Ascot Forum

First Generation Ascots => Tech Section => Topic started by: AwL on February 02, 2018, 06:00:03 pm

Title: front brake master cylinder
Post by: AwL on February 02, 2018, 06:00:03 pm

Hi - looking for source of front brake master cylinder that has the correct 10m bolt hole for mirror.
Many on ebay with brake line banjo bolt facing forward like the stock one but they all seem to have 8m bolt hole for mirror.
Others with banjo bolt pointed parallel to handlebar seem to have correct mirror bolt hole but are larger bore 16mm - don't think that would make a difference?. 
Any experience with these units?  Mine is beyond rebuild.  (sorry for double posting - inadvertently put it second generation tech section.) 

Title: Re: front brake master cylinder
Post by: J6G1Z on February 02, 2018, 11:20:08 pm

For the FT Ascot, or the VT Ascot?

Here is one option for the single cylinder FT500 Ascot: https://www.randakks.com/honda-ft500-ascot-single.html

J.

Title: Re: front brake master cylinder
Post by: J6G1Z on February 02, 2018, 11:35:03 pm

I used a master cylinder from a Ducati Monster for my FT500 Ascot with a dual disk brake CBR600 front-end.
http://ascot500.com/index.php?topic=16.msg50#msg50
The original Ascot mirror fit perfect.

Don't know how well it might work with a single disk.

J.

Title: Re: front brake master cylinder
Post by: AwL on February 10, 2018, 01:37:42 pm

Found a new unit on ebay that had the correct 10M bolt hole for the mirror.
$29 from MegaCtore.
The listing specifically said it had the 10M mirror bolt hole.
There are a lot of similar items on ebay but most don't specify bolt hole size and some at least are 8M.
Chinese made copy of OEM unit and seems well made.  Price fit my "get'r on the road" approach to project.

Title: Re: front brake master cylinder
Post by: J6G1Z on February 10, 2018, 02:45:56 pm

What is the piston bore diameter?

Thanks
J.

Title: Re: front brake master cylinder
Post by: AwL on February 15, 2018, 01:52:12 am

Piston bore diameter is 14mm.  Here's link to the one i got:
https://www.ebay.com/itm/Honda-CX500-CX650-FT500-GL500-Ascot-XBR500-CB250-CB450-650-Brake-Master-Cylinder-/271183213152

Title: Re: front brake master cylinder
Post by: J6G1Z on February 15, 2018, 09:12:57 am

Please let us know how well it works after you test it.

Thanks
J.

Title: Re: front brake master cylinder
Post by: triguyracer on February 15, 2018, 12:24:45 pm

14 mm piston bore is the right size for a single disk, Dual disks will have a larger bore to move more fluid ,going to a smaller bore on a single disk will increase the firm ness on your lever up to a point,12 mm seems to be the lower limit for a front brake ,some bikes there rear master cylinder will be as low as 10 or 11 mm bore size,your 14 mm is just  about right for most applications for a single disk, it should be firm without excessive lever travel,by going to a larger than 14 mm bore size you will increase lever travel and your lever will have a softer feel as you will be having to move more fluid,16 mm is a dual disk size   

Title: Re: front brake master cylinder
Post by: AwL on May 26, 2018, 02:07:22 am

Yes that one i got from ebay works just fine and does have the 10mm bolt hole for mirrors