Slack-R Tensioner 53mm
Slack-R Tensioner 53mm

Slack-R Tensioner 53mm

0000-1346

Regular price $40.00 USD
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Shipping calculated at checkout.

Select Compatible Slack-R Kit

The 9point8™ Slack-R™ kit changes the head tube angle on bikes with IS headsets. (IS41 and IS42* upper bearing and IS52 lower bearing only.)

Have you found a Kit that fits your bike? There are convenient kits that group the parts you need HERE. But if you want to buy individual Slack-R parts, you are in the right place! You need three individual parts to adapt your bike (Upper Cup, Tensioner, and Lower Cup); use our KIT SELECTOR on the kit page to get the right combo.

Confirm the three checks below and complete the drop down menus to see what Slack-R kits are available for you.

1. Confirm your headset is the IS Standard
If you are not sure, read this article on headset identification by the experts at Park Tools.

 2. Confirm you have enough steer tube length to install a Slack-R
If measurements A + B are greater than below there is enough steer tube to install a Slack-R

3. Measure or look-up your bike's head tube length (HTL)
Bicycle manufacturers often list your bike's HTL in geometry charts on their websites. You can also measure this yourself as shown below.

 

What does installing a Slack-R do to your bikes geometry?
Click HERE to take a deeper look.

Want more customization?
Add additional parts to your Slack-R Kit to fine tune your HTA and test the extremes. Individual parts located HERE.

**Important Compatibility Information**
**MUST READ**

Slack-R is now compatible with MOST Tapered IS headsets. There are 3 different styles of upper cups now to go along with the IS52 lowers. IS41, IS42, and IS42S.

IS41/IS52 will fit a number of bikes from manufacturers such as Yeti, Santa Cruz, and Trek (eliminates the need for a Knock Block in most cases). Cube is an exception as they use a deeper upper bearing seat and the Slack-R IS41 will not sit properly in the Cube frames.

IS42/IS52 will fit many bikes from Cannondale, Norco, Marin, Orbea, GT, Revel, Scott and many more including some Specialized with a standard depth IS42/IS52 headset. Standard bearing seat depth is 3mm

IS42S/IS52 will fit Specialized bikes that have the 6.8mm deep upper bearing seat. (some Specialized bearings sit deeper than the standard IS42 geometry so they require their own specific top cup to insure proper fitment)

Headset types do vary across the same manufacturer, make sure you are sure what kind of headset you have. (IS/EC/ZS or hybrids of these)

Some IS bearing seats in the frames have a smaller bearing seat inside diameter than others so in some cases a bit of sanding will be required to fit in the 34.5mm upper sleeve and 44.5mm lower sleeve. In most cases the frame allow the kits to drop right in but in some cases opening up the upper and/or lower bearing seat inside diameter(s) will be required so double check your frame clearance prior to ordering if unsure.

Contact support@9point8.ca if you are unsure about your application prior to ordering.

Does your bike have a Trek Knock Block headset?
The Stop Chip must be removed from all Trek Knock Block headsets before installing a Slack-R. Read more here.

For your HTL and desired Angle Change, look up the Kit you need, and the Upper Cup, Tensioner, and Lower Cup part numbers you need.

Slack-R IS Kit Reference Chart

Kit HTL (Target middle-of-range) Nominal Angle (Deg.) Upper Cup Upper Cup Length (mm) Lower Cup Lower Cup Length (mm) Tensioner Tensioner Length (mm) Added Stack (mm)
Alpha IS41 90-98 1.5 0000-1343 22-26 0000-1349 25-29 0000-1345 43 20
Alpha IS42 90-98 1.5 0000-1371 22-26 0000-1349 25-29 0000-1345 43 20
Alpha IS42S 90-98 1.5 0000-1373 22-26 0000-1349 25-29 0000-1345 43 25
Bravo IS41 100-108 1.4 0000-1343 22-26 0000-1349 25-29 0000-1346 53 20
Bravo IS42 100-108 1.4 0000-1371 22-26 0000-1349 25-29 0000-1346 53 20
Bravo IS42S 100-108 1.4 0000-1373 22-26 0000-1349 25-29 0000-1346 53 25
Charlie IS41 110-118 1.3 0000-1343 22-26 0000-1349 25-29 0000-1347 63 20
Charlie IS42 110-118 1.3 0000-1371 22-26 0000-1349 25-29 0000-1347 63 20
Charlie IS42S 110-118 1.3 0000-1373 22-26 0000-1349 25-29 0000-1347 63 25
Delta IS41 120-128 1.2 0000-1343 22-26 0000-1349 25-29 0000-1348 73 20
Delta IS42 120-128 1.2 0000-1371 22-26 0000-1349 25-29 0000-1348 73 20
Delta IS42S 120-128 1.2 0000-1373 22-26 0000-1349 25-29 0000-1348 73 25
Echo IS41 97-105 1.7 0000-1343 22-26 0000-1350 32-36 0000-1345 43 20
Echo IS42 97-105 1.7 0000-1371 22-26 0000-1350 32-36 0000-1345 43 20
Echo IS42S 97-105 1.7 0000-1373 22-26 0000-1350 32-36 0000-1345 43 25
Foxtrot IS41 107-115 1.6 0000-1343 22-26 0000-1350 32-36 0000-1346 53 20
Foxtrot IS42 107-115 1.6 0000-1371 22-26 0000-1350 32-36 0000-1346 53 20
Foxtrot IS42S 107-115 1.6 0000-1373 22-26 0000-1350 32-36 0000-1346 53 25
Golf IS41 117-125 1.5 0000-1343 22-26 0000-1350 32-36 0000-1347 63 20
Golf IS42 117-125 1.5 0000-1371 22-26 0000-1350 32-36 0000-1347 63 20
Golf IS42S 117-125 1.5 0000-1373 22-26 0000-1350 32-36 0000-1347 63 25
Hotel IS41 127-135 1.4 0000-1343 22-26 0000-1350 32-36 0000-1348 73 20
Hotel IS42 127-135 1.4 0000-1371 22-26 0000-1350 32-36 0000-1348 73 20
Hotel IS42S 127-135 1.4 0000-1373 22-26 0000-1350 32-36 0000-1348 73 25
India IS41 110-118 1.5 0000-1344 42-46 0000-1349 25-29 0000-1345 43 20
India IS42 110-118 1.5 0000-1372 42-46 0000-1349 25-29 0000-1345 43 20
India IS42S 110-118 1.5 0000-1374 42-46 0000-1349 25-29 0000-1345 43 25
Juliet IS41 120-128 1.4 0000-1344 42-46 0000-1349 25-29 0000-1346 53 20
Juliet IS42 120-128 1.4 0000-1372 42-46 0000-1349 25-29 0000-1346 53 20
Juliet IS42S 120-128 1.4 0000-1374 42-46 0000-1349 25-29 0000-1346 53 25
Kilo IS41 130-138 1.4 0000-1344 42-46 0000-1349 25-29 0000-1347 63 20
Kilo IS42 130-138 1.4 0000-1372 42-46 0000-1349 25-29 0000-1347 63 20
Kilo IS42S 130-138 1.4 0000-1374 42-46 0000-1349 25-29 0000-1347 63 25
Lima IS41 140-148 1.3 0000-1344 42-46 0000-1349 25-29 0000-1348 73 20
Lima IS42 140-148 1.3 0000-1372 42-46 0000-1349 25-29 0000-1348 73 20
Lima IS42S 140-148 1.3 0000-1374 42-46 0000-1349 25-29 0000-1348 73 25
Mike IS41 117-125 1.7 0000-1344 42-46 0000-1350 32-36 0000-1345 43 20
Mike IS42 117-125 1.7 0000-1372 42-46 0000-1350 32-36 0000-1345 43 20
Mike IS42S 117-125 1.7 0000-1374 42-46 0000-1350 32-36 0000-1345 43 25
November IS41 127-135 1.6 0000-1344 42-46 0000-1350 32-36 0000-1346 53 20
November IS42 127-135 1.6 0000-1372 42-46 0000-1350 32-36 0000-1346 53 20
November IS42S 127-135 1.6 0000-1374 42-46 0000-1350 32-36 0000-1346 53 25
Oscar IS41 137-145 1.5 0000-1344 42-46 0000-1350 32-36 0000-1347 63 20
Oscar IS42 137-145 1.5 0000-1372 42-46 0000-1350 32-36 0000-1347 63 20
Oscar IS42S 137-145 1.5 0000-1374 42-46 0000-1350 32-36 0000-1347 63 25
Papa IS41 147-155 1.5 0000-1344 42-46 0000-1350 32-36 0000-1348 73 20
Papa IS42 147-155 1.5 0000-1372 42-46 0000-1350 32-36 0000-1348 73 20
Papa IS42S 147-155 1.5 0000-1374 42-46 0000-1350 32-36 0000-1348 73 25

Click on the image, or click here to download the Slack-R Instructions PDF

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