Chris Borneo Posted December 29, 2011 Report Share Posted December 29, 2011 I'm in the market for a chain tensioner for my Rocket build and I'm trying to sort out the options. Goin to need something that applies pressure under the chain as I want the option to run a 12t rear sprocket and I want to get as much chain wrapped round it as possible. Think I've written of the idea of using an old mech like I used to back in the day. I'll be carrying enough weight around anyway and it just seems a bit overkill. Been lookin at some of the sprung single speed chain tensioners on the market and some of them look pretty simple. Thinking I could make one by modifying an old v brake arm. I figure it's already sprung, I just need to bolt an old brake boss to my mech hanger and a sliding jockey wheel to the other end? Anyone else done something like this before? Also is there any real advantage to having two jockey wheels? I'm planning to run the absolute minimum amount of slack and maybe a half link if I need it so I figure one should do? The other option I've been looking at is a spoke tensioner but it seems a bit bodge. Anyone been running one for a decent amount of time? Does it do the chain any damage? Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted December 29, 2011 Report Share Posted December 29, 2011 Also is there any real advantage to having two jockey wheels? Yes, chain wrap. If you are running a 12t you will need 2 wheels. Quote Link to comment Share on other sites More sharing options...
Chris Borneo Posted December 29, 2011 Author Report Share Posted December 29, 2011 Yes, chain wrap. If you are running a 12t you will need 2 wheels. Won't you get that with one jockey wheel pushing up on the chain from underneath? Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted December 29, 2011 Report Share Posted December 29, 2011 In theory, yes. In reality, it wouldn't work unfortunately, as the chain will hit underside of the chainstay (assuming your other sprocket is bigger than 12T). There are combinations of frame/tensioner/sprocket sizes, etc. that work better than others, your best bet is to get stuck in and have a play. I would strongly recommend a 2 wheel tensioner though if you want to use 2 different rear sprockets. Quote Link to comment Share on other sites More sharing options...
ogre Posted December 29, 2011 Report Share Posted December 29, 2011 Yes, chain wrap. If you are running a 12t you will need 2 wheels. i'm geting away with no tentioner running a 12t sprocket on a pro2, which are notorious for needing chain wrap... maybe you can find out how much tention you can acheive without a tensioner first? if you have a relatively snug set up then a bodge to apply tension should be fine however if you're chain is slacker than hannah shucksmith you'll need a proper tensioer, the single wheel ones are pants. these are excellent value for money we put one on a friends budget build and it's just as good as the try-all one tarty do 1 Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted December 29, 2011 Report Share Posted December 29, 2011 I think I may have mis-read the original post, I thought it was to be used with 2 sprockets (one of them being a 12t). Quote Link to comment Share on other sites More sharing options...
Chris Borneo Posted December 29, 2011 Author Report Share Posted December 29, 2011 Going to be running a 24 on the front I think. Suppose I was thinking I'd run the chain with such a small amount of slack that it wouldn't be able to hit the stay but I guess the chances of it working out like that may be a bit slim. Think I need to do a mockup tonight and see where I'm at. Two jockey wheels is going to add a whole load of issues to my homemade plan!Oh yeah, I'm going to be swapping between 12 and 16 I think but I'm not 100% certain yet. Quote Link to comment Share on other sites More sharing options...
ogre Posted December 29, 2011 Report Share Posted December 29, 2011 if you want to use 2 different sprockets on the rear you'll need a 2 wheel tensioner so you can run more chain in your set up and take up the slack with the tensioner. the superstar one allows for side to side adjustment so with some allen keys you can adjust betwen the two with a bit of effort and be rellatively confident in the set up. looking forward to seeing this done.. Quote Link to comment Share on other sites More sharing options...
Chris Borneo Posted December 29, 2011 Author Report Share Posted December 29, 2011 Sorry, should have explained this better. I'm not looking to have two cogs on the hub at one time. I'll swap the cog and the chain over depending on what setup I want to ride on that day. Also I'll be running a 1/8 chain and cog for the 12t setup. Would that be an issue with any chain tensioners? Quote Link to comment Share on other sites More sharing options...
The Mechanic Posted December 29, 2011 Report Share Posted December 29, 2011 (edited) I have made my own tensioner which seems to work well although it works over the chain rather than under that you require, The torsion spring is the tough bit, making a mounting not so hard, I went for a coil rather than leaf type spring good movement in either direction which I think is important.Leaf spring are good in compression but restricted expansion. Edited December 29, 2011 by The Mechanic Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted December 30, 2011 Report Share Posted December 30, 2011 works so good,i cant believe it(plastic) Quote Link to comment Share on other sites More sharing options...
Chris Borneo Posted December 31, 2011 Author Report Share Posted December 31, 2011 That looks amazing. What's the arm made from?Is it a reflector bracket? Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted January 2, 2012 Report Share Posted January 2, 2012 (edited) no,its a mudguard mount from a cheap supermarket atb i´ve been throwing away. from those rear mudguards for cheap fullys. works awesome edit:reflector bracket would be even better i think,would be more adjustable. i´ll try one out. Edited January 3, 2012 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
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