Upgrade Bike Boom Model

[email hidden] writes:

I don't think the grand prix is a fabulous frameset, so $70 will not
be repaid in much additional value added to your bike. I have two
suggestions.

1. A tourney should work as long as it has its own derailleur
hanger. The derailleur hanger length was changed by shimano since the
1970's so as to make shimano's stuff not work with campagnolo
hangers. A campy hanger i think puts the derailleur too close to the
larger sprockets.

2. Why not consider just getting a cyclone GT rear derailleur? They
are available on ebay every week for $10-$20, they are one of the best
bargains in derailleurs, imho, and they are one of the best shifting
and lightest derailleurs of 1970's and 1980's.

Does the sunrace freewheel have the proper spacing for indexed
operation? It's an important consideration. I think it should be 5
mm between cogs to index, but to be sure, check out the freewheel
chart at http://www.sheldonbrown.com/k7.html.

I think that a 126mm axle should probably be o.k. as long as there
isnt vibration in the drivetrain (can you guess that i broke an axle
last month, my first in 30 years of riding, from my shimano derailleur
on a huret dropout hitting the 34T sprocket?)

- Don Gillies
San Diego, CA

Donald Gillies said:

[email hidden] writes:

I don't think the grand prix is a fabulous frameset, so $70 will not
be repaid in much additional value added to your bike. I have two
suggestions.

The only value I expect is better gear spacing and a gear for hills.
But I was wondering about indexing if it only cost $30-35 more.

Quoted message said:

1. A tourney should work as long as it has its own derailleur
hanger. The derailleur hanger length was changed by shimano since the
1970's so as to make shimano's stuff not work with campagnolo
hangers. A campy hanger i think puts the derailleur too close to the
larger sprockets.

Sheldon (Harris) sells Tourney RD with an adapter claw

Quoted message said:

2. Why not consider just getting a cyclone GT rear derailleur? They
are available on ebay every week for $10-$20, they are one of the best
bargains in derailleurs, imho, and they are one of the best shifting
and lightest derailleurs of 1970's and 1980's.

Will it take the 34 gear? The tourney w/claw is $20 from Harris. I
really need lower than 42x28. Also, the jump from 24 to 20 is too much
for me now. I'm up to an hour ride at 10.5 mph, so I'm in the 24 most
of the time and want the 22 of the seven speed.

Quoted message said:

Does the sunrace freewheel have the proper spacing for indexed
operation? It's an important consideration. I think it should be 5
mm between cogs to index, but to be sure, check out the freewheel
chart at http://www.sheldonbrown.com/k7.html.

It is the Sunrace shifters that were a question. The Shimano 14-28
freewheel is no problem.

Quoted message said:

I think that a 126mm axle should probably be o.k. as long as there
isnt vibration in the drivetrain (can you guess that i broke an axle
last month, my first in 30 years of riding, from my shimano derailleur
on a huret dropout hitting the 34T sprocket?)

It's my only drop bar bike, and I figure the change would help me
through a year or two until I get a new bike.

Quoted message said:

I have an Atala Grand Prix from 1973. It is like the following chart
except the to be replaced rder is original Valentino, and the fder is
now a Suntour Cyclone GT.

http://www.classicrendezvous.com/Italy/atala/Atala_advert.htm

All I'm really looking to do is have a tech spread the frame to 126,
and put in the 7-speed Shimano 14-34 freewheel on the existing hub, and
put in a wide range (Tourney) rder and a new chain. Seems to me this
might be $70 in delivered parts, and the labor to install, re-dish
wheel, etc.

Is there much reason not to get the SunRace 7-speed downtube shifters
and go to indexed? What else if required? My weight is 245lbs, is going
to 7 speed maybe too much for the wheel? It is alloy 36 hub and has a
piece of a yellow label that can't be read.

At 245 lbs, rider weight could be a problem with a hollow axle; to
reduce the probability of failure, I would go with a solid rear axle
in the 7sp setup. Otherwise, I see no significant issues in what you
propose.
--
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Hi...

well as somebody said before... that atala isnt nothing out of this world
anyways... all the changes are posible to do... follow the recomendations
people is doing to u...

The only thing i never liked was indexed shifters.. thats for lazy people
hehehe... well i think going in retrofriction will help a lot more just in
case the frame is not in straight line u know... it'll be easier to adjuts
the RD using friction than using the shifters in indexed mode... hope u
have the custom to drive a manual car, if u know what i mean...

Good luck.

Noname 🙂

ps: r u sure u want to spend like 150 in parts and stuff? u can get a whole
new bike like for 300 at ebay u know.

Quoted message said:

Donald Gillies said:

[email hidden] writes:

I don't think the grand prix is a fabulous frameset, so $70 will not
be repaid in much additional value added to your bike. I have two
suggestions.

The only value I expect is better gear spacing and a gear for hills.
But I was wondering about indexing if it only cost $30-35 more.

Quoted message said:

1. A tourney should work as long as it has its own derailleur
hanger. The derailleur hanger length was changed by shimano since the
1970's so as to make shimano's stuff not work with campagnolo
hangers. A campy hanger i think puts the derailleur too close to the
larger sprockets.

Sheldon (Harris) sells Tourney RD with an adapter claw

Quoted message said:

2. Why not consider just getting a cyclone GT rear derailleur? They
are available on ebay every week for $10-$20, they are one of the best
bargains in derailleurs, imho, and they are one of the best shifting
and lightest derailleurs of 1970's and 1980's.

Will it take the 34 gear? The tourney w/claw is $20 from Harris. I
really need lower than 42x28. Also, the jump from 24 to 20 is too much
for me now. I'm up to an hour ride at 10.5 mph, so I'm in the 24 most
of the time and want the 22 of the seven speed.

I assume you have two chainrings 52 and 42. Why don't you change the
crankset toward 42X30 and maybe 22 using a triple from ATBs? Or
something similar. This might be cheaper and will spare you the wheel
change stuff. Without changing the BB this will be cheaper than 70$ and
it might work. With a change of the BB it will be aroung $70 I guess.

You can also get a new wheel andd freewheel 14X28 with 7 speed to have
closer gear ratio than before. From my experience 44X14 allows you to
ride 20mph without pedaling too fast.

HERVE

PS: indexing is apparently difficult to set up and it is not so useful.
A new freewheel and a new chain already brings a lot to shifting with
friction.

Quoted message said:

Quoted message said:

2. Why not consider just getting a cyclone GT rear derailleur? They
are available on ebay every week for $10-$20, they are one of the best
bargains in derailleurs, imho, and they are one of the best shifting
and lightest derailleurs of 1970's and 1980's.

Will it take the 34 gear?

Yes, it will. The Cyclone GT is a fabulous derailleur, and shifts even
better with modern chains and cogs. But it certainly won't index...

Quoted message said:

Quoted message said:

Does the sunrace freewheel have the proper spacing for indexed
operation? It's an important consideration. I think it should be 5
mm between cogs to index, but to be sure, check out the freewheel
chart at http://www.sheldonbrown.com/k7.html.

It is the Sunrace shifters that were a question. The Shimano 14-28
freewheel is no problem.

I have (or rather, my girlfriend has) a similar bike with a Shimano
derailleur on an adapter claw, and I could never really get the SunRace
shifters to index properly. I ended up unscrewing them from the clamp
and replacing them with a pair of Shimano 7-speed shifters, which work
just fine. IMHO the SunRace shifters are crappy shifters on a very nice
downtube clamp. They also don't have a non-index mode. So, I guess,
off to eBay or your local dumpster for a set of Exage, RX100, 105SC, or
whatever shifters - they're all good!

Herve Henry said:

PS: indexing is apparently difficult to set up and it is not so useful.

And you base this statement on what experience?

From my somewhat limited, but actual experience, i find both of the
above to be wrong.

Life is Good!
Jeff

Donald Gillies said:

I don't think the grand prix is a fabulous frameset, so $70 will not
be repaid in much additional value added to your bike.

I have an Atala Grand Prix of similar vintage, and you're right -- the
frame is nothing at all special. It does make a nice fixed gear bike,
though:

http://www.os2.dhs.org/~john/atala.jpg

Be aware that the frame was designed for 27" tires and plenty of fender
clearance, so you'll need drop bolts to put 700C wheels and/or modern
brakes on it.

--

John ([email hidden])

Suntour VGT and Suntour Cyclone use the same pulley cage and have the
same stroke.

http://www.yellowjersey.org/stour80a.html

Suntour VGT-Luxe / Cyclone capacity is 36T
Suntour VGT-Luxe / Cyclone max cog is 32T definitely.
some say the VGT-Luxe can do 34T, others say cyclone
tops out at 32T.

http://groups.google.com/groups?hl=en&lr=&q=suntour+capacity+V-GT&qt_s=Search

Suntour Cyclone MKII can handle 34T

http://groups.google.com/group/rec.bicycles.misc/browse_thread/thread/9cd1ced4042ebb46/23f612a5e4cdeae4?lnk=st&q=suntour+capacity+cyclone&rnum=1&hl=en#23f612a5e4cdeae4

- Don "Suntour Lover" Gillies
San Diego, CA

Quoted message said:

I have an Atala Grand Prix from 1973. It is like the following chart
except the to be replaced rder is original Valentino, and the fder is
now a Suntour Cyclone GT.

http://www.classicrendezvous.com/Italy/atala/Atala _advert.htm

All I'm really looking to do is have a tech spread the frame to 126,
and put in the 7-speed Shimano 14-34 freewheel on the existing hub, and
put in a wide range (Tourney) rder and a new chain. Seems to me this
might be $70 in delive red parts, and the labor to install, re-dish
wheel, etc.

Is there much reason not to get the SunRace 7-speed downtube shifters
and go to indexed? What else if required? My weight is 245lbs, is going
to 7 speed maybe too much for the wheel? It is alloy 36 hub and has a
piece of a yellow label that can't be read.

I think you are too heavy for a 126mm freewheel rear hub with
conventional axle. You would need something like a Phil Wood with an
oversized axle. But that is talking serious money then for all the
modifications and new parts.

Since the bike as described in the ad has a steel cottered crankset,
and judging from your description of your riding, you would be much
better off keeping everything else as is (except perhaps the rear
derailleur), but replacing the crankset with something that would give
a lower high, a lower low, and a closer selection of 10 gears with the
same 14-28 5sp freewheel. This would also be much easier, not involving
changing the rear wheel or triangle in any way. Total price can be
similar and you would save weight and add the convenience of cotterless
cranks.

You know enough to find the right combination of rings to suit you-
14-28 with 50-39 gives a great selection of very usable gears, but if
you still find that low not low enough, go to 110mm bcd like Sugino XCD
and choose a suitable pair. Or, make it a triple if you really want
closer spacing and a very very low low. Either way, a better solution..

There are a lot of cheap triples, but I don't how that would work with
the existing down-tubes. I don't know if I can use a modern BB (ISIS)
for a compact crank like Nashbar, or if it makes more sense to wait
until the 2006 Mirage CT crank is available. Campy says you "need" to
use the CT Fder with it but I doubt that. But since my Rder is
Valentino [censored], maybe it is best to go with all Mirage Rder and CT
Fder/crank. I think the 48-34 crank might be the ticket...

Quoted message said:

There are a lot of cheap triples, but I don't how that would work with
the existing down-tubes. I don't know if I can use a modern BB (ISIS)
for a compact crank like Nashbar, or if it makes more sense to wait
until the 2006 Mirage CT crank is available.

Nothing has changed much since the bike boom in the bottom bracket
area. Threads of your bike are mostly 68-ss (english) or 70ss
(italian, as your rear derailleur suggests.) So you can put any new
bottom bracket on your frameset. However, you may need a "general
purpose" bottom bracket like Tange, TA or Shimano UN-52/3, UN-73/4,
etc. A "special purpose" bottom bracket like Campagnolo, that only
comes in 4 sizes, may not give you the spacing you need.

Quoted message said:

Campy says you "need" to use the CT Fder with it but I doubt
that.

Yeah, the marching morons of marketing have taken over at Campy. Very
sad, actually. Profligate consumer spending is sure to follow.

Quoted message said:

But since my Rder is Valentino [censored], maybe it is best to go with all
Mirage Rder and CT Fder/crank. I think the 48-34 crank might be the
ticket...

A valentino probably shifts a 14-21 just fine. A Mirage will do much
better on a wider freewheel, if that's where you're headed.
Meanwhile, sell the valentino pulleys on ebay for $20 and up ..

- Don Gillies
San Diego, CA