Rich Pearson Posted February 14, 2005 Report Share Posted February 14, 2005 I'm sure someone has thought of this before, but can anyone think of a reason not to run a front freewheel AND a rear freewheel, simultaniously? I understand there may be some difficulties with different numbers of engagement points, but I just got bored and started wondering. Because you could have each freewheel taking half the original stress that was taken by just one freewheel. Dumb? Clever? Abstract? Just an idea for the brainiacs to ponder... Rich Quote Link to comment Share on other sites More sharing options...
andyroo Posted February 14, 2005 Report Share Posted February 14, 2005 Wouldnt there just be more to go wrong... :P Quote Link to comment Share on other sites More sharing options...
Tartridge Posted February 14, 2005 Report Share Posted February 14, 2005 I'm sure someone has thought of this before, but can anyone think of a reason not to run a front freewheel AND a rear freewheel, simultaniously?← Half the engagements :P (well, basically) My mate once had a Hope XC and an ACS Claws up front. Oh my word, was awful! Quote Link to comment Share on other sites More sharing options...
Phatmike Posted February 14, 2005 Report Share Posted February 14, 2005 Because you could have each freewheel taking half the original stress that was taken by just one freewheel. ← Not really, both freewheels would be taking the stress, except one would have pawls etc taking stress as oppose to just a cog. Not to mention twice as likely to skip, near enough half the engagements. And also, if they're ACS's, then they're usually not straight, so if you're unlucky then you'll have a tight chain and a slack chain at different points. :P Mike. Quote Link to comment Share on other sites More sharing options...
Rich Pearson Posted February 14, 2005 Author Report Share Posted February 14, 2005 Half the engagements :P (well, basically) My mate once had a Hope XC and an ACS Claws up front. Oh my word, was awful! ← In what way are we talking awful? and where does half the engagements come from? (bear in mind I'm not considering this, just interested in the theory...) Rich Quote Link to comment Share on other sites More sharing options...
Phatmike Posted February 14, 2005 Report Share Posted February 14, 2005 In what way are we talking awful? and where does half the engagements come from? (bear in mind I'm not considering this, just interested in the theory...) Rich ← You've got to allow the one freewheel to engage, then the other... Quote Link to comment Share on other sites More sharing options...
dave85 Posted February 14, 2005 Report Share Posted February 14, 2005 If theyre both 36 point freewheels, worst case is that one freewheel travels 10 degrees before it engages, then pulls the second one round another 10 degrees to engage that. So youve moved 20 degrees before youve got any power down, equivalent to an 18 point freewheel. Quote Link to comment Share on other sites More sharing options...
Phatmike Posted February 14, 2005 Report Share Posted February 14, 2005 If theyre both 36 point freewheels, worst case is that one freewheel travels 10 degrees before it engages, then pulls the second one round another 10 degrees to engage that. So youve moved 20 degrees before youve got any power down, equivalent to an 18 point freewheel. ← If you're running 1:1 gearing, yeah. :wink2: Quote Link to comment Share on other sites More sharing options...
dave85 Posted February 14, 2005 Report Share Posted February 14, 2005 If you're running 1:1 gearing, yeah. :wink2: ← ah, go home mr "I took GCSE maths a year early" :P Quote Link to comment Share on other sites More sharing options...
eMAyaRKay Posted February 14, 2005 Report Share Posted February 14, 2005 What about running two freewheels either side of your bike? left and right hand drives I mean, Surly it would work on mods if you got two threaded cranks etc and got the trhreadfs the right way, some euro riders use left hand drive dont they? Quote Link to comment Share on other sites More sharing options...
Matt_Tupman Posted February 14, 2005 Report Share Posted February 14, 2005 ah, go home mr "I took GCSE maths a year early" :P ← What the hell!!!! :P I got an E ......and then a D :wink2: maths not really my subject :D Quote Link to comment Share on other sites More sharing options...
Mr Motivator Posted February 14, 2005 Report Share Posted February 14, 2005 You could hold the bike still and spin the chain backwards :wink2: Quote Link to comment Share on other sites More sharing options...
Phatmike Posted February 14, 2005 Report Share Posted February 14, 2005 ah, go home mr "I got an A* at GCSE maths a year early" :P ← *Cough. :- Meh, i think this thread's deteriorated into nothing now. :wink2: Quote Link to comment Share on other sites More sharing options...
JT! Posted February 14, 2005 Report Share Posted February 14, 2005 What about running two freewheels either side of your bike? left and right hand drives I mean, Surly it would work on mods if you got two threaded cranks etc and got the trhreadfs the right way, some euro riders use left hand drive dont they? ← Way too heavy and pointless. Theres the odd rider who rides left side, mainly bmxer who do grinds a certain may. :wink2: Quote Link to comment Share on other sites More sharing options...
FAT~DAN Posted February 15, 2005 Report Share Posted February 15, 2005 What about running two freewheels either side of your bike? left and right hand drives I mean, Surly it would work on mods if you got two threaded cranks etc and got the trhreadfs the right way, some euro riders use left hand drive dont they? that would not work as you would have to have 2 right pedals and the one on the left would come loose due to going the same was as undoping the pedal Dan Quote Link to comment Share on other sites More sharing options...
eMAyaRKay Posted February 15, 2005 Report Share Posted February 15, 2005 Why would it? If you had a left hand crank with oppisite threads for the freewheel, the threads for the pedals would stay the same. Quote Link to comment Share on other sites More sharing options...
Siders77 Posted February 15, 2005 Report Share Posted February 15, 2005 My mate had a double drive on his koxx at one time, but he had the freewheels at the back and just a chainring on the front. He had the thread in the crank arm re-threaded so that the pedal wouldn't come lose. Personally I didn't like it one bit, but he said he liked it. I would never go double drive because it's too much messing about and costs too much in my opinion. :wink2: Quote Link to comment Share on other sites More sharing options...
JT! Posted February 15, 2005 Report Share Posted February 15, 2005 Thinking more about it today: If you have two freewheels, one would be less restrictive, so one would stay with the pawls against the teeth. So it would feel the same, but if you got your trousers caught, the other freewheel would kick in. One advantage i supose. :- Non of them finger loss storys :) Quote Link to comment Share on other sites More sharing options...
Will Arnold Posted February 15, 2005 Report Share Posted February 15, 2005 yeah, the chain would move only when power is put down :- thats not really an advantage though lol Will Quote Link to comment Share on other sites More sharing options...
eMAyaRKay Posted February 15, 2005 Report Share Posted February 15, 2005 just think, if one skipped or snapped you'd have another to kick in straight away to save you from a big crash! Quote Link to comment Share on other sites More sharing options...
JT! Posted February 16, 2005 Report Share Posted February 16, 2005 just think, if one skipped or snapped you'd have another to kick in straight away to save you from a big crash! ← Erm no you wouldnt. It would just do the same as having a fixed cog. Quote Link to comment Share on other sites More sharing options...
nb88 Posted February 16, 2005 Report Share Posted February 16, 2005 Just think of the fixed cog being a freewheel with no delay - full engagement, that is always engaged and can't slip. 2 freewheels wouldnt work. at all. Quote Link to comment Share on other sites More sharing options...
Da Make Posted February 16, 2005 Report Share Posted February 16, 2005 If thinking about "double drive" i.e. one free wheel per crank. The left side freewheel would have to be LSD (Left Side Drive in this case...) model and crank threads would be opposite then. If running normal crank/freewheel setting on left side everything would come loose immediately. That is ok if you have always wanted to ride backwards with your trial bike though... Stick with the normal system, nothing to fix with it. Optimal. Quote Link to comment Share on other sites More sharing options...
eMAyaRKay Posted February 16, 2005 Report Share Posted February 16, 2005 I'm not saying that it would be in a nyway practical or benificial to run two freewheels in a double drive way, just that it could be done ;) Quote Link to comment Share on other sites More sharing options...
Mark W Posted February 16, 2005 Report Share Posted February 16, 2005 Not necessarily. It'd be pretty much impossible. The thing is is that you'd have to have a different sized rear sprocket due to the fact that flip-flop hubs on trials bikes can only take 16t+ freewheels on one side, and micro-drive (i.e. 14t-) freewheels on the other. This means you couldn't have two 12t sprockets on the back, which means you might be f**ked. This is 'cos you'd have two different ratios on each side, so you wouldn't actually properly engage it on one side whilst you did on the other due to the chain-slack being taken up differently. I know when you ride mod you've got front freewheel so it means that the chain's always got some slack taken up, but it'd still be messed up. Two freewheels would indeed leave you with half the engagements, a lovely mushy drive, two possible points of bike death, and it'd be straight up pointless. The rear freewheel might as well just be a fixed sprocket. No, you don't get the fact that you won't catch your trousers as easily, but as long as you're not a 'tard it's not too hard a problem to overcome... Mark. Quote Link to comment Share on other sites More sharing options...
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