77 MC5 250 gearing and suspension setup

[MauriceR]

What is the recommended gearing for the bike, I am running 14/54 as per a recommendation from someone but it seemed a bit too short
when I raced the bike over the wknd
14/52 seems like it might pull a longer and eliminate some of the short shifts but will it have enough bottom end in the tight corners without
using the ultra low 1st gear

What weight of oil are you guys running in the forks and how many cc's or how far from the top are you setting oil level

Maurice

[Slakewell]

14/52 on mine but my clutch works correctly and I can fan it out of slow corners. I start with 15 wieght and 150mm/6 ich from the top. 

[MauriceR]

Thanks for the info Slakewell, have you ever seen a 15 tooth countershaft as 15/54 would be pretty close to 14/52 and cheaper than a new rear sprocket. Al Buehner doesn't list a 15 on his site though.
I still may need the info on the pipes you were talking about, still looking around here for awhile though and hopefully can find a good used one.

Maurice

[ozktm]

You can use modern KTM sprockets, either make a spacer to suit, or change the bush out for one from the 541 series engine (80/81/82 250 motors).
That is if you are using the 520 style chain, or are you using 530??

[Gippslander]

Hi OZKTM, butting in here  , have been watching this thread with interest because my 74.5 250 and my 77 250 KTM's both need new sprockets, and I was thinking about ordering from Al B in the US, but you have alerted me to the use of later sprockets, so, what year KTM's have sprockets that will fit, or is it not as easy as that?

And any other mods required?

Also, both my bikes have very low 1st gears, so I start off in 2nd and try not to use 1st in races, other than that the gear spacing seems good, no gaps.

Thanks

[Slakewell]

Im unsure about what sprockets to buy anything with drum brake I think. To convert to 520 you just need to carefully cut the shoulder off an old 530 sprocket with one of those thin 1mm grinding blades then touch up and fit inside the new 520 sprocket.

[ozktm]

Yep, you can use any sprocket that suits a KTM from 1980 to 2013.... All modern FRONT sprockets fit, they never changed the spline.

On the rear, you will need to order from Al B, or from Andre @ KTM Klassiker.

Adrian

[ozktm151]

Stock gearing for 77 MC and GS should be 13:52 so 14:54 is a higher ratio. MC should be run as 5 speed box. 3rd gear starts ie second on an MC are possible with 13:52. It would be harder to get it off the line and out of corners with 14:54