Triumphrat

rodneybrown · 09-24-2006

Finally got it off. Took progressively thicker flat tip screwdrivers and wedged them between the top plate and the adjusting nut. Apply hammer to screwdriver and watch it creep up and off. The plate had frozen to the axle of the triple tree between the top (smaller) and the wider bottom threads. So far this makes the front axle bolt, rear axle stake nut, and two or three sprocket bolts that have been frozen due to corrosion or galvanic action. I'm beginning to think Triumphs are bio-degradeable.

The adjusting nut definitely isn't a 36mm, maybe a 38. In any event. This is the last time I grease these frickin' bearings. It ain't like they are hitting 10K rpm.

MNSpintST · 09-24-2006

Hmm

Stock
25x52x15
Tapered roller
25x52x16.25

1.25 millimeters = 0.0492125984 inches

1/16" = 0.0625

1/20" = .05

Any way did I mention that despite being american that the SAE system sucks as compared to metric units....

I'm guessing that the 1.25mm increase in width does'nt matter...

Another lowbuck smart mod to add to the list..

rodneybrown · 09-24-2006

There is a tapered roller bearing at the bottom of the triple tree that really does all the work. the one at the top pretty much just keeps the axle (or whatever you want to call it) centered. So using a tapered roller bearing is IMO overkill. I just replaced the top bearing with the anular contact bearing but right now I'm not all that sure if greasing the bottom bearing is worth it. It might be best to run it till it breaks.

Stlakid · 09-25-2006

Glad you got it figured out Rodney. The assembly is under a little load when you loosen things up because the weight of the tire is trying to drop straight down, but the steering head is at an angle.

I never took out my bottom bearing to grease it. Just let the assembly drop about an inch out of the crown and get some fresh grease on the lower bearing. I had my front wheel off the ground about 1.5" so I just let it drop until it hit the ground. Try to get things in alignment when you reassemble the bearings as the forks will try to pull them out of alignment without both triple trees in place and you will remove aluminum from the top tree when you try to reassemble it if it's not aligned. As me how I know!

rodneybrown · 09-25-2006

Because I was replacing the top bearing I had to take it out. You have to put something up the neck to knock out the old bearing because it is press fitted. You are correct about lining things up but I didn't see any aluminum. I'm still not done because the frozen top plate made a 15 minute job take a couple of hours.

Stlakid · 09-25-2006

I guess that's another one of the joys of living in California, it doesn't get that wet here. My top bearing slipped right out with my fingers once the shaft had been lowered out of it. Sounds like you have a handle on things though.

rodneybrown · 09-25-2006

It's back together. If you want to see pics of this stuff look in
http://www.triumphrat.net/modules.ph...view_album.php
where you'll see stuff like

After action report says the nut is 38mm or 1.5 inches. Old bearing has to be knocked out and new driven in place. 32nm is way too much and will lock up steering.

nortoncharlie · 10-02-2006

The 32 Nm is simply to set the bearings in place, they then need to be backed off to zero preload/zero play. I guess a little preload is better than a little play. Any play will allow the bearings to hammer against the race and dimple them up pretty quick.

rodneybrown · 10-02-2006

I'm not sure what I wound up with but it wasn't anywhere near the 32nm. When I put that torque on, my bars wouldn't even turn. Actually, when the top piece initially came off, you could spin the adjusting nut with two fingers. Funny, it wasn't nicked, notched or whatever, the bars seemed to be totally free and there was no play but I'll swear it stears better now.

Grae_ST · 11-15-2007

Thought I'd dig up this post, as I'm having probs with my head bearings.

As the 20000Km service is fast approaching, i figure it's a good time to fit Tapered Roller Bearings Bottom and Top.

So, my question is are these the correct dimensions for my '07 Sprint or have they changed?

Stock
25x52x15
Tapered roller
25x52x16.25

The fiche on BikeBandit shows different dimensions:- 30 x 55 x 17.

Thanks in advance for your help!!

Cheers, G