After 52,600 miles, 15,000 under my stewardship, the forks were leaking and a baggy feeling. The two-piston callipers had suffered over the winter and were binding. So I thought I'd give the front end a refresh.
I did the brakes first. I thought I'd give the callipers from my dormant Daytona a bit of a birthday with a scrub up and use those for a while. That would allow me to spend some time on the Trophy two-piston callipers. The Daytona uses Nissin opposed-piston callipers, two per side of each disk (four per calliper, eight in total). This contrasts with the Trophy callipers, which rely on two pistons acting on one side of the disk, with sliding pins bringing a secondary brake pad into contact with the other side. Sliding pins are pretty notorious for getting sticky. Opposed piston callipers should be more robust, as long as corrosion does not creep behind the piston seals.
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| Splitting one of the Nissin four-piston callipers, and pleased to find it was in good shape |
I decided to replace the master cylinder piston and seals because they are 21 years old (the Daytona was made in 1994). They looked to be in good shape, with the exception of the dust seal around the piston. This had a small tear. I've see water accumulate behind these before with nasty corrosive consequences so it was worth changing this anyway.
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| Daytona disks stripped cleaned and centres repainted silver |
The forks were pretty straightforward to strip because I made up a tool to hold the Trophy's inner damper units when I did them first. These units are retained by a large allen-headed bolt through the bottom of the aluminium outer. The damper has to be held still with a hex-headed rod to undo the allen bolt. It can be a real pain without something that fits the hex. I found some big nuts - (30mm see next blog post) - and suitable threaded rod at an agricultural supplier. I locked the nuts against each other at each end of the threaded rod so they would not rotate on the rod and it worked a charm with a large adjustable spanner to keep it still as I cracked the thread on the allen bolt with a 3/8 drive Allen bit on a tommy bar.
There are two bushes in each leg: one is at the top of the aluminium outer, or 'slider', and the other is on the bottom of the stanchion. The bushes were easy enough to do, the top bush coming out with vigourous working of the stanchion in the outer, after removing a retaining ring, and using a small flat screw driver to spring open the lower bush to slide it off of the chromed stanchion. I had trouble plastic oil control rings that fit into the dampers - I bought the wrong ones for these forks. Doh! So I reused the old ones.
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| The bodywork always seems to come up well with wax shampoo |
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| All shiny again, but more brakey! |
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| Ride out in the dusk of a beautiful Spring day |
7 comments:
Another excellent and informative article - thank you. Makes me feel quite ashamed of the feeble 25k miles my old Trophy has managed to rack up in it's 23 years. Must plan more long range trips.
I've just fitted some four pot callipers along with some low mileage discs from a much later model and have been astonished at the difference in stopping power. Problem is it's highlighted just how soft the front end is so now looking into upgrading the springs and fork oil. Any suggestions as to the best option to firm it all up?
Is there any way I can contact you for more info regarding your forks overhaul and how to make the hex nut bolt holder thingy? Thanks, Gray.
Thanks Gray. Good to hear you are still enjoying your Tremendous Trophy. There's no shame in a relatively modest number of miles. There are plenty of folks out there who do more than me, and others who do less than you. It's the caring that counts.
I'm happy with the 20% stiffer springs I got from Sprint Manufacturing so I'd recommend those. You can then do finer adjustments with spacers/washer for the preload if you like.
I've written another blog post to explain about the stripping the forks with a home-made tool: http://trimotorevival.blogspot.co.uk/2015/06/a-tool-to-help-strip-trophy-trident-and.html
Thanks for replying. I hadn't realised I could change the springs without separating the stanchions - doh! I know my forks have been re-chromed not too long ago but may as well do a complete overhaul when I change the springs if I can locate some nuts and threaded rod.
I can't seem to find the 20% stiffer springs from Sprint Manufacturing you mentioned. There's some 10% stiffer ones but not sure they are for the '92 model? What spring length should they be and are they Showa or Kayaba forks?
Don't know what I'd do without your blog - I'm sure it's the most used bookmark in my browser! Your latest post will be invaluable as usual. I've noticed you've not posted so much lately - is that down to time constraints or because Ruby is pretty much sorted now? My old girl has been through a fair few changes recently and I'm regretting not keeping some sort of account of it all. I'll have to send a pic.
The best thing would be to phone Trevor to ask about the 20% springs. I'm pretty sure the forks are Kayabas but Trevor will know if you give him your VIN (better do that rather than rely on registration year). I've just had a look at his website and see he says they are made for Showas but will fit Kayabas if you sort out your own spacers. They are metal tubes that fill up the space above the springs to set the preload. He might be able to help you out with those too. I made mine up out of some spare tubing I had from another set of forks. I'll whip them out at the weekend to let you know how long I made them.
A pic of your bike would be great: I'd love to post it on this blog. It's true I haven't been blogging so much recently. Yes not so much to say about Ruby with mechanicals essentially sorted now but also life getting in the way. I've a few jobs in mind so there'll be some more posts to come and I'd like to do a big trip some time this year. Life depending ...
Yeah I'll ring Trevor just to make sure I get the right ones. Just curious why you had to fit spacers if you fitted 20% stiffer springs?
And can't for the life of me remember how to post a pic on here. I may have sent some before by email but not sure. I'd also like to contact Tim through here if that's possible as I'm wanting to remove the oil cooler and need some advice before I go ahead with it.
Look forward to following your adventures if you do get a chance to do another big trip. Would be good to meet up with you for a chat if you make it North of Watford Gap!
Hi Gray
You emailed your pics to me before; it was way back in 2013. I tried replying to the address you had then (a virginmedia account) but got a bounce. Maybe you've moved ISP.
Yes I'd forgotten, I've changed it to oldbiker13 @ virginmedia.com without the spaces of course. :-)
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