Drive chain info needed

My Pino tandem has had some repairs carried out by Chas Roberts and is
going off to be powder coated tomorrow. I've taken all the gubbins
off it for this and have been perusing the drive train.

The rear chain set looks a bit worn, and needs new rings at the very
least. I'll be replacing the rear chain and, more than likely, the
cassette.

The chain rings are 74mm and 110mm pcd, 26T and 38T respectively. The
chainset is a Dotek YF PR04, whatever that means. The small chain ring
fixes to it using bolts into tapped holes on the chainset.

It's a 7 speed Sachs Powerglide cassette, run from Sachs twistgrip
shifters.

Questions:

Should I get steel chainrings for longevity? At present the 26T is
steel, the 38T aluminium. What super tough yet amazingly good value
aluminium rings are available?


If I can't get a replacement Sachs cassette (they seem to all be 9
speed) will a 7 speed Shimao fit? The sprocket spacing is the same,
but I'm not sure about the spline pattern.


Tim

"Tim Hall" wrote in message
...

The chain rings are 74mm and 110mm pcd, 26T and 38T respectively. The
chainset is a Dotek YF PR04, whatever that means. The small chain ring
fixes to it using bolts into tapped holes on the chainset.

It's a 7 speed Sachs Powerglide cassette, run from Sachs twistgrip
shifters.

Questions:

Should I get steel chainrings for longevity? At present the 26T is
steel, the 38T aluminium. What super tough yet amazingly good value
aluminium rings are available?

TA rings are not the cheapest, but they are the most durable. They'll be
easier to get hold of than steel rings, which will be a bit heavier too.
They're available in the PCD you specify.

If I can't get a replacement Sachs cassette (they seem to all be 9
speed) will a 7 speed Shimao fit? The sprocket spacing is the same,
but I'm not sure about the spline pattern.

Yes, I believe so.



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.650 / Virus Database: 416 - Release Date: 04/04/2004

Tim Hall wrote:

Should I get steel chainrings for longevity?

Steel makes sense for small rings as they wear quicker, but 26T is large
enough for alumnium to last reasonably well, especially if used with
chains in good condition.

At present the 26T is
steel, the 38T aluminium. What super tough yet amazingly good value
aluminium rings are available?

TA post free from http://www.settlecycles.co.uk/shop
- "ATB5" for 74 and 110mm

http://www.sjscycles.com/store/vIndex.htm for steel (and cheap alloy) 74mm
rings.

Avoid Biopace unless you're already sure you like them. These things
ain't round!

~PB