Upgrading from DT to STI, 7 to 8 speed

I'm contemplating upgrading my 7-speed DT to 8 speed STI.

I believe some RSX shifters were 7-speed, but it seems most were 8. If I go
this route, I would need new brakes (I have single-pivot now) at least, but
would I need to replace my wheel or hub or freehub? I was under the
impression that 7 and 8-speed cog spacing is the same, so they could be
interchanged easily, but the hub spacing is 130mm vs. 126mm, no?

--
Phil, Squid-in-Training

I just went from 6 speed on my 10 yo's 80's Terry to Sora 8 speed STI. I
did swap the rear 600 derailer for a 105 that had a cable tension
adjustment. I also went to a 130mm cassette rear wheel and threw an 8
speed Ultegra cassette on it. She loves the setup, and it was pretty easy
to adjust. I also did Ultegra 9 spd STI on my wife's early 90's Medici,
reusing both 7 speed derailers without any problems. Her's had indexed
downtube shifters to begin with. Both bikes shift great. I still need to
cold set the rear to 130mm, but haven't had any real issues putting a 130
wheel in them and just riding it.


Grenouil wrote:


"Phil, Squid-in-Training" wrote in message
om...
I'm contemplating upgrading my 7-speed DT to 8 speed STI.

I believe some RSX shifters were 7-speed, but it seems
most were 8. If I go
this route, I would need new brakes (I have single-pivot
now) at least, but
would I need to replace my wheel or hub or freehub? I was
under the
impression that 7 and 8-speed cog spacing is the same, so
they could be
interchanged easily, but the hub spacing is 130mm vs.
126mm, no?

--
Phil, Squid-in-Training



RSX came in both seven speed (ST-A410 - approx 1995-8) and
eight speed (ST-A416/ST-A417 - 1999 on)

Why would you need new brakes? (I've run single pivots with
Sora and 105SC STI levers. I also have a bike with Alivio
cantilevers and seven speed RSX STI)

Per Sheldon Brown, seven speed spacing is 5.0mm, eight is
4.8mm. You'll need an eight/nine speed freehub to make room
for the extra sprocket if what you have currently is a seven
speed hub, and 130mm OLD for eight speed

If you currently have a seven speed setup, the easiest would
be to find a set of early seven speed RSX - or you could get
seven speed Sora. If you have a triple chainring, make sure
you get a set with a triple left lever - some are double
only

--
Mark Wolfe http://www.wolfenet.org
gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6 8C71
Um. There is no David conspiracy. Definitely not. No Kate conspiracy either.
No. No, there is definitely not any sort of David conspiracy, and we are
definitely *not* in league with the Kate conspiracy. Who doesn't exist. And
nor does the David conspiracy. No. No conspiracies here. - Thorfinn, ASR

I'm contemplating upgrading my 7-speed DT to 8 speed STI.

If you must go the STI route Shimano Sora comes in 7 speed
double/triple. Or you could try:

http://www.kellybike.com/2nd_xtra_takeoff.html

and look at their Take-Off lever mounts which put your DT shifters
right next to your brake levers. Another beautiful option is bar-end
shifters. You should be able to use your 7speed DT shifters with
these mounts:

http://www.rivbike.com/webalog/shift...urs/17068.html

impression that 7 and 8-speed cog spacing is the same, so they could be
interchanged easily, but the hub spacing is 130mm vs. 126mm, no?

Sheldon Brown's site talks about hubs, but yes, 8/9 Shimano hubs are
wider at 130mm. There are still plenty of 7v cassettes out there and
then you don't need a new wheel. Performance.com brand ones are very
inexpensive and work great. Another option ala Sheldon Brown is to
use 9speed STI's with 8 of the cogs on a 7speed hub like yours, since
the 9v cogs are narrower. Personally I like that fact that 7v
components have more metal on them and require replacement, generally,
less often.

STI's are nice, don't get me wrong, but if you like using what you
have and saving money 7 speeds are still quite viable.

Mark Beattie
Portland, OR

"Mark Beattie" wrote in message
om...
I'm contemplating upgrading my 7-speed DT to 8 speed STI.

Hey mark, thanks for all the info - never see the take-offs before.

I've already got a new SRAM chain and Performance cassette ready to go for
another couple thousand miles...

--
Phil, Squid-in-Training

"Mark Beattie" wrote in message
om...
I'm contemplating upgrading my 7-speed DT to 8 speed
STI.

If you must go the STI route Shimano Sora comes in 7 speed
double/triple. Or you could try:

http://www.kellybike.com/2nd_xtra_takeoff.html

and look at their Take-Off lever mounts which put your DT
shifters
right next to your brake levers. Another beautiful option
is bar-end
shifters. You should be able to use your 7speed DT
shifters with
these mounts:


http://www.rivbike.com/webalog/shift...leurs/17068.ht
ml

impression that 7 and 8-speed cog spacing is the same,
so they could be
interchanged easily, but the hub spacing is 130mm vs.
126mm, no?

Sheldon Brown's site talks about hubs, but yes, 8/9
Shimano hubs are
wider at 130mm. There are still plenty of 7v cassettes
out there and
then you don't need a new wheel. Performance.com brand
ones are very
inexpensive and work great. Another option ala Sheldon
Brown is to
use 9speed STI's with 8 of the cogs on a 7speed hub like
yours, since
the 9v cogs are narrower. Personally I like that fact
that 7v
components have more metal on them and require
replacement, generally,
less often.

STI's are nice, don't get me wrong, but if you like using
what you
have and saving money 7 speeds are still quite viable.

Mark Beattie
Portland, OR

The "take-offs" are an interesting idea, but if you buy the
kit it's not a lot cheaper than Sora - Nashbar currently has
Sora doubles for $89.99, and triples for $99.99. Or try
eBay - I bet there are a lot of ppl 'upgrading' from Sora
and selling off the old stuff.

Incidentally, you can set up eight speed Sora to work with
your existing seven speed cassette/freewheel, so all you'd
need is the levers.