Author Topic: Completing the Ring cycle  (Read 3197 times)

geocycle

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Completing the Ring cycle
« on: December 09, 2013, 05:19:20 pm »
You may recall me on other threads reporting problems in getting a Surly chain ring to match a thorn chainset.  This led to asymmetry and uneven chain tension despite lots of fruitless fiddling.  Well thanks to sales@SJS it has been solved.  I was using the wrong chainring bolts.  The thorn chain ring is recessed to always sit squarely on the bolts whereas the Surly is flat faced therefore wider double-sided chain ring bolts are much better.  In addition the Surly is much thinner so 2mm spacers are needed to allow you to get the necessary chain tension.  In theory I could have got the ring centralised but trial and error would have been very difficult.  Now very happy I can use my chainglider without compromise!
 

Danneaux

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Re: Completing the Ring cycle
« Reply #1 on: December 09, 2013, 05:49:14 pm »
Yay!  ;D

So glad things have worked out for you, Geo' and very kind thoughtful of you to pass on the results of your query to SJSC.

'Bet this helps a number of other folks.

Best,

Dan.

JimK

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Re: Completing the Ring cycle
« Reply #2 on: December 09, 2013, 06:00:50 pm »
yeah thanks for the post! I had the Surly chainring on my wish list but your experience put me off. Nice to know the fix!

Not sure how long chainrings last & I already have one spare in a box! Might be a while before I'm in the market again!

geocycle

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Andre Jute

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Re: Completing the Ring cycle
« Reply #4 on: December 09, 2013, 06:41:21 pm »
Congratulations, Geo. I didn't have any problems fitting the Surly centrally on Sugino Cospea crank because the right spacers came with my bike, before they were necessary; they're apparently supplied with OEM Rohloff boxes. Irritatingly, only four were supplied with the Rohloff (I think the actual purpose may be for correct rear brake disc spacing...) but at least they were to hand to measure and order more. I didn't grasp this was a common problem, or I would have mentioned it; I thought it was to do with switching from a single ring, fixed crank system to a compact twin crank and having to adjust to an oddball chain line.

I'm not so sure I'll get the BBB alloy chainring bolts off again because even when using a torque wrench the ali is marginal with that size of torx bit and the bolts were on the verge of stripping. Not that it matters if I have to drill them out, as I wouldn't dream of reusing ali bolts. I bought the ali ones in desperation because they were all I could get in the right length. Very pretty though, in black on the stainless Surly ring. Thanks for the reminder to lay in some stainless chainring bolts when I see them.

I'm exceedingly satisfied with my Surly stainless ring, which in 2600km has shown zero wear (that's getting on for the life of two Nexus ali cranksets with fixed rings already). It is well worth the little extra care required once in its life to fix it properly to the crank.

il padrone

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Re: Completing the Ring cycle
« Reply #5 on: December 09, 2013, 08:33:30 pm »
2600kms or 26,000kms Andre? Because my alloy chainrings have always lasted well over the 2600km mark.

Danneaux

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Re: Completing the Ring cycle
« Reply #6 on: December 09, 2013, 08:48:31 pm »
Ah!

On reading the above, I think I see why I had no problems with my Deore (external BB 4-arm 104BCD) crankset and my 36T Surly 'ring:

I had specified the Thorn bash guard, so the 'ring simply bolted up with no issues whatsoever using the existing bolts (already sized for a double chainring setup, meaning the larger sleeve-nut portion of the fastener set was serving to locate the 'ring by its through-holes, no countersinking for head-location necessary.

Best,

Dan.

Andre Jute

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Re: Completing the Ring cycle
« Reply #7 on: December 10, 2013, 11:10:36 am »
2600kms or 26,000kms Andre? Because my alloy chainrings have always lasted well over the 2600km mark.

Lucky you.

That's 2600km that my present chain has run on the factory lube, with the experiment still ongoing and apparently unlimited. The Surly chainring was conveniently fitted at the same time as this chain, and after 2600km is unmarked. Which comes as no surprise, I think, or so many of use wouldn't have fitted it.

My other remarks concerned the wear on Shimano's Nexus groupset fixed cranksets, which are cr@p. If I got 2000km out of one of those, I was doing well. That two thousand, two with three zeros... These good-looking Nexus cranksets were beloved of Dutch OEM for their pricier city bikes with the Nexus Premium 8sp rear hub, of which I have two (one is the automatic Smover, but the base of it is a Nexus Premium hub gearbox, too).
« Last Edit: December 10, 2013, 05:15:03 pm by Andre Jute »

il padrone

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Re: Completing the Ring cycle
« Reply #8 on: December 10, 2013, 01:23:26 pm »
Just ordered those longer chainring bolts and spacers from SJS. It will be a while before I need to ditch the drivetrain and fit the Surly ring, but no harm having the bits all ready to go  ;)

geocycle

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Re: Completing the Ring cycle
« Reply #9 on: December 10, 2013, 03:45:01 pm »
Just ordered those longer chainring bolts and spacers from SJS. It will be a while before I need to ditch the drivetrain and fit the Surly ring, but no harm having the bits all ready to go  ;)

Good forward planning.  Glad the post was of use to you.  I'd not have sussed it without the help of the guys at SJS.