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Post by brianbutler on Feb 18, 2023 16:08:51 GMT
I have been trying to convert my Sebring to use a triple crankset, with minimal success. I can't seem to get acceptable shifting from the small chain ring to the middle. All other shifts are good. the chainline is good, derailleur properly aligned and spaced for 4mm clearance above the big chain ring. I have tried two chainsets - 52/42/32 TA Cyclotouriste, and 52/42/28 Sakae Sugino GT. I was originally using a Suntour ARx front derailleur intended for a double, which worked perfectly on a half-step and granny (50/45/30) setup, but works very poorly on the more evenly spaced chainsets. I installed a "triple" front derailleur (
Microshift R538) that says it is optimized for a 52/42/30 8-speed Shimano drivetrain. I am using using a Shimano 6-speed (14-34) freewheel and a 6-speed chain with terrible results.
I will try an 8-speed chain to see if that makes a difference. If anyone has any suggestions for troubleshooting, please let me know.
Brian
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Post by brianbutler on Feb 18, 2023 17:58:24 GMT
Update - the chain was the problem. With an 8 speed chain, it works about as well as any triple. I guess the shape of the plates on the chain are very important, which I would not have guessed. I am still fiddling with derailleur height and alignment angle. I raised it a bit, which improved shifting. The alignment seems particularly fiddly.
I have been spoiled by my single speed bike this winter but the Sebring will become my touring bike so I need low gears. I don't need high gears so I might consider converting it to a "low range" compact chain set. The rear will remain 14-34. I can easily make up a 42/28 front double, giving an overall gear range of 22 to 81 inches and a top pedaled speed of about 22mph at a cadence of 90. I can also make up a more conventional 52/34 giving a range of 27 to 100 inches. That would support pedaled speeds up to about 28mph, certainly more than I need.
Brian
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Post by oldroadietehachapi on Feb 19, 2023 14:29:09 GMT
I have had a triple do that and I also used an 8 speed chain as a fix. More commonly, I have had a few old (flat tooth) freewheels skip and slide on center cogs. After checking that the dropouts and derailleur cage were not bent, it turned out that modern chains were the problem. Installation of an old style chain with flat plates, or swapping the freewheel for a modern design usefully has been the fix. I have one Helicomatic freewheel that seems especially stubborn and prone to this; I may have to find an old Regina chain as that was the chain with which they were originally paired.
Cheers Jim
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Post by brianbutler on Feb 19, 2023 17:21:35 GMT
I have had a triple do that and I also used an 8 speed chain as a fix. More commonly, I have had a few old (flat tooth) freewheels skip and slide on center cogs. After checking that the dropouts and derailleur cage were not bent, it turned out that modern chains were the problem. Installation of an old style chain with flat plates, or swapping the freewheel for a modern design usefully has been the fix. I have one Helicomatic freewheel that seems especially stubborn and prone to this; I may have to find an old Regina chain as that was the chain with which they were originally paired. Cheers Jim Thanks for that info. I am still somewhat stunned that chains make that much difference. There are obvious variations when you look at them carefully, but still the whole thing depends on slight bulges and lines that affect nothing but friction. I would think lubrication, chain tension, etc. would all overwhelm that seemingly minor effect. What bugs me the most is that it is a black art.
Brian
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Post by oldroadietehachapi on Feb 20, 2023 14:25:35 GMT
"What bugs me the most is that it is a black art."
Me too!
Cheers Jim
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Post by brianbutler on Feb 20, 2023 15:22:29 GMT
I have a Fuji del Rey set up with a "compact" 52-34 chainset and a 14-34 6-speed freewheel. The resulting 27" low gear is probably low enough for hauling panniers almost anywhere I am likely to go. I will test it today on some steep hills and if it is OK, I'll abandon the idea of a triple on the Sebring and implement a compact chainset on that one, too.
Brian
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Post by oldroadietehachapi on Feb 20, 2023 16:57:17 GMT
I have a Fuji del Rey set up with a "compact" 52-34 chainset and a 14-34 6-speed freewheel. The resulting 27" low gear is probably low enough for hauling panniers almost anywhere I am likely to go. I will test it today on some steep hills and if it is OK, I'll abandon the idea of a triple on the Sebring and implement a compact chainset on that one, too. Brian I like compacts. On my triples, I am almost always on the middle ring (38-42 teeth) and slip down to the small ring (28-34) for steep (at least for this old man) climbs. The large ring seems best suited for screaming descents. these days I usually just wind out on the middle ring and kick back; thus, compacts serve me just as well. The setup on my (12-28 / 46-32) Vitus works well for me. An 18 tooth difference for the crank may be a stretch for some derailleurs. I generally set up with a 16 tooth difference as my max. Interesting to see how you fare with 18.
Cheers Jim
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Post by brianbutler on Feb 20, 2023 21:38:21 GMT
Aside from the fact that the 52T chain ring is too big to be useful for me, the 52/34 setup worked OK. Were you talking about the front or the rear derailleur not handling a difference of 18 teeth? My FD (Suntour ARx) had no problem (i.e. did not bottom out on the small gear.) I'm not sure the RD (Suntour ARx) can wrap 18T but I am running a "suicide" setup where the chain is too short to support a shift to the biggest rear cog while on the big front ring. It would probably cause damage. The next-to-biggest/biggest combination works. The smallest/small combination is a bit loose but unlikely to be used.
I kept track of which gears I actually used and ordered a 44T chainring to replace the 52T.
I had only recently overhauled this Fuji and evidently got distracted before snugging up the pedals. I got about 100 yards before by wide winter shoes unwound the left pedal until it fell off. Somehow I did not fall. Other that that, the bike checked out OK.
Brian
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Post by oldroadietehachapi on Feb 21, 2023 0:14:43 GMT
I am so glad to hear that your setup works. I was thinking of the front derailleur capacity and 16 teeth was off the top of my head. Looking back at some of my (from 1978 as I live in the past) reference information, I see that 18 teeth is fairly common; especially for Suntour. Suicidal setups are fine, so long as you remember your gears. I once forgot and overstretched my drive train. It was in a bind and I could no longer shift; I had to break the chain to set it right (I was lucky to have the tool with me). According to Velobase, A short Cage ARX rear derailleur is rated at 28 total wrap with a max cog of 26. A long cage ARX is rated at 32 total wrap with a 34 max cog. A bit of info follows.
Cheers Jim
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Post by brianbutler on Feb 21, 2023 4:52:46 GMT
Thanks, Jim. I think I will end up with two similar setups:
1. Front 42/28, rear 14-34 on the Viscount Sebring for camping trips. 2. Front 44/34, rear 14-34 on the Fuji del Rey for hilly riding, mainly in New Hampshire.
Both setups use Suntour ARx long cage RD and Suntour ARx FD, so I am within the max cog size and well within the chain wrap limits. Now that I plan not to use big front chainrings, I will be able to shorten my chains and still have no slack in small/small and no suicide potential in large/large, AND actually use the entire range of available gears.
Brian
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Post by oldroadietehachapi on Feb 21, 2023 5:41:29 GMT
I like your choices. I have a rather extreme setup on my Trek 520. It is setup with cyclocross tires making sort of a gravel bike. The 3 pulley Suntour ARX has extreme capacity allowing a great deal of flexibility. The three pulley rig only runs on two pulleys in smaller cogs. It liked to skip until I replaced the Suntour freewheel with a late model Shimano; go figure.
Cheers Jim
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Post by brianbutler on Feb 21, 2023 13:21:15 GMT
Nice Trek. I didn't realize your three-pulley RD was an ARx. All of my ARx's are two-pulley and long-cage. I particularly like the crank in your photo. Looks like about an 80mm BCD, which could really help me sort out the chainline on my Sebring. My 42/28 setup uses the inner 110 BCD position for the 42 and the "granny" 74 BCD for the 28. It requires 3mm of bottom bracket spacers on the right, and 10mm spacers where the outside 110 chainring would normally be. I had to get rid of the outer chainring to allow shifting onto the 42.
I have several TA chainsets (Both Viscount and "regular") and a selection of TA cranks with different spindle depths. Most of my rings are worn and I can't seem to find good 80 BCD replacement, and. I especially can't find any decent outer rings drilled for the TA crank. Maybe my next research project.
Brian
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robt
Viscount
Posts: 559
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Post by robt on Feb 21, 2023 18:43:40 GMT
I have several TA chainsets (Both Viscount and "regular") and a selection of TA cranks with different spindle depths. Most of my rings are worn and I can't seem to find good 80 BCD replacement, and. I especially can't find any decent outer rings drilled for the TA crank. Maybe my next research project. Brian Brian, I had some success adding a 34T 80mm BCD inner ring to a Lambert 'porthole' chainset, as shown below fitted to my Sebring along with a Suntour Cyclone f/d. It all shifts beautifully with a Tourney GS r/d on the skiptooth freewheel: IMG_4470 by RMT@261, on Flickr The chainring and extra bolts I used came from the excellent Spa Cycles in Harrogate, Yorkshire, who appear to hold a small range of TA CycloTouriste chainrings: www.spacycles.co.uk/m8b0s148p0/Drivetrain/Chainrings-CyclotouristSpa Cycles' website indicates that they can ship small items to the USA.
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Post by brianbutler on Feb 21, 2023 21:43:55 GMT
I have several TA chainsets (Both Viscount and "regular") and a selection of TA cranks with different spindle depths. Most of my rings are worn and I can't seem to find good 80 BCD replacement, and. I especially can't find any decent outer rings drilled for the TA crank. Maybe my next research project. Brian Brian, I had some success adding a 34T 80mm BCD inner ring to a Lambert 'porthole' chainset, as shown below fitted to my Sebring along with a Suntour Cyclone f/d. It all shifts beautifully with a Tourney GS r/d on the skiptooth freewheel: The chainring and extra bolts I used came from the excellent Spa Cycles in Harrogate, Yorkshire, who appear to hold a small range of TA CycloTouriste chainrings: www.spacycles.co.uk/m8b0s148p0/Drivetrain/Chainrings-CyclotouristSpa Cycles' website indicates that they can ship small items to the USA. Rob,
Thank you for the information and link to Spa Cycles. They are certainly a great source for the Cyclotouriste chainrings, and at much better prices than are available in the US, so even after shipping it is probably worth it. I happen to have the other parts you mentioned - Suntour Cyclone FD, Shimano skip tooth (34T big cog, I believe), and Crane GS rear derailleur. I was actually thinking of your Sebring when I decided to make mine my "touring" vehicle. I am going to experiment with front gears using my current Sakae Sugino triple crankset and various combinations of chainrings until I know what I want and then probably order what I need from Spa.
Brian
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Post by wheelson on Feb 21, 2023 22:14:25 GMT
Brian, I still owe you Lambert/Viscount rings to de-tooth and use as a base for a single or two speed. I may have some other rings I’m not going to use, a certain 40something TA “reinforce” ring comes to mind. Let me check. Best, John “wheelson”
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Post by brianbutler on Feb 22, 2023 1:44:48 GMT
Brian, I still owe you Lambert/Viscount rings to de-tooth and use as a base for a single or two speed. I may have some other rings I’m not going to use, a certain 40something TA “reinforce” ring comes to mind. Let me check. Best, John “wheelson” John, don't send me anything just yet. I recently went through all of my Lambert/Viscount/TA rings, cranks, and hardware with a critical eye. Several of the 52T porthole rings are badly worn and I can use them if I want to make a bash guard. The problem is that it would still interfere with the front derailleur. What I like about the Spa Cycles inventory is the availability of smaller "outside" rings that are drilled for crank attachment.
I did find a very interesting chain ring in my collection. It is a 40T TA Cyclotouriste tandem timing ring for the left side of the bike. It is drilled for the TA cranks and, in fact, had an attached crank with left-hand pedal threading. I swapped in a right hand crank and used it on a Viscount Aerospace flip-flop conversion.
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Post by oldroadietehachapi on Feb 22, 2023 6:37:19 GMT
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