I believe this is a reasonably decent calibration chart as I hit 0.5% or 0.75% on the chart, the other Park Tool CC-3.2 pass/fail gauge nicely slides in at the 0.5% and 0.75% sides respectively. The conversion table is of course not perfect as some chains came with an initial stretch measurement less than 0% (i.e., the CC-2 gauge would not fit in place). As such, 0% does not represent true zero. That said, we are really interested in the 0.5% or 0.75% wear, which the chart seems to approximate well (for how Park Tools measures chain wear). This change of mind return policy is in addition to, and does not affect your rights under the Australian Consumer Law including any rights you may have in respect of faulty items. This change of mind return policy is in addition to, and does not affect your rights under the Australian Consumer Law including any rights you may have in respect of faulty items. To return faulty items see our Returning Faulty Items policy. For hygiene reasons, any intimate garments such as facemasks, underwear and swimsuits can only be returned if the items are faulty. This shop declares the total paid for the goods for customs value, no exceptions. We will not declare low values as thats fraud and we will not be party to it.

If you find an item at a lower price with another commercial internet retailer, you will receive it from us at the same price, provided the conditions listed in the link are met.As you can see your measurement of 120mm suggests 0.4% stretch. Typically I will measure the chain with Vernier calipers in three random places and take an average, then compare against the chart. I also record these measurements and regress them against the current distance or duration to get a better estimate of the current wear rate, as well as projecting service intervals. Predicting Service Life You should always keep proof of postage and we advise you to use a ‘signed for service’ when returning goods. Faulty items should be returned within a reasonable time and in a clean and dry condition. PLEASE NOTE, WE WILL NOT PROCESS DIRTY ITEMS.

The granting of a best price is not combinable with other promotions (e.g. "free articles) from Bike-Discount. Customs clearance fees -these vary from country to country and also vary by declared value in some juristictions. Because you are also attempting to use Vernier calipers to estimate chain wear I thought I would share a method I derived for using Vernier calipers. I decided to follow the same method as the Park tools (inner measurement - your L1 approach - for 10 links) as I wanted to include wear on the bushings (as this is what the cog interacts with). As many have pointed out there is no perfect way to measure chain elongation. If you wish to return your bike to us please keep it in the box it arrived in and call us on 01772 644340 and we will arrange a collection. Finance is subject to application, financial circumstances and borrowing history. Performance Cycling Limited FRN: 720557 trading as Tredz are authorised and regulated by the Financial Conduct Authority. We are a credit broker not a lender – credit is subject to status and affordability and is provided by Mitsubishi HC Capital UK PLC. Terms & Conditions Apply.The most accurate way seems to be hang the chain off the bike and use a calibrated ruler/tape measure over several links (in the hanging case, they suggest 100+ links, the longer measurement reduces measurement error). If you don't want to do that, a good ruler/caliper on the bike and measuring lengths. a) If we have sent you the incorrect bicycle, we will cover the cost of collection and delivery of the correct model. It is scary how bad the Tiagra chain is, out of the box it's stretch measurement is nearly 0.5% and I would be surprised if I get 40 hours of riding out of it (less than a month commuting) if I wait to 0.75% before I change. Whether it’s a jersey that doesn’t fit, or the colour is not quite right, sometimes you’ll need to return items to us. I repeated three measurements of the CC-2 gauge at the 0%, 0.25%, 0.5%, 0.75% and 1% gauge readings. I then took the average and did a simple linear regression against the gauge readings (below).

I settled on your inner measurement approach (pictured above) and calibrate my Vernier calipers against a CC-2 device, so I could translate a linear measurement into an approximate % wear. I did this by creating a calibration regression chart converting the Vernier L1 measurement to a stretch percentage (see below). I figured that while the CC-2 can be difficult to use consistently, it should at least be generally accurate. Note that my calibration measurements involved only a very light push on the CC-2 gauge. Calibration Most riders will be able to change the chain at a (real) wear of 0.5% but I have seen some where they can do so at nearly 1% wear, without skipping. Perfectly uniform wear (to the nth degree) is not that likely, but if the chain is wearing unevenly to a noticeable extent, this may be a clue that it isn't just ordinary wear that is the culprit; it may mean that the chain is corroding as well. Our experts recommend certain products for every rider, including stands. Your bike addict options in this category include event, portable repair, and wheel truing stands. And we’ve got shop aprons, bar style shop stools, and mechanic gloves along with coffee mugs when you’re ready to take a break! don't mention variable elongation vs replacement in the same way. But the CC4 is a better design which measures pin wear only.Please enclose all your details and a covering note explaining the fault and any other useful details. I also have moved to measuring chain stretch via Vernier calipers, however my approach differs from yours as I try to mimic the cc-2 type inner measurement but with more precision (see below for methods). According to my calibration chart your L1 measurement suggests a chain stretch of 0.4%, which seems like a lot for 600 km, but not impossible. I would try repeating your L1 measurement a couple more times to be sure. Either way, you will likely need to change your chain soon. Using Vernier Calipers To Measure Chain Stretch However this isn't ever a fixed point; it varies with the chain type, the rider, and the pattern of use. So some folk get away with changing the chain at (a real, pin-wear only ) elongation of 0.75%, others can't go more than 0.5% safely.

but the CC2 is an older design which also includes roller wear in the measurement. CC3.2 instructions say the same thing and this tool also includes roller wear in the measurement. Dunno about CC-3 which is the one that Horizon has I suppose.

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Your high CC-2 reading likely relates to how much pressure are applying. The CC-2 device is not particularly solid and its readings are sensitive to how much pressure you apply to the pivoting gauge. Lightly push pivoting gauge just until it stops. Forcing gauge will damage the CC-2’s pins, resulting in inaccurate measurements. If the items we have sent you are faulty, damaged or not as we described, we will cover the cost of collection and the delivery of the correct item. So I happen to be interested in an exact number for chain wear, but it arguably isn't so relevant for any given rider; whether the measurement includes roller wear or not doesn't really matter, because the exact chain wear won't tell them if they can fit a new chain or not anyway. The point which you have definitely left it too late depend on many things, not just the exact pin wear in the chain. A better quality chain tool can help, or using calipers/a ruler as you are using. See this article from Zinn, for example -- essentially, you need to get an idea of the errors your tool makes, and you can be conservative with the replacement requirements (analogous to oil change intervals for cars; this can be a bit wasteful). Or, get a more accurate measurement (analogous to oil life meters in newer cars). It looks like he uses the Progold or Rohloff tools, which are inaccurate, but by getting an idea of the errors it makes, you can make a rough guess if you need to look closer for measurement, or just say screw it and replace the chain (even if its early)