I already wrote about the bike in the text Marin Pine Mountain – adventure bike but the later text about my beginnings with bikepacking caused a discussion about the conversion of this bike from the 27.5+ to version 29 “. I promised to develop this issue then.
The search for the perfect bike in my case means reconciliation of the terrain ride, fun on mountain trails, touring and everyday city commute. I knew that the 27.5+ format would give me this freedom. Buying this bike in the friendly One More Bike store I knew that the next step would be to make the second set of wheels. For a moment, I was considering just changing the tires to a slightly narrower ones with less off-road tread. WTB Ranger 2.8 was at stake, WTB Trailblazer or Maxxis Chronicle, however, I finally decided that this is not the way. I want to have a second, exchangeable set of more “civilized” wheels period.
At first the matter appeared trivially simple if it were not for stupidity of Marin, namely the use of a completely new and unprecedented size of hubs for this model. For details, I refer to the bicycle text mentioned at the very beginning. Generally, in Marin we deal with 110×9 mm hubs on the front and 141×9 mm on the back wheel. I did not notice that buying a bike and this issue became the biggest challenge in the mission of making a second set of wheels. Let’s start from the beginning.
I entrusted the construction of wheels to Adrian from One More Bike. We chose the cheap and light Alexrims XD-ELITE 29 “DISC 32H rims. The rim has a size of 622×19 mm (ERD = 594 mm) and a weight of 490 g. Three cavities, pin connections and single eyelets give hope that they will tolerate the load of my weight and luggage as well as the heavy use that awaits them. The rim is tubeless ready so if you do not like tubes you can loose them.
Huston – we have a problem!
The time has come for the biggest problem, i.e. the hubs. At first I hoped to get the original Joytech hubs, which Marin use for factory wheels, but it turned out to be inaccessible as a spare part at the Polish distributor. I hope that it will change sometime because even though these hubs are not a miracle of technology they are the ONLY ones (although this applies more to the rear hub) to meet the Marin size requirements.
The front hub – Novatec NT-D711SB-Boost 15mm. Business adapters are enough and a ready-made solution for the front wheel is already available.
My good experiences have made me choose Novatec hubs. I have gone through such a lot and they have never let me down. The front turned out to be much simpler.
Novatec factory adapters allow for reduction from QR15 to QR9
It was enough to buy the Novatec NT-D711SB-B15 Boost 15mm, which have the same width as the Marin fork. The only difference is the diameter of the axle, but luckly Novatec offers special reduction caps QR15mm to QR9 (idiotically used by the bike manufacturer).
No manufacturer offers hub 142 (and more 141!) with QR9 so the starting point was Novatec in size of 142×12
The real adventure began in the back. The Novatec NT-D772SB hubs, which are 142 mm wide, are closest to the dimension. It’s just a millimeter more than the spacing of the frame hooks but that’s no problem with the steel frame. The diameter of the axes turned out to be a challenge. It was necessary to fit the QR12 hub to the prehistoric QR9. We could not find anything ready on the internet (okay, I saw some offers from China but I did not want to wait so long for a delivery without a guarantee of success). We decided that the best would be to manufacture required reduction axle.
Karol (thank you so much!) Turned out to be an invaluable help here. He dealt with the issue of drawing and commissioning this unusual part. The adapter is made of 54H tool steel. Unfortunately, we could not find any tube that would allow the use of a quick-release and currently the hub is in “bolt-on”. Karol has prepared a drawing with dimensions that will say more than 1000 words of my description. At the end of the article you will find a link to a pdf file with this picture.
Since I did not find (for now) screws with a sufficiently large head, it was necessary to use washers. Maybe it is not the most aesthetic solution but it works perfectly.
Problem number 2
After fitting a wheel to the bike, it turned out that 1 mm difference in the width of the hub makes a difference for the derailleur. Maybe it would not even be there but the difference in the construction of the hubs under QR9 and QR12 made us lose the full range of gears in the back. The derailleur was not able to reach the largest rack of the cassette. A temporary solution was to move the trolley by placing washers. Perhaps we can solve the use of hub caps from the same hub in size 135×12, but this is still to be checked.
Continental Double Fighter III – a proven tire that will certainly handle situations in which the 29 “wheels will be used
I decided to use the Continental Double Fighter III 29×2.0 tires. I have very good experiences with them, they worked great on my 26” bike. I decided that they would be perfect in most situations in which I would use this set of 29 “wheels. I assume that in the winter or when driving in mountains or terrain, I will return to the 27.5 plus wheels with the powerful Schwalbe Nobby Nic. This whole operation it is not only changing from 3.0 to 2.0 tires but also from aggressive, terrain tread to much more “asphalt” type.
The modification changes the character of the bicycle, suddenly the speeds that become available suggest the modification of the drivetrain (at least the fitting a larger chain ring). So far, I have not felt any flaws in this mod. We are dealing with a stiff 29er, which works great in the city, on the road and on hard road. Sure, sometimes I miss the comfort of a big balloon and a wide tire, but I can return to it by simply changing the wheel set at any time. And that’s what comfort I meant.
The technical drawing of the 142×12 adapter on 142×9 mm can be found HERE.