How to put a trailing slash from a mod rewrite - php

Question

I'm having a problem using this rewrite:
RewriteCond %{HTTP_HOST} www.example.com$
RewriteRule ^(.*)$ http://example.com$1 [R=301,L]
to remove the www url
But the return is a url without a trailing slash. For example: example.com/subfolder which supposedly has a url of example.com/subfolder, but the result is example.comsubfolder whch breaks the url. Anyone could help me solving this? Many thanks!
EDIT: here's my whole .htaccess
Header unset Pragma
FileETag None
Header unset ETag
# 1 YEAR
<FilesMatch "\.(ico|pdf|flv)$">
Header set Cache-Control "max-age=29030400, public"
</FilesMatch>
# 1 WEEK
<FilesMatch "\.(jpg|jpeg|png|gif|swf)$">
Header set Cache-Control "max-age=604800, public"
</FilesMatch>
# 2 DAYS 172800
<FilesMatch "\.(xml|txt|css|js)$">
Header set Cache-Control "max-age=604800, proxy-revalidate"
</FilesMatch>
# 1 MIN
<FilesMatch "\.(html|htm)$">
Header set Cache-Control "max-age=60, private, proxy-revalidate"
</FilesMatch>
<FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)$">
Header set Expires "Thu, 15 Dec 2011 20:00:00 GMT"
</FilesMatch>
RewriteEngine On
RewriteCond %{QUERY_STRING} (^|\?)f=([0-9]+)&t=([0-9]+)($|&)
RewriteRule ^viewtopic\.php$ /index.php?threads/%3/ [R=301,L]
RewriteCond %{QUERY_STRING} (^|\?)f=([0-9]+)($|&)
RewriteRule ^viewforum\.php$ /index.php?forums/%2/ [R=301,L]
RewriteCond %{HTTP_HOST} www.example.com$
RewriteRule ^(.*)$ http://example.com/$1 [R=301,L]
# Use PHP5.4 Single php.ini as default
AddHandler application/x-httpd-php54s .php
#
# Uncomment the statement below if you want to make use of
# HTTP authentication and it does not already work.
# This could be required if you are for example using PHP via Apache CGI.
#
## EXPIRES CACHING ##
<IfModule mod_expires.c>
# Enable expirations
ExpiresActive On
# Default directive
ExpiresDefault "access plus 1 month"
# My favicon
ExpiresByType image/x-icon "access plus 1 yearâ€
# Images
ExpiresByType image/gif "access plus 1 month"
ExpiresByType image/png "access plus 1 month"
ExpiresByType image/jpg "access plus 1 month"
ExpiresByType image/jpeg "access plus 1 month"
# CSS
ExpiresByType text/css "access 1 monthâ€
# Javascript
ExpiresByType application/javascript "access plus 1 year"
</IfModule>
## EXPIRES CACHING ##
#<IfModule mod_rewrite.c>
#RewriteEngine on
#RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
#</IfModule>
<Files "config.php">
Order Allow,Deny
Deny from All
</Files>
<Files "common.php">
Order Allow,Deny
Deny from All
</Files>
DirectoryIndex portal.php index.php index.html index.htm
RewriteCond %{HTTP_REFERER} !^http://example.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://example.com$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.example.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.example.com$ [NC]
RewriteRule .*\.(jpg|jpeg|gif|png|bmp)$ - [F,NC]
# Start CloudFlare:example.com rewrite. Do not Edit
RewriteCond %{HTTP_HOST} ^example.com
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]
# End CloudFlare rewrite.
# Mod_security can interfere with uploading of content such as attachments. If you
# cannot attach files, remove the "#" from the lines below.
#<IfModule mod_security.c>
# SecFilterEngine Off
# SecFilterScanPOST Off
#</IfModule>
ErrorDocument 401 default
ErrorDocument 403 default
ErrorDocument 404 default
ErrorDocument 405 default
ErrorDocument 406 default
ErrorDocument 500 default
ErrorDocument 501 default
ErrorDocument 503 default
<IfModule mod_rewrite.c>
# If you are having problems with the rewrite rules, remove the "#" from the
# line that begins "RewriteBase" below. You will also have to change the path
# This line may be needed to enable WebDAV editing with PHP as a CGI.
#RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^(data/|js/|styles/|install/|favicon\.ico|crossdomain\.xml|robots\.txt) - [NC,L]
RewriteRule ^.*$ index.php [NC,L]
</IfModule>