Sub Unity

For discussions about bikes and equipment.
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Mick F
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Sub Unity

Postby Mick F » 15 Jan 2015, 2:15pm

Just been out on a test ride.
I'd stripped Bike down completely during the week, and checked and serviced everything, polished the frame, then re-assembled.

Meanwhile, I'd fitted a 28t inner ring to my Campag Chorus Triple. The rings were 53/42/30, and now they're 53/42/28. This, coupled with my 12-30 Centaur cassette gives a sub unity bottom gear. First time I've ever been this low. :shock:
Basically, my 2nd gear is almost the same as my bottom gear was before, so all I've done is extend the bottom end.

The new Zircal 28t chainwheel came from Spa for £10 plus p+p. The teeth are a little thicker than the Campag rings but everything is sweet and the changes are fine. All in all, I'm quite pleased.

I think the Campag Comp front mech I use would manage a 26t even with the 42t and 53t, but I think 28t is small enough for now.
Mick F. Cornwall

tatanab
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Re: Sub Unity

Postby tatanab » 15 Jan 2015, 2:29pm

I've used 50/40/24 on a Record triple with a Daytona triple front mech ok.

At present I am using 24 front with 28 rear so perhaps a whole 2" lower than you. I tour with camping kit and like hillyish country so have geared low enough that I can winch it up most things.

You could possibly go all the way down to a 24 ring, it would just mean that you could not use the 2 or 3 smallest sprockets when on the little ring because the chain would drag on the bottom of the front mech. Of course, if you are on the little ring you are unlikely to be using those sprockets anyway.

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Mick F
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Re: Sub Unity

Postby Mick F » 15 Jan 2015, 2:52pm

I confess that I often end up in small/small. Big/big is rare because the transmission gets noisy so I notice, but small/small is fine and I can end up in that combination sometimes without thinking. It's only when I go to change up a cog, that I find out! :oops:

With the 28t up front, if I select small/small, there is a 1cm clearance, so possibly a 26t would just clear the front mech cage bottom.
Mick F. Cornwall

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al_yrpal
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Re: Sub Unity

Postby al_yrpal » 15 Jan 2015, 3:30pm

Give it another 10 years and perhaps you will be getting to where I am with the Salsa Vaya, 50, 40, 22 and 14-32 on the back. I never use the granny ring unless I am touring with my 16kg of kit on board. On unloaded day rides around here I very rarely use the middle ring either. The bike originally came with a 30t granny ring and I was a bit worried about the 22t ring but it changes quite smoothly up and down with the same number of chain links.

Al
Touring on a bicycle is a great way to explore and appreciate the countryside and towns you pass through. What do you do to make a difference?

Valbrona
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Re: Sub Unity

Postby Valbrona » 15 Jan 2015, 3:38pm

Mick F wrote:Just been out on a test ride.
I'd stripped Bike down completely during the week, and checked and serviced everything, polished the frame, then re-assembled.


I have usually found that it buckets it down on the first ride after a good clean and service.

I have for a while been using a 26t inner chainring, so a bit smaller than my 29 or 30 I have at the back. I take the view of getting something as low as possible - a 24 inner would probably also work.

I think I might buy the Spa chainrings next time.
I should coco.

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Mick F
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Re: Sub Unity

Postby Mick F » 15 Jan 2015, 4:31pm

Valbrona wrote:
Mick F wrote:Just been out on a test ride.
I'd stripped Bike down completely during the week, and checked and serviced everything, polished the frame, then re-assembled.


I have usually found that it buckets it down on the first ride after a good clean and service.
:lol: :lol:
Yes.
This morning, I drove into town - vision express/coffee/bank - and was home again soon after 10am in cloudless blue skies.
The bike was finished except for adjusting the headset and checking the tyres. Jobs done, cycling gear on ................... then it was heaving down! :lol:

I waited ten minutes, then I was off and away. Drizzled a bit as I came home, but the roads were filthy and wet throughout so I rinsed Bike off with the hose afterwards. (and stood it to dry in the kitchen :D )
Mick F. Cornwall

manybikes
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Re: Sub Unity

Postby manybikes » 15 Jan 2015, 5:33pm

@MickF Did you make sure the car was always in sight whilst in town Mick? :D

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Mick F
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Re: Sub Unity

Postby Mick F » 15 Jan 2015, 5:38pm

No. :lol:

It's a red Fiat 500 and I understand they are very "steel-able". It was locked, but there's no alarm.
Maybe I should have used my Kabrus alarm threaded through the spokes of the alloy wheels. :wink:
Mick F. Cornwall

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Re: Sub Unity

Postby fastpedaller » 16 Jan 2015, 9:25am

Mick F wrote:No. :lol:

It's a red Fiat 500 and I understand they are very "steel-able". It was locked, but there's no alarm.
Maybe I should have used my Kabrus alarm threaded through the spokes of the alloy wheels. :wink:


I've found some stickers which fit on the inside of the glass and state "Alarm and Immobiliser fitted", and until someone tries to break in they are possibly effective in moving the thief onto another vehicle (though of course that's not ideal)

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Re: Sub Unity

Postby PH » 18 Jan 2015, 2:44pm

Careful MickF, you're getting very close to the Rohloff's gearing range...
I have 50-40-24 on a 14-28 9 speed cassette which works well for me, the 24 gets used on every visit to the Peaks and the 50/14 rarely gets spun out.

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Mick F
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Re: Sub Unity

Postby Mick F » 18 Jan 2015, 3:40pm

:shock:
What?
Rohloff?

:lol:
Mick F. Cornwall

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Re: Sub Unity

Postby niggle » 19 Jan 2015, 4:29pm

Well one of my bikes has 44-32-22T chainset and 11-32 8 spd cassette, but it is geared for loaded touring and when not loaded I do not normally use the inner ring.

OTOH my Equilibrium road bike's chainset is currently 50-39-28T with 12-27 9 spd cassette so just above unity in its lowest gear. I do have a 26T inner ring I could fit, but I don't like the big jump that gives to/from the middle ring.

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[XAP]Bob
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Re: Sub Unity

Postby [XAP]Bob » 19 Jan 2015, 10:16pm

Sub 50%, on a 20" wheel ;)
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

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Mick F
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Re: Sub Unity

Postby Mick F » 20 Jan 2015, 8:35am

[XAP]Bob wrote:Sub 50%, on a 20" wheel ;)

If I went that low on my upwrong, I'd fall off! :lol: :lol:
Mick F. Cornwall

Tonyf33
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Re: Sub Unity

Postby Tonyf33 » 20 Jan 2015, 9:49am

for a while I used a Shorter with Campag 3x8 and a loaded touring half step plus granny Campag 46/43/24 + 14-30 all ally special cassette, the triple front (Mirage) & long cage rear worked perfectly fine though I think it didn't take up all the chain slack on the 24 + 14/15 sprockets from memory (not that I would use those combos anyway)
I never had reason to use the lowest gears but if you were going up steep stuff with a fair old weight or even lesser ones right at the end of a hard ride then knowing you have really low gears to get you out bother can be of real benefit..don't knock it I say.