Stick a Fork in Me

Yeah, okay, that was a bad pun...

Hmm, something's missing here.

Most motorcycles come with suspensions that are set up for a rider who is about 175 pounds, and well, I haven't seen those numbers on the scale in quite some time.  The ST1300 is no exception and comes under-sprung and too softly damped causing poor braking performance, limited bottom-out resistance, and harshness over high speed bumps.  While a lot of folks never notice these shortcomings, after spending many 8+ hour days in the saddle back in May, it became very obvious that I had to do something to the front suspension.

After researching the options, I decided to go with a non-progressive setup from Sonic Springs. Costing under $90 for a set of high quality chrome silicon steel springs, this seemed like a reasonable place to start - if the results were terrible, I wouldn't be out a lot of money, and reviews at ST-Owners were overall very positive.  I considered progressive springs, but after taking into consideration how heavy the bike is, and that there is so little suspension travel to begin with, I felt I would run out of suspension travel just as the heavier side of the progressive spring was being put into action.

Based on Sonic's spring rate calculator, I ordered a set of springs rated at  1.2kg/mm. This is a pretty vast difference from the stock springs which are rated at .860 kg/mm, and should support the weight of the bike with me on it much better. I cut my spacers at 140mm, giving me about 25mm worth of preload on the front end.  This will reduce the amount of suspension sag, or travel, that will be used up just to support the bike, leaving more active suspension available for riding.

To finish off the rebuild, I used BMW's 7.5w fork oil, set to a level of 125mm.  The general rule of thumb is to set fork oil fairly close the amount of travel that the forks have - the ST1300 has 117mm of fork travel - and I went slightly over that to help stiffen the front end up a tiny bit more.

With new fork seals, new fork wipers, Sonic Springs, spacers, and fresh oil installed, it was time to put the front end back together again.

It was then time to turn my attentions to the rear shock.  Honda was thoughtful enough to put a remotely adjustable preload module on the rear, and while it doesn't change the spring rate from being too low, it does help to offset some of the demand that us larger guys put on the shock.

To service the preload system, I removed the controller from the bike, and flushed it and the preload module with fresh fork oil. After reinstalling the controller the full range of preload options was restored.

Unfortunately, the rear shock is not user rebuild-able and I'll eventually have to send it off to a suspension specialist to have it upgraded. For now, I have to say I'm a lot happier with the suspension on the bike, especially when you consider that the total cost involved for the springs, fork seals and wipers, and fork oil was under $200 total.

Turnin' Wrenches on the Maxima

This afternoon I braved the hot and humid weather and got caught up on some maintenance that was due on the Maxima.

I was recently able to trace the source of a minor oil leak to the oil cooler housing.  Seems that after 119,000 miles the O-Ring seal wasn't sealing any more.  Not too hard of a fix - pull the right front wheel, remove the splash guard, remove the oil filter, and then you can access the 22MM fitting that holds the oil cooler onto the engine block. The car was due for an oil change anyway, so pulling the oil filter was something I needed to do anyway.

Wheel off, splash shield almost down...

After the oil drained from the filter housing and the oil pan, I started taking the cooler off.

There are two small diameter coolant hoses that attach to the oil cooler housing.  I was ready to disconnect both of them (those yellow SnapOn hose pinch pliers remain one of the best tool purchases I've ever made) , but only needed to pull the one on the right.  Comparing the new O-Ring to the old made it obvious just how much the old one had shrunk.  After cleaning the housing and engine block mating surfaces, I put the new O-Ring in and put everything back together again.  After adding 4.25qt of Mobile 1 5w30 and a bit of coolant to top the radiator off, I started the engine, and....

No leaks, yeah!  The local dealership wanted almost 200$ to replace this O-Ring, and that didn't even include an oil change.  I bought the O-Ring on Amazon from a Nissan parts house for $9 and it only added about half an hour's worth of work to the oil change I was going to do anyway.