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MC Bore Size Suggestions
scootz - 1/5/11 at 08:14 PM

The trike has a set of Wilwood Powerlite (small 4-pots) on the front, and a single Powerlite on the rear.

The pedal-box is set-up for individual cylinders - would the tried-and-tested 0.7 and 0.625 MC combo's still be in order, or do I need something a bit different?

Cheers!


designer - 2/5/11 at 08:47 AM

Sadly, with a trike I think it's a matter of 'suck it and see' with brake balance.

Ideally balance should be just about proportional to the weight front to rear; e.g. 45/55%. But, it's a 'black art' to me, so I intend to fit an adjustable valve on the rear circuit and do the adjustments on the road, in the dry and in the wet. Then lock the valve at the setting.


blakep82 - 2/5/11 at 08:57 AM

what way does it work again, is it the smaller master cylinder normally goes on the front, bigger on the back?

i'd think, because you've only got one caliper on the back, you might want a 0.625 on the front and the biggest you can on the back i think there's a bigger one than 0.75. think you probably want less pressure on that one, as the cylinder only needs to do half the work.
never built a trike though, surprised no one who has, has answered yet


scootz - 2/5/11 at 06:42 PM

Cheers guys... anyone else got any starters-for-ten?


Mark Allanson - 9/5/11 at 07:05 PM

Why not go for a single MC and a pressure reducing valve for the rear, then you can adjust it until it is perfect and lock for IVA/MSVA


phelpsa - 9/5/11 at 07:07 PM

quote:
Originally posted by designer
Ideally balance should be just about proportional to the weight front to rear; e.g. 45/55%


You'd be locking the rears all the time with that sort of bias! Weight transfer....


scootz - 9/5/11 at 07:14 PM

quote:
Originally posted by Mark Allanson
Why not go for a single MC and a pressure reducing valve for the rear, then you can adjust it until it is perfect and lock for IVA/MSVA


Cheer Mark... that was a consideration!

Were you thinking of a 'single' single MC to work all three calipers, or a single 'tandem' MC?

Any thoughts on sizes?


Mark Allanson - 9/5/11 at 07:35 PM

I was thinking a 19mm Fiesta non servo unit with a Fiat Uno bias valve made adjustable, I think the effort to the rear would have to be negligible.

Bias valve operating on the rear only (edited)

[Edited on 9/5/11 by Mark Allanson]


scootz - 9/5/11 at 07:36 PM

Thanks Mark... I'll look into it.


scootz - 9/5/11 at 08:18 PM

I'm getting in a muddle here with the suitability of either a Tandem MC or Single MC.

Obviously a Tandem is designed to work front and rear, and would work in my case. Job done!

However, would a large capacity single cylinder such as this Wilwood 3/4 bore be man enough for 3 calipers (proportioning valve on the single-caliper rear-line)?



MC Specs


daviep - 9/5/11 at 09:07 PM

From the safety angle I personally wouldn't be happy with a single master cylinder doing all three wheels, if you have a failure anywhere in the system you've got no brakes at all, at least with a split circuit such as the fiesta you would still have some breaks if you had a failure.

Davie


scootz - 9/5/11 at 09:16 PM

Yep - that makes sense!

Cheers!