Wednesday 20 December 2017

The new TR1 motor - the gearbox conundrum and reassembly (part 15)

Now every interesting build starts with one or two things you want to learn or try out in the process. With regards to gearboxes, there's conflicting infos on whether the XV1100 sports the regular (0.90) or the longer (0.85) 5th gear. (If you're only here for the picture or suffer from attention span issues: yes it does have the longer 5th. And yes it will fit into the chaindrive cases.)

When I took my very first XV1100 engine apart I stashed away the gearbox of said bike, because it was nearly brandnew (less than 30k on the clock) and kept the original TR1 gearbox, because it worked pretty flawless.

But first a quick how-to on how to get the old gearbox out.

First pull out the shifter fork shaft, so you can remove gearbox shafts (incl. gears) as one.

If you're like me and often end up with sh*te in boxes and have to assemble an engine from said leftovers, you may find this picture useful.

This picture should be self explanatory. 😏

At this point is is (once more) a good time to clean out all the old dirt, debris and little furry animals that have decided to apply for permanent residency.

Now onto the meat of this post. Is the gearing of a XV1100 and TR1 the same?

As you can see in the picture, this is a gearbox with 5th gear(s) facing towards the front. 

TR1 gearbox: (29/34 - 0.85)

XV1100 gearbox: (30/33 - 0.90)

Both gearboxes side by side.

Gearbox installation is pretty straight forward. Make sure that you know where the dot (which is the neutral light plunger) on the selector shaft is and you're pretty much golden. 

Install the gearbox shafts as a pair and be aware that the #3 selector fork should be installed on 5th gear prior to install or you'll prove to your neighbours that you truly are capable of cursing like a sailor. 

Install the selector fork shaft (this will require a bit of wiggling for and aft to get all the forks to alighn with the selector drum).

Don't be surprised that in order to achieve this, the venerable gearbox-assembly-mallet makes an appearance. (In my case it was the selector drum, which needed a gentle tap to become fully seated.)

The primary drive ratio between shaft and chain drive models is different, so the primary drive sprocket has to be swapped out, in case you're using a XV1100 gearbox. 

Shaft-drive on the left, chain drive on the right.

And that's the gearbox installed in the cases. Try spinning the gears a bit and also trying changing gears by operating the selector drum manually and you should be good to go.

No comments:

Post a Comment