choutali
400cc級騎士 (大型重型)
註冊時間: 2006-09-03 文章: 544 居住地: 台北市
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發表於: 星期五 六月 01, 2012 12:17 am 文章主題: |
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再分享一個討論: single row bearing 跟 double row bearing
現在的改成15mm後應該只有6205 single row可以用, 不過有人還是上20.6mm的double row, 不過要切spacer.....老外真的很會嚐試
>>以下轉貼:
Update, I wanted to expand on my comment as to why and I found a posting in another forum that explains it better as to why and what I want to do as well with trying to use a double row bearing >>>>
Copied explaination >> I have been reading a lot of forum posts about failures with the 25 mm bearings that HD is presently using. When HD went to the sealed wheel bearings back in 2000, they used an international industry standard OD (52 mm) and Width (20.6 mm), but kept the ID in inches (3/4" and later, 1"). These were pretty stout double row deep-groove ball bearings, and from forum accounts I have read, have relatively few failures compared to the late model (2007 or 2008 onward, depending on model) bearings currently in use.
Then, in 2007 to 2008, depending on model, HD went all the way to an internationally standard bearing size (OD 52 mm, Width 15 mm, ID 25 mm). That international size designation is 6205. Notice the decrease in width, from 20.6 mm to 15 mm. That's because the bearing went from a double row bearing to a single row bearing. From what I can tell from bearing catalogs, going from a double row bearing to a single row bearing represents a drop of 33% in dynamic load rating, and almost 50% reduction is static load rating. So it is not surprising to me to see that more bearing failures are being reported in late model HDs.
As far as converting back to tapered Timken bearings, may I offer a less radical suggestion, which I am also implementing on my '07 Ultra? I like the look of the '09 touring wheels, so I bought a dealer take off front wheel. Instead of going with the original single row bearings, I am swapping them out for 5205-sized bearings, which are double row ball bearings (52 mm OD, 20.6 mm Width, 25 mm ID). They fit in the same bearing space as the originals, but are 5.6 mm wider. The wheel spacers need to be cut down by that same 5.6 mm, but it promises to be a bolt-in swap, while retaining the strength of the double row ball bearings. NOTE: This may not be as easy to do on a bike with the ABS sensor.
What was HD thinking when they went to single row ball bearings? Maybe they worked in their labs, but out in the real world, the number of reported failures is alarming. |
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