Teddydanson Posted May 14 Report Share Posted May 14 Hi all, just had a couple of hours on the old girl. Runs sweet as, but I noticed the chain was very slack after an hours ride, brought her back, undid the hub bolt, and it’s got to like cog adjusters on either side, I’ve turned them both the same and it’s tightened with a little slack, but not sure if the correct tension. I can get my thumb on the top of chain under inbetween the top guide, and thumb under the chain on the swing arm. I’ve tried to look but nothing video wise I can see to check. Thanks for any help.. kris Quote Link to comment Share on other sites More sharing options...
lemur Posted May 14 Report Share Posted May 14 (edited) If the chain tensioner is doing something when the bike is at rest with no rider aboard you are good to go, if the rubber block is touching the swingarm at rest that's not good. ... so far this year alone I spotted 3 bikes with the axle set crooked and I noticed it because the chain tensioner was doing nothing when they parked their bikes. Make sure the axle is good and tight and that your wheel bearings are perfect, wheel bearings wear out fast. Edited May 14 by lemur Quote Link to comment Share on other sites More sharing options...
zippy Posted May 15 Report Share Posted May 15 What I typically aim for on chain tension on my 2015 GasGas: Bike on stand, wheel off ground. Able to place 1 finger between top of chain tensioner block and swingarm. From the back, look at tire and chain, give the tire a spin and make sure the chain runs straight and the rear sprocket is not crooked. 2 Quote Link to comment Share on other sites More sharing options...
Teddydanson Posted May 15 Author Report Share Posted May 15 Thanks for your help guys. Just got home, put it on my stand, back wheel free hanging, finger gap ontop of tension block to swing arm back on the ground not touching swing srm so free gap, also spins free true and not offset.. thankyou 👍🏻 1 1 Quote Link to comment Share on other sites More sharing options...
lemur Posted May 15 Report Share Posted May 15 If you grab the tire by the front and rear and give it a sturdy wiggle rotating action about the vertical axis and can observe any change in the chain slack, that is a clear indication the wheel bearings need replacement or the swingarm bearing needs attention. Bad bearings also contribute to reduced braking. I end up replacing wheel bearings more then chains and that is buying the higher quality bearings ymmv. Quote Link to comment Share on other sites More sharing options...
RonH Posted May 16 Report Share Posted May 16 21 hours ago, lemur said: I end up replacing wheel bearings more then chains and that is buying the higher quality bearings ymmv. Lemur, what brand of bearings do you use? Quote Link to comment Share on other sites More sharing options...
lemur Posted May 16 Report Share Posted May 16 (edited) 2 hours ago, RonH said: Lemur, what brand of bearings do you use? SKF from a local being supply 6 or 8 at a time. You can buy different specs, expensive bearings have more balls and tighter specs. ... made up a puller to change them super easy, the steel sleeve to extract the bearing spacer is cut from a used CO2 canister. Edited May 16 by lemur 1 Quote Link to comment Share on other sites More sharing options...
RonH Posted May 16 Report Share Posted May 16 (edited) 17 minutes ago, lemur said: SKF from a local being supply 6 or 8 at a time. You can buy different specs, expensive bearings have more balls and tighter specs. ... made up a puller to change them super easy, the steel sleeve to extract the bearing spacer is cut from a used CO2 canister. Awesome! Thanks for the puller photo also! I’ve got everything to build one. Edited May 16 by RonH Quote Link to comment Share on other sites More sharing options...
lemur Posted May 16 Report Share Posted May 16 You are going to find bearings have a precision rating, low numbers are low quality, higher number ABEC rating cost more. Same tool is good for pressing in the new bearing, use an old bearing to push the new one in, works slick. 1 Quote Link to comment Share on other sites More sharing options...
faussy Posted May 19 Report Share Posted May 19 (edited) Personally ive found wheel bearings to wear out no matter what brand or cost they were. Once water and dirt get in they are toast so I wouldn't put yourself out too much sourcing quality wheel bearings. Its the only bearing on a bike I don't care where they came from Edited May 19 by faussy Quote Link to comment Share on other sites More sharing options...
lemur Posted May 19 Report Share Posted May 19 (edited) 51 minutes ago, faussy said: Personally ive found wheel bearings to wear out no matter what brand or cost they were. Once water and dirt get in they are toast so I wouldn't put yourself out too much sourcing quality wheel bearings. Its the only bearing on a bike I don't care where they came from So you figure a 4$ roller bearing with only 7 balls and zero claim to tolerance is as good as the one with 9 balls, costs 4 times the price and meets a high tolerance spec 🤔 interesting. Yes you need to keep the water out of any roller bearing, that is what the grease and oil does, it displaces the water. ... if it was for the track idler wheel on a 1968 snowmobile I would agree with you. Edited May 19 by lemur Quote Link to comment Share on other sites More sharing options...
faussy Posted May 19 Report Share Posted May 19 (edited) Its a wheel bearing on a trials bike, what do you need high tolerance for? The water and dirt gets into the expensive one every bit as easy as the cheap one, and once it does they're done Edited May 19 by faussy 1 Quote Link to comment Share on other sites More sharing options...
lemur Posted May 20 Report Share Posted May 20 21 hours ago, faussy said: Its a wheel bearing on a trials bike, what do you need high tolerance for? The water and dirt gets into the expensive one every bit as easy as the cheap one, and once it does they're done Because there is only 2 bearings and they are carrying a wheel that is 27 something inches in diameter. Small amount of play in the axle bearing results in large amount of movement in the wheel. You can push thin oil into a wheel bearing with an insulin syringe and displace the water, might be wise after your next deep water crossing, makes them last longer. Quote Link to comment Share on other sites More sharing options...
konrad Posted May 20 Report Share Posted May 20 Just to have a concrete example, the 6905 is a pretty common trials wheel bearing. Here is the cheapest one ($5 CAD) I found advertised in Canada: https://mapleace.com/en-us/products/6905-2rs-61905-2rs-ball-bearing-25x42x9mm-6905-2rs-rubber-sealed lemur, are you saying that's not good enough for a trials wheel? What do you use? Quote Link to comment Share on other sites More sharing options...
lemur Posted May 20 Report Share Posted May 20 1 hour ago, RonH said: Holy cow! I was considering SKF bearings at $35 USD each but I can buy 17 of these MapleAce bearings for the same amount. Maybe I’ll have to change them more frequently but that’s ok with me. Non graded bearings will simply never be as good as a better bearing even when you first install them, that's a reality, will they spin your wheel around and around, yes and maybe even a little bit sideways give or take. Guess I'm saying how do you think they come up with 5 grades of deep groove roller bearings and then there are the ones y'all are buying at 4 bucks each and not graded at all. Wheel bearings are obviously very important and highly stressed on a trials bike, was asked what I use and recommend and that's it, graded name brand bearings. I don't pay that much but I don't buy them in US, maybe it's a tariff thing Quote Link to comment Share on other sites More sharing options...
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