1985 K100 RS.  Trying to find the right size battery for this bike.  Most new batteries seem to be too tall (so battery's clamping bolts are not long enough to secure battery).

Any thoughts most welcome.

Hello!

Vor German K rides this Battery is the best for the price.
18 Ah is enough even with ABS.
Runs in more than 100 K bikes
There is a 22 Ah version but no real need.

Kung Long WP18-12 12V 18Ah UPS Battery


Cheers

Odyssey PC680

So much has been written (and so many questions asked) about batteries, tyres, oil, etc in the forum. The best advice I can give is to use the previously discussed, collective wisdom of the members. Try going to the the forum's main page and in the search engine type in 'battery' and watch what pops up. There are so many choices, sizes and varied opinions. The BMW OEM battery part numbers are 61 21 2 346 800 (Exide Gel BMW small version) and 61 21 1 459 650 (lead/acid BMW large version). From there you can find cross references to the various aftermarket numbers, like PC680, for example. Two batteries will fit the battery tray. Pick one, but on an 1985 model they both fit.

Here's a link to some good info as well:

http://www.largiader.com/articles/whichbat.html