Pleasant Discovery



Got frustrated with my first build "Red Peril" and havn't been here for a few months. Had to mention a discovery though that is either just news to me or may interest others in here. Tried to complete my second build 2 days ago and I'll skip all the nightmare details about fitting the drive chain. Me and two other men were mystified about the total inability to get the drive chain to function even after we replaced the engine sprocket, chain, rear sprocket, rear hub, and 3 idler wheels ... long story shortened is simply that some bikes have very low or deeply curved/angled wheel support arms.This causes the idler wheel to need positioned close to the rear wheel drive gear which produces clicking, chain lift, or pop offs due to the erratic chain angles and idler wheel innacuracys in its position relative to the chain.Moving it to its more more normal forward position causes you to need more (and unavailable)idler arm height, or trying to drop another link which can be impossible to sync to the regular peddle chains length/tightness and wheel positioning.

After an all day attempt at every config I could think of with numerous additions and/or subtractions of links,and wheel adjustments that just would not please both chains equally, I recalled a pic of a bike in an ebay vendors ad that showed the idler wheel on the peddle chain rather than on the engine chain. At the time I had thought it was simply a busy vendors attempt to throw a bike together quickly and he had simply made a mistake.

But I'll tell you, try this for a real shock if you're assuming as I did that you must be content with the rattle/clang of the engine chain movement as you peddle in your off engine moments,or even when the engine is on. I reversed the procedure and fitted the engine chain for tightness first, with a strict 1/4 deflection,removed the idler arm and idler wheel and locked the rear wheel nuts down . Then I shortened the peddle chain as much as possible but naturally you'll always have slack (why oh way doesn't someone invent a HALF size speed link?) I then took up the peddle chain slack with the idler arm inverted so the idler wheel is pulling the chain down tightly with about 3/8 inch deflection.

Man, what a suprise ! The bike runs totally 'slapless' and as silent chainwise as a bike with no motor. smoothness and sync in relation to the throttle changes are as perfect now as my Nomad motorcycle ....bounce,pulsing , and 'chain on idler' sounds are totally gone as you coast downhill with closed throttle.

I honestly do not know why favoring the engine chain tightness over the peddle chain isn't in the general instruction sheets. I did find one sheet that stated if the chain was deflecting within the normal 1/4 to 1/2 deflections than the idler is not necessary, but never have I seen a recommendation to actually use the idler for peddle chain adjustment. WAY better.
just to answer a couple question
,there are half links for chain you can get ,,

i had a post early on about the idler on the bicycle chain side ,if i remember correct i tighten the motor chain first by putting spacers on the back motor mount , that would push the motor ahead and tighten the chain ,,, i did have some success with it ,but the motor side chain will stretch allot ,and for some reason the small sprocket on the motor seems to like more rap-a-round ,that may not be the right term of word to use but the small sprocket seems to run smoother with more angle by using the idler ,,
i wanted to mention when i first got my kit i blamed the chain many times how rough it run ,but come to find out later that these 2 cycle motors need 500 miles on them before they become smooth

if you do a search on idler .and half links ,,there should be lots of information ,there are not many subjects that has not been discussed on this forum
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Thanks Japat

I'm going to watch this set up closely and see what happens but for now I'm really speechless at the overall silence and improved 'sync' or I guess I mean throttle response with no chain lag, chain noise, or the sloppy feeling I had.

Not sure what you mean by 'likes more wrap around" because on both my builds, the idler against the bottom part of the chain doesn't seem to enhance angle differences to the part of the chainright at the engine sprocket bottom exit opening .... I think your idea of spacers at the rear mount to tighten the chain was a clever idea. What I did after I decided to let the engine chain determine the tightness rather than the bicycle chain was to cut the engine chain 1 added link short so the finished tension on both chains makes my wheel adjustment move foward to allow me about a half inch of axel slot to move back into in case of the stretch you mentioned.
My only concern without the idler is the slight added weight of the chain the sprocket must support, but as I mentioned, there is one set of installation instructions that says the idler is optional if the chain can be adjusted to the 11/4 to 1/2 deflection point.
japat, About using search ....

Forgot to comment on this in my first reply to you.... I've decided I must be "search challanged" or something because I've tried and tried to use it and the responses to my searches make absolutely no sense to me at all ... I think a few actually had no part of the original search word or words in them at all ... one if my memory serves was "spark gap setting" .... In fact I'll try it now after I post this ...
i find the search works better if you go to advance search ,,punch in your word or words ,,and just below that you can change type of search ,, click on ,, topics only ,

worth a try
yes, a very nice search engine...but it does require some basic knowledge...try using at least 2 keywords you'd like to see in a search result title.

which brings us to another point: when starting a new topic, remember someone will be trying to find it someday, so use relevant and specific terms in your title.

not to make fun, but not too many folks will think to look for "pleasant discovery" to learn about chain-tensioners. then again...some folks may be searching for "pleasant discovery" for any issue :LOL: (ok, that part was making fun, it was too juicy a straight-line to ignore)
Please Post a Pic

Please Post a Pic of what you are saying and what you have done.. Since I do not get it.. and a picture to me is worth a thousand words.. Thanks.. Enjoy the ride.. or.. Email me a pic.. Thanks..
search and posting a pic

I hear you Augi about the "pleasant discovery" terminology, but to tell the truth I do know about using more specific titles but only if I'm positive I have posted great advice. I didn't care too much on this idler discovery because I'm really just testing it for the feasability and also I know about your post on hobbyists posting bogus or bad advice.

... gallery pics don't seem to show any bike useing this trick and in fact I was waiting for someone to post a "NO-NO" warning to me about some specific problem with this method. I tested it today with a longer test run and frequent tension checks and I'm extatic with the new feel, lack of sound,and overall performance at throttle variation.

I've learned that with the old method the idler wheel can be very deceptive in its tracking appearance and tracking can change depending on if you are watching its action while walking the bike and observing, under full power pulling, throttle back downhill, clutch lever in downhill, etc .... To the Dax post for a pic , I plan to add it to my pics gallery as soon as Im positive the build is over ! My RED PERIL build had just too many changed pics and I want to take only 1 pic of my new creation I'm calling " PLATED STALLION"

Heh, now heres a perfect example of why I need to practice finding similar topics in search ... Thanks for these posts srdavo cause I see its all been covered ! I can't believe even the 1 link removal trick with wheel adjust is in there ! Funny that no one seems to have done it this way in the gallery pics I've seen .... One question srdavo, how or what did you search specifically to recover those specific posts for me? idler wheel ? chain tension ?
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