Is a 27 inch wheel v similar to 700C? (Gearing q)

Tumbleweed said:

(you can guess how old my soon-to-be-replaced bike is :-)

Just trying to work out how similar the gearing is. Some of the bikes
I am looking at have v similar numbers of teeth on the chainwheel to
mine.

The difference in gearing that 27" and 700c wheels provide isn't worth
worrying about, IMO, but you can work out the exact numbers via Sheldon
Brown's gear calculator on his website. It's more of a serious factor
with 26" v 27" or 700c. Don't forget to take the tyres into account:
wider tyres are also larger in diameter.

Quoted message said:

mine is 52/42 & 6 speed 14-25
Ones I am looking at include 52/42/30 & 9 speed 11-25 (from memory)
on 700C, and
48/36/26 9 speed 11-32 (not sure what size wheels its a dawes
discovery 701)

Would the first one be pretty close to what I have now (the 30 would
have come in useful last week:-)

No, the 30 would provide much lower bottom gears despite the different
wheel size.

Quoted message said:

But I generally find I dont use the
52 much, or not at the top end of the cassette anyway.

The 52 would be rather nuts (for normal riding) with the small end of that
cassette. It's a shame they don't supply smaller rings as standard.

Quoted message said:

Also, most of these bikes have Shimano gears, is the hierarchy of how
'good' they are,
LX, XT, 105, Ultegra?

"Mountain bike" range (also used on some tourers & other bikes), main
ones, from bottom to top: Tourney, Altus, Acera, Alivio, Deore, Deore LX,
Deore XT, XTR.

"Road" range from bottom to top: Sora, Tiagra, 105, Ultegra, Dura-Ace

(Components from these two ranges can be mixed to some extent).

Quoted message said:

And am I going to notice much difference
between them if I am NOT pushing it hard?

No, to give a short answer. Main difference is weight. More expensive
groups are often said to be more durable as well but that doesn't seem to
make sense always when you look into what exactly the components consist
of.

~PB

Tumbleweed said:

(you can guess how old my soon-to-be-replaced bike is :-)

Just trying to work out how similar the gearing is. Some of the bikes I am
looking at have v similar numbers of teeth on the chainwheel to mine.

mine is 52/42 & 6 speed 14-25
Ones I am looking at include 52/42/30 & 9 speed 11-25 (from memory) on 700C,
and
48/36/26 9 speed 11-32 (not sure what size wheels its a dawes discovery
701)

Would the first one be pretty close to what I have now (the 30 would have
come in useful last week:-) But I generally find I dont use the 52 much, or
not at the top end of the cassette anyway.

Also, most of these bikes have Shimano gears, is the hierarchy of how 'good'
they are,
LX, XT, 105, Ultegra? And am I going to notice much difference between them
if I am NOT pushing it hard?

--
Tumbleweed

email replies not necessary but to contact use;
tumbleweednews at hotmail dot com

I have experience of Shimano 105, Ultegra and Deore XT gears and they are all [1] and not *too* expensive. I try not to use anything lower down the scale than 105 for road or XT for MTB[2] (I use some XT kit on my tourer). Cost sometimes means I have break my rule though. Ultegra and DA only really adds pose value. Performance wise you'll not notice much with the transmission, the brakes may be a difference matter though, the frames will matter more too. The frame has a major influence on how your power is transmitted to the rear wheel. Different groupsets on the same frame will feel very similar indeed. Remember its usually better to get a half decent frame and replace poorer components as you can/need/want that vice versa.

[1]Easy to set up and keeps its adjustment.
[2]I wouldn't let this stop me buying a complete bike with lower grade components, these can be replaced after while with nicer pieces.

"Pete Biggs" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Tumbleweed said:

(you can guess how old my soon-to-be-replaced bike is :-)

Just trying to work out how similar the gearing is. Some of the bikes
I am looking at have v similar numbers of teeth on the chainwheel to
mine.

The difference in gearing that 27" and 700c wheels provide isn't worth
worrying about, IMO, but you can work out the exact numbers via Sheldon
Brown's gear calculator on his website. It's more of a serious factor
with 26" v 27" or 700c. Don't forget to take the tyres into account:
wider tyres are also larger in diameter.

Quoted message said:

mine is 52/42 & 6 speed 14-25
Ones I am looking at include 52/42/30 & 9 speed 11-25 (from memory)
on 700C, and
48/36/26 9 speed 11-32 (not sure what size wheels its a dawes
discovery 701)

Would the first one be pretty close to what I have now (the 30 would
have come in useful last week:-)

No, the 30 would provide much lower bottom gears despite the different
wheel size.

Sorry, I meant, would the 52/42 would be similar to now (seems it is,
thansk), obviously the 30 would be a huge improvement for hills.I did the
IOW on the 42 in the granny ring for a large portion of the hills would have
been nice to be able to change down rather than get off and walk. (getting
fitter would help as well :-)

Quoted message said:

Quoted message said:

But I generally find I dont use the
52 much, or not at the top end of the cassette anyway.

The 52 would be rather nuts (for normal riding) with the small end of that
cassette. It's a shame they don't supply smaller rings as standard.

So, if I were to go for a bike like this do you think I should get something
a bit lower put on it? Or should I look into changing the cassette?
What is your opinion on the Dawes with such a big jump between top and
second chainwheel (ie 48->36)?

Maybe I should see father Xmas and get a Rohloff!

--
Tumbleweed

email replies not necessary but to contact use;
tumbleweednews at hotmail dot com>

Tumbleweed said:

So, if I were to go for a bike like this do you think I should get something
a bit lower put on it? Or should I look into changing the cassette?
What is your opinion on the Dawes with such a big jump between top and
second chainwheel (ie 48->36)?

My tourer has 50 and 36 on the front and with an evenly spaced cassette on the rear the jump is not really a problem as I use the large ring most of the time. My rear cassette is 13-15-17-19-21-25-28-32. I rarely use 50x13 on this bike BTW, I use the middle of the cassette mostly which preserves a good chainline.

Its difficult to give advice since every rider is different and prefer different rides. I am no climber but I like riding in hills so I have gears that I can handle, some riders will have gears that are not as low as mine and be OK.

Tumbleweed <[email hidden]> wrote:

: Ones I am looking at include 52/42/30 & 9 speed 11-25 (from memory) on 700C,
: and

These are very, very big gears for normal use

: 48/36/26 9 speed 11-32 (not sure what size wheels its a dawes discovery
: 701)

This is a sensible chainset for touring, recreational riding etc. Maybe get
the shop to swap out the cassette when you but it for a 12-25 cassette. That
would give you a top gear slightly bigger than your current one (same as 52x13)
and a much lower low, while keeping everything nice and close.

Arthur

--
Arthur Clune http://www.clune.org
"Technolibertarians make a philosophy out of a personality defect"
- Paulina Borsook

in message <[email hidden]>, Tumbleweed

(') said:

(you can guess how old my soon-to-be-replaced bike is :-)

OK, I will now humiliate myself in public. I bought my current roadbike
in 1992. It has wheels which to all intents and purposes look like 27".
I assumed they were 27". The tyres on them were marked 20x622. This
week I decided to buy new tyres, so I did a web search for anyone who
still had 20mm wide 27" tyres, and no-one had. But St John St Cycles
had 25mm in 27", so I phoned them. Fortunately, I mentioned 20x622. The
person at SJS said 'oh, those aren't 27", they're 700C'. Now comes
humiliation number two: not only did I not know what size wheels my own
bike had, I did not recognise 700C as the new standard size - I thought
'Oh, damn, I've got something else exotic'. However, thanks to SJS
knowing their onions I did order 20x622 tyres which fit and (on initial
test) ride very nicely.

Quoted message said:

Just trying to work out how similar the gearing is. Some of the bikes
I am looking at have v similar numbers of teeth on the chainwheel to
mine.

I cannot tell the difference by eye between my road bike (which I
*thought* was 27"😉 and Juliette's (which definitely is). Frankly, the
difference between a 20mm and a 32mm tyre on the same wheel is greater
than the difference between a 700C and a 27".

Quoted message said:

mine is 52/42 & 6 speed 14-25
Ones I am looking at include 52/42/30 & 9 speed 11-25 (from memory) on
700C, and
48/36/26 9 speed 11-32 (not sure what size wheels its a dawes
discovery 701)

The only issue with upgrading a bike of this age to a new drive train is
that the new rear axles are longer, so you will need to 'cold
set' (i.e. bend) the rear end of your frame. If it's aluminium you're
stuffed but most frames of this age are steel which will bend OK.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; better than your average performing pineapple

Tumbleweed said:

So, if I were to go for a bike like this do you think I should get
something a bit lower put on it? Or should I look into changing the
cassette?

I would change both the cassette and chainrings on the 52/42/30 bike, or
just the cassette perhaps on the one with 48/36/26. In fact 48/36/26
looks very good to me. (I'm forced to use a 39 middle with my Campag
crank because that's the smallest that'll fit, though it is very good for
crusing speeds; I use 26/39/50 on my tourer with 14-30 9-speed cassette).

re 11-32 cassette: Nice at the large end to provide low granny gears from
the inner and also low gears from the middle ring (to save shifting to
granny so frequently), also wouldn't need to shift to big ring much!, but
the small end is a waste for non-racing use and jumps between all gears
are large. It's more of an MTB off-roading cassette. 12-27 would be
better, IMO, or even better a customised 13-30 or similar (DIYable or
available from Harris Cyclery, USA).

re: 11-25: Gawd knows what that's intended for.

Quoted message said:

What is your opinion on the Dawes with such a big jump between top and
second chainwheel (ie 48->36)?

That's not too much of a big jump: front derailleur should handle it; step
up in gear is rather large but you can just change down one at the back at
the same time if you like.

Quoted message said:

Maybe I should see father Xmas and get a Rohloff!

I'd need to rob father Xmas.

~PB

I said:

12-27 would be better, IMO, or even better a customised
13-30 or similar (DIYable or available from Harris Cyclery, USA).

Or even a 13-34 or 14-34. See:
url:http://www.sheldonbrown.com/harris/special.html#cassettes

~PB

Just to endorse what Pete said about cassettes. I made a custom 13-32 cassette (13-15-17-19-21-25-28-32) from a 13-25 and a 11-32 cassette. I have done the 8 from 9 on 6 trick. As I said I tend to use the 17-19-21-25 mostly with the big ring and the 25-28-32 with the little

Try to use Sheldon gear calculator to see what you have now and then try combinations to give you what you know you are comfortable with and what you are looking for.