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Date: 14 Aug 2007 05:59:28
From: rbmrwb@yahoo.com
Subject: Is my chain to wide?
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One of my road bikes is equipped with Suntour Superbe Pro rear
derailleur and 7 speed Suntour Accushift bar ends. I recently put a
new Sram 8 speed chain and NOS Suntour New Winner 7 speed freewheel on
and I'm getting what appears to be periodic grinding between the chain
and freewheel, not enough to skip the chain, but enough to be
noticeable and really annoying. At first, it appeared that one of the
pins in the chain was a little to far out and was catching on the
freewheel cogs, I pushed it in slightly and inspected the others, but
is didn't solve the problem. The symptoms appear only when riding,
when I put the bike in the workstand and turn the cranks, all is
smooth. Could it be that an 8 speed chain to to wide for an ultra
seven freewheel and periodically rubs against the adjacent cog?
Should I install a nine speed chain?
Thanks in advance.
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Date: 14 Aug 2007 22:13:39
From: velodancer
Subject: Re: Is my chain to wide?
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There is a new Shimano group with an 11-33 8 speed cassette with 8
speed spacing. Shimano specs a 9 speed chain which doesn't fit neatly
into your rule of thumb. Admittedly, it is an unusual cassette made
for some automatic shifting system and is supposed to reduce upshift
shock by 70 percent. Apparently the odd sized chain is part of the
technology.
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Date: 14 Aug 2007 18:38:17
From: A Muzi
Subject: Re: Is my chain to wide?
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rbmrwb@yahoo.com wrote:
> One of my road bikes is equipped with Suntour Superbe Pro rear
> derailleur and 7 speed Suntour Accushift bar ends. I recently put a
> new Sram 8 speed chain and NOS Suntour New Winner 7 speed freewheel on
> and I'm getting what appears to be periodic grinding between the chain
> and freewheel, not enough to skip the chain, but enough to be
> noticeable and really annoying. At first, it appeared that one of the
> pins in the chain was a little to far out and was catching on the
> freewheel cogs, I pushed it in slightly and inspected the others, but
> is didn't solve the problem. The symptoms appear only when riding,
> when I put the bike in the workstand and turn the cranks, all is
> smooth. Could it be that an 8 speed chain to to wide for an ultra
> seven freewheel and periodically rubs against the adjacent cog?
> Should I install a nine speed chain?
New freewheel and new chain? Worn parts may be the cause.
Did you use the supplied snap link (good) or did you rivet the chain
(not so good)?
Assembly issues with freewheel cogs? If one is upside down the spacing
between cogs will be screwy. Suntours are slightly tighter spaced in the
4 lowest positions but it's not a radical difference. If one space is
visibly smaller, there's your problem.
If you change chain at all I'd use a seven speed chain. Always use the
widest appropriate chain, not the narrowest, for best shifting.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
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Date: 14 Aug 2007 09:50:54
From: Mark
Subject: Re: Is my chain to wide?
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rbmrwb@yahoo.com wrote:
> One of my road bikes is equipped with Suntour Superbe Pro rear
> derailleur and 7 speed Suntour Accushift bar ends. I recently put a
> new Sram 8 speed chain and NOS Suntour New Winner 7 speed freewheel on
> and I'm getting what appears to be periodic grinding between the chain
> and freewheel, not enough to skip the chain, but enough to be
> noticeable and really annoying. At first, it appeared that one of the
> pins in the chain was a little to far out and was catching on the
> freewheel cogs, I pushed it in slightly and inspected the others, but
> is didn't solve the problem. The symptoms appear only when riding,
> when I put the bike in the workstand and turn the cranks, all is
> smooth. Could it be that an 8 speed chain to to wide for an ultra
> seven freewheel and periodically rubs against the adjacent cog?
> Should I install a nine speed chain?
I've run SunTour ultra-6 and ultra-7 (same spacing, different # of cogs)
for years with SRAM PC-48s and never had a problem. The SRAMs shift
much better than the SunTour chains that were made for these freewheels.
I'd look for some other problem. In the unlikely event that someone has
disassembled the freewheel and reassembled with the wrong spacers, that
would cause trouble. SunTour also used to produce micro-shims (0.1 and
0.2 millimeters, IIRC) to fine-tune spacing.
Mark J.
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Date: 14 Aug 2007 14:01:49
From: Qui si parla Campagnolo-www.vecchios.com
Subject: Re: Is my chain to wide?
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On Aug 14, 6:59 am, "rbm...@yahoo.com" <rbm...@yahoo.com > wrote:
> One of my road bikes is equipped with Suntour Superbe Pro rear
> derailleur and 7 speed Suntour Accushift bar ends. I recently put a
> new Sram 8 speed chain and NOS Suntour New Winner 7 speed freewheel on
> and I'm getting what appears to be periodic grinding between the chain
> and freewheel, not enough to skip the chain, but enough to be
> noticeable and really annoying. At first, it appeared that one of the
> pins in the chain was a little to far out and was catching on the
> freewheel cogs, I pushed it in slightly and inspected the others, but
> is didn't solve the problem. The symptoms appear only when riding,
> when I put the bike in the workstand and turn the cranks, all is
> smooth. Could it be that an 8 speed chain to to wide for an ultra
> seven freewheel and periodically rubs against the adjacent cog?
> Should I install a nine speed chain?
>
> Thanks in advance.
Hard to say w/o hearingf/seeing it but try a 9s chain and see.
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