• NEW USERS: If you haven't received your Confirmation Email: There has been an ongoing issue with the forum's send mail function and many new users haven't received the email to confirm their registration. I've done my best to manually process these, so there's a good chance if you've signed up in the past 30 days that you've already been validated and can proceed with posting on the forum (don't forget to introduce yourself!). If you still can't get in, please use the Contact Us link on the bottom of any page to send me a message and I'll process you manually. Thanks for your patience! ~Jerk

Harley street 750/500 calipers thread

Andyb

Well travelled
Location
UK
In the past I have noticed that in India that quite a few motorbikes and cycles do not have working front brakes. I remember talking to one person who was adamant that front brakes were dangerous as if you used them the bike would tip over forwards. Attitudes may have changed, but certainly in the past Indian two wheel riders relied on the rear brake much more than the front which at slow road speeds was fine.
 

brother i

Getting there...
Location
NorCal, US
I just picked up mine from the dealer (new 2022) and rode 40 miles home. I always use both front and rear brakes when coming to a stop. Because it is in the break-in period, I did not went over 50 mph...

Overall? I did not see any issues with stopping power. I will give it the full 300 miles break-in before making changes.

Wish? Yeah, wished the front would be a bit more aggressive, that it had more initial bite. I think that in my case, just changing pads might do the trick. But I will wait the 300 miles and see how it feels then.

Nevertheless, I got the caliper and will measure and test as well with it.
Wohoo congrats!!!
I’ll do measurements and share findings when I get around to doing that project, look forward to comparing notes :)

Also - thanks for the input, everyone else!
 

MikeM

Well travelled
Location
So Cal USA
Haven’t been here in a while but saw this thread. Wanted to post a link to the caliper I used. I’ve updated my YouTube post to show the correct part numbers in the description.

 

Attachments

MikeM

Well travelled
Location
So Cal USA
TL;DR:

Looks like there are two different calipers that might work a direct bolt-on replacement, both have bigger (and even bigger) pistons (which may affect lever travel? tbd); one type takes OEM size pads another larger pads.

TS;WM:

Hi friends!

Search showed there's a little bit of discussion in this thread of potentially swapping the front caliper for an Indian-made Harley caliper. Seems promising, so maybe it might merit a thread of it's own!

The inspiration came from Mike on Youtube - he's done a number of things to his bike, and this was the latest mod so far. After a half an hour test ride he reports better feel.


Searching through eBay for "harley davidson street 750 front brake caliper" it seems there are two different looking calipers that are listed as coming / fitting the same bike. One has no logos on the front, that one is exactly like Mike's in the video (I'll refer to it as type 1). Second one has a Harley logo (I'll refer to it as type 2).



Mike reports in the video that his new caliper (type 1) takes the same pads as OEM.

For Himalayan, EBC part finder page suggests part number FA181HH.
Interestingly, for Harley XG Street the EBC part finder page suggests a different part number - FA643HH 🤔.


But wait, there's more!

I ordered one of the calipers, of "type 2", the one with Harley logo on it (mainly because I thought it looked cooler, and it was nearby so shipping was quick). Holding it up against the wheel appears to have the same mounting position - so I'm hopeful it will fit (might attempt tomorrow or over the weekend). HOWEVER! I had also ordered EBC brakes as part finder suggested for Himalayan (FA181HH), but the pads inside that new-for-me caliper are markedly larger. The marking on the pads says "brembo", with part numbers 07.5270.36 and 07.5270.46. Searching the internet for these part numbers found this Russian site - which has a fitment tab ("ПОДХОДИТ ДЛЯ") that lists a ton of bikes, including the Harley we expect, which is promising. Searching official brembo site for this Harley model doesn't reveal the same part numbers (maybe they mark the pads with a code that isn't a part number? ¯\_(ツ)_/¯), but for the pads it does suggest an interesting different overlap - for the pads it does find, it says they'd also fit Royal Enfield Continentals and Interceptors of some years. Fascinating, maybe calipers from other RE models could be a direct bolt-on?

I cleaned it up to make all shiny-like, and took some pictures for you. Also took a picture of the brembo pads that came in the caliper side-by-side with EBC pads for OEM caliper, where you can see the size difference.





More pad should be more friction, right? Should be more deceleration! Also more heat, but at Himalayan speeds that probably won't come into play.


But wait! There's more!!!

Mike in the YouTube video above mentioned he measured the piston diameter of OEM caliper (26mm) and the replacement caliper of type 1 (without logo) had pistons 2mm larger - 28mm.

If my calculatoring is correct, that would mean a piston surface area increase of π * 14^2 / π * 13^2 = 14^2 / 13^2 = 196/169 ~1.16 - so around 16% increase over OEM.

I went ahead and measured the pistons on the type 2 Harley caliper (the one with the logo, which we don't even know yet if it will even fit at all).



The pistons on "type 2" Harley caliper are markedly larger, at 30mm and 32mm diameters. That same calculation over OEM would now need to include both OEM pistons and areas of two differently sized Harley pistons - but still trivial: (π * 15^2 + π * 16^2) / 2π * 13^2 = π(15^2 + 16^2) / 2*π*169 = 481π / 338π = 481/338 ~ 1.42, so a whopping 42% increase in piston surface area.

----

With that much more surface area, presumably it will take quite a bit more brake fluid to push these pistons the same distance to clamp the pads to the disk. Assuming the caliper fits on the same mounting points and everything "just fits", given the larger amount of fluid required I would assume the lever travel will be increased compared to stock? Might that be mitigated with a different master cylinder, and if so - is that something a not-very-talented but very love-to-tinker person like myself could potentially manage?

What do you all think?

Also, did I miss anything important or did my maths lead me astray anywhere?

Also, thoughts on potentially fitting calipers from Continentals or Interceptors - brembo says the pads would fit calipers of those bikes, but is the mounting hardware the same?
I updated the Youtube Video with a link to this discussion.
 
Top Bottom