Can Too High Gears be Lowered on SRAM Dualdrive?

Artemisia

Hi All!

Back safe and sound from Provence and first major tour on the recumbent
trike.

Among the technical issues I noticed, this trike, which has a 27-speed
SRAM Dualdrive shifter (three SRAM gears that can be shifted at a
standstill plus a derailleur with nine gears on it) is geared rather
stiff. I spend a lot of time in I-1, and never practically go beyond
III-6, even on the last day when I found myself on the Nationale 7, a
dual carriageway where trikes fear to tread! Comfortable cruising on
flat straight roads is at around III-4 or II-5. The last two gears seem
so high that I cannot see a use for them, since at those speeds,
downhill, I tend not to pedal anyway.

My favorite upright also has a SRAM Dualdrive, but with only 7 plates on
the derailleur. On this bike, I often use the highest gear.

I should mention that the cranks have been changed on the trike which is
now fitted with special short cranks, to go with my medium height. But I
was told one effect of this is that the gears might go stiffer.

The lowest gear is not really low enough to get me up my nightmare hill
on the way to work. I have to push furiously and can only manage a few
strokes before giving up to take a breather.

Now I have heard of people apparently changing the plates on a
derailleur to raise or lower the gear set. So I want to know, before I
get in touch with the Darth, if the request is feasible, if it is easy
or exorbitantly complicated to do, and what sort of price range are we
talking about.

I'm afraid also of disappointing my Darth, because when I bought the
trike in November we were discussing fitting him with a Schlumpf
Mountain Gear in addition to the SRAM. This would cost some 400€ extra,
and of course would add weight and fiddle. Is this a better solution, or
should I prefer substituting the original SRAM cassette for a lower version?

Thanks for your opinions - you people are so helpful!

EFR
Back doing laundry in sweltering Isle de France

Paul M. Hobson

Artemisia wrote:
> Now I have heard of people apparently changing the plates on a
> derailleur to raise or lower the gear set. So I want to know, before I
> get in touch with the Darth, if the request is feasible, if it is easy
> or exorbitantly complicated to do, and what sort of price range are we
> talking about.

Should be possible to get a new 9spd cassette. Cheaper thing to do
probably would be to simply get a smaller chainring (front gear)

\\paul
--
Paul M. Hobson
..:change the f to ph to reply:.

Artemisia

Paul M. Hobson wrote:

> Should be possible to get a new 9spd cassette. Cheaper thing to do
> probably would be to simply get a smaller chainring (front gear)

No front gears with a SRAM Dualdrive, though.

EFR
Ile de France

Paul M. Hobson

> Paul M. Hobson wrote:
>> Should be possible to get a new 9spd cassette. Cheaper thing to do
>> probably would be to simply get a smaller chainring (front gear)

Artemisia wrote:
> No front gears with a SRAM Dualdrive, though.

No gears that you can change while riding, yes. But you have a crank
with a chainwheel up front where the pedals are. Getting a smaller
chainring will lower the gearing of all gear combinations and cost $25
to $40 (US).

--
Paul M. Hobson
..:change the f to ph to reply:.

Marc

Artemisia wrote:
> Paul M. Hobson wrote:
>
>> Should be possible to get a new 9spd cassette. Cheaper thing to do
>> probably would be to simply get a smaller chainring (front gear)
>
> No front gears with a SRAM Dualdrive, though.
>
>

The chainring is a gear

Artemisia

Paul M. Hobson wrote:

> No gears that you can change while riding, yes. But you have a crank
> with a chainwheel up front where the pedals are. Getting a smaller
> chainring will lower the gearing of all gear combinations and cost $25
> to $40 (US).

Cool! I'll try to find out more.

EFR
Ile de France

Martin

Artemisia wrote:

> The lowest gear is not really low enough to get me up my nightmare hill
> on the way to work. I have to push furiously and can only manage a few
> strokes before giving up to take a breather.

How often do you cycle to work?
and did you cycle to work during winter?

If you have recently started cycling to work after taking a long winter
break, it might be worth persevering, as your leg muscles will improve,
and in a few week you will wonder what the trouble was.

Tom Sherman

Artemisia wrote:
> Paul M. Hobson wrote:
>
>> Should be possible to get a new 9spd cassette. Cheaper thing to do
>> probably would be to simply get a smaller chainring (front gear)
>
> No front gears with a SRAM Dualdrive, though.
>
Not as stock. However, if your trike has a derailer post, adding a
triple crank and front shifter is easy (though likely a 100-200 Euros).

However, Paul Hobson's suggestion of a smaller chainring is entirely
sensible if you currently have high gears you never use.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Rob Morley

In article <xhoVj.35348$815.32386@newsfe16.ams2>, Martin
martin.dann@virgin.net says...

> If you have recently started cycling to work after taking a long winter
> break, it might be worth persevering, as your leg muscles will improve,
>
Not much point having better leg muscles if your knees have exploded ...

Peter Clinch

Paul M. Hobson wrote:
>
>> Paul M. Hobson wrote:
>>> Should be possible to get a new 9spd cassette. Cheaper thing to do
>>> probably would be to simply get a smaller chainring (front gear)
>
> Artemisia wrote:
>> No front gears with a SRAM Dualdrive, though.
>
> No gears that you can change while riding, yes. But you have a crank
> with a chainwheel up front where the pedals are. Getting a smaller
> chainring will lower the gearing of all gear combinations and cost $25
> to $40 (US).

As Paul says...

Roos' Dual-Drive equipped touring 'bent sports a 52 tooth front
chainring if we're going to the NL, but a 42 tooth one at home where the
hills are more freely available.

Changing from the 52 to the 42 gives a ~20% reduction to each of the
gears. There's no reason not to go /very/ low on a trike, as you're not
going to have balance issues at low speed.

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 p.j.clinch@dundee.ac.uk http://www.dundee.ac.uk/~pjclinch/

Dave Larrington

In news:68qebvF2rnup7U1@mid.individual.net,
Peter Clinch <p.j.clinch@dundee.ac.uk> tweaked the Babbage-Engine to tell
us:

> Changing from the 52 to the 42 gives a ~20% reduction to each of the
> gears. There's no reason not to go /very/ low on a trike, as you're
> not going to have balance issues at low speed.

Though you /may/ run out of traction, as I discovered to my cost 2/3 of the
way up the Koppenberg a few years ago :-(

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
I have a shell collection, have you seen it? I keep it scattered
on the world's beaches.

Artemisia

Peter Clinch wrote:

> Roos' Dual-Drive equipped touring 'bent sports a 52 tooth front
> chainring if we're going to the NL, but a 42 tooth one at home where the
> hills are more freely available.

That's interesting. Is it easy to swap around like that? I know Roos has
the privilege of living with a seasoned bike expert, and perhaps is one
herself, but in my case the Darth is quite a distance away. Does not the
chain need shortening or lengthening when you change the spec on the
chainring?

EFR
Ile de France

Artemisia

Dave Larrington wrote:

> Though you /may/ run out of traction, as I discovered to my cost 2/3 of the
> way up the Koppenberg a few years ago :-(

How's that - wheels spinning around in place? Would this be because of
slippery or muddy roads, or is it a mechanical problem? Could you regain
traction by gearing up and then down again?

Cheers,

EFR
Ile de France

Peter Clinch

Artemisia wrote:

> That's interesting. Is it easy to swap around like that? I know Roos has
> the privilege of living with a seasoned bike expert, and perhaps is one
> herself

She's pretty much as competent as me, and while you may have me as a
"seasoned bike expert" that doesn't make me a great mechanic by any
stretch of the imagination! Nevertheless, it's pretty straightforward
by our fairly, but not spectacularly, low standards.

You unhook the chain from the chainwheel, undo the bolts holding the
chainwheel onto the crank, remove it, put the new one in place and
replace the bolts. If there's a chain protector disc you'll probably
have to take that off and put it back on too, but again it's just a case
of turning bolts.

> Does not the
> chain need shortening or lengthening when you change the spec on the
> chainring?

Potentially: to some extent the chain tensioner at the back will take up
the slack, but you may put it over its limits, depending on the size of
the step. It's easy enough to find out empirically: if your gears start
giving trouble, especially the higher ones, you'll probably need to
shorten the chain a little. That's quite easy with a chain tool. If
you get one, ask at the shop whether they have a spare bit of old chain
to practise on. I use one of Park's "foolproof" ones, and I haven't
managed to bugger it up yet, despite only using it once a blue moon. If
it's a bit scary then /any/ bike shop should be able to do the job for
you in minutes, if not seconds.

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 p.j.clinch@dundee.ac.uk http://www.dundee.ac.uk/~pjclinch/