Saturday 12 September 2020

Triumph Bonneville T100 brake upgrade - Part 2 Front

 

Disclaimer

This article concerns making modifications to a bike's braking system. Due to the potential hazards, do not attempt this unless you are mechanically competent in carrying out the work safely. I'm posting this in an advisory rather than instructional capacity, so any work you carry out is at your own risk.

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Turning now to the front caliper which I believe is similar or the same as that fitted to some Hondas including versions of the CBR 600. This isn't very powerful, the lighter CBR 600 used two of the calipers, but can be upgraded. When I bought mine the front brake was a bit sticky, so I stripped it down and replaced the seals and pistons with stainless replacements.



Link to Ebay listing

It's also worthwhile replacing the locating pin with a stainless one to prevent grief later.



Link to supplier

For some weird reason, although the front caliper banjo bolt has a metric thread it has an inch head. I had to buy a 9/16” socket to remove it, stupid stuff like this annoys me so I replaced it with a metric stainless Allen headed bolt.



Once I'd stripped and rebuilt my caliper the braking was better, but still pretty poor. There are a couple of ways you can upgrade the brakes to improve braking.

Firstly, the expensive route. There are a number of replacement calipers that are a straight bolt on.



Link



link


Link

Both of the above suppliers also sell floating replacement discs. (more about that later.)

Note: there may be other brake upgrades, if you discover any let me know and I'll add them.


A cheaper alternative is using a different Nissin caliper, these are available used and can be fitted with some modification.

Before going any further, read the Disclaimer at the top of this page and these following articles:

Link 1

Link 2

Link 3

Link 4

Firstly, find a suitable 3 piston left hand side Nissin caliper as fitted to a number of Honda models. List from one of the articles mentioned:

2009 NSA700A F-10-1 L FRONT BRAKE CALIPER
2008 NSA700A F-10-1 L. FRONT BRAKE CALIPER
2010 CBF600SA F-12-20 FRONT BRAKE CALIPER (L)
2010 CBF600NA F-12-20 FRONT BRAKE CALIPER (L.)
2009 CBF600SA F-10-1 FRONT BRAKE CALIPER (L)
2009 CBF1000T F-11-2 FRONT BRAKE CALIPER
2006 CBF1000A F-11-2 L.FRONT BRAKE CALIPER
2012 CBR600FA F-10-2 F. FRONT BRAKE CALIPER
2010 CBF1000TA F-11-2 LEFT FRONT BRAKE CALIPER
2009 CBF1000S F-12-2 L. FRONT BRAKE CALIPER
2011 CBR600FA F-10-2 LEFT FRONT BRAKE CALIPER
2010 CBF1000SA F-11-2 LEFT FRONT BRAKE CALIPER
2009 CBF600NA F-10-1 FRONT BRAKE CALIPER (L)
2009 CBF1000A F-11-2 L. FRONT BRAKE CALIPER
2008 CBF1000TA F-11-2 L. FRONT BRAKE CALIPER
2010 CBF1000FTA F-12-20 LEFT FRONT BRAKE CALIPER
2008 CBF1000SA F-11-2 L. FRONT BRAKE CALIPER
2012 CBF1000FT F-12-20 L. FRONT BRAKE CALIPER
2011 CBF1000FT F-12-20 L.FRONT BRAKE CALIPER
2010 CBF1000A F-11-2 L. FRONT BRAKE CALIPER
2008 CBF1000A F-11-2 L. FRONT BRAKE CALIPER
2011 CBF1000FS F-12-20 L. FRONT BRAKE CALIPER
2010 CBF1000FSA F-12-20 LEFT FRONT BRAKE CALIPER
2010 CBF1000FA F-12-20 L. FRONT BRAKE CALIPER
2012 CBF1000FS F-12-20 L.FRONT BRAKE CALIPER
2012 CBF1000FA F-12-20 L. FRONT BRAKE CALIPER
2011 CBF1000FA F-12-20 L. FRONT BRAKE CALIPER
2011 CB600FA F-10-2 L. FRONT BRAKE CALIPER
2009 CB600F3A F-10-2 L. FRONT BRAKE CALIPER
2010 CB600FA F-10-2 L. FRONT BRAKE CALIPER
2008 CB600FA F-10-2 L. FRONT BRAKE CALIPER
2007 CB600FA F-10-2 L. FRONT BRAKE CALIPER
2008 CBF600SA F-10-2 FRONT BRAKE CALIPER (L.)
2008 CBF600NA F-10-2 FRONT BRAKE CALIPER (L.)
2012 CB1000RA F-11-2 L. FRONT BRAKE CALIPER
2011 CB1000RA F-11-2 L. FRONT BRAKE CALIPER
2010 CB1300SA F-11 R. FRONT BRAKE CALIPER
2009 CB1000RA F-11-2 L. FRONT BRAKE CALIPER
2010 CB1000RA F-11-2 L.FRONT BRAKE CALIPER
2007 CBF1000T F-11-2 L. FRONT BRAKE CALIPER
2007 CBF1000S F-11-2 L. FRONT BRAKE CALIPER
2007 CBF1000A F-11-2 L. FRONT BRAKE CALIPER
2012 CB600FA F-10-2 L. FRONT BRAKE CALIPER
2009 CB600FA F-10-2 L. FRONT BRAKE CALIPER

There are a number of similar calipers, the one you want looks like this.



There are two versions of this, those used on models with linked brakes and those without. Unlinked calipers are much rarer but are easier to fit. Linked calipers have to be 'delinked' before fitting.

Delinking a caliper.

The 3 pistons in the caliper are operated by 2 inputs: the outer two pistons by the upper inlet (operated by the front brake lever on Hondas), and the centre piston by the lower inlet (rear brake). The outer pistons are connected by a passage behind the centre piston. To 'delink' you need to remove the pistons and drill through the back of the centre chamber to break into this passage. A good tip is to remove the end bleed nipple and push the tube from a spray can of WD-40 or similar in until it can be seen through the outer chambers. You want to drill through the back of the centre chamber in line with this tube (I used a long 3mm drill). When you see flakes of the plastic tube appearing in the aluminium swarf then you know you're reached it.




When you've drilled a neat hole give the caliper a thorough clean to remove any flakes and chips of metal and plastic.

Rebuild the caliper using new seals. A lot of pattern seals are poor quality (don't ask!), so either use Genuine Honda seals or ones from a reputable supplier. I got mine here: Link

You now have to block the lower input as now all 3 pistons will be operated by the upper input. Use a short screw with a finer than standard M10 x 1.25 thread and seal with a copper banjo bolt washer.

You need a mounting bracket to fit the caliper to the fork. Part to use is Honda 45190-MFA-D11. This is used on the following bikes:

Honda 2009 DN-01

Honda 2011-2015 CB1000RA

Honda 2013 CB1100AD

I searched for ages but was unable to find a used one, so had to buy new. Cheapest place I could find was Partzilla in the US who, even taking in postage and import costs, was cheaper than suppliers in the UK. Link



Now it's just a case of bolting the caliper and bracket on, connecting the brake hose, and bleeding the caliper. You have to bleed it from both nipples, but the lower nipple traps very little air.


I fitted a new brake hose as mine was a bit untidy looking. I had ordered the one listed by Venhill for the Bonneville, but although it would work, I didn't like how tight it was. I ordered another one 30mm longer, this won't be a problem if your bars aren't as high as mine.



If you have a spoked wheel Bonneville you will now encounter another problem – the lower mudguard stay fouls on the (longer) caliper. Rotate the stay down the mudguard until it clears the caliper and drill 2 holes in the mudguard and attach it with screws and nuts. Put some short screws into the old mounting holes to tidy them up. Whilst doing this I also fitted a rubber mudflap.



I also fitted a new, floating disc as I was using my newly rebuilt wheels. This isn't necessary as your old disc will work fine with the new caliper.

Check everything is attached properly and no fluid is leaking and take the bike for a ride to bed in the brake pads. Once pads are bedded in the brake should be a lot more powerful but, more importantly, there will have a lot more 'feel' so you will have more control over braking. There will be a very small increase in lever travel, but it's insignificant.



Only problem is that the improved brake shows up how poor the springs in the front forks are – next job, uprated fork springs!









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