An 8 tooth jump between chainrings does not necessarily require a tensioner.
One example of such a build is my Quickbeam as originally delivered. The Quickbeam had 32 and 40 teeth chainrings with a 22 tooth freewheel. No need for a chain tensioner as the dropouts supplied enough travel for the rear wheel to take up all the slack in the chain with either the 32 tooth or 40 tooth chainring. Regards, Corwin On Thursday, September 26, 2024 at 2:58:44 PM UTC-7 Ryan wrote: > Although I guess, with an 8-tooth jump on the front you do have to have > some kind of tensioner > > On Thursday, September 26, 2024 at 4:53:09 PM UTC-5 Ryan wrote: > >> Philip after shortening chain and putting on a new 19t WI freewheel , did >> you use the Melvin, the Dura Ace or nothing as a tensioner?...since you're >> just shifting between the 2 front chainrings? >> >> On Thursday, September 26, 2024 at 4:24:35 PM UTC-5 Edwin W wrote: >> >>> Bill, >>> >>> If god wanted you to use a tensioner with a single speed, she wouldn't >>> have created track ends. >>> >>> Seriously, I will be interested to hear how this shakes out, and what >>> you discover, as it is a bit baffling why a multi gear freewheel will work >>> and a single speed freewheel would not. >>> >>> Edwin >>> >>> On Thursday, September 26, 2024 at 3:39:28 PM UTC-5 philip....@gmail.com >>> wrote: >>> >>>> That's interesting Bill. >>>> >>>> While finishing mine this week I ran into the same or similar issue >>>> using an 8pd chain, Paul Melvin and a White Industries 46/38 upfront. >>>> >>>> The freewheel in question was old and not great, mind you. >>>> >>>> I tried using an old Dura Ace RD instead of the Melvin. Same issue. >>>> >>>> I replaced the shitty freewheel with a new White Industries 19T and >>>> reduced the chain to the shortest length I could get away with and still >>>> shift gears smoothly in the stand. >>>> >>>> I've only ridden it around a few blocks, unloaded, so far, but it's now >>>> as smooth as smooth could be. >>>> >>>> I'm surious to see, based on your experience, if it feels the same way >>>> tomorrow on its maiden, longer voyage... I'll throw a few things in the >>>> basket just to load it down some and put it through its paces properly... >>>> >>>> On Thu, Sep 26, 2024 at 11:54 AM Bill Lindsay <tape...@gmail.com> >>>> wrote: >>>> >>>>> My first instantiation of my 58cm RoadUno was as a 14-speed, as >>>>> immortalized in Will's email update. I used my wheel set which has a >>>>> customized 120mm O.L.D. cassette hub which fits 7 cogs from a 9 speed >>>>> cassette, updated with 10-speed spacers on what was traditionally a >>>>> 5-speed >>>>> spaced rear hub. Naturally we call it 7of9with10on5. >>>>> >>>>> I had it set up that way for a Mount Diablo Summit, and having done >>>>> that, I wanted to reconfigure it with the stock wheels for normal city >>>>> use. I put the stock Saint Jump wheels on there, with a White Industries >>>>> freewheel, using my Suntour rear derailleur as a tensioner. >>>>> >>>>> Pics prove it: >>>>> https://flickr.com/photos/45758191@N04/54022678302/in/dateposted/ >>>>> >>>>> Problem was that in the stand, the chain was wanting to rise off the >>>>> cog on my brand new DOS ENO freewheel. It was worse on the 19 than the >>>>> 16, >>>>> but clearly it wanted to rise off on both of them just pedaling. Weird. >>>>> I >>>>> attributed it in part to the goopy factory lube on a brand-new SRAM 870 >>>>> chain, and lubed it up and went to bed. In the morning, I tried it out >>>>> in >>>>> the stand again and it was still riding up the cog. I went into my >>>>> freewheel box and found a USED White Industries single freewheel, 18T, >>>>> and >>>>> fired that on. In the stand, that was perfecto, and that's what is in >>>>> the >>>>> photograph linked above. >>>>> >>>>> I rode down the hill that night to the local family grocery store for >>>>> cilantro and few mushrooms for a soup. Turning back up the hill, >>>>> DISASTER. Under load, the same riding up and skipping was happening. I >>>>> took the most shallow slope back up the 400ft hill to my house, and put >>>>> the >>>>> bike up in the stand. >>>>> >>>>> I returned the 10-speed spaced chain on there, that I had been using >>>>> with my 7of9with10on5 configuration, and rode that around the block. >>>>> Same >>>>> skipping under load. >>>>> >>>>> I called it a failure and put the 7speed rear wheel back on, which is >>>>> still perfecto. >>>>> >>>>> My top hypothesis is that in a tensioner configuration, the system >>>>> wants more tension from the tensioner than my 35 year old Suntour RD is >>>>> providing. I may experiment with shortening the chain to the minimum >>>>> length for the two-speed configuration. Some Suntour Rear Derailleurs >>>>> have >>>>> two different holes for the spring, so one can effectively make the >>>>> spring >>>>> a little stronger. That would be experiment #2. Finally, I may borrow >>>>> the >>>>> Paul Melvin from my 3x1 Romulus, to see if that's a far better tensioner. >>>>> >>>>> That Romulus 3x1 drivetrain has been perfect. For now it's a two speed, >>>>> but it is running on the 18T cog of a 7sp cassette. >>>>> >>>>> Maybe this is all just the universe telling me to buy a purple >>>>> anodized Melvin? >>>>> >>>>> Bill Lindsay >>>>> El Cerrito, CA >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "RBW Owners Bunch" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to rbw-owners-bun...@googlegroups.com. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/rbw-owners-bunch/5775d82f-b98d-4d7a-9c02-937c054b50fan%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/rbw-owners-bunch/5775d82f-b98d-4d7a-9c02-937c054b50fan%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> >>>> >>>> -- >>>> — >>>> >>>> Philip M. Watts >>>> (917) 514 2207 <(917)%20514-2207> >>>> >>>> — >>>> >>> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/402d9f69-3d16-4759-93a3-31ae00fcfe53n%40googlegroups.com.
