Folders, 8 speed cassettes, etc.

CT said:

I have a folder for commuting that currently has an 8-speed 11-28 cassette and 52 chain ring.
The chain tends to skip off more than I'd like (I've been told the short chain stay makes
things worse),

That's true.

Quoted message said:

and instead of fitting some form of retaining device or a front mech, I've been looking at fitting
a closer-ratio cassette and tightening up the chain.

That is unlikely to cure the problem. If chain tension were determinant, all you'ld have to do would
be pedal a bit harder while shifting, since the tension from pedaling is WAY higher than the tension
supplied by the derailer's spring.

Quoted message said:

I never use anything bigger than the 16 (the bike has 20" wheels), but unfortunately I can't find
a Shimano 8-speed cassette that fits the bill. The 12-21 is closest, but I use the 11 on the
current cassette a lot and wouldn't want to lose it.

So, from all this I have a few questions:

1. Firstly, will putting a closer set of ratios, and taking a few links out of the chain help the
situation?

No.

Quoted message said:

2. Does anyone make an 11-12-13-14-15-16-17-18 or an 11-12-13-14-15-16-17-19 8-speed cassette?

We'd be glad to put together a 11-12-13-14-15-16-17-19 for you, $49.95.

We'd use a 12-23, remove the 23 and stick an 11 on t'other end.

Quoted message said:

3. I have an 11-19 7-speed cassette from an old road bike, would it be possible to add the 21 from
the existing 8-speed cassette with an appropriate spacer? As I understand it, the spacing is
the same and I can take the existing cassette apart by at worst removing some rivets?

The spacing is _not_ the same, so you'd need to replace all of the spacers to make this fit.

Sheldon "Custom K7" Brown +--------------------------------------------+
| In order to understand recursion, | first, you have to understand recursion. |
+--------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

"CT" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Hi all

I have a folder for commuting that currently has an

8-speed 11-28

Quoted message said:

cassette and 52 chain ring. The chain tends to skip off

more than I'd

Quoted message said:

like (I've been told the short chain stay makes things

worse), and

Quoted message said:

instead of fitting some form of retaining device or a

front mech, I've

Quoted message said:

been looking at fitting a closer-ratio cassette and

tightening up the

Quoted message said:

chain.

I never use anything bigger than the 16 (the bike has 20"

wheels), but

Quoted message said:

unfortunately I can't find a Shimano 8-speed cassette that

fits the

Quoted message said:

bill. The 12-21 is closest, but I use the 11 on the

current cassette

Quoted message said:

a lot and wouldn't want to lose it.

So, from all this I have a few questions:

1. Firstly, will putting a closer set of ratios, and

taking a few

Quoted message said:

links out of the chain help the situation?

2. Does anyone make an 11-12-13-14-15-16-17-18 or an 11-12-13-14-15-16-17-19 8-speed cassette?

3. I have an 11-19 7-speed cassette from an old road bike,

would it be

Quoted message said:

possible to add the 21 from the existing 8-speed cassette

with an

Quoted message said:

appropriate spacer? As I understand it, the spacing is

the same and I

Quoted message said:

can take the existing cassette apart by at worst removing

some rivets?

Quoted message said:

Many thanks in advance for any help.

Chris

Build-yer-own........

Use the 11-19 sprockets from the seven speed with your current eight speed cassette spacers, and add
the 16 from the 11-28, (should have 11-12-14-16-18-21-24-28). You could also replace the 19 with the
18 if you wish.

Or you could get a 12-21, (12-13-14-15-16-17-19-21), take off the 21 and the 19, and add the 11 and
the 18 from your current cassette at either end.

CT said:

Hi all

I have a folder for commuting that currently has an 8-speed 11-28 cassette and 52 chain ring. The
chain tends to skip off more than I'd like (I've been told the short chain stay makes things
worse), and instead of fitting some form of retaining device or a front mech, I've been looking at
fitting a closer-ratio cassette and tightening up the chain.

I never use anything bigger than the 16 (the bike has 20" wheels), but unfortunately I can't find
a Shimano 8-speed cassette that fits the bill. The 12-21 is closest, but I use the 11 on the
current cassette a lot and wouldn't want to lose it.

So, from all this I have a few questions:

1. Firstly, will putting a closer set of ratios, and taking a few links out of the chain help the
situation?

2. Does anyone make an 11-12-13-14-15-16-17-18 or an 11-12-13-14-15-16-17-19 8-speed cassette?

3. I have an 11-19 7-speed cassette from an old road bike, would it be possible to add the 21 from
the existing 8-speed cassette with an appropriate spacer? As I understand it, the spacing is
the same and I can take the existing cassette apart by at worst removing some rivets?

Alternate suggestion: Perhaps a 110mm crank with a 58t ring and a pair of aluminum ring guards as
the downhillers use? Somewhat like Moulton's approach. That's all readily available equipment
-albeit a bit more expensive. But if you make the commitment you'll be able to use standard
cassettes. (Chains/cassettes are consumables. )The smaller cassette wouldn't do much for the chain
derailment problem.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

Sheldon Brown <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

That is unlikely to cure the problem. If chain tension were determinant, all you'ld have to do
would be pedal a bit harder while shifting, since the tension from pedaling is WAY higher than the
tension supplied by the derailer's spring.

Makes sense. Interestingly, the chain always comes off to the right, away from the frame, but (if
memory serves) it happens shifting up and down.

As an alternative solution would stripping down and modifying an old front mech be a good option? I
have an old 105 double kicking around somewhere...

Or has anyone tried those downhill MTB roller chain devices? Presumably a front mech will be less
prone to wear than a (nylon?) roller sitting on the chain.

Thanks for the response.

Chris

"Grenouil" <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Build-yer-own........

Use the 11-19 sprockets from the seven speed with your current eight speed cassette spacers, and
add the 16 from the 11-28, (should have 11-12-14-16-18-21-24-28). You could also replace the 19
with the 18 if you wish.

Yup, that sounds like a good option. I think I'll do this and look for a separate fix on the
chain problem.

Cheers

Chris

A Muzi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Alternate suggestion: Perhaps a 110mm crank with a 58t ring and a pair of aluminum ring guards as
the downhillers use? Somewhat like Moulton's approach. That's all readily available equipment
-albeit a bit more expensive. But if you make the commitment you'll be able to use standard
cassettes. (Chains/cassettes are consumables. )The smaller cassette wouldn't do much for the chain
derailment problem.

Excuse my ignorance, which dimension of the crank does the 110mm refer to?

Cheers

Chris

(CT) said:

A Muzi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Alternate suggestion: Perhaps a 110mm crank with a 58t ring and a pair of aluminum ring guards
as the downhillers use? Somewhat like Moulton's approach. That's all readily available equipment
-albeit a bit more expensive. But if you make the commitment you'll be able to use standard
cassettes. (Chains/cassettes are consumables. )The smaller cassette wouldn't do much for the
chain derailment problem.

Excuse my ignorance, which dimension of the crank does the 110mm refer to?

The diameter of the circle described by the centers of the chainring fixing bolts.

--
Ted Bennett Portland OR

I opined:

Quoted message said:

Quoted message said:

That is unlikely to cure the problem. If chain tension were determinant, all you'ld have to do
would be pedal a bit harder while shifting, since the tension from pedaling is WAY higher than the
tension supplied by the derailer's spring.

CT said:

Makes sense. Interestingly, the chain always comes off to the right, away from the frame, but (if
memory serves) it happens shifting up and down.

As an alternative solution would stripping down and modifying an old front mech be a good option?
I have an old 105 double kicking around somewhere...

Yes, this would be an excellent solution.

Quoted message said:

Or has anyone tried those downhill MTB roller chain devices? Presumably a front mech will be less
prone to wear than a (nylon?) roller sitting on the chain.

Right. Also, it wouldn't create any friction _except_ while the chain was trying to fall off.

Another option, if the chain always falls of outward, would be to install a cyclocross-type
chainguard disc.

Sheldon "Derailers Come In Pairs" Brown +-------------------------------------------+
| Never do today what you can do tomorrow. | Something may occur to make you regret | your
| premature action. --Aaron Burr |
+-------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

CT said:

Hi all

I have a folder for commuting that currently has an 8-speed 11-28 cassette and 52 chain ring. The
chain tends to skip off more than I'd like (I've been told the short chain stay makes things
worse), and instead of fitting some form of retaining device or a front mech, I've been looking at
fitting a closer-ratio cassette and tightening up the chain.

I doubt that will help as much as using a front derailleur cage to guide the chain.

Quoted message said:

I never use anything bigger than the 16 (the bike has 20" wheels), but unfortunately I can't find
a Shimano 8-speed cassette that fits the bill. The 12-21 is closest, but I use the 11 on the
current cassette a lot and wouldn't want to lose it.

How much trouble would it be for you to go to 9-speed? That way you can easily find your 11. Of
course, with a 52 chainring, you are never going to get a really large gear with 20" wheels, but if
52/11 is big enough for you, then you can easily get that with 9-speed.

Quoted message said:

1. Firstly, will putting a closer set of ratios, and taking a few links out of the chain help the
situation?

I don't believe so. It's the chainline angle that is the problem, not the size of the cogs.

--

David L. Johnson

__o | the people can always be brought to the bidding of the leaders. _`\(,_ | That is easy. All
you have to do is tell them they are being (_)/ (_) | attacked, and denounce the peacemakers for
lack of patriotism and exposing the country to danger. It works the same in any <country. --
Hermann Goering

Quoted message said:

A Muzi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Alternate suggestion: Perhaps a 110mm crank with a 58t ring and a pair of aluminum ring guards as
the downhillers use? Somewhat like Moulton's approach. That's all readily available equipment
-albeit a bit more expensive. But if you make the commitment you'll be able to use standard
cassettes. (Chains/cassettes are consumables. )The smaller cassette wouldn't do much for the chain
derailment problem.

CT said:

Excuse my ignorance, which dimension of the crank does the 110mm refer to?

Sorry.. That's the diameter of the chainring bolts. Most modern road cranks are 135mm ( or 130mm) .
It isn't a functional difference just that 110mm rings are ubiquitous and cheap.. Sugino's 58t 110mm
ring can be found easily at about half the price of a big ring for any other diameter.

"Ignorance" is loaded word isn't it? "Unfamiliarity " perhaps. . .

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

I've now built the cassette up as an 11-18, and it all seems to be working really well.

As it turns out it may well help the chain problem for reasons other than tension. The gear I use
most around town (14) is now located further down the cassette and as a consequence is now more in
line with the chain ring. I guess this makes it less likely to throw the chain?

Anyway, I'm not using the folder for a few weeks and I'll be trying the front derailleur idea out
when I'm back at work. I'll post the results in a few weeks.

Thanks for all helpful posts.

Chris