Hi Willie,
principially there’s not that much difference between 60 mm (SX, LT, 5) and 95 mm (EVO) eccentric bottom brackets regarding belt tensioning method.
One could say the smaller brackets are stepless adjustable and the EVO bracket in (pretty small) steps - that is caused by the presence of the so-called “locating block” at the underside of the drive. That’s also the main difference next to the size of these brackets for my meaning.
You may check here what the locating block does:
stridacanada.ca/strida-ks3-gearbox-replacement/
Please do note that the advice of the Strida manual, page 21, regarding belt tension is actually WRONG!
The mistakes are:
- Ming cycle doesn’t even mention hook key or groove nut - just that is essential.
- To describe a belt’s tension are TWO physical dimensions implicitly required - but Ming supplied just one.
Belt tensioning method (including hook key of course) - there is NO WAY without!
- Loosen the big groove nut (Just loosen for one turn.)
- Remove bolt 274 (plus kickstand)
- Locating block will not fall down!
( - as long as the Strida was standing upside down whole the time
) - Rotate eccenter into desired direction
- Check belt tension
- Insert the locating block
It may happen here - that’s what I meant with steps - that the locating block’s teeth and that on the outside of the drive do not engage properly. In that case one has to rotate the eccenter a tiny bit forward or backward - therefore; - Check belt tension once more
- Mount bolt 274 (plus kickstand)
- Tighten big groove nut
(Hint for the original tool without using a torque key:
I’d wrap a piece of cloth around the grip and tighten it that way really hard.
As long as you do not use an extension you won’t be able to destroy the nut - just beware of slipping off!)
And how to check the belt’s tension?
Let me say it this way:
Even with best equipment we can measure the whole day, just it makes absolutely no sense.
There is no index value known - so it is impossible to tell if another value is above or below.
vaust.com/fahrradteile/riem … ungsmesser
Above tool works with weigth and deflection - TWO dimensions.
And what if we simply refer to the datasheets of bike belts?
Ah - no, I’m afraid that doesn’t work that easy because our belt is listed as a car belt.
(A while ago I told the Continental support that HTD 8M belts are used on folding bikes - they did not know… )
I’d recommend to follow Mark’s advice to keep belt tension as low as tolerable.