Derbi Variant pyramid reed bearing and seal sizes

Does anyone know the specific seal sizes for a Pyramid reed variant engine? Dos sells a party pack of all of them but they are currently sold out, but they have all of the sizes listed. The bearing sizes all make sense but the amount of seals listed is what is confusing me. It seems like there is multiple sets of crank seals listed and I couldn't tell if one set was for the PP and one was for the PR but they just included both? I know the crank seals on the PR I have are 17 x 28 x 6 as I have replaced them before.

Here is what they have listed:

15 x 30 x 7 - x1

25 x 40 x 7 - x1

16 x 24 x 4 - x2

16 x 28 x 7 - x2

17 x 28 x 6 - x2

12 x 18 x 3 - x1

Just seems like a lot of seals to me but I have never rebuilt a derbi so I don't really know. individually buying all of them is starting to add up and I just want to make sure Im not ordering something I don't need

Re: Derbi Variant pyramid reed bearing and seal sizes

Here you go:

15 x 30 x 7 - x1 - Output shaft, sprocket side

25 x 40 x 7 - x1 - output shaft, rear pulley side

16 x 24 x 4 - x2 - pedal shaft

16 x 28 x 7 - x2 - crankshaft seals option 1

17 x 28 x 6 - x2 - Crankshaft seals option 2

12 x 18 x 3 - x1- pedal engagement seal

So you don't need the 16x28x7. You also probably don't need the 12x18x3 as it sits on top of the case so it's not really doing much.

Also, check if your rear sprocket is held on with a circlip or nut and lock washer. If its a clip you're good but if it's a nut you'll need a 20x30x7 as there is an additional spacer that sits behind the sprocket.Edited 1 time(s). Last edit at 01/15/19 12:04AM by spudley.

Re: Derbi Variant pyramid reed bearing and seal sizes

Ah I see okay thanks! I kinda assumed that they would provide a few options based on what I have read about diff years of the pyramid reed having diff size crank seals. I contacted dos and they made the party pack of everything available again so I went ahead and picked that up. Pretty good deal compared to pricing out individually. I’m pretty sure I have a nut on the sprocket but it’s up at the shop so I’ll have to check later tonight.

Re: Derbi Variant pyramid reed bearing and seal sizes

No problem, good luck with the rebuild.

Couple pointers:

- when re-assembling make sure that you have the little clip on the pedal selector in the right place. there is a spot in the case it fits that doesn't allow it to rotate much either direction.

- hard to describe but there is a little wishbone thing that move a gear on the pedal shaft. Don't remove said gear on pedal shaft. there are two small ball bearings with and a spring that will pop out. they are a real sombitch to get back in

Re: Derbi Variant pyramid reed bearing and seal sizes

Okay good to know thanks! I had actually been wondering if there was a was a way I could delete the pedal selector seeing as Ive accidentally switched into pedal mode with my pant leg a few times while riding and that's a lil sketch.

Was considering bringing it to the Zeros/MCR swap meet to rebuild to see if I could get some eyes from someone whos rebuilt a pyramid reed before on it while I do it.

Re: Derbi Variant pyramid reed bearing and seal sizes

Rand Jacobson /

Is it confirmed what model/year they switched? I had a yellow TT once upon a time ago.

Re: Derbi Variant pyramid reed bearing and seal sizes

Like get rid of the pedal function completely? As in, completely remove the pedal shaft?

Hmmm I don't have an engine in front of me so i'm not sure how feasible that is....but since it's a completely separate shaft from the rear output shaft that tie in via a chain I suppose it would somehow be possible....not sure if it's worth it tbh. You'd be better off getting a flat reed as there is an easy kit treats sells to delete the pedal function.

Re: Derbi Variant pyramid reed bearing and seal sizes

ah I gotcha, yeah was just wondering if it would be as easy as the flatreed pedal delete. but the times I have had to walk the bike home the pedal shift makes a big f'n difference

Re: Derbi Variant pyramid reed bearing and seal sizes

You could get rid of the pedal mechanism but keep the detent for the gears.

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