What no Balance shaft

[Eddie Evans]

How balanced is a the balance shaft?
I was musing that, should the need arise to remove the shaft for bearing replacements, could the opportunity be taken to remove some weight, without upsetting the balance, and thus possibly get the best of both worlds, to a degree.
So a livelier motor, but still with some finesse.
My Mk3 has the 125, forks on it, but their probably wasted for what terrain we mostly have in our area.
Mike

Any weight reduction will also start to reduce the balance and increase the vibes.

I locked the shaft up soon after switching from pro circuit front pipe to a Dep one but I believe that the snap is due to removing the gear. It would be good if someone who has got used to their bikes feel tried the mod and confirms or disagrees with the livelier motor.
IMO it is no good for road riding but worth a go for the trails.

Do you know what year CR the forks were off and what year the changes are. The later ones are the same size as CRF which I know are bigger that the CRM.

[fallenmikethebike]

Hi Eddie, yes cr125 1997, I just recently, re-bushed and re-sealed, = new oil, so they feel great at the moment.
But, the yokes need to be reamed out to accommodate the larger diameter forks, and, work required for a speedo, or go digital.
Mike

[knackeredMk1]

Just been comparing stems (Ooer ), and the XR400 is exactly the same as the Mk3 except the XR one is aluminium (weight saving ).

So I'll send you the XR400 one. You can compare this with the XR650 and if they are the same you can take off the Mk3 yokes with the knowledge that the 650's will fit straight on. Or use the 400's if they are different .

[Eddie Evans]

Just been comparing stems (Ooer ), and the XR400 is exactly the same as the Mk3 except the XR one is aluminium (weight saving ).

So I'll send you the XR400 one. You can compare this with the XR650 and if they are the same you can take off the Mk3 yokes with the knowledge that the 650's will fit straight on. Or use the 400's if they are different .

The 650 yoke does not have a stem. They were a late nigh e bay purchase for a project that did not work out.
Think the man who sold them had used the stem for a CRF fork change.
Thanks again this could make it a easy swap.
If the weather is going to be as bad as they say I can always spend the holiday in the garage and not out riding as I want to.

[knackeredMk1]

I know all about those late night buys

I'll send the XR400 stem tomorrow .

[knackeredMk1]

Quote from me - 'I did think that maybe if you ground off the weights on the end of the flywheel you might get the same effect of having no balancer shaft but keep the balancing.'

Don't know what I was thinking about this having relooked at my flywheel - There are no weights . Must have got confused with another bike I was looking at at college .

Luckily I checked before buying another flywheel that was offered me

[Mudfacetony]

On the subject of forks
I do have a modern enduro bike, a huasberg 450 and the real difference is riding ruts. The technique is to look far enough ahead and nail it. It this does work but is something best worked up to unless I happen to be standing close by with a camera. I do try the same on the CRM but it is much harder work as the forks get deflected and the front wheel clips the edges of the rut. I can live with that but can't help thinking how much fun can be had leaving the latest Jaffa offerings for dead on a 20 year old bit of "scrap iron".

In the garage is a spare set of XR650 forks that may fit the bill. I have done some work on these before to get a much plusher ride on the trails. The big XR is very front heavy and after 2 days trail riding my forearms are toast but the forks can be made to absorb the light stuff but still take the big hits without any fear of bottoming out It could be seen as a backwards step as they are not upside down forks but they do have a lot of adjustment. The CR forks would need similar mods and they will be much firmer for MX but I have no experience of those.

The other thoughts I had was to buy a cheap gas gas, berg, husky and graft the front end on to the CRM. I;m in no rush to do it just something for a wet afternoon when the mood takes me.

Long Live The CRM

Some years ago I went on the i2i course in yorks with a load of mates. The trick to ruts as they said was speed up when the rut gets narrow, not wack the throttle open but just enough speed to go a little fastrer. This has the effect of keeping the wheels in line. When the rut gets wider, slow down a little. Try it, it does work and improved my riding loads.
Trust m, I ride like a loon at times and it stopped me falling of so much