Sunrace query

[student]

Hello everyone.

I'm having a bit problem with deciphering something.

One of my friends told me that he actually measured several 7seven and 8eight speed cassettes from sunrace (taiwanese company who makes quite decent equipement for cheap) and interestingly all of them used 5mm spacing. Apparently sunrace assumed that it's cheaper to manufacture one cog and spacer thickness for the seven and eight speed cassettes, and just use those, instead of making them with dfferent dimensions.

Is there anyone who can confirm it? He said it and measured it with a digital caliper, but it sounds too good to be true. Cause that would mean that anyone can hazz a shimano compatible rear wheel and a sunrace cassette with older 8spd campag drivetrains.

I assume there are lot of members who are familiar with sunrace, and even own a few of those cassettes. If anyone would be so kind to measure them. :\ Unfortunately the shops here are out of stock from the road cassettes, only offering 11-32 mountain cassettes, which are out of the question for me (I have 53-39 cranks and a short cage derailleur from the 94 athena group)

thank you :\ :\

[Brucey]

IMHO this query is a bit of a red herring; you may as well just buy a cassette and be done with it, because....

1) The biggest error you will ever get in the indexing of 8s 4.8mm spacing vs 5.0mm spacing is 0.5mm. This is because gear 1 and gear 8 are determined by the mech stops, not the indexing, and if you centre the mech on the midpoint between 4 and 5 then the biggest error is seen in gear 2 and gear 7, two and a half clicks away. You won't even notice this with most systems because the top pulley has over 0.5mm float in it.

2) Even if it is 'wrong' you can fix it. A small adjustment to how the cable is mounted in the rear mech, or a few shims (cut from beer can with scissors) between the sprockets. Easy.

cheers

[student]

Thanks Brucey!

Actually i'd just buy one, as it's 10 bucks. But, currently there are only mtb cassettes available, and i'd opt for either 12-25 or 12-23 (both ratios are available for order, but not in stock).

I'd assume that it can be make to work. Especially with the clamping of the cable or adjusting the tension accordingly.

[student]

Straight report from the trenches:

yesterday I was given a mavic cosmos wheelset with 8spd Sunrace Cassette fitted.

Put the rear wheel in, tried it: like a charm. No adjusment needed, it was straight perfect. No noise from the chain. Silent running and fast shifting, without delay and hesitation.

Even the limit screws were untouched, and the cable tension needed zero adjustment. Went perfectly, after the test I gave the wheel back and rode home on my Athenas.

So, anyone having trouble sorting 8spd campy wheelset: just buy something with shimano freehub body, fit a sunrace cassette, and be happy.

Also, it seems now that sunrace cassettes are in stock at ebike.hu, in 12-25 option. too bad I've ordered a miche cassette two weeks ago to replace my worn campy one.. though for a snrace cassette I'd still need to get a wheelset, but that's no probelm.

[BigG]

Suntour (and I think Campagnolo ) used 5.0 mm spacing for both 7 speed and 8 speed systems with both free wheels and cassettes although the 8 speed ones are fairly rare. Shimano changed to 4.8 mm spacing for 8 speed but as Brucey points out, there is little practical difference between the two. Indeed, Suntour used varying spacing on its later Winner series freewheels.

[student]

Probably, but sunrace and suntour are not "created equal" especially as the former is often associated with poor quality and low-end componets. Whereas in fact you only get what you pay for: cheap sunrace products are cheap quality, on the other hand their mid-priced stuff will perform reasonably.

I was very pleased with the shifting performance and "chain travel" on the cassette, longevity is another issue, though at the cost of those cassettes, it's not a big pain if they only last half as long as the campag cassettes.