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 Post subject: roller crank
PostPosted: Wed Apr 23, 2008 10:05 am 
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Joined: Fri Nov 09, 2007 12:49 pm
Posts: 58
Location: stow, oh
what do you guys know and think about a roller crank? I have the option of picking up a brand new stroker crank with roller bearings for $250. I am wondering if this will be a good strong crank for woods riding. It all is pressed together wich worries me about the strength. I believe it is an 82mm stroke. I read a couple things about them and I am getting a couple different opinions. The guy told me it cost 600 bucks new so maybe i could just resell it on ebay if i buy it and make some money to buy a good crank. thanks


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 Post subject:
PostPosted: Wed Apr 23, 2008 10:14 am 
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Joined: Mon Apr 30, 2007 3:35 pm
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Location: Rome Ohio
I would buy it for that price. As far as it being pressed together is no big deal. A lot of MC, ATV and snowmobile manufactures have been using pressed cranks for years. A stock Skidoo twin 700 puts out 127 HP at 8000 RPM. So basically It will work great. Im sure there will be different opinons on this subject so stay tuned :lol:

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 Post subject:
PostPosted: Wed Apr 23, 2008 10:31 am 
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Joined: Fri Nov 09, 2007 12:49 pm
Posts: 58
Location: stow, oh
i read somewhere on the internet that if you rev it up and dump the clutch it could twist. I don't really know if thats possible. your right, i do remember seeing some motorcycles with roller bearing cranks but they don't really have that much weight to get moving. What would be the advantage of this crank? the guy told me it is supposed to be good up to 10,000 rpm. At that speed it seems like everything else will be stressed to the breaking point. I really appreciate your opinions.


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 Post subject:
PostPosted: Wed Apr 23, 2008 11:26 am 
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WoodsBuggy Addict
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Joined: Mon Feb 19, 2007 2:23 pm
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Location: Central Indiana
So who is making those new roller cranks these days?
Is it a one of?
I know the plain bearing style crank works exceptionally well for what we do with them.
I'd be hard pressed to try one without some real world feedback on them
Who needs to turn 10K RPM anyway?
There are a lot of components that would give up before that number was achieved...... :lol:

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 Post subject:
PostPosted: Wed Apr 23, 2008 1:39 pm 
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Joined: Fri Nov 09, 2007 12:49 pm
Posts: 58
Location: stow, oh
I have no idea who made this thing but i was lead to believe it has been sitting on this guys shelf for years. I am guessing it is probably pretty old. It has never been used though. I was kinda hoping someone on here has used one at sometime so they could tell me to pass on it or go for it. I really don't want to use this sucker if I can't get some first person feedback. I have heard of these being used years ago. I am just worried there is a reason why nobody runs them or even makes them anymore. I really don't see any reason to turn those kind of numbers but if it is a good reliable crank then i will use it. I don't think the rest of the motor would like 10k too much either. thanks


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 Post subject:
PostPosted: Wed Apr 23, 2008 11:15 pm 
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Joined: Mon Mar 05, 2007 9:06 pm
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Location: worst hillclimbing state in the country IL
Check out geneberg.com he has an opinion on them and its not very good just my 2 cents.
aaron


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 Post subject:
PostPosted: Thu Apr 24, 2008 2:55 am 
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Location: Newark Ohio
Its more than likely a old SPG. Does he have the main brgs for it? They are special ,they have a cut in them to "spray" oil at the rods to oil the roller brgs(crank doesn't oil internally) . I'll look to see if I still have some to show ya were to cut them. AND yes they will twist! I ran an 82 stroke in sand drags and it lasted about 10 passes before it twisted! I think I still have a 69 stroke I'll have to dig it up. Would I buy another one?,,,,,,,,,no. But 250 is a cheap stroker! If ya need more info PM me your phone number


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 Post subject: Roller Crank
PostPosted: Thu Apr 24, 2008 8:11 am 
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Joined: Tue Jan 01, 2008 3:58 pm
Posts: 51
Location: pittsburgh,pa.
mjb600 wrote:
I have no idea who made this thing but i was lead to believe it has been sitting on this guys shelf for years. I am guessing it is probably pretty old. It has never been used though. I was kinda hoping someone on here has used one at sometime so they could tell me to pass on it or go for it. I really don't want to use this sucker if I can't get some first person feedback. I have heard of these being used years ago. I am just worried there is a reason why nobody runs them or even makes them anymore. I really don't see any reason to turn those kind of numbers but if it is a good reliable crank then i will use it. I don't think the rest of the motor would like 10k too much either. thanks


Roller cranks must maintain pristine bearings surfaces or they fail in short order. Since off road buggy motors end up with moisture in their crankcases sooner or later, you would contaminate the bearings and they will corrode a bit. Only one spec of rust in a roller bearing spells failure sooner rather than later. This is why jet skiis should be fogged down after each use.


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