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Jockey Wheels

Posted: 31 Oct 2012, 6:45pm
by scotsmanincumbria
Looking for a bit of advice.

I have been given an old Raleigh 10 speed racer. I have changed the bars to butterfly bars and i am keeping the downtube shifters. I have changed the wheels and now have a 9 speed casette on it.

My question is as the rear derailleur will move far enough and I have purchsed a new 9 speed SRAM chain, will I need to change the jockey wheels or not?

Thanks

Re: Jockey Wheels

Posted: 31 Oct 2012, 7:50pm
by meic
If they are not so worn out that they wobble all over the place then they should be fine. The only way to know is to give them a try. The pulleys can be replaced without having to break the chain, it is just a bit fiddly.
Personally I would not replace pulley wheels as I tend to wear out the rest of the dérailleur more quickly than the pulley wheels which can cost as much as a cheaper dérailleur.

Re: Jockey Wheels

Posted: 31 Oct 2012, 9:14pm
by Brucey
both these things depend on the type and condition of the rear mech, and the size of the sprockets you are using.

You can buy new jockey pulleys for less than five pounds, but as Meic says, you are well on the way to the cost of a new mech. Last time I looked, you could buy a new Acera mech (e.g. woollyhat shop) for about £13 or something.

cheers

Re: Jockey Wheels

Posted: 1 Nov 2012, 12:23pm
by BigG
All jockey wheels that I have come across will handle 5,6,7,8,9 and 10 speed chains without problems. The wear on the teeth is irrelevant as many older mechs had toothless jockey wheels. However, the top jockey wheel must not have too much play in the bearing if you want slick and reliable changes. The bottom jockey wheel is almost completely non-critical.

Re: Jockey Wheels

Posted: 1 Nov 2012, 2:26pm
by Brucey
modern chains have sideplates that stick out less than older ones. This means they don't run anything like so well as old-style chains on worn or toothless pulleys.

This means my ancient Steel/bronze Camagnolo gran sport gives a rotten change on its toothless top pulley, and I have seen other mechs wear horribly where the chain enters on the lower pulley, again because a worn pulley won't guide the chain properly if it enters at an angle.

I would recommend using a mech that is at least close to the correct type, or is fitted with the correct pulleys, simply because running a 9s chain through (say) a 5s mech doesn't allow the cage plates to push the chain during the shift so much. This doesn't always make a big difference, but it does enough of the time for it to be a legitimate concern.

cheers

Re: Jockey Wheels

Posted: 1 Nov 2012, 2:53pm
by Mick F
BigG wrote:However, the top jockey wheel must not have too much play in the bearing if you want slick and reliable changes.
My Campag rear mechs have play in the top pulley by design. Goodness knows why, but that's the way they are made. The top pulley is directional too.

Re: Jockey Wheels

Posted: 1 Nov 2012, 3:08pm
by Brucey
Mick F wrote:
BigG wrote:However, the top jockey wheel must not have too much play in the bearing if you want slick and reliable changes.
My Campag rear mechs have play in the top pulley by design. Goodness knows why, but that's the way they are made. The top pulley is directional too.


Shimano rear mechs have had an intentional side play 'float' in the top pulley since indexing became the standard. The pullies are typically marked 'centeron G-pulley' and ideally should not be exchanged with bottom pullies. I think the idea is that the indexing can go out of adjustment and it doesn't immediately make a terrible noise.

It also has the side effect of allowing inaccurate/uneven shift lever clicks and/or sprocket spacing to be mostly tolerated. Some Campagnolo shifters have unevenly spaced clicks and/or sprockets, and SunTour index systems had unevenly spaced sprockets. Quite why I don't know, but I have wondered if Shimano held a patent on perfectly evenly spaced sprockets or something.

With a proper matched system, well adjusted, the top pulley can usually be changed for one with no float, like a Tacx one, with no worries.

cheers

Re: Jockey Wheels

Posted: 1 Nov 2012, 4:03pm
by BigG
Mick F wrote:
BigG wrote:However, the top jockey wheel must not have too much play in the bearing if you want slick and reliable changes.
My Campag rear mechs have play in the top pulley by design. Goodness knows why, but that's the way they are made. The top pulley is directional too.

I am not sure why the top sprockets float on Campag and Shimano mechs except that it apparently improves shifting performance. My only point is that too much float (and I don't know how much is too much) jeopardises the indexing system.
I run two Huret Duopars at the moment, one with a smooth top sprocket and one with a toothed sprocket. I cannot tell the difference in the change performance.
Suntour changed from equally spaced sprockets (5 mm) on the early 6 and 7 speed "narrow" freewheels when they introduced the New Winner model. This had a body compatible with everything from 6 speed to 8 speed, something that could only apparently be achieved by varying the sprocket spacing slightly. I have happily used evenly and unevenly spaced freewheels with the same indexing system using Suntour XC Pro and Suntour Command shifters. Which type these levers were designed for is not known (to me).

Re: Jockey Wheels

Posted: 3 Nov 2012, 12:54pm
by Brucey
BigG wrote: I run two Huret Duopars at the moment, one with a smooth top sprocket and one with a toothed sprocket. I cannot tell the difference in the change performance.


I am of a view that Duopars are a 'special case' because of the way the top pulley moves. I don't think you can necessarily infer that toothed or smooth pulleys will perform similarly on other mechs.

cheers

Re: Jockey Wheels

Posted: 3 Nov 2012, 4:19pm
by scotsmanincumbria
Thanks for the replies. As the wheels are badly worn I will invest in a new derailleur.

George