Hello all, I've got my 1957 M21 on the road and am more confident in taking longer trips (10-20 minutes around the neighborhood).

One "problem" I'm finding is downshifting. I shift up through the gears fine (although I'm finding that "false neutral between 3 and 4), but downshifting is a bit problematic, sometimes I try just a couple of attempts, grind the gears, come to a stop (carefully) downshift back to first, then start up again. Sometimes the gearbox works better.

I'm going to move the shift lever, I think I have it set high for my foot so I'm not getting a good pull on it, but was wondering if there are other things to check?

Many thanks in advance!

Hello Jack,

Did you try to rev the motor a little bit before shifting down?
I usually rev for half second,
I pull the throttle quickly about 2 cm leave the throttle immediately,
And then shift down, as I am slowing down before traffic lights or whatever.
It helps to even up and sync the revolution speed of the main and lay shafts,
For a smoother engagement.

Of course, you would also like the clutch to be completely separating.

Noam.

Thank you Noam, I'll certainly try that this evening and let you know!

I rev the engine to downshift as well. I wasn't sure if that was the right way to do it but I found it to work.

email (option): xeon25@hotmail.com

Some of the after market clutch friction plates can be too thick, and with a full set of those, there's not enough room in the clutch basket for them to separate properly and can cause serious clutch drag. My method (along with many other guys) is to leave out one steel and one friction plate. No slip, no drag and a much lighter clutch at the handlebar lever.

Also worth checking the centre nut of the clutch is tight so the the whole thing is not sliding on the shaft.

I think Ian Wright has complete sets of proper clutch plates at a very reasonable price.

Ron

email (option): ronpier@talk21.com

Yes as the revs die off you momertarily take the load off the gear dogs.

My right foot does not bend so I have to pull the lever with the inside of my heel.

I do hope you are running oil in the box and not liquid grease

email (option): bsansw1@tpg.com.au

Thank you, yes OIL! I am running motor oil in the gearbox, same oil as in the engine. I did put red automatic transmission fluid in the chain case to see where I'm leaking from. I'm also having a nasty, nasty wet sumping issue and am now pouring oil (loads of it) all over the ground. It looks like it actually fills up my chaincase if that's possible?

I'm working through that problem, seeing how much oil I need to drain and put back into the tank - which may be related to my downshifting problem (to much oil in the chaincase if it's leaking in there maybe?).

I'm still learning about these bikes so please forgive my very amateur thought process if it's wrong!

Yes wet sumping oil can leak through the main bearings and oil will get onto the 'dry clutch'.

First thing the check, is remove the little hex plug near the bottom of your timing case and check the ball and spring (or better still fit new ones for a couple of quid). Squirt it clean inside and give the new ball a light sharp tap with a punch and hammer to give it a fresh seat.

If your clutch is contaminated with oil, you will have to strip it and clean it all up thoroughly. Ron

email (option): ronpier@talk21.com

Thanks Ron, I fear that's what has happened. First, the downshifting problem, SOLVED! THANK YOU ALL! Now the bad news, I had my first "long walk home!" Before today's ride, I drained a load of oil out of the chain case and main case (didnt reuse that) and she started with some fight on the Kickstarter. I was riding home, stopped at a stop sign, went to release the clutch and stalled. Then she would not kick through, like there is gum in the Kickstarter, but other than that she has compression, gas, even checked for spark and saw it. Here is a video, I'll tear her apart, use kerosene or brake cleaner I assume?

Once I look inside I'll get the ball bearing and spring. I bought new clutch plates but think they are not right, I think they are for the earlier gearbox. Thank you all, onward!

https://youtu.be/DyXg2qnZ3uc

AH! all along I was assuming you have the single spring dry clutch with the bowler hat cover. I think they changed to the 4 spring Triumph clutch in 58. You need to confirm what clutch you have. Previous to the single spring clutch was the horrible 6 spring clutch, but I doubt you could mix the plates up.

If your bike is wet sumping almost as you are riding it I wonder if you actually have that little ball and spring in place

Ron

email (option): ronpier@talk21.com

Hi Jack.

Congratulations solving the first problem !

Looking at the clip, I cannot really see anything wrong (?)
Meybe what you feel is the clutch slipping a bit under the load of starting,
As the motion transferred from the kick starter to the motor trough the clutch.

You can try and slack the clutch cable a bit. that often helps.

Another point-
In order to get more momentum on one hand and ease the stress from
The starting mechanism in the gearbox on the other hand,
You can press the completion release lever/exhaust valve lifter,
Kick the starter, and release the lever only when you are at getting near the end of
The "foot stroke" so there is less stress on the system, and the starting revs are higher.
It also helps a lot to use this process in order to start the motor,
If your clutch does slip, to extent.
(Apologize for the bulky description, English is not my native language... )

Best regards,
Noam.