giant hunk of aluminum, or made with several "rings" with spacers in between.
I'm guessing no one can visualise what I'm talking about
but it is a solution in my mind
Lastly, Matt, do you have a good way to measure clearance at maximum compression of the suspension? I can't get much more then my own body weight in compression with the bike not moving and that only really tells me how much "sag" the bike is set up for. Which would be about 20-35" of the overall travel. I guess I could compare clearance with with and without sag, them measure the difference in shock stroke and try to extrapolate out to full travel. But that would assume linear wheel travel and linear behaviour of the shock compression throughout the full travel. Might be a poor approximation.
I might just make a mock up box from your dimensions, tape it to the bike, set the shock as soft as possible, and go outside with it and bounce around and go wild and see if I can bottom out in such a way that I smash the mock up, then reposition or adjust the shock so that I can't.