spinning hub problem (slippage)

[tikiharl]

On my Burrito I had a cheap chinese rear coaster brake. When I went to really pedal down on it from a stop the crank would go around 3 or so times to every once of the hub. I thought of it as spinning the bearings. I replaced the wheel w/ a brand new Shimano coaster hub and it is doing the same thing. It can be ridden, but I would be afraid to put too much pressure on it. Any ideas whats going on?

[cman]

my guess. When you sit on the bike, the frame is flexing and tightening the chain. This may cause the hub to act funny. Usually if binds it up so it is hard to pedal. Try adding slack to the chain.

[deorman]

Maybe loose axle bearings?

[nomoregears]

Hello,

If I understand right (´cause I don´t know so many special technical words in your language), you have a singlespeed-hub. For aught I know, these modern-day hubs aren´t as precise built as the older ones. I prefer pre-war- or early post-war-hubs from "Sachs Torpedo". One of them I ride now for over 30.000km (ca. 19.000 miles) without any problems.

Here in Germany there is a bicycle-oldtimer-dealer (http://www.velo-classic.de)*, who sell these hubs, new old stock or restored. At last I payed 65 Euro for it. Expensive, I know, but you can ride in peace . . .

regards, Paul

*: . . . although I guess, you can get some old Torpedo somewhere in your land of unlimited possibilities .

[tikiharl]

Hey Cman,I think you are on to something about the chain tension. It would be quite the coincidence for both hubs to be faulty.This would explain how it seemed to fix itself a few months back on a ride and how it is riding fine now after this last episode.I belive that there is a sweet spot where the chain needs to be as far as tension. If it does it again the first thing I will do is adjust accordingly. Thx guys

[Bendix]

Hey Cman,I think you are on to something about the chain tension. It would be quite the coincidence for both hubs to be faulty.This would explain how it seemed to fix itself a few months back on a ride and how it is riding fine now after this last episode.I belive that there is a sweet spot where the chain needs to be as far as tension. If it does it again the first thing I will do is adjust accordingly. Thx guys

if it's that finicky on chain tension then they are still both faulty hubs. the worst you should have to worry about would be the chain bouncing off (too loose) or the hub being noisy- popping, knocking sounds from binding (too tight). a long shot, but perhaps it's a problem with the chainring rotating on the crankset, is the little 'nub' on the crankarms contacting the chainring solidly (if it's a one piece).......?

[deorman]

Hey Cman,I think you are on to something about the chain tension. It would be quite the coincidence for both hubs to be faulty.This would explain how it seemed to fix itself a few months back on a ride and how it is riding fine now after this last episode.I belive that there is a sweet spot where the chain needs to be as far as tension. If it does it again the first thing I will do is adjust accordingly. Thx guys

if it's that finicky on chain tension then they are still both faulty hubs. the worst you should have to worry about would be the chain bouncing off (too loose) or the hub being noisy- popping, knocking sounds from binding (too tight). a long shot, but perhaps it's a problem with the chainring rotating on the crankset, is the little 'nub' on the crankarms contacting the chainring solidly (if it's a one piece).......?

Or the rear "nubs" slipping on the hub? I can't see how chain tension could effect hub function in this way unless the hub was falling apart, loose or missing bearings.

[tikiharl]

Problem solved. Last Fri. nite there was a big ride in Scottsdale (350 bike pub crawl). I was messin with the bike in a fixed position and noticed that when I applied pressure to the pedal the crank would rotate but not the chainring.When I got home,upon further inspection I seen that the nub,pin had sheared off of the crank arm.I switched out the crank and presto problem solved.

[Bendix]

What do I win?