Can you get...

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karlt
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Can you get...

Post by karlt »

...a wide range 8 speed cassette that doesn't have an 11t ring? I'm rebuilding a bike that has a 42/52 chainset and I have little need for an 11 tooth cog, but will need some reasonably low gears so a standard road 12-25 or 12-26 isn't really going to cut the mustard. All the MTB standards though seem to have an 11 - probably because of the relatively small large chainwheel you'd expect on one. I'll go with 11-30 if that's all that exists, but thought it was worth asking.

One thought - the SRAM cassettes at this end of the market (cheap) tend to have a separate smallest cog - if I got the 11-30 would I be able to swap the 11 for the 12 from the 12-26 I have on one of my existing bikes? I could use the 11 with a 50/39/30 triple much better than I could with 52/42. Or would the jump from 13-11 prove too great and result in loss of momentum at the top of the cassette? But even if so, wouldn't it be better than the 11-14 jump the 11-30 will have? Potentially I'd then have one bike with 50/39/30 and 11-26, and one with 52/42 and 12-30. My brain tells me that would be better - SRAM don't seem to agree and it'd be interesting to know why!
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NATURAL ANKLING
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Re: Can you get...

Post by NATURAL ANKLING »

Hi,
I am using 11 - 32 the second is 13 t.
11-13-15-18-21-24-28-32
The jump up 13 to 11 for me is not that bad but my top ring is 42.
This is a compact cassette and you want to use a old style 52 / 42, I think that 52 13 would be max on the road, but could you live with 35 " bottom gear.
This is a pure road bike :?: Not tourer......
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
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531colin
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Re: Can you get...

Post by 531colin »

Here is one I prepared earlier....http://forum.ctc.org.uk/viewtopic.php?f=5&t=54328&hilit=nightmare

My 8 speed solution is on page 2.
"Rose Versand" are a good source of cassettes, and they tell you the intermediate sprockets.
They still have some spare sprockets filed in 9 speed...http://www.rosebikes.co.uk/products/bike-parts/cassettes/9-speed/9-speed/?page=3#anchor_products
JohnW
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Re: Can you get...

Post by JohnW »

I'd think along the same lines as NATURAL-ANKLING on this.

If you are happy with a 32T big sprocket and a 42T small chainring, then an 11-32 cassette with a single 42 chainring will probably be sufficient for you and would reduce the complication and maintenance of a front changer. 42-11 will still give a top gear of 103", which is as high as I ever had for over 50 years of serious adult cycling...........until very recently when I was in the same position as you, with a 52 big chainring and I could only get a cassette with an 11T small sprocket.

I never use the big ring now and when other chainrings wear out I shall replace with smaller rings all round.

If you're using STI levers, you are best to ensure that everything is going to be compatible before you spend money.
karlt
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Re: Can you get...

Post by karlt »

JohnW wrote:I'd think along the same lines as NATURAL-ANKLING on this.

If you are happy with a 32T big sprocket and a 42T small chainring, then an 11-32 cassette with a single 42 chainring will probably be sufficient for you and would reduce the complication and maintenance of a front changer. 42-11 will still give a top gear of 103", which is as high as I ever had for over 50 years of serious adult cycling...........until very recently when I was in the same position as you, with a 52 big chainring and I could only get a cassette with an 11T small sprocket.

I never use the big ring now and when other chainrings wear out I shall replace with smaller rings all round.

If you're using STI levers, you are best to ensure that everything is going to be compatible before you spend money.


Compatibility may not be an issue. This is a 1980s frame with friction shift. I've already established it can cope with an 8-speed cassette. I am concerned however about the largest sprocket the derailleur can cope with. It's marked Shimano SIS which makes me think it may not be the original ;) - it could be - SIS came in in 1984 according to t'intertubes, but I'm not convinced.
MartinC
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Re: Can you get...

Post by MartinC »

Karlt, to answer the original question I don't think so. Even Miche who make totally custom cassettes (if you can find a stockist) don't do this for 8 speed.

So you're left with bodging a standard cassette. I do this with 9 speed Shimano cassettes replacing the 11 and 13 sprockets on an 11-34 cassette with a 13,14 - easy 'cos the first 2 sprockets aren't pinned and it's easy to source individual sprockets (Rose). I can also make a 13-30 cassette by taking the 13,14 and 15 from a 13-25 cassette and marrying it with the 16-30 from an 11-30 cassette. This requires dismantling the pinned sprocket set. Both mods retain the sequence of the sprockets and the relation of their change ramps where applicable (first and maybe seecond sprocket don't have any).

Like you I find the mathematical leap to 11 or 12 sprockets too big a gap percentage wise especially if the big chainring is less than 52 so my preference for a triple is to have a big chainring of 53 and a cassette that starts at 13. There's a trade off sometimes in that having small spockets that you're unlikely to use in the big chainring will extend the range of use of the middle - it all depends what's useful to you. If I were you I'd dig out the Shimano Techdocs and see what options you have in mixing and matching 8 speed cassettes. They're not too expensive now so it my not be a big deal to have to get 2 cassettes to make one.
karlt
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Re: Can you get...

Post by karlt »

I have two bikes involved in this. One (the one I'm doing up, hereafter the White Bike) has 52/42 chainrings and currently no cassette, The other, hereafter the Red Bike, has 50/39/30 and a 12-26.

Well my cunning plot is:

1. buy an 11-30.
2. remove the 12-26 from the Red Bike
3. swap the 11 and the 12 smallest sprockets between the cassettes.
4. I now have a custom 11-26 and a custom 12-30. The 11-26 goes on the red bike, the 12-30 on the White Bike.

The problems comes if the White Bike mech can't take the 30; if St Sheldon of Brown is to be believed http://sheldonbrown.com/k8.shtml the 11-28 already has a 12 as the second highest sprocket, so my plan falls over. In this event I suppose I'll just put the 11-28 on and know I'll seldom get any use out of the 11.

Edit - it's more complex than I thought. The 12-26 I have is SRAM; the SRAM MTB cassettes all have a 12 as second highest. I'll be mixing Shimano and SRAM - this should work, from what I understand.
Last edited by karlt on 22 Jul 2014, 10:03am, edited 1 time in total.
Brucey
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Re: Can you get...

Post by Brucey »

there is a possible solution for you; buy a 9s cassette and simply

a) remove the 11T sprocket and discard it

b) fit a different lockring (or use Loctite if the original one will hold but won't engage the serrations)

c) fit the 8s spacers between the cogs where you can

d) use no shims or beer can shims between the #7 and #8 sprocket.

Similarly it may be possible to buy a 7s cassette and respace/add a large sprocket to that.

hth

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
JohnW
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Re: Can you get...

Post by JohnW »

karlt wrote:...............Compatibility may not be an issue. This is a 1980s frame with friction shift. I've already established it can cope with an 8-speed cassette. I am concerned however about the largest sprocket the derailleur can cope with. It's marked Shimano SIS which makes me think it may not be the original ;) - it could be - SIS came in in 1984 according to t'intertubes, but I'm not convinced.


Ah - friction downtube levers - attaboy karl ; you're a man who knows a thing or two - all my bikes have that, even my 2006 frame - to my mind much the better system, and everything is compatible with everything. Mine cope easily with 8-speed cassettes, and could cope with 9-speed if necessary, as there's still some movement left when I've gone through the gears - although it will probably also depend upon which levers you use. On an 8-speed cassette I don't think you'll have a problem with jumps from gear to gear unless you're racing.

The gear changer - try it and see, it won't cost anything and if you do have to buy another then you've lost nothing by trying. The SIS stands for "Shimano Indexed System" and whether or not it'll cope with a 32T big sprocket will depend upon which changer it is. 32T big sprockets were available in the 80s, but not common. The two issues are whether the top jockey wheel will sufficiently clear the big sprocket and whether the cage is long enough to cope with the chain length. Shimano made more than one sprocket size options within ranges - e.g. the "Crane" and the "Crane GS"......the GS would cope with a 34T sprocket.
karlt
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Re: Can you get...

Post by karlt »

Heh. I'm old enough to have had several bikes with downtube shifters because it were all we 'ad in them days. What's funny about the SIS derailleur is that the lever appears to be an original; it has a Raleigh crest on it, but all the online information suggests this model did in fact have indexed gears on the rear, albeit downtube. Going properly retro with it would however require obtaining an ultra-6 freewheel and I'd prefer to use the newer wheels I've got with 8-speed since the original wheels have had it, even though it means cold setting the frame from 120mm to 130mm - it should take it; it springs out to that size quite easily but I'd prefer to cold set it properly.

Had to obtain some proper enclosed cam skewers as well - the horizontal dropouts mean the puny standard external cam things you get standard can't clamp it hard enough. Not when I was testing it uphill anyway.
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Mick F
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Re: Can you get...

Post by Mick F »

If you're friction, you don't need timing gates and ramps and you don't need to restrict yourself to 8sp.
Mick F. Cornwall
karlt
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Re: Can you get...

Post by karlt »

This is true, but I remember as a lad finding it hard enough to shift just one cog with only five on the back*. I wonder how good your precision needs to be coping with 9+ on friction, with the cogs being that much thinner and closer together?

*I had a 10-speed, like we all did, MTBs not having been invented** and only used six of them - 1-1, 1-3, 1-5***,2-1***,2-3,2-5. I think the even numbered cogs were pristine when the rest of the bike had died through lack of knowledge about maintenance****

**Bikes Montum non inventa est - Ablative Absolute (one for those who suffered a traditional education)
***No-one had told us about cross-chaining in them days.
****Few drops of 3 in 1 on the chain when it got rusty
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Mick F
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Re: Can you get...

Post by Mick F »

As an experiment, I fitted my friction shifters to my 10sp Triple Campag.

It worked like a dream, and TBH I think Ergos are a waste of time and money as far as changing gear is concerned. However, Ergos are convenient so you can change gear, steer, and brake all at the same time. The gear-shifting is besides the point because friction levers work so well.
Mick F. Cornwall
MartinC
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Re: Can you get...

Post by MartinC »

Yes, I suspect that all the changes made to sprocket and cassette profiles, chain links, floating jockey wheels to facilitate indexed shifters have made them redundant - the chain is so happy to find the next sprocket and align itself that the indexing isn't needed!

Mick did you ever try it with a Miche cassette with it's untimed sprockets?
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Mick F
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Re: Can you get...

Post by Mick F »

Good question.
Never gave this point a thought! :shock:

Looking at my records, I did the experiment in October 2011.
The 12-29 10sp Miche cassette was on from August 2010 to June 2012.

So, yes, it was the Miche that I experimented with.
It wasn't timed properly like a full Campag cassette would be, though it did have some ramps and stuff.
Mick F. Cornwall
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