1912 Excelsior Tribute

indian22

Well-Known Member
Dec 31, 2014
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Oklahoma
Thanks to everybody!!! I’m now headed in the right direction. First learning about belt wrap and my lack of Belt wrap! Added a few. Links to belt which helped.. looking into my tensioner box tomorrow and hoping to find a good location on the bike to mount. The biggest change was the clutch . I moved up to a13t from a 10t.. Brought bike to a nice spot for cruising at low and higher speeds. Next tensioner to help wrap belt . Belt only slips when I jump on it. For now I’m very happy with the ratio_Once again thanks for all the help.
That's what communities do and this is a great resource for all of us.

Rick C.
 

Tony01

Well-Known Member
Nov 28, 2012
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sf bay area
Can you post a pic of your drivetrain side as it was with dual belts for me?
instead of going bigger on the chain clutch maybe go bigger by 30% on the pulley, so go to a 5”. You may not even need a tensioner.

but since you already have the 13, go a few teeth higher on the bigger sprocket as well. Smaller sprockets eat chains which in turn eat the system, much faster than bigger sprockets.

I learned something from reading the lawnmower racing forums. Those that still run stock drivetrains use big pulleys for maximum grip. Standard is running pulleys in the range of 5 to 9 inches, running manual clutch which also ensures maximum wraparound. Those engines push well over 30hp.
 
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curtisfox

Well-Known Member
Dec 29, 2008
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minesota
instead of going bigger on the chain clutch maybe go bigger by 30% on the pulley, so go to a 5”. You may not even need a tensioner.

but since you already have the 13, go a few teeth higher on the bigger sprocket as well. Smaller sprockets eat chains which in turn eat the system, much faster than bigger sprockets.

I learned something from reading the lawnmower racing forums. Those that still run stock drivetrains use big pulleys for maximum grip. Standard is running pulleys in the range of 5 to 9 inches, running manual clutch which also ensures maximum wraparound. Those engines push well over 30hp.
Tony his ratio was to low to begin with, so the 13 made it better, and back to what he had before or close...........Curt
 

MotoMagz

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Aug 2, 2010
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Can you post a pic of your drivetrain side as it was with dual belts for me?
These pictures are all I could find of original Set up. Side note ..32T sprocket and the 4” pulley can not be any larger because of clearance issues on motor mount and clutch cover. I do feel pretty good On the ratio now..it may need little tweaks.But I’m riding!
 

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MEASURE TWICE

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Jul 13, 2010
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I had tried using the Link Belt a long time ago of various brands and it was slipping bad. I did though change to a cogged belt on just one pair of pulleys that had one very small like 2.5 inch diameter. I thought it would help. I have tensioner of back idler and movable jackshaft for adjustments. I eventually went to gear and chain on some of the tranny. The drive sheave like I see you have on the rear wheel is like mine. I only paid like 45 dollars for it. I finally found that the pressed steel sheave as it is bent and made circular, had a butt joint weld that had a bump. Aside from it being able to adjust to get better centered, the bump I eventually fixed with A Dremel Grinder and then sanded by hand with emory cloth. It was an amazing difference. If water gets on the pulleys and belts then until it dries it has adverse effect. Dust not so much, but oil fumes I clean the sheave with acetone and wash the belts with dish wash liquid and then dry occasionally. I ride though streams doing trails is how I found out, but that is not all. Rim brakes are no good for a while too, which is dangerous to note. From that point just now if I go up too steep a grade I have no slipping, just I could burn up a centrifugal clutch I have. The steeper slopes I could deal with better if the 12:1 ratio ending up on 26 inch rear wheel were switched back to 20:1 ratio. I plan on doing that as I had before a 20:1 ratio, only when swapped in another Briggs engine that was less worn out it would not work the clutch. It is since the current Briggs has a stubby crankshaft that will not permit enough length for my centrifugal belt clutch. The gear tooth clutch does not need as much length. Belt clutch on hiatus the last few years now. I may one day open up the engines cases and swap the crank shafts if they are compatible. As Tony said I could also raise compression, shave head some, port, and the like for more power. Thinking a mfr trail bike but is harder to transport legally. My registration got Spec Constrc for use as MC only OHV. Your machine has a charm to it and the tank like that beats my rotary mover plastic tank by far.
 
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MotoMagz

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Aug 2, 2010
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MotoMagz

Well-Known Member
Aug 2, 2010
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Michigan
It screams and she’s a squeaker too! I’m happy with it the set up .Sh doesn’t like being choked....not even alittle oh well! Lol giver her one pull and she’s ready to go! Will be switchback to ax belt and tensioner. I found a old tensioner I had made that fits perfect And I have a bunch of belts.Just have to get motivated to work on it...not now going ridding...!
 

MEASURE TWICE

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Jul 13, 2010
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As a teenager the first of motorbike of mine built back in the 70's on 24 inch wheel Rolls with 2hp Briggs 4 stroke was using pressed stamped steel washing machine pulley. I was told to sandwich with wedge shape pie pieces of wood the washing machine 10 inch pulley. It was clamped inside and outside on one half side of wheel spokes. The tabs on the pulley were not at the correct angle. Told to just bend them to shape, I worried that was not good. No problem though never broke. Told also no tensioner needed, just pop in place while rotating on larger pulley. No clutch, just push start an go. Stop engine stops. Belt stretching made it a loosing battle with keeping buying belts again an again every month or two. Engine platform with slots solved that. Slipping not a problem. Link belts do not go well with popping onto pulleys, but they do have a look that is an advantage with antique I might say. If synchronous belts and pulleys were found economical, like timing belts is what I would probably use if not v-belt or chain. Dual Belts another crazy idea? Harley an other MC have synchronous belts on some bikes. Well shaft drive and V or Opposed Cylinder MC might be nice too!
 

MotoMagz

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Aug 2, 2010
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Rick said squeaky belt I said No! OMG does it squeak now... and a very weird squeak at that. Took her out on a 4 mile trip. I definitely have to stop riding and switch to the ax belt and tensioner. I have it setup to lift if we get rain hopefully I’ll get it done. My only complaint of a Vbelt is To install I have a lot to do.. in comparison to the link belt but it’s worth it. I was wondering what you guys think ; a tensioner with stationary wheel or a Spring loaded tensioner ? Thanks
 

indian22

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Dec 31, 2014
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Oklahoma
Sorry Mags about the squeak ' cause I'd really rather have been wrong. I've used both on belts and chains. not just bicycles, but a wide variety of mechanisms & found great utility in both. I really prefer spring tensioning on bike chains, motorcycle or bicycle, but lean towards a stationary for belts. I feel the springs are too weak, in most of the commercially available spring tensioners, to work well with a belt. If you build your own spring tensioner, which I'd recommend, I feel your belt engagement & disengagement will be smoother and tension under way more consistent; especially if perfect rotational concentricity and/or alignment is ever an issue. Spring strength is the critical variable in my mind the making the most of spring tension on a belt. Weak spring tensioner on a chain is a much more forgiving setup...even on complex multi speed pedal racers, the tension spring is puny yet work great.

I'm a huge fan of spring tensioners on every bike I build and that's on both pedal (if I'm planning on actually pedaling said motor bike) and motor drive lines. Some might say I just don't know how to set up chain lines which function together properly.

Rick C.