fred@umcp-cs.UUCP (03/14/84)
This weekend I was looking at a Lotus ``America'' at a local bike shop. This model has the ratchet mechanism located between the crankarms and the front sprocket, rather than the more traditional location on the rear axle. This, of course, means that the entire chain & sprocket assembly is in motion whenever the bike is. The salesman insisted that this is a wonderful advantage, but I don't see it that way. If you assume (probably incorrectly) that you spend roughly half the time coasting, this would double the wear on the entire chain assembly. Even worse, if a stray limb or pants leg were to get caught in the chain, (yes, I use those little metal clips, but accidents can still happen.) it would be pulled into the front sprocket by the momentum of the bike & rider, possibly jamming and locking the rear wheel throwing you into a skid. With the ratchet in the rear axle, if something got caught in the chain, only the pedals lock, and you can backpedal to release whatever is stuck. Am I just being paranoid, or is there really an advantage to having the freewheel mechanism on the front sprocket rather than the rear? - Fred Blonder harpo!seismo!umcp-cs!fred
toma@tekchips.UUCP (Tom Almy) (03/14/84)
I opted for a front freewheel for my 10 year old son's Schwinn. The advantage is that you don't have to pedal while shifting, and you can shift gears by pushing the bike. This seemed to be greatly worthwile for a kids bike, but for an adult (who can presumably shift properly) there doesn't seem to be any advantages yet plenty of disadvantages. It has worked fine so far. (BTW, the Schwinn also has a rear freewheel, designed not to normally slip, so if you do get something caught in the chain, it will stop moving -- this does seem to be a VERY important safety feature). Tom Almy (many major systems)!tektronix!tekchips!toma
ishizaki@saturn.UUCP (Audrey Ishizaki) (03/14/84)
I don't understand the set-up you describe. Could you be more specific? For example, where are the chainrings? are the front/rear derailleurs in the same place? if not, where? What is this 'sprocket' you mention? is it the bottom bracket? please describe this strange set-up again for me. It sounds unusual and I have never seen/heard of such a bicycle. Audrey Ishizaki hplabs!ishizaki
janney@unm-cvax.UUCP (03/14/84)
Shimano had a front freewheel out a few years ago. The idea was to
make it easy to shift derailleurs: you stop pedalling and then shift.
The chain still moves, and you don't have to worry about applying too
much force on the pedals. This seems like a dubious advantage to me: I
think your objections are sound.
If I remember correctly, the FF was big and heavy and didn't stay on
the market for long.
Jim Janney
{parsec,ucbvax,gatech}!unmvax!unm-cvax!janney
{purdue,lbl-csam,cmcl2,csu-cs}!lanl-a!unm-cvax!janneygrt@hocda.UUCP (G.TOMASEVICH) (03/14/84)
You anticipated a good question on the front freewheel; the rear cluster is a stiff freewheel for safety. The clerk should have told you that. I think it is a gimmick for people too sloppy to stop pedalling hard while they shift. I never saw it on high quality bikes.
jlw@ariel.UUCP (03/15/84)
The supposed advantage to having the freewheel in the bottom bracket rather than in the rear hub is that you can shift at any time that the bike is rolling and not just when you are pedalling. This is a weak point at best, I think. Joseph L. Wood, III AT&T Information Systems Laboratories, Holmdel (201) 834-3759 ariel!jlw
spoo@utcsrgv.UUCP (Suk Lee) (03/15/84)
<>
The advantage is that you can shift,
since the chain and clusters are moving,
without having to pedal.
Big Deal. I agree that it doesn't
seem to be much of an advantage,
considering the possibility of having
your leg eaten.
--
From the pooped paws of:
Suk Lee
..!{decvax,linus,allegra,ihnp4}!utcsrgv!spoojeff@dual.UUCP (Jeff Houston) (03/17/84)
> The supposed advantage to having the freewheel in the bottom bracket > rather than in the rear hub is that you can shift at any time that > the bike is rolling and not just when you are pedalling. This is a > weak point at best, I think. Help, I would also like to see an explanation of just how this type of setup works. What happened to the bikes front chain-rings? How is the rear wheel setup, with a single sprocket? Just how is the freewheel incorporated into the bottom bracket unit? This sounds mighty peculiar to me, I'll stick to my standard Campy crank and Regina freewheel setup, thank you. Jeff Houston Dual Systems Corp., Berkeley, CA {ucbvax,ihnp4,cbosgd,amd70,zehntel,fortune,decwrl}!dual!jeff
thielges@uiuccsb.UUCP (03/20/84)
#R:hocda:-38200:uiuccsb:16200005:000:616 uiuccsb!thielges Mar 19 16:54:00 1984 I think the worst problem with the front freewheel system is the friction load it creates while coasting. Consider a normal freewheel system : when you coast, the only moving parts are the two wheels. The front freewheel system adds friction from three more bearings (two on rear chain tension mechanism and one for the front freewheel) -PLUS- the friction of a clunky old chain (at least all the bikes I've seen with a front freewheel system had a clunky old chain). The added friction from the F-F system produces a very noticable drag while coasting and is pretty worthless in my opinion. Bart Thielges
thielges@uiuccsb.UUCP (03/20/84)
#R:saturn:-200100:uiuccsb:16200006:000:611 uiuccsb!thielges Mar 19 17:00:00 1984 A bike with a front freewheel has the freewheel (the thing that slips and goes click-click-click.... while you coast) mounted on the same axel as the chainrings and a fixed hub on the rear cluster where most bikes have their freewheel. Everything else more or less looks the same as a normal 10 speed bike. The effect of this F-F setup is to keep the chain moving whenever the bicycle is moving whether coasting or pedaling. The chain is still on normal bikes while coasting. You would probably not even know a bicycle had a front freewheel unless you looked closely at it or rode it. Bart Thielges