|
|
 Up |
|
  |
Author: Jenny BrienJenny Brien Date: Aug 19, 2006 16:44
I have a late-80's Cannondale tourer (Sugino AT chainset, bar end
shifters, 126 dropout spacing, 27' wheels and a screw-in hub) It had
''half step and granny" gearing which was a delight when it was newer,
allowing me to trim between the two close top rings to find *exactly*
the right gear.
But that was long ago. The original block and back mech is long gone,
replaced for now by a 14-28 six from a cheap mountain bike. That worked
surprising well with a middle chainring one tooth larger than the
original, but now the chainrings are also so worn that I tend to keep
to one or the other. I want that old feeling back!
Where is a good UK source for new chainrings - currently 48 45 28?
What would be a good modern replacement for the front changer?
As good tyres for 27" are getting harder to find would it be a good
idea to change to 700c?
If that is the case, could I fit a cassette hub with a 12-28 seven?
|
| |
|
| | 10 Comments |
|
|
Author: Ryan CousineauRyan Cousineau Date: Aug 20, 2006 03:46
> I have a late-80's Cannondale tourer (Sugino AT chainset, bar end
> shifters, 126 dropout spacing, 27' wheels and a screw-in hub) It had
> ''half step and granny" gearing which was a delight when it was newer,
> allowing me to trim between the two close top rings to find *exactly*
> the right gear.
>
> But that was long ago. The original block and back mech is long gone,
> replaced for now by a 14-28 six from a cheap mountain bike. That worked
> surprising well with a middle chainring one tooth larger than the
> original, but now the chainrings are also so worn that I tend to keep
> to one or the other. I want that old feeling back!
> Where is a good UK source for new chainrings - currently 48 45 28?
> What would be a good modern replacement for the front changer?
> As good tyres for 27" are getting harder to find would it be a good
> idea to change to 700c?
> If that is the case, could I fit a cassette hub with a 12-28 seven?
|
| Show full article (2.33Kb) |
|
| | no comments |
|
|
Author: Chris Z The WheelmanChris Z The Wheelman Date: Aug 21, 2006 05:43
Believe it or not, many of the "road" (a.k.a. "double" or "racing")
mechs have enough throw to handle a triple crankset, and the inner and
outer plates are even enough that they make half-step shifting a breeze.
I have an albeit old Shimano 600 double changer on my tourer which is
also equipped with a Sug. AT triple crankset, 26-44-48 / seven cog rear
and it works beautifully. I use Sh. Bar-Con shifters (index rear).
Just make sure the cage is long enough to accomodate the Granny.
- -
Comments and opinions compliments of,
"Your Friendly Neighborhood Wheelman"
My web Site:
http://geocities.com/czcorner
To E-mail me:
ChrisZCorner "at" webtv "dot" net
|
| |
| no comments |
|
|
Author: russellseaton1russellseaton1 Date: Aug 21, 2006 16:15
Jenny Brien wrote:
> I have a late-80's Cannondale tourer (Sugino AT chainset, bar end
> shifters, 126 dropout spacing, 27' wheels and a screw-in hub) It had
> ''half step and granny" gearing which was a delight when it was newer,
> allowing me to trim between the two close top rings to find *exactly*
> the right gear.
>
> But that was long ago. The original block and back mech is long gone,
> replaced for now by a 14-28 six from a cheap mountain bike. That worked
> surprising well with a middle chainring one tooth larger than the
> original, but now the chainrings are also so worn that I tend to keep
> to one or the other. I want that old feeling back!
>
> Where is a good UK source for new chainrings - currently 48 45 28?
> What would be a good modern replacement for the front changer?
...
|
| Show full article (2.50Kb) |
| no comments |
|
|
Author: Jenny BrienJenny Brien Date: Aug 21, 2006 18:25
Ryan Cousineau wrote:
> I had a fantasy at one point that the fast shifting of brifters meant
> that the time was ripe for a return to half-step-plus-granny shifting
> patterns on modern 9- and 10-speed drivetrains, until I realized that
> compact drive setups offer most of the benefits with less shifter
> fiddling.
>
I imagine it would be hard to figure out a 9 or 10 speed half-step
set-up to give anice even progression of gears. Compared with a 44-24
chainring and a 13-26 ten speed cassette, my present setup has about
the same range and gives away four gears below 45" to gain two. Works
for me!
|
| |
| no comments |
|
|
Author: Jenny BrienJenny Brien Date: Aug 21, 2006 18:48
>
> I bought TA chainrings from Settle Cycles in the UK. TA makes almost
> every conceivable tooth count in almost every bolt circle diameter.
> Pretty sure you have 110mm bcd for the outer and middle rings and 74mm
> bcd for the inner ring.
>
Thanks. I 've had good dealings with Settle Cycles back in the '80s, so
I'll try them again. Just a little unsure about all the pins and ramps
on chainwheels these days. Have they any advantage in this application
or will plain rings work just as well?
Your other advice is good too, so it's just new chainrings for now, and
I'll leave any other changes till the mext bike.
|
| |
| no comments |
|
|
Author: bjwbjw Date: Aug 21, 2006 20:52
> Stick with 27" wheels. Easier to just sell this bike and buy a similar
> used bike with 700c tires and wider rear dropout spacing when you feel
> the need to have 700c tires and 7 speed. Trying to put a 7 speed
> freewheel onto your wheel will require it to be spaced to 130mm.
> Usually you can just force a 130mm rear wheel into a bike with 126mm
> spacing. But your Cannondale with big stiff seat and chainstays might
> not take the spreading as well as steel bikes. So best to just leave
> it alone.
I have a Cannondale touring bike of similar vintage to the OP's
(mine is 1988). It originally had 27" wheels, short reach caliper
brakes (unusual for a touring bike) and a sort-of-half-step gearing,
something like 50/46/28 Biopace in front and 14-28 6 speed in rear.
Because of the short reach calipers, converting to 700c wheels
was easy; I had to use an inexpensive Tektro long reach brake for
the front, but the rear short reach brake worked ok. If you have
cantilever brakes, converting is more of a nuisance.
|
| Show full article (1.43Kb) |
| no comments |
|
|
Author: bjwbjw Date: Aug 21, 2006 21:05
I wrote:
> 7 speed road freewheel and cassette hubs are spaced at 126mm,
> so one fits right into a 126mm Cannondale. I have a 7 speed cassette
> hub in there now. I break freewheel axles on 7 speed (even without any
> loaded touring), so a cassette hub is an improvement.
More precisely, I break freewheel axles every couple of years on
126mm spacing, whether the freewheel is 6 or 7 speed. This is
presumably weight and load dependent - I weigh ~175 lb and climb
a fair amount and sometimes ride off road. Somebody who weighed
120 lb might never have a problem.
Ben
|
| |
| no comments |
|
|
Author: russellseaton1russellseaton1 Date: Aug 21, 2006 21:24
Jenny Brien wrote:
>>
>> I bought TA chainrings from Settle Cycles in the UK. TA makes almost
>> every conceivable tooth count in almost every bolt circle diameter.
>> Pretty sure you have 110mm bcd for the outer and middle rings and 74mm
>> bcd for the inner ring.
>>
> Thanks. I 've had good dealings with Settle Cycles back in the '80s, so
> I'll try them again. Just a little unsure about all the pins and ramps
> on chainwheels these days. Have they any advantage in this application
> or will plain rings work just as well?
|
| Show full article (1.78Kb) |
| no comments |
|
|
|
|
|
Author: russellseaton1russellseaton1 Date: Aug 21, 2006 21:31
Jenny Brien wrote:
> Ryan Cousineau wrote:
>
>> I had a fantasy at one point that the fast shifting of brifters meant
>> that the time was ripe for a return to half-step-plus-granny shifting
>> patterns on modern 9- and 10-speed drivetrains, until I realized that
>> compact drive setups offer most of the benefits with less shifter
>> fiddling.
>>
> I imagine it would be hard to figure out a 9 or 10 speed half-step
> set-up to give anice even progression of gears.
No its very easy. Outer and middle chainrings of either 48-45, 45-42,
or 42-39 paired with a 9 speed cassette such as
12-14-16-18-20-23-26-30-34, or 11-13-15-17-20-23-26-30-34, or
11-12-14-16-18-21-24-28-32. The 12-34 is becoming harder and harder to
find now days. Its the very best progression. The 11-32 is next best
except the 11 cog does not fit in, so you really have an 8 speed half
step cassette. And then add a very tiny inner ring to get a super
granny for mountain climbing.
|
| Show full article (1.14Kb) |
| no comments |
|
|
|
|
