Mountain bike cassette on a road bike query

[vernon levy]

I have a road bike with a Sora group set. The rear derraileur is a long arm
one and I have triple chain ring at the front. The rear cassette is an
eight speed close-ish ratio 12-23 road cassette. I'd like to lower the
gearing but the only cassettes that will do the job appear to be mountain
bike ones e.g. 11 - 28. Will the change be /that/ noticeable? Will the
wider ratio spacing cause problems. Is it a change worth considering?

TIA

-=V=-

 

[Pete Biggs]

vernon levy wrote:
> I have a road bike with a Sora group set. The rear derraileur is a
> long arm one and I have triple chain ring at the front. The rear
> cassette is an eight speed close-ish ratio 12-23 road cassette. I'd
> like to lower the gearing but the only cassettes that will do the job
> appear to be mountain bike ones e.g. 11 - 28. Will the change be
> /that/ noticeable? Will the wider ratio spacing cause problems.

Should be able to get that working, but there will be more occasions of
not being able to select a gear that feels right, especially on flatter
roads.

> Is it a change worth considering?

I wouldn't consider it while there are 13-26 cassettes* and smaller
chainring(s)**. A road Shimano type triple chainset takes an inner ring
down to 24 teeth, middle 38t. Note that minimising the size of the outer
ring as well will help you get the lower gears working better by allowing
the chain to be shorter than it would have to be otherwise, and the front
mech to be lower.

I know changing the both cassette and chanrings could work out expensive,
but customising the gears is one of the very best ways of improving a
bike, IME. It may be cheaper to replace the whole chainset if you find
another with more suitable rings, but check whether it requires the same
bottom bracket or not.

* www.settlecycles.co.uk/shop
* www.chainreactioncycles.com/Models.aspx?ModelID=1864
* Also possible to build a custom cassette (eg 13-28) by canibalising
various cassettes or using Marchiso sprockets.

** Stronglight and TA (TA best) from www.settlecycles.co.uk/shop
- Inner: 74mm or "ATB5"
- Middle and outer: 130mm or "Shimano Race". Middle doesn't /have/ to be
middle specific, a double inner will work.

~PB, suggesting 26/38/50 + 13-26

 

[MSeries]

vernon levy wrote:
> I have a road bike with a Sora group set. The rear derraileur is a long arm
> one and I have triple chain ring at the front. The rear cassette is an
> eight speed close-ish ratio 12-23 road cassette. I'd like to lower the
> gearing but the only cassettes that will do the job appear to be mountain
> bike ones e.g. 11 - 28. Will the change be /that/ noticeable? Will the
> wider ratio spacing cause problems. Is it a change worth considering?
>
> TIA
>
> -=V=-

My tourer has a 12-28 cassette, it has had a 14-32 in the past. The
change will be noticable. I made a custom cassette to get my 12-28 to
give me the close steps in the middle of the cassette which is where my
chains is most often. My rings are 48/38/28 original Deore 110/74mm BCD
chainset, 105 front mech, XT rear mech, Dura Ace & 105 dowtube levers.

 

[Simon Brooke]

in message <[email protected]>, vernon levy
('[email protected]') wrote:

> I have a road bike with a Sora group set. The rear derraileur is a
> long arm
> one and I have triple chain ring at the front. The rear cassette is an
> eight speed close-ish ratio 12-23 road cassette. I'd like to lower the
> gearing but the only cassettes that will do the job appear to be
> mountain
> bike ones e.g. 11 - 28. Will the change be /that/ noticeable? Will
> the
> wider ratio spacing cause problems. Is it a change worth considering?

All Shimano 8 speed cassettes have the same cog-to-cog spacing (I
believe; someone better informed will correct me if I'm wrong). There's
no actual difference between a 'mountain bike cassette' and a 'road bike
cassette' apart from the number of teeth.

28 teeth is 17% larger than 23 teeth and so driven by the same front
chainring will give you a 17% lower gear. That's a lot - a difference
that makes a difference. Make sure your derailleur has enough capacity,
although as it's a long arm it should do.

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

((DoctorWho)ChristopherEccleston).act();
uk.co.bbc.TypecastException: actor does not want to be typecast.
[adapted from autofile on /., 31/03/05]

 

[Brian G]

vernon levy wrote:
> I have a road bike with a Sora group set. The rear derraileur is a long arm
> one and I have triple chain ring at the front. The rear cassette is an
> eight speed close-ish ratio 12-23 road cassette. I'd like to lower the
> gearing but the only cassettes that will do the job appear to be mountain
> bike ones e.g. 11 - 28. Will the change be /that/ noticeable? Will the
> wider ratio spacing cause problems. Is it a change worth considering?

I have a similar setup on my road bike (but Tiagra). I live in a hilly
part of the country and when I want to do a longish ride with lots of
uppy bits I swap to a 12-32 "mountain bike" cassette. It works fine and
the change is very noticeable. The spacing doesn't cause problems as
such, but does need a different mindset, if you like, when selecting ratios.

--
Brian G

 

[Paul - xxx]

vernon levy came up with the following;:
> I have a road bike with a Sora group set. The rear derraileur is a long
> arm one and I have triple chain ring at the front. The rear cassette is
> an eight speed close-ish ratio 12-23 road cassette. I'd like to lower the
> gearing but the only cassettes that will do the job appear to be mountain
> bike ones e.g. 11 - 28. Will the change be /that/ noticeable?

Yes. Changing the rear cassette is very noticeable. A 'better' route might
be to change the front chainrings instead, which is also easier to do.

> Will the wider ratio spacing cause problems.

Potentially yes, there are likely to be more 'odd' gear ratios that won't
feel as though they work right, in my experience.

> Is it a change worth considering?

Only you can really answer that, but if you're thinking about it and know
you need lower gearing then yes.

--
Paul ...
(8(|) Homer Rules ..... Doh !!!

 

[Pete Biggs]

Paul - *** wrote:

> Yes. Changing the rear cassette is very noticeable. A 'better'
> route might be to change the front chainrings instead,

The ideal solution, in my 'umble opinion, to change both the cassette and
chainrings.

> which is also easier to do.

Not in the case of a tripple inner ring, because the crank will need
removing, but that's a job well worth doing if a lower bottom gear is
desired.

~PB

 

[davek]

vernon levy wrote:
> I'd like to lower the
> gearing but the only cassettes that will do the job appear to be mountain
> bike ones e.g. 11 - 28. Will the change be /that/ noticeable? Will the
> wider ratio spacing cause problems. Is it a change worth considering?

Harris Cyclery (Sheldon's shop) sells custom cassettes that would suit
your needs much better - IIRC the 'Cyclotouriste' ones should be ideal
for you. They give you the low-end gears but start with a 13 or 14t
smallest cog, so the spacing between gears is much smaller.

Also SRAM do some good off-the-peg cassettes that are considerably
cheaper - eg, I have a 9spd 14-25.

Shimano's insistence on putting an 11 or 12t smallest cog on all their
own-brand cassettes, regardless of the size of the largest cog, is
incredibly infuriating. An 11t cog is of no real use to most cyclists.

d.

 

[vernon levy]

"Pete Biggs" <[email protected]> wrote in
message news:[email protected]...
> vernon levy wrote:
>> I have a road bike with a Sora group set. The rear derraileur is a
>> long arm one and I have triple chain ring at the front. The rear
>> cassette is an eight speed close-ish ratio 12-23 road cassette. I'd
>> like to lower the gearing but the only cassettes that will do the job
>> appear to be mountain bike ones e.g. 11 - 28. Will the change be
>> /that/ noticeable? Will the wider ratio spacing cause problems.
>
> * www.settlecycles.co.uk/shop
> * www.chainreactioncycles.com/Models.aspx?ModelID=1864
> * Also possible to build a custom cassette (eg 13-28) by canibalising
> various cassettes or using Marchiso sprockets.
>
> ** Stronglight and TA (TA best) from www.settlecycles.co.uk/shop
> - Inner: 74mm or "ATB5"
> - Middle and outer: 130mm or "Shimano Race". Middle doesn't /have/ to be
> middle specific, a double inner will work.
>
> ~PB, suggesting 26/38/50 + 13-26
>
Thanks for that. I'll do a tooth count and consider my options.

Cheers

-=V=-

 

[vernon levy]

> Vern
> I see on Ribble (dodgy company I know) that you can still get the Sora
> 13-26 cassette. Wouldnt this do 90% of what you are after with little
> trouble?
>
> Stan Cox

That's an option put on my list to consider. I could always become less
porky but I want a speedier aid to overcome gravity

 

[vernon levy]

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

> ** Stronglight and TA (TA best) from www.settlecycles.co.uk/shop
> - Inner: 74mm or "ATB5"
> - Middle and outer: 130mm or "Shimano Race". Middle doesn't /have/ to be
> middle specific, a double inner will work.
>
> ~PB, suggesting 26/38/50 + 13-26
>
After digesting the suggestions here and looking at my own specific
needs......

I'm quite happy with the outer and middle rings on the chain set in fact I
do much of my riding on the outer ring and use the middle ring for rolling
terrain. My problem lies with hilly terrain when I could do with much lower
bottom gears.

Would I get away with just changing the inner ring to a 26 and the rear
cassette to a 13-26?

-=V=-

 

[Pete Biggs]

vernon levy wrote:

>> ~PB, suggesting 26/38/50 + 13-26
>>
> After digesting the suggestions here and looking at my own specific
> needs......
>
> I'm quite happy with the outer and middle rings on the chain set in
> fact I do much of my riding on the outer ring and use the middle ring
> for rolling terrain. My problem lies with hilly terrain when I could
> do with much lower bottom gears.
>
> Would I get away with just changing the inner ring to a 26 and the
> rear cassette to a 13-26?

Certainly worth a try anyway. I have got away with similar with Campag,
and I think Shimano users have too.

It will be a very big difference of gear between middle and granny, but I
know it's livable-with from my experience with 24/39/x. You'll have to
rear-shift at the same time by more than one gear to compensate.
Offsetting the inner chainring slightly inwards with washers will help the
chain land on it; a Deda Dog Fang will stop it falling off as well.

Having a 52t outer ring may mean you'll have to avoid more of the smaller
rear sprockets when on the granny ring, because the chain may be longer
than it would be otherwise. But again, you can probably live with that,
and it may not be an issue anyway.

To play safe, and to provide the almost same bottom gear as your original
plan, you could fit a 28t granny instead of 26. Shifting would be
slicker, but the steepest hills woudn't be quite so easy to climb... So
still a dilemma. It might help to just try the new 13-26 cassette first
with your existing chainrings to get a feel for how much further you want
to go.

~PB

 

[vernon levy]

"Pete Biggs" <[email protected]> wrote in
message news:[email protected]...
> vernon levy wrote:
>
> To play safe, and to provide the almost same bottom gear as your original
> plan, you could fit a 28t granny instead of 26. Shifting would be
> slicker, but the steepest hills woudn't be quite so easy to climb... So
> still a dilemma. It might help to just try the new 13-26 cassette first
> with your existing chainrings to get a feel for how much further you want
> to go.
>
> ~PB
>
I've just got back from the new Edinburgh Bike Shop in Leeds having
purchased a new cassette and found that my step at a time approach is in
accord with your advice.

Not overly impressed with the shop's range of goodies, the cassettes were
locked away out of sight, no sign of chain rings. I like to see what I want
instead of having to ask.

Did get £10 off the cassette through their introductory offer to customers
who's signed up to the mailing list though....

 

[MartinM]

vernon levy wrote:
> I have a road bike with a Sora group set. The rear derraileur is a long arm
> one and I have triple chain ring at the front. The rear cassette is an
> eight speed close-ish ratio 12-23 road cassette. I'd like to lower the
> gearing but the only cassettes that will do the job appear to be mountain
> bike ones e.g. 11 - 28. Will the change be /that/ noticeable? Will the
> wider ratio spacing cause problems. Is it a change worth considering?

I also have a similar set up; IMX a triple chainset and a 23 will get
you up pretty much everything, although for those little hills that it
won't a 26 is sometimes necessary; a 13/12-26 is readily obtainable for
8speed;. I wouldn't go for an MTB cassette; the jump between gears in
the middle too big and is no good for road riding IMO and you'll end
up pushing the same gear.
HTH