59 - 60 tooth chainring?
David L. Johnson
>
> I remember seeing a guy this past summer riding with a huge, pie plate
> chainring (it was something like 59 or 60 tooth). It was on his
> regular road bike, not even used for TT. I'm figuring that he's going
> to have some serious knee problems down the road. I can't even recall
> seeing such a huge chainring selling anywhere, who makes these things
> or do they have to be custom?
Well, of course it really depends on what gears he was riding, not really the
size of the chainring. But you are right to wonder what sort of gears he
pushes if he feels the need for such a beast. If he really is into custom
gearing he may just want to get a bigger spread between the chainrings. With
an 8-gear cassette, or a 9, you tend to get a lot of overlap gears between the
two chainrings. Increasing the spread gives you more really different
combinations, though it does sometimes mean more awkward shifting. But most
cranks will only allow a minimum of a 39, so to get a wide spread a big ring
of that size is reasonable. But, OTOH, unless his cogs are nonstandard, he'll
end up with uselessly large gears at the big end (presuming he is not a
time-trialer or serious road racer). He could get 14 really distinct ratios
from an 8-speed cassette with a 60/39, but it would be best if his cluster
were on the order of 15-24, which would be hard to manage.
Back in the old days, we all had 52/42 chainrings, and 14-18 clusters. That
gave 7 or 8 distinct gears. But if you go to even a straight block 13-20
8-speed cassette, that same set of chainrings won't give that many more gears
(12); the other 4 being repeats. Changing to a 60/39 gives 15 distinct gears,
but there won't be much call for the 120" top gear.
As far as availability, I have (I don't use it any more) a 55, which I used to
use for crit's. I have seen 58's that were stock Campy, though you probably
had to order it. Of course, most people wanting a big gear now would go for a
very small cog on their cassette, instead.
--
David L. Johnson david....@lehigh.edu
Department of Mathematics http://www.lehigh.edu/~dlj0/dlj0.html
Lehigh University, 14 E. Packer Avenue, Bethlehem, PA 18015-3174
You will say Christ saith this and the apostles say this; but what canst
thou say? -- George Fox.
Carla Anastacio
chainring (it was something like 59 or 60 tooth). It was on his
regular road bike, not even used for TT. I'm figuring that he's going
to have some serious knee problems down the road. I can't even recall
seeing such a huge chainring selling anywhere, who makes these things
or do they have to be custom?
- CA
Peter Rathmann
>
> I remember seeing a guy this past summer riding with a huge, pie plate
> I can't even recall
> seeing such a huge chainring selling anywhere, who makes these things
> or do they have to be custom?
I have chainrings of 60/42 on my Bike Friday to help compensate for the
smaller wheels. Together with an 11-tooth cog, I get close to the same
high gear as on my 700c-wheeled bike using a 52 chainring and 13 tooth
cog.
You might check with the Bike Friday (Green Gear) company at:
http://www.greengear.com
Richard Underwood
Highpath Engineering in Wales will make chainrings any size you like!
In addition to strange (large) sizes, he specialises in rings for
obsolete chainsets, oval (eggrings) and adaptor rings (2>3 & 3>4 etc)
I /almost/ had a 42T ring made up to solve a compatibility problem 4/5
years back which was going to cost about GBP55 - until I saw sense and
changed my chainset instead.
Contact details are:-
Highpath Engineering
Cornant
Cribyn Llanbedr
PS
Ceredigion SA48 7QW
UK
Tel: +44 1570 470035
Fax: +44 1570 470035
... which I got off the Encycleopedia web site at:-
http://www.encycleopedia.com/encycleopedia4/content/manudetail.html
Hope this helps.
Richard
Reading CTC:- http://www.i-way.co.uk/reading-ctc
Carla Anastacio wrote:
>
> I remember seeing a guy this past summer riding with a huge, pie plate
> chainring (it was something like 59 or 60 tooth). It was on his
> regular road bike, not even used for TT. I'm figuring that he's going
> to have some serious knee problems down the road. I can't even recall
> seeing such a huge chainring selling anywhere, who makes these things
> or do they have to be custom?
>
> - CA
Jon Isaacs
patterns.
Regarding the knee problems. Everyone's knees are different. Some people have
stronger more durable knees than other people. The difference between a 53 and
a 60 tooth chainring is only about 13%, about the difference between a 17 tooth
cog and a 15 tooth cog. This probably makes more sense to use a 60 tooth chain
ring with a 12 or 13 tooth cog than a 52 with an 11.
Jon Isaacs
alex wetmore
news:384f0694...@news.pathcom.com...
> I remember seeing a guy this past summer riding with a huge, pie plate
> chainring (it was something like 59 or 60 tooth). It was on his
> regular road bike, not even used for TT. I'm figuring that he's going
> to have some serious knee problems down the road. I can't even recall
> seeing such a huge chainring selling anywhere, who makes these things
> or do they have to be custom?
They can be ordered through standard bike parts distributors. I have a 60t
chainring on my Tandem Two'sday, which uses ~20" wheels. The bike has a
roughly 100" gear when combined with an 11t cog.
alex
no...@praxcomm.com
>I have a 60t
>chainring on my Tandem Two'sday, which uses ~20" wheels.
I have a 60 tooth chainring on my hot-rodded Raleigh Twenty folder (stock frame,
drop bars, single bar-end shifter, Brooks saddle, Bike Friday seat-post - think of it
as a poor man's Bike Friday Pocket Rocket). With a standard 11/28 cassette, I've
got a 43.6 to 110.5 gear inch range.
Lots of recumbents with 20" drive wheels have 60-tooth or larger chainrings. Mine
is a Real Downhill single - light and strong.
Regards,
Alan Thwaits
Digital Cycling
mailto: no...@praxcomm.com
http://www.praxcomm.com/
Mark Hickey
>Highpath Engineering in Wales will make chainrings any size you like!
>In addition to strange (large) sizes, he specialises in rings for
>obsolete chainsets, oval (eggrings) and adaptor rings (2>3 & 3>4 etc)
>
>I /almost/ had a 42T ring made up to solve a compatibility problem 4/5
>years back which was going to cost about GBP55 - until I saw sense and
>changed my chainset instead.
That is insanely cheap for a "custom" chainring. Sounds like Highpath
is probably in possession of both bike junkies and spare CNC mill
time.
Mark Hickey
Habanero Cycles
http://www.cynetfl.com/habanero/
Home of the $695 ti frame
>Contact details are:-
>
>Highpath Engineering
>Cornant
>Cribyn Llanbedr
>PS
>Ceredigion SA48 7QW
>UK
>Tel: +44 1570 470035
>Fax: +44 1570 470035
>
>... which I got off the Encycleopedia web site at:-
>http://www.encycleopedia.com/encycleopedia4/content/manudetail.html
>
>Hope this helps.
>
>Richard
>
>Reading CTC:- http://www.i-way.co.uk/reading-ctc
>
>
>
>
>
>Carla Anastacio wrote:
>>
>> I remember seeing a guy this past summer riding with a huge, pie plate
>> chainring (it was something like 59 or 60 tooth). It was on his
>> regular road bike, not even used for TT. I'm figuring that he's going
>> to have some serious knee problems down the road. I can't even recall
>> seeing such a huge chainring selling anywhere, who makes these things
>> or do they have to be custom?
>>
>> - CA
Roger
>
> I remember seeing a guy this past summer riding with a huge, pie plate
> chainring (it was something like 59 or 60 tooth). It was on his
> regular road bike, not even used for TT. I'm figuring that he's going
> to have some serious knee problems down the road. I can't even recall
> seeing such a huge chainring selling anywhere, who makes these things
> or do they have to be custom?
Well, Moultons need them...
--
Roger
Web: http://freespace.virgin.net/roger.cantwell
ICQ: 40038278
*** Please remove 'filler' from the Reply address ***
Adam Rice
(Carla Anastacio) wrote:
>I remember seeing a guy this past summer riding with a huge, pie plate
>chainring (it was something like 59 or 60 tooth). It was on his
>regular road bike, not even used for TT. I'm figuring that he's going
>to have some serious knee problems down the road. I can't even recall
>seeing such a huge chainring selling anywhere, who makes these things
>or do they have to be custom?
Until recently at least, Avitar made 62-toothers. I've got one (for an
upcoming recumbent project).
I remember seeing a picture in a bike history book of a bike from the
early part of this century; it was a 1-speed (of course) and had a monster
chainring, easily 60 teeth. It looked very imposing until you realized it
also had roughly a 26-tooth cog. Obviously marketing-driven, even back
then.
Adam Rice | adam...@crossroads.net
Austin TX USA | http://www.crossroads.net/
Bill Lloyd
"Jon Isaacs" <joni...@aol.com> wrote in message
news:19991209081634...@ng-fk1.aol.com...
Nah that's stupid. Because derailleurs can't really handle a jump between a
60 and
a resonably sized small chainring. You'd have to have a 45x60 at the most.
What's the beef with the 11? It's a great cog. I rode down the coast here
in California
today, with a fairly good tailwind, for 5 or 6 miles at 37 mph in a 53x11.
And I was
just sitting in a paceline, loafing along. It's more relaxing than spinning
faster when
you're trying to rest the legs.
-B
alex wetmore
news:oTX64.6607$Wc.2...@tw12.nn.bcandid.com...
> Nah that's stupid. Because derailleurs can't really handle a jump between
a
> 60 and
> a resonably sized small chainring. You'd have to have a 45x60 at the
most.
I have a Sachs 5000 front derailleur which shifts across a 60/50/34 pretty
well. I plan to try a 60/50/32 pretty soon. 60/50/30 didn't work when I
tried it a few months ago. This is on a bike with 20" wheels, and with
larger wheels I would expect 60/XX/28 to work with no problems. The smaller
wheels change the angle of the chain from the chainring to the cassette
(since the hub on a 20" bike is below BB level, vs being above it on a
larger wheeled bike).
alex
Andrew Coggan
Seems to me that if your b.b. height is normal, the smaller wheels just
make the front derailleur's task even harder, since more chain is
wrapped around the chainring than with a larger wheel. In any case,
doesn't your experience support Bill's point, i.e., that front
derailleurs generally work best when the difference between rings isn't
too large? 60/50 is closer than the 60/45 combo that he suggested was a
reasonable limit.
FWIW, I briefly used a 60/42 combo on a 650C-wheeled bike (didn't have
anything bigger to put on the inside). Downshifting was fairly reliable,
but upshifts were slow and painful (Shimano 105 front derailleur, bar
end shifters).
Andrew Coggan
Jon Isaacs
>doesn't your experience support Bill's point, i.e., that front
>derailleurs generally work best when the difference between rings isn't
>too large? 60/50 is closer than the 60/45 combo that he suggested was a
>reasonable limit.
I have a bike with a 28-48 that shifts "OK." Not the fastest front shift in
the world, but then people don't generally choose chainrings based on shifting
speed. The best front shift I know of is back and forth between a 50 and a 46,
and it seems to get worse the wider it gets.
Jon Isaacs
alex wetmore
news:38615A...@erols.com...
> alex wetmore wrote:
> > "Bill Lloyd" <bll...@my-deja.com> wrote in message
> > news:oTX64.6607$Wc.2...@tw12.nn.bcandid.com...
> > > Nah that's stupid. Because derailleurs can't really handle a jump
between
> > a
> > > 60 and
> > > a resonably sized small chainring. You'd have to have a 45x60 at the
> > most.
> >
> > I have a Sachs 5000 front derailleur which shifts across a 60/50/34
pretty
> > well. I plan to try a 60/50/32 pretty soon. 60/50/30 didn't work when
I
> > tried it a few months ago. This is on a bike with 20" wheels, and with
> > larger wheels I would expect 60/XX/28 to work with no problems. The
smaller
> > wheels change the angle of the chain from the chainring to the cassette
> > (since the hub on a 20" bike is below BB level, vs being above it on a
> > larger wheeled bike).
>
> Seems to me that if your b.b. height is normal, the smaller wheels just
> make the front derailleur's task even harder, since more chain is
> wrapped around the chainring than with a larger wheel.
I think you misunderstood what I was trying to say there, but that is okay
because so does everyone else that I try to explain it to.
What I was trying to say is that bikes with smaller wheels have the BB
higher in relation to the hub height. For instance on a bike using ISO
622mm wheels the BB might be 4cm? below the hub. On a bike using 406mm
wheels its probably more like 2-3cm above the hub.
Now, if you picture the angle of the chain going between a chainring and cog
of the same size (say, 32/32) then we can see that on a bike with BB drop
that the chain from the top of the cog to the top of the chainring will
slope at an upwards angle from the chainring. On a bike with a higher BB in
relation to the hub this will be reversed.
What does this have to do with capacity? A large part of front derailleur
capacity comes from the length of the cage. On a bike with a higher BB the
cage would need to be longer to get the same useful capacity, because the
chain angle is lower.
> In any case,
> doesn't your experience support Bill's point, i.e., that front
> derailleurs generally work best when the difference between rings isn't
> too large? 60/50 is closer than the 60/45 combo that he suggested was a
> reasonable limit.
I was looking more at the 50/34 here, which is a bigger jump then 60/45. I
don't see any reason why 60/46 shouldn't work, and in fact I have a 46 that
I plan to install when I put on the 32 (so then I'll have 60/46/32). I'll
report back when I do this.
alex