Radical gearing change: advice needed...



Simon Brooke <[email protected]> wrote:

>But my bet is that in a year's time
>you'll be riding the bike with more or less the gearing it has now.

If he currently has to stand which as I read it only just gets him up
the climbs he needs to scale then I'd say he will never be able to get
up that gradient whilst sitting down, no matter how fit he will become.

--
Membrane
 
On Mon, 20 Aug 2007 08:19:10 +0100, Simon Brooke
<[email protected]> wrote:

>A road bike isn't a mountain bike. It doesn't weigh as much, doesn't have
>energy-sapping suspension, and has lower rolling resistance.

This depends very much on the bikes in question, but is most certainly
not a given. My front-suspended, carbon-framed MTB of about ten years
ago weighed in at around 12.5kg, and ally-framed stuff of the same
vintage wasn't much heavier. At them same time I also had an old
Holdsworth tourer, at around 14kg and I then acquired a Dawes Galaxy,
around 13kg. The 531-tubed Mercian I got later is a little lighter, at
just over 12 IIRC, and my new2 full-suspension MTB is 12.9kg.

Many of the 'road' bikes I see around here (France and Switzerland)
are of the commuter variety and _much_ heavier than the above, so
perhaps your statement would best read 'road-racing bikes tend to
weigh less then MTBs'.

--
Ace in Alsace - brucedotrogers a.t rochedotcom
 
Ace wrote:

> Many of the 'road' bikes I see around here (France and Switzerland)
> are of the commuter variety and _much_ heavier than the above, so
> perhaps your statement would best read 'road-racing bikes tend to
> weigh less then MTBs'.

Fair point, up to a point, but having moaned for ages about the
distinction myself I finally realised that in the UK "road bike"
effectively means "road racing bike" and have got with the programme,
since I'm not going to get anywhere trying to change it! Simon tried
using "hill bike" for a while as MTBs rarely see actual mountains, but
it's like pointing out that there's no such thing as centrifugal force
and expecting the term to disappear.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email protected] http://www.dundee.ac.uk/~pjclinch/
 
Bonge Boo wrote:
> Commuting
> to work (2.5 miles) is the plan. I have some steep hills around me.

Where are you (which is code for how steep are the hills :) ?

BugBear
 
Tony Raven wrote:
> On Mon, 20 Aug 2007 07:58:01 +0100, Bonge Boo wrote:
>
>> Sorry, but I won't be.
>>
>> I have some fairly restrictive parameters to work in, related to a
>> medical condition. I can't put on muscle mass. So the only option is to
>> just to have more efficient muscle. And there ain't much of it to make
>> efficient in the first place. Hence the need to small gears.
>>
>
> Regardless as your muscles, circulatory system and lungs become adjusted
> to it it will get better and easier.

Trust me on this. The sort of radical improvement that would be needed
won't happen. I can bore the pants of you with my life story, but who
needs that?

Suffice to say that I'm not going to be able to push those sort of gears
up the sort of climbs required unless Jesus comes back and lays on hands.

Miracles are in painfully short supply. Kit changes are more prevalent.
 
Rob Morley wrote:
> In article <[email protected]>, Bonge Boo
> [email protected] says...
> <snip>
>> Help! Any suggestions gratefully received.
>>
>
> Something like this?
> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300141789355
> There are a few other rings for this on eBay ATM, including 40 and 42
> tooth.
> I run 32/44 on 12/26 with Ultegra mechs with no problems, but with 28/45
> you'd probably have to get the chain length spot on and be careful to
> avoid the big/big and small/small combinations. The front mech will
> probably be on its limits too.

Would this work with STI shifters? As I (maybe mistakenly) thought that
the shifter/derailleur was designed to work with certain size
chainrings. As they don't use friction shift at the front, I'm a little
wary of playing.

I assume if I get a compact drive chainring I could use a 13 tooth
difference (as the current is a 52x39). Then it's just a question of
dropping the front derailleur down to the correct height on the seat-tube?

Sorry, but gear-tinkering is all new to me...
 
On Mon, 20 Aug 2007 12:06:33 +0100, Bonge Boo wrote:
>
> Trust me on this. The sort of radical improvement that would be needed
> won't happen. I can bore the pants of you with my life story, but who
> needs that?
>

In which case ignore some of the temporary but cheap solutions I have
suggested - you need to do a proper conversion to lower gears. One you
might consider is the Schlumpf Mountain drive which is basically a new
bottom bracket that has a 2.5 step down gearing activated by knocking a
button in the center of the crank with your heel. Quite a few Brompton
owners have fitted them as the other options are quite limited on a
Brompton. Not cheap but by the time you've added up all the bits to do
it another way.....
http://www.schlumpf.ch
http://www.bikefix.co.uk/index.php?get_ol_id=6&get_gl_id=68&get_sgl_id=158

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell
 
On Mon, 20 Aug 2007 12:14:28 +0100, Bonge Boo <[email protected]>
wrote:

>Rob Morley wrote:
>> In article <[email protected]>, Bonge Boo
>> [email protected] says...
>> <snip>
>>> Help! Any suggestions gratefully received.
>>>
>>
>> Something like this?
>> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300141789355
>> There are a few other rings for this on eBay ATM, including 40 and 42
>> tooth.
>> I run 32/44 on 12/26 with Ultegra mechs with no problems, but with 28/45
>> you'd probably have to get the chain length spot on and be careful to
>> avoid the big/big and small/small combinations. The front mech will
>> probably be on its limits too.
>
>Would this work with STI shifters? As I (maybe mistakenly) thought that
>the shifter/derailleur was designed to work with certain size
>chainrings. As they don't use friction shift at the front, I'm a little
>wary of playing.

The chainring size is irrelevant to the shifter and derailleur
function, provided they're properly set up, of course. The critical
measurement is the spacing between rings, but that will be the same
for the cranksets mentioned as it is for your existing ones, so should
therefore work with no problem.

>I assume if I get a compact drive chainring I could use a 13 tooth
>difference (as the current is a 52x39). Then it's just a question of
>dropping the front derailleur down to the correct height on the seat-tube?

Proper setup may include moving the front derailleur mechanism further
down the tube such that it spans the two chain heights, which will
clearly be lower if you use smaller chainrings. But the size
difference between them is not critical, so you could go for a larger
or smaller range between the two rings with no ill effect.

--
Ace in Alsace - brucedotrogers a.t rochedotcom
 
>> The bike has a Sora 2005 groupset, apart from a 9 speed Tiagra rear
>> mech. Chainset is a 52x39 and the cassette is a 12-25.
>
> Don't throw anything away, as once you have reasonable fitness the gears
> you have now are the ones you're going to want in normally hilly country
> in Britain (if you live in /very/ hilly country you may want a triple in
> the long term, and if you can learn to spin like a dervish you may want a
> compact double in the long term). But my bet is that in a year's time
> you'll be riding the bike with more or less the gearing it has now.

I prefer to spin. Hate grinding, it damages things.

> However, the question is how to get from here to there. If the bike isn't
> fun to ride in your present state of fitness you won't ride it and you
> won't get fitter. My advice would be, fit a compact double (e.g. 50-34) at
> the front and wider range cassette (e.g. 12-27) on the back.
>
> If you did this you'd only have to replace chainset and cassette;
> everything else would be fine. And, as you get your fitness back, it would
> be reasonably simple to change back to your current gearing.

This is were I am reading contradictory stuff. I didn't think I could
replace the front rings with anything smaller without screwing the
indexing? And as far as I know, the rear mech only works over a 13-tooth
spread. But are you saying I can push these figures by a few teeth
either way and not notice the difference?

I think a visit to the local bike shop is in order to try to get clear
in my mind what is possible.

>> Having done these rides on my mountain bike, which has a front 48x38x28
>> and 12-30 rear, I frequently have to get in the lowest gear and just
>> spin up the hills.
>
> A road bike isn't a mountain bike. It doesn't weigh as much, doesn't have
> energy-sapping suspension, and has lower rolling resistance. Spinning up
> hills is good, of course, but you don't need gears like that to do it on
> the road.

MTB is rigid (1990 Rockhopper). 29lbs. The rolling resistance and weight
was where I was hoping to make all the gains, and on level-ish ground
the difference is stunning. The bike feels so much more alive!

But as soon as the incline goes beyond 3-4%, frankly that makes no
difference. And when you get to 10%+ its so irrelevant.

To give you some idea, one of the hills I was gonna use is 30%. It
completely bypasses a really unpleasant and dangerous stretch of road.
If I don't use that, another option is the ride I did yesterday. Only
15-20%. Even the main road is about 10% average, with stretches of 15%.

They are short-ish pitches, but steep. Like a lot of the riding around
here. I guess I massively over-estimated the efficiency gains a racer
would bring.

I think maybe I should keep the Allez for a few months and see how
frequently i use it. If it gets a fair bit, then I guess I should eye up
a replacement with suitable gearing off the bat and flog the Allez.

Not worth throwing good money after bad...
 
On Mon, 20 Aug 2007 12:48:30 +0100, Bonge Boo wrote:
>
> To give you some idea, one of the hills I was gonna use is 30%. It
> completely bypasses a really unpleasant and dangerous stretch of road.
> If I don't use that, another option is the ride I did yesterday. Only
> 15-20%. Even the main road is about 10% average, with stretches of 15%.
>

Where on earth do you live?

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell
 
On Mon, 20 Aug 2007 12:48:30 +0100, Bonge Boo <[email protected]>
wrote:

>>My advice would be, fit a compact double (e.g. 50-34) at
>> the front and wider range cassette (e.g. 12-27) on the back.
>>
>> If you did this you'd only have to replace chainset and cassette;
>> everything else would be fine. And, as you get your fitness back, it would
>> be reasonably simple to change back to your current gearing.
>
>This is were I am reading contradictory stuff. I didn't think I could
>replace the front rings with anything smaller without screwing the
>indexing? And as far as I know, the rear mech only works over a 13-tooth
>spread. But are you saying I can push these figures by a few teeth
>either way and not notice the difference?

As I've said in another post, the indexing is only dependant on the
spacing between rings - the tooth difference between them is
irrelevant, so yes, you can swap the rear cassette and/or chainrings
with impunity. And not necessarily only by a few teeth. A rear
cassette with a huge granny ring is also a possibility.

--
Ace in Alsace - brucedotrogers a.t rochedotcom
 
Bonge Boo wrote:
> I hope someone has some suggestion on how I should best proceed?
>
> After a very very long time off the bike, I recently started riding my
> ancient mountain bike again. However off-road isn't an option any more,
> so I decided to get a racer so I could go faster and further. Commuting
> to work (2.5 miles) is the plan. I have some steep hills around me.
>
> Ebay came up trumps and I got myself a slightly scruffy, but
> mechanically sound Specialized Allez. It's great! Apart from the fact
> that the gears are way to long. You'd need to live in Holland to make
> use of the gearing, unless you've got the thighs of Ullrich and oxygen
> carrying capacity of Armstrong...
>
> Today I decided to see how feasible it would be to ride to work. Getting
> there is great. Getting back is purgatory. I was on the lowest gear and
> couldn't possibly do anything but stand up and stamp on the pedals.
> Really exhausting, bad for the joints, etc.
>
> The bike has a Sora 2005 groupset, apart from a 9 speed Tiagra rear
> mech. Chainset is a 52x39 and the cassette is a 12-25.
>
> Having done these rides on my mountain bike, which has a front 48x38x28
> and 12-30 rear, I frequently have to get in the lowest gear and just
> spin up the hills.
>
> So my question is really this. What is the most cost effective way of
> getting myself some gearing that is going to be more usable? If I could
> get to near a 1:1 ratio I'll be fine.
>
> I believe that if I try to put a triple on the front I'll have to
> replace the chainset, mech and STI lever? Is that right?
>
> So another alternative might be to swap the rear cassette with an
> 8-speed 34 tooth "mega-range" and put a MTB rear mech on it? That would
> mean a new chain as well I s/pose.
>

I remember having a Sora rear mech that didn't have enough clearance for
anything over 26. So you would probably need a new rear mech as well.



> Alternatively I could try to find a much smaller front chainring. I
> reckon a 30x44 would do the job nicely. But I'm guessing that will balls
> up the STI?
>
I don't see why it would mess up the indexing. So I would think it is an
option.

It might be cheapest to sell this bike and buy one with a triple.



> Help! Any suggestions gratefully received.
 
Bonge Boo <[email protected]> wrote:

> I hope someone has some suggestion on how I should best proceed?
>
> After a very very long time off the bike, I recently started riding my
> ancient mountain bike again. However off-road isn't an option any more,
> so I decided to get a racer so I could go faster and further. Commuting
> to work (2.5 miles) is the plan. I have some steep hills around me.
>
> Ebay came up trumps and I got myself a slightly scruffy, but
> mechanically sound Specialized Allez. It's great! Apart from the fact
> that the gears are way to long. You'd need to live in Holland to make
> use of the gearing, unless you've got the thighs of Ullrich and oxygen
> carrying capacity of Armstrong...
>
> Today I decided to see how feasible it would be to ride to work. Getting
> there is great. Getting back is purgatory. I was on the lowest gear and
> couldn't possibly do anything but stand up and stamp on the pedals.
> Really exhausting, bad for the joints, etc.
>
> The bike has a Sora 2005 groupset, apart from a 9 speed Tiagra rear
> mech. Chainset is a 52x39 and the cassette is a 12-25.
>
> Having done these rides on my mountain bike, which has a front 48x38x28
> and 12-30 rear, I frequently have to get in the lowest gear and just
> spin up the hills.
>
> So my question is really this. What is the most cost effective way of
> getting myself some gearing that is going to be more usable? If I could
> get to near a 1:1 ratio I'll be fine.
>
> I believe that if I try to put a triple on the front I'll have to
> replace the chainset, mech and STI lever? Is that right?
>
> So another alternative might be to swap the rear cassette with an
> 8-speed 34 tooth "mega-range" and put a MTB rear mech on it? That would
> mean a new chain as well I s/pose.
>
> Alternatively I could try to find a much smaller front chainring. I
> reckon a 30x44 would do the job nicely. But I'm guessing that will balls
> up the STI?
>
> Help! Any suggestions gratefully received.

hello there clive.

one other option is to keep the road bike as it is and put slicks on the
old MTB while has lower gearing, and use the old MTB for the commutte,
though knowing the area ish you live in you'll probably want to lower
the gearing any way, for the road bike.

i find that having my old MTB with road tires, that i can get up some of
the 30% and more hills arond my folks place with too much problems, the
bike has 22/32/42 to a 28-11 cassette.

obvously i don't have the medical history you do etc.

roger
--
www.rogermerriman.com
 
Tony Raven <[email protected]> wrote:

> On Mon, 20 Aug 2007 12:48:30 +0100, Bonge Boo wrote:
> >
> > To give you some idea, one of the hills I was gonna use is 30%. It
> > completely bypasses a really unpleasant and dangerous stretch of road.
> > If I don't use that, another option is the ride I did yesterday. Only
> > 15-20%. Even the main road is about 10% average, with stretches of 15%.
> >
>
> Where on earth do you live?

some of the hills near my folks hit around that sort of figure, being a
gorge helps....

roger
--
www.rogermerriman.com
 
Bonge Boo wrote:
> Rob Morley wrote:
>> In article <[email protected]>, Bonge
>> Boo [email protected] says...
>> <snip>
>>> Help! Any suggestions gratefully received.
>>>
>>
>> Something like this?
>> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300141789355
>> There are a few other rings for this on eBay ATM, including 40 and 42
>> tooth.
>> I run 32/44 on 12/26 with Ultegra mechs with no problems, but with
>> 28/45 you'd probably have to get the chain length spot on and be
>> careful to avoid the big/big and small/small combinations. The front
>> mech will probably be on its limits too.
>
> Would this work with STI shifters? As I (maybe mistakenly) thought that
> the shifter/derailleur was designed to work with certain size
> chainrings. As they don't use friction shift at the front, I'm a little
> wary of playing.
>
> I assume if I get a compact drive chainring I could use a 13 tooth
> difference (as the current is a 52x39). Then it's just a question of
> dropping the front derailleur down to the correct height on the seat-tube?
>
> Sorry, but gear-tinkering is all new to me...

Don't get a pre-index crankset like the Stronglight 99 mentioned. Modern
index deraileurs have a wide cage which will hit the crank. The oddball
boltcircle isn't a big plus either.

A compact crankset with two rings replaced will be nice but a lot more
expensive than a cheap mtb triple with an unused ring




-
/Marten

info(apestaartje)m-gineering(punt)nl
 
Quoting Tony Raven <[email protected]>:
>Although I find my hill climbing ability is usually limited by the
>slowest speed at which I can still balance not by the gears.

Also - if you get down to walking speed, may as well walk (on a solo).
--
David Damerell <[email protected]> flcl?
Today is Aponoia, August.
 
Quoting Bonge Boo <[email protected]>:
>MTB is rigid (1990 Rockhopper). 29lbs. The rolling resistance and weight
>was where I was hoping to make all the gains, and on level-ish ground
>the difference is stunning. The bike feels so much more alive!
>But as soon as the incline goes beyond 3-4%, frankly that makes no
>difference. And when you get to 10%+ its so irrelevant.

Uh - as distinct from the psychosomatic effects, it's exactly on a steep
incline where weight matters.
--
David Damerell <[email protected]> flcl?
Today is Aponoia, August.
 
In article <StE*[email protected]>,
David Damerell <[email protected]> writes:
|> Quoting Bonge Boo <[email protected]>:
|> >MTB is rigid (1990 Rockhopper). 29lbs. The rolling resistance and weight
|> >was where I was hoping to make all the gains, and on level-ish ground
|> >the difference is stunning. The bike feels so much more alive!
|> >But as soon as the incline goes beyond 3-4%, frankly that makes no
|> >difference. And when you get to 10%+ its so irrelevant.
|>
|> Uh - as distinct from the psychosomatic effects, it's exactly on a steep
|> incline where weight matters.

Yes, but it's mainly your spare tyre that makes the difference :)

More seriously, quite. All-up weight is the factor - 10 pounds isn't
a big deal for most people, but it means you are 4-8% slower.


Regards,
Nick Maclaren.
 
In article <gRC*[email protected]>, David Damerell
[email protected] says...
> Quoting Tony Raven <[email protected]>:
> >Although I find my hill climbing ability is usually limited by the
> >slowest speed at which I can still balance not by the gears.
>
> Also - if you get down to walking speed, may as well walk (on a solo).
>
Why do you say that? When you're on a bike most of your leg effort goes
into propulsion, but when you're walking most goes into keeping your bum
off the ground and moving your legs.
 
In message <[email protected]>
Tony Raven <[email protected]> wrote:

> Quite a few Brompton
> owners have fitted them as the other options are quite limited on a
> Brompton. Not cheap but by the time you've added up all the bits to do
> it another way.....

Ooh, something to save for! Thanks, Tony.

I wonder if any Brommies have reviewed it?

I must work out what gearing inches/numbers mean, to a simpleton; are
there any suggested links?

--
Charles
Brompton P-type T6 in Motspur Park
 
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