The Hope T-Rex ratio expander allows you to upgrade your existing 11-36 10spd cassette to give an 11-40T range. The T-Rex simply installs behind your existing cassette and replaces one of the smaller sprockets, usually the 17T.
Shimano and Sram specific 40T sprockets have been designed, this gives us the following benefits which wouldn’t be possible with a larger sprocket size or with a universal type design:
1. Precise matching of the tooth profiles and shifting points specific to each cassette
2. Perfect mating of supporting tabs reducing flex and aiding shift performance
3. Lower B-tension adjustment is needed ensuring good shifting throughout the cassette range compared to fitting a 42t
For a 1 x 10 set-up with a newly converted 11-40 cassette you will need a rear derailleur with a 29T capacity [ 40-11=29 ]. For a 2 x 10 set-up with 40/28 chainrings and a newly converted 11-40 cassette you will need a rear derailleur with a 41T capacity [ (40-11)+(40-28)=41 ].
In most cases we recommend removing the 17T sprocket. In the case of the Shimano
CS-M980 and CS-M771-10 this is the only sprocket that can be easily removed. In the case of the SRAM PG-1030, PG-1050 and PG-1070 it is possible to remove alternative individual sprockets.
If your B-tension screw is not long enough use the supplied M4 x 20mm screw. Refer to the manufacturer’s instructions for further guidelines on adjusting your rear derailleur.
With the chain mounted on your largest front chainring and the 40T-REx sprocket, check that your chain is not being pulled tight. If your chain is not long enough, replace it with a new longer one
Cassettes and freewheels for bikes are a cluster of sprockets in a range of sizes offering a multitude of gear ratios. The difference between the two is, a cassette slots onto the freehub, which has the ratchet built in and is then secured with a lockring, whereas a freewheel is a cluster of sprockets built around a ratchet and threads directly on to the hub. Cassettes and freewheels come in many ratios, close ratio is when the number of teeth increase in small increments of 1 or 2 at a time, whereas a wide ratio is when the teeth increase in larger increments of 3 or 4 at a time. Most systems will use a cassette hub as these allow for a wider bearing spacing and increased axle life, you can also fit a larger quantity of sprockets onto a cassette hub with 11 speed systems now becoming available. With cassettes you must use the appropriate spacing for your gear levers and rear mech, Shimano and Campagnolo are not interchangeable so you will need to match the cassette to your levers for smooth and precise shifting. Sram and Shimano chains and cassettes will work together as they use the same spacing.
Hope are makers of CNC precision cycling components such as braking systems and accessories, hubs, bottom brackets, wheelsets, lights, stems, headsets, quick releases, tools and cycle clothing and merchandise. Hope has for many years sponsored many of the World Cup teams in downhill and cross-country. Their own team has become a formidable force in the United Kingdom and on the World Cup scene, allowing them to test their bicycle parts at the highest level. Hope is a company working at the leading edge of engineering technology, they use the most advanced materials and computer aided design techniques to produce bicycle components of unrivalled quality. At Hope, they have always maintained that their people are their most valuable asset and so they invest heavily in training to ensure that they all add to their knowledge, learn new skills and keep abreast of relevant developments. Product development and improvement is part of their business philosophy, and with their commitment to technical excellence Hope will continue to produce cycling products of unrivalled quality and value for money.
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Wiggle Ltd. 1000 Lakeside, Suite 310, Third Floor N E Wing, Portsmouth, Hampshire, PO6 3EN, United Kingdom /
Company No: 2667809 /
VAT No: 884 2571 94
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Executive Director: Stefan Barden.