Singletracks Mountain Bike News, Reviews, MTB Trails and Community › Protected: Forums › Mountain Bike Forum › SRAM's bottom bracket preload ring
Tagged: bb, bearing, Bottom Bracket, sram, truvativ
-
AuthorPosts
-
-
August 20, 2019 at 16:07 #268418
Hi Singletracks Community,
My bike came equipped with SRAM’s Truvativ Stylo 6K DUB crankset (FC-STYL-6K-B1). Unfortunately, it appears that SRAM had spent all their money on ink to print the long name of the crankset, and then, had to go on a cost cutting exercise for the bottom bracket preload ring.
I am looking for a replacement preload ring, but this time, I’d like something made of metal (steel or aluminium alloy) and with a proper thread for the pinch bolt. Is anyone aware of a company manufacturing such a part? Or possibly a compatible spare from another model of SRAM crank? A Google search around the usual small manufacturers of replacement part has not given me any results.
On my other bikes that came with Shimano 105 5800 and Ridea Al/Ti cranksets, the bearing preload is locked in place by the pinch bolts on the left crank. <span style=”display: inline !important; float: none; background-color: #ffffff; color: #333333; font-family: Georgia,’Times New Roman’,’Bitstream Charter’,Times,serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;”>The Truvativ crankset comes by default with a cheap plastic ring to preload the BB bearings. The preload is then locked only by the world’s cheapest self-tapping screw (rather than an M2 or M3 steel bolt a matching Nylon-ring nut).</span>
When riding, the left-to-right axial loads on the BB go through the plastic ring rather than a metal crank (on the Shimano/Ridea design). The result is an varying bearing preload, especially as the plastic expands and contracts (with temperature, humidity, etc.). Subsequently, the spindle and the BB bearing will wear out much faster.
My Shimano 105 5800 cranks have travelled over 20,000 km with no sign of wear. The Ridea cranks, despite their softer titanium spindle, have accumulated over 10,000 km with no sign of wear. I can’t say the same for the SRAM cranks; their surface coating is wearing off fast after less than 3,000 km.
I am hoping that a metal preload ring will solve the issue. Let’s hope someone is making the part, and someone is aware of it. Thanks for your help/ideas finding the part.<b></b><i></i><u></u><span style=”text-decoration: line-through;”></span>
-
February 18, 2021 at 14:45 #581034
Found 2 of them, both quite expensive.
Crankset Preload Adjuster for Sram, Easton & Race Face
I have same issue with wear out anodised surface under non-drive side.
After little research I found that It might be bearings missaligment due to f****ed bottom bracket shell or (and I hope so) lack of preload, as you mentioned.
Let me now if you figure out something.
-
-
AuthorPosts
You must be logged in to reply to this topic.