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Post by brianbutler on Jul 2, 2020 14:02:42 GMT
I was readying my Sebring for next Sunday's DFR by installing one of the newly refurbished 34T skiptooth blocks when I discovered that the Shimano 600 RD does not clear the big cog. At least I found out the easy way (on the stand and carefully) instead of the hard way (on the road with a horrible sound). I know several members are running skiptooth blocks and have three questions:
1. Is your big cog 34T or something smaller? 2. If 34T, what RD are you using? 3. Can someone suggest a [vintage] RD that will accomodate the 34T block. I might need a long cage plus more clearance because I will need to wrap 33 or 34 links in case I ever get into the small-small combination and don't want a loose chain.
I am also readying the Aerospace GP and, in fact, will probably use it next Sunday. Took it for a 7 mile checkout this morning to see how it does on 8% grades - not bad. I will have to use some other pedals. The Viscount quills are too narrow. I'll probably use some MKS Touring pedals from another bike.
Brian
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Post by cusqueno on Jul 2, 2020 16:50:42 GMT
Is that a long cage 600? Not sure if it would make a difference to clearing the big cog though. I'm pretty sure I run a skip tooth 34 with a Crane long cage RD on one of my bikes but I need to check. Disraeli gears quotes 34T maximum for Crane GS (long cage) and for the 600 GS whereas the standard 600 and Crane have only 28T maximum. |
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Post by franco on Jul 2, 2020 17:13:36 GMT
I’m not familiar with that RD but in the past I have adjusted the B tension screw to clear a 32T cog, this was on a 1980’s Sachs Huret. Probably not an option here as you would have already done that. You’re not messing about Brian for DFR8 with a 34T, I’ll be slogging away with 28T  |
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Post by brianbutler on Jul 2, 2020 18:32:55 GMT
Is that a long cage 600? Not sure if it would make a difference to clearing the big cog though. I'm pretty sure I run a skip tooth 34 with a Crane long cage RD on one of my bikes but I need to check. Disraeli gears quotes 34T maximum for Crane GS (long cage) and for the 600 GS whereas the standard 600 and Crane have only 28T maximum. Short cage 600. I should have thought of checking Disraeli gears - gotten lots of info from there in the past. I see a few long cage Crane's on US eBay for around $50 in nice condition. Does that seem reasonable? In the mean time I have a modern Shimano SIS something-or-other long cage RD fitted to an old French bike but it might have an axle slot hanger and I would prefer one that bolts directly to the dropout. If you have a chance to check the long cage Crane and 34T I would be grateful.
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Post by cusqueno on Jul 3, 2020 10:17:17 GMT
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Post by brianbutler on Jul 3, 2020 15:12:09 GMT
Thanks, Cusqueno. I will most likely look for the long cage Crane GS for the Sebring and/or Aerospace GP. But for DFR8 I am out of time for major changes. I haven't used either bike much and need to work out some kinks without introducing more variables. I appreciate the info and photos.
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Post by franco on Jul 3, 2020 18:56:23 GMT
Same here, I hoped to use the Aerospace Pro for DFR8 but not had it long and the Suntour freewheel is 24T max which isn’t enough for a bigger ride. Not happy with the derailleur I fitted either, without checking I think it’s an old Shimano Atlus and the chain somehow jumps out if I pedal backwards and the friction shifter isn’t perfectly in line.
They were temporary just to get it up and running and not got the time/money to make the changes before the 12th.
I’ll probably use the Aerospace 400.
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Post by wheelson on Jul 4, 2020 22:07:34 GMT
Thanks, Cusqueno. I will most likely look for the long cage Crane GS for the Sebring and/or Aerospace GP. But for DFR8 I am out of time for major changes. I haven't used either bike much and need to work out some kinks without introducing more variables. I appreciate the info and photos. Also, the Shimano Titlist GS and Tourney GS are dimensionally close to the Crane GS with the major exception being the cage is steel and the cable fixing bolt is a little different. Same performance.
Best, John "wheelson" Wilson
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Post by brianbutler on Oct 9, 2020 11:33:12 GMT
Just an update on the long cage derailleur for the 34T skiptooth on my Sebring. As a stopgap, I installed a new Shimano Tourney TX800 ($23 shipped from China) for DFR8. It looks out of place but it works flawlessly, as good as any vintage RD I have tried. Makes me wonder about outfitting some of the frames I have hanging around with modern components.
Here is the Tourney:
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Post by wheelson on Oct 9, 2020 15:41:38 GMT
These derailleurs do work quite well for their cost. We use a lot of them for replacement at the shop. They come in both a claw and non-claw (as pictured) version. Just make absolutely sure you have your low end (spoke side) limit set properly as an over-shift into the spokes is the primary reason we do the replacements.
Best,
John "wheelson"
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Post by brianbutler on Oct 9, 2020 19:37:12 GMT
"... Just make absolutely sure you have your low end (spoke side) limit set properly as an over-shift into the spokes is the primary reason we do the replacements."
Always the first thing I set, and conservatively at that! Lesson learned the hard way.
Brian
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Post by franco on Oct 29, 2020 17:49:18 GMT
Just an update on the long cage derailleur for the 34T skiptooth on my Sebring. As a stopgap, I installed a new Shimano Tourney TX800 ($23 shipped from China) for DFR8. It looks out of place but it works flawlessly, as good as any vintage RD I have tried. Makes me wonder about outfitting some of the frames I have hanging around with modern components.
Here is the Tourney:
What is the maximum size freewheel cog that Tourney RD will go up to Brian? I found a new Suntour Sunshine Pro Freewheel (14 - 38) in the LBS today and bought it but looking through Sutherlands book there doesn’t appear to be an older type long cage RD that will work with 38T other than a couple that are probably now impossible to find and overpriced. So it looks like I’m going to have to go modern. Here is the freewheel, quite a find, 5 Speed but plenty of range  |
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Post by brianbutler on Oct 29, 2020 18:39:26 GMT
Franco, is that a five speed freewheel or a four speed?
I will say yes, it will clear a 38 tooth freewheel. With my 34 tooth, there is 1.25 inches of clearance available. I did a quick calculation and came up 42.68 maximum, so it must be 42 or 43. The specifications say is has a 43 tooth maximum, so I guess they are talking about about the largest cog it can handle. I thought maybe they were talking about the maximum amount of chain it can wrap. It has big pulleys and a lot of swing so I think it can wrap enough. They do not provide that specification.
Brian
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Post by franco on Oct 29, 2020 19:12:54 GMT
Franco, is that a five speed freewheel or a four speed? I will say yes, it will clear a 38 tooth freewheel. With my 34 tooth, there is 1.25 inches of clearance available. I did a quick calculation and came up 42.68 maximum, so it must be 42 or 43. The specifications say is has a 43 tooth maximum, so I guess they are talking about about the largest cog it can handle. I thought maybe they were talking about the maximum amount of chain it can wrap. It has big pulleys and a lot of swing so I think it can wrap enough. They do not provide that specification. Brian That’s great, thanks for the info Brian. Yes it’s a five speed, the smallest cog is behind the alloy ring. |
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Post by wheelson on Nov 2, 2020 23:44:52 GMT
Just an update on the long cage derailleur for the 34T skiptooth on my Sebring. As a stopgap, I installed a new Shimano Tourney TX800 ($23 shipped from China) for DFR8. It looks out of place but it works flawlessly, as good as any vintage RD I have tried. Makes me wonder about outfitting some of the frames I have hanging around with modern components.
Here is the Tourney:
[br Just a note that at the shop we’ve been impressed with the Microshift product line. The shifters, front, and rear derailleurs work very, very well for replacement. Best, John “wheelson” |
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Post by franco on Nov 3, 2020 10:44:41 GMT
Has anyone used a ‘wolftooth’ type hanger extender before to clear lower gearing?
I know they don’t look great but maybe a solution to keeping an existing RD. I’m tempted to try one so I can use the Suntour freewheel without having to buy a new RD, I’ve got a long cage Sunrace RD as well but I doubt it will clear the 38T cog.
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Post by wheelson on Nov 3, 2020 12:04:07 GMT
Has anyone used a ‘wolftooth’ type hanger extender before to clear lower gearing? I know they don’t look great but maybe a solution to keeping an existing RD. I’m tempted to try one so I can use the Suntour freewheel without having to buy a new RD, I’ve got a long cage Sunrace RD as well but I doubt it will clear the 38T cog. Yes, I’ve used the Wolfs Tooth extender several times with success. It won’t replace a long cage derailleur but it will give that extra bit of clearance between the big cog and the upper pulley. It’s a great alternative, just used one on the shop owners Trek road bike that he was setting up for hilly touring. Best, John “wheelson” |
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