If you need a hand selecting a bottom bracket or crank combination have a read of our article: Which Bottom Bracket and Cranks do I Need?

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Bottom Bracket and Crank Help

If you need help selecting the correct derailleur cage length checkout our great blog: How to Choose Derailleur Cage Length.

If you still have questions contact our awesome customer service team on live chat or at help@mtbdirect.com.au who will help

<header id="isPasted" style="box-sizing: inherit; max-width: 72.6rem; margin: 5rem auto 2rem; padding: 0px; line-height: calc(0.8 / var(--font-body-scale)); color: rgba(18, 18, 18, 0.75); font-family: Montserrat, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: 0.6px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><h1 itemprop="headline" style="box-sizing: inherit; font-family: var(--font-heading-family); font-style: var(--font-heading-style); font-weight: var(--font-heading-weight); letter-spacing: calc(var(--font-heading-scale) * 0.06rem); color: rgb(var(--color-foreground)); line-height: calc(1 + 0.3/max(1,var(--font-heading-scale))); word-break: break-word; font-size: calc(var(--font-heading-scale) * 4rem); margin: 0px 0px 1rem;" id="we-were-recently-asked-how-do-i-tell-if-i-need-a-medium-or-long-rear-derailleur"><span id="isPasted" style="color: rgba(18, 18, 18, 0.75); font-family: Montserrat, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: 0.6px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">We were recently asked: &quot;How do I tell if I need a medium or long rear derailleur?&quot;</span></h1><h1 itemprop="headline" style="box-sizing: inherit; font-family: var(--font-heading-family); font-style: var(--font-heading-style); font-weight: var(--font-heading-weight); letter-spacing: calc(var(--font-heading-scale) * 0.06rem); color: rgb(var(--color-foreground)); line-height: calc(1 + 0.3/max(1,var(--font-heading-scale))); word-break: break-word; font-size: calc(var(--font-heading-scale) * 4rem); margin: 0px 0px 1rem;" id="excellent-question-and-while-there-are-a-few-factors-that-impact-your-choice-of-cage-length-long-medium-or-short-you-can-work-it-out-using-a-simple-formula">Excellent question! And while there are a few factors that impact your choice of cage length (Long, Medium or Short), you can work it out using a simple formula.</h1></header><div itemprop="articleBody" style="box-sizing: inherit; max-width: 72.6rem; margin: 1.5rem auto 3rem; padding: 0px; color: rgba(18, 18, 18, 0.75); font-family: Montserrat, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: 0.6px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><p style="box-sizing: inherit;"><img data-fr-image-pasted="true" alt="Derailleur sizes" src="https://test.mtbdirect.com.au/assets/images/derailleur-sizes.jpg" style="box-sizing: inherit; height: auto; max-width: 100%; border: var(--media-border-width) solid rgba(var(--color-foreground),var(--media-border-opacity)); border-radius: var(--media-radius); box-shadow: var(--media-shadow-horizontal-offset) var(--media-shadow-vertical-offset) var(--media-shadow-blur-radius) rgba(var(--color-shadow),var(--media-shadow-opacity));" class="fr-fic fr-dii"></p><h2 style="box-sizing: inherit; font-family: var(--font-heading-family); font-style: var(--font-heading-style); font-weight: var(--font-heading-weight); letter-spacing: calc(var(--font-heading-scale) * 0.06rem); color: rgb(var(--color-foreground)); line-height: calc(1 + 0.3/max(1,var(--font-heading-scale))); word-break: break-word; font-size: calc(var(--font-heading-scale) * 2.4rem);" id="why-does-it-matter"><strong>Why does it matter?</strong></h2><p style="box-sizing: inherit;">The derailleur cage is a swinging link, with two pulleys. As the chain moves between different size sprockets (front and rear), the amount of chain required changes. The derailleur cage picks up this slack.</p><p style="box-sizing: inherit;">A cage that&apos;s too short has the potential to rip your derailleur off your bike, when the cage reaches its capacity....</p><p style="box-sizing: inherit;"><img data-fr-image-pasted="true" alt="Broken derailleur" src="https://test.mtbdirect.com.au/assets/images/broken-derailleur.jpg" style="box-sizing: inherit; height: auto; max-width: 100%; border: var(--media-border-width) solid rgba(var(--color-foreground),var(--media-border-opacity)); border-radius: var(--media-radius); box-shadow: var(--media-shadow-horizontal-offset) var(--media-shadow-vertical-offset) var(--media-shadow-blur-radius) rgba(var(--color-shadow),var(--media-shadow-opacity));" class="fr-fic fr-dii"></p><p style="box-sizing: inherit;">A cage that&apos;s too long adds unnecessary weight to your bike, runs closer to the ground (when it&apos;s not necessary) and there&apos;s also the potential for more dropped chains (a longer cage generally has less leverage, and therefore runs less spring tension).</p><h2 style="box-sizing: inherit; font-family: var(--font-heading-family); font-style: var(--font-heading-style); font-weight: var(--font-heading-weight); letter-spacing: calc(var(--font-heading-scale) * 0.06rem); color: rgb(var(--color-foreground)); line-height: calc(1 + 0.3/max(1,var(--font-heading-scale))); word-break: break-word; font-size: calc(var(--font-heading-scale) * 2.4rem);" id="working-it-out">Working it out:</h2><p style="box-sizing: inherit;"><i style="box-sizing: inherit;"><b style="box-sizing: inherit;">[ Largest Front Ring - Smallest Front Ring ] + [ Largest Rear Ring - Smallest Rear Ring ] = Required Capacity</b></i></p><p style="box-sizing: inherit;">e.g. if you are running a 22-32-42T front crankset, and a 11-34T rear cassette.</p><p style="box-sizing: inherit;"><strong style="box-sizing: inherit;">[ 42 - 22 ] + [ 34 - 11 ] = 43T</strong></p><h2 style="box-sizing: inherit; font-family: var(--font-heading-family); font-style: var(--font-heading-style); font-weight: var(--font-heading-weight); letter-spacing: calc(var(--font-heading-scale) * 0.06rem); color: rgb(var(--color-foreground)); line-height: calc(1 + 0.3/max(1,var(--font-heading-scale))); word-break: break-word; font-size: calc(var(--font-heading-scale) * 2.4rem);" id="choosing-a-cage">Choosing a cage:</h2><p style="box-sizing: inherit;">Then you can choose which cage length you need. General guidelines for maximum capacity for each brand are (though it does vary between models, so best to check the model-specific capacity):</p><p style="box-sizing: inherit;"><b style="box-sizing: inherit;"><i style="box-sizing: inherit;">Shimano</i></b></p><ul style="box-sizing: inherit; padding-left: 2rem;"><li style="box-sizing: inherit; list-style: inherit;">Long = 45T</li><li style="box-sizing: inherit; list-style: inherit;">Medium = 33T</li><li style="box-sizing: inherit; list-style: inherit; margin-bottom: 0px;">Short = 28T</li></ul><p style="box-sizing: inherit;"><b style="box-sizing: inherit;"><i style="box-sizing: inherit;">SRAM</i></b></p><ul style="box-sizing: inherit; padding-left: 2rem;"><li style="box-sizing: inherit; list-style: inherit;">Long = 45T</li><li style="box-sizing: inherit; list-style: inherit;">Medium = 37T</li><li style="box-sizing: inherit; list-style: inherit; margin-bottom: 0px;">Short = 30T</li></ul><p style="box-sizing: inherit;">So in the example above, you would opt for a <strong style="box-sizing: inherit;">Long Cage derailleur</strong> in either brand. (Be sure to check the rating for the exact model you are looking at).</p><p style="box-sizing: inherit;">The other factor to consider is if you are riding a long travel dual suspension bike - if the calculation is on the edge, you may wish to go for the longer option cage (as the rear suspension goes through travel, it may pull on the chain if the cage is too short). There is no hard and fast rule on this, however, there is an easy way to test - once you have your new derailleur set up, shift to the largest ring(s) on your bike, release all the pressure out of your rear shock (or remove it, if you have a coil sprung bike), and then check your chain does not limit your travel.</p><p style="box-sizing: inherit;"><br></p><p style="box-sizing: inherit;">If you&apos;re having any trouble choosing the right derailleur, then feel free to contact us and we&apos;ll sort it out!</p></div><p class="no-margin">If you still have questions contact our awesome customer service team on live chat or at help@mtbdirect.com.au who will help you get sorted!</p>

Derailleur Cage Lengths

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Drivetrain

Bottom Bracket and Crank Help

Derailleur Cage Lengths