From the Pinion catalogue –
the Pinion gearbox is compatible with belt-drive
systems such as the gates® Carbon Drive tm. as
an option, instead of the standard chainring that
mounts with a spline, an adaptor can be fitted to
the output shaft of the P1.18 to give a mount with
a standard BCD of 104 mm. this can be fitted with
a chainring suitable for a carbon belt

No-one has ordered one yet but it should be relatively simple as the chainline can be adjusted fairly easily at the back (a problem using belt on Alfine where clearance is very tight and matched to a ‘middle’ rather than ‘outer’ chain ring position which adds clearance issues at the front).

Personally I want a Pinion on a steel hardtail… not something that seems to be on the cards yet though.

Just looked into the details of those Mi:Tech bikes a bit more… Their Pinion frame (26er or 29er) is €2150 (~£1750) including the gearbox/cranks/chainring.
Also they will do custom geometry for an additional €100
Seems like very good prices to me, especially when you consider the supposed Nicolai upcharge of £1400 for Pinion…

Here’s a review of one:

http://twentynineinches.com/2010/10/07/mi-tech-tyke-29er-final-review/

Maßrahmen = custom options/build (I think)

Translated mi-tech

I notice the majority of companies on board with the whole concept seem to be German.

Looks like they’re charging 1500 Euro over their frame price for the Pinion. Remember that the euro exchange rate was sub 1.15 until the last month or two.

A bargain for custom geo. They do custom carbon at very keen prices as well. Interesting.

The order generator only allows you to order a Helius AM Pinion but we’ve got customer orders in for an Argon Pinion, an AC29 Pinion and waiting for confirmation on a 650b Helius AC Pinion.

How do you figure that, looks like it just bolts onto a ‘standard’ of some sort, it’d be harder to make from anything other than machined aluminium, but not impossible.

Plus this

Steel hardtails are a Brittish quirk, aliminium FS bikes are a global market.

From my understanding they produce the case and that connects to the frame via three bolts, ergo, excluding bimetalic corrosion and all that, the case can be bolted to any material

Ah, right, I assumed wrongly again.
That would explain this Spanish titanium frame that I found on a link on the Pinion website then.

Graham – go have a look at the
Pinion Catalogue. There’s a description of the mounting ‘bridge’ on pages 20-21. The description specifies that it’s been forged and stress tested which suggests Pinion probably can supply this part. Can’t see any reason why the bridge couldn’t be made from another material if the manufacturer designed it properly – on the Nicolai frames I’ve seen look like the bridge is two machined parts welded together.

So they are, it’s just me getting confused. And they mention the possibility of carbon frames in that catalogue too.

Apparently that was a pre-production prototype which used a rear chain tensioner, however the production version is supposed to have a front tensioner like on this bike:

http://www.pinkbike.com/news/Pinion-Gearbox-First-Ride.html

I know what you mean but they’re always going to be necessary on a full-sus unless it pivots around the BB.

The only (?) way to ensure zero chain extension is to pivot around the centre of the drive. Nicolai did that on their own GBoxx designs. The downsides are that you add bulk (as you’ve separated drive and input) which implies additional weight – the Pinion is remarkably compact. You also restrict suspension to single pivot designs. A tensioner of some kind is a lighter, simpler solution and, since it’s just a tensioner, if it gets knocked you can bend it back straight enough to work. The Pinion tensioner is tucked out of the way as well.

I cant see a little added weight being an issue to anyone buying a full suspension bike with gearbox.

plus most FS bikes are single pivot (either traditional or lever driven shock) anyway.

Fit a smaller chainring on the pinion for clearance, extend the rear pivot to take a twin sprocket on the drive side & stick some sliding dropouts on it… I know its not “quite” that easy but there is your most basic solution.