I will add that having a larger diameter front wheel is a big deal relating to a tandem mountain bike. Way moreso than a single bike. I would agree that 27.5 might just be the perfect balance of wheel sizes for single mountain bikes, but for a tandem, where you can't lift the front wheel, the larger diameter wheel (29") has an advantage. Slower handling may be a consequence of riding larger wheels, but I'll take the trade off so that we can roll over certain obstacles that were problematic on the 26" wheels.If I were building a custom or had a choice of tandems with each wheel size, I'd go with the 27.5" size. I ride a 27.5er single bike and am totally sold on the size. With a tandem, you already have slow steering in which a 29" wheel is just going to make it even handle slower.
On my Ventana El Testigo, it has sliding rear dropouts that can accommodate 27.5" wheels, just need a fork to seal the deal.
Good info. I'm not interested in a debate either.The rollover of a 29er wheel and all the subsequent info about the bigger wheel being faster is only partly true(trust me, I've done my experiments on single bikes).
While true, on a tandem, your not easily going to lift the front wheel over obstacles, your either going to unweight the front end as much as possible, or just ram into them.
I would never ride an off road tandem with nothing less than 5" travel fork, preferably 6"+, so the fork takes up a lot of the impacts.
In my testing on wheel size, while not totally scientific, my results had the 27.5" wheels faster in just about any condition, the only area that the 29er was or seem faster was on climbs with "baby head" sized rocks.
I've been in way too many discussions on this and was told that there is no way it could be this way, "because bigger is always better" i was told, my findings have found otherwise.
I'm not trying to start a debate into which wheel size is best, your results may vary, just thought I'd share my results.
Front suspension or full suspension? In my opinion the 29er is best for both, but for a hardtail the 29er even more so. We have been using the Ergon CF-3 on the road bike to smooth out the stokers ride. I used to use this seatpost on my hardtail single and loved it. Our marathon racing tandem would be a 29er HT with CF-3 seat post and some sort of high range 2x10 or 11 gearing. Our ECDM FS 29er is built up and reliable at 42lbs. It could be a couple pounds lighter with the right parts. A carbon HT could easily loose 5lbs over the aluminum FS.I was looking for advice on which wheel size I should go with.
I will be doing marathon races on it.
The bike can fit 27.5”x2.8“ and up to 29”x2.6“. The 29 option gives a bit more pedal clearance and the 27.5” option has a bit lower center of gravity for stability. We use 29”x2.6” for clearance, but it comes down to where you will be riding and also what standover height works for your team.Resurrecting this old thread. I'm giving up the ghost on my old 26" Santana Rio and I'm curious now 6 years later if this thread is still relevant wrt wheel size.
Having had a El Saltamontes and El Ciclon a decade or so ago, I'm thinking about a Ventana ECDM. I still ride a 27.5 Turner RFX but love my 29r Evil Offering. I get the point in this thread about rollover with the bigger wheels but maybe 27.5+ might be more maneuverable on techy trails. Can you run both wheelsets on a ECDM with a 29" fork? Any feedback appreciated.
Thanks for the reply! Maybe I'll stick with the idea of having two wheelsets then especially if there is no difference in frame geometry with regard to wheel size. And perhaps over-fork it with a 150 for ramming over obstacles. Trails are rocky in my neck of the woods. Lots to ponder on a 70" wheelbase bike.The bike can fit 27.5”x2.8“ and up to 29”x2.6“. The 29 option gives a bit more pedal clearance and the 27.5” option has a bit lower center of gravity for stability. We use 29”x2.6” for clearance, but it comes down to where you will be riding and also what standover height works for your team.