Turbo Levo 29” front - 27.5” rear wheel?

[DrKrown]

Hi everybody, just thinking to upgrade my Turbo Levo FSR 2018 with a 29” wheel on the front, maintaining 27.5” on the rear.
This seems to be the trend on many modern ebikes.
Anyone already upgraded this way? If so, what are your impressions?
Any tought about tyre width in this mixed configuration? Better the same or wider on the back?

Thanks for sharing your experience!

 

[levity]

Mrs levity and I did exactly that on our 2018 Levos. We had previously put 29" front wheels and 3.0 tires on our Stumpjumper 6-Fatties (keeping the OEM 27.5x3 wheels/tires in the back) and liked it so much we did the same with the e-bikes.

Levo "79er" specs:
front: 29er rim, 30mm inner width, Bontrager 29x3.0 XR2 (Chupacabra) tire
rear: 27.5 rim, 45mm inner width, Bulldozer 29x3 tire
fork: reduced travel from 150mm to 140mm (the 29x3 tire raises the axle by ~15mm)

Rollover with the 29x3 front is much better than with the 27.5x3 tires we used (Purgatory or Rocket Ron on i45mm rims). Handling is also much improved. I think the 51mm offset on the OEM 29/27.5+ forks is too much giving too little trail with a "small" 27.5 wheel. Even with a 10mm shorter travel fork the larger 29er wheel adds trail (~10mm) and slackens the head tube angle (~0.5°). It feels much better to us - precise steering, stable tracking, no wheel flop. It also raises the bottom bracket a bit (~5mm). We wish we could fit a 29x3 in the back, but 29x2.5 is the upper limit and we won't give up the volume, traction and cushion of 3.0 tires

 

[DrKrown]

Mrs levity and I did exactly that on our 2018 Levos. We had previously put 29" front wheels and 3.0 tires on our Stumpjumper 6-Fatties (keeping the OEM 27.5x3 wheels/tires in the back) and liked it so much we did the same with the e-bikes.

Levo "79er" specs:
front: 29er rim, 30mm inner width, Bontrager 29x3.0 XR2 (Chupacabra) tire
rear: 27.5 rim, 45mm inner width, Bulldozer 29x3 tire
fork: reduced travel from 150mm to 140mm (the 29x3 tire raises the axle by ~15mm)

Rollover with the 29x3 front is much better than with the 27.5x3 tires we used (Purgatory or Rocket Ron on i45mm rims). Handling is also much improved. I think the 51mm offset on the OEM 29/27.5+ forks is too much giving too little trail with a "small" 27.5 wheel. Even with a 10mm shorter travel fork the larger 29er wheel adds trail (~10mm) and slackens the head tube angle (~0.5°). It feels much better to us - precise steering, stable tracking, no wheel flop. It also raises the bottom bracket a bit (~5mm). We wish we could fit a 29x3 in the back, but 29x2.5 is the upper limit and we won't give up the volume, traction and cushion of 3.0 tires

Thank you for sharing your toughts...
I have a couple of questions for you: do you think it’s really necessary to reduce the fork travel? In your opinion, leaving the original travel (150) makes the handling of the bike worse than before?
What about lowering (maybe a couple of spacers) the handlebar to recreate the original biker balance on the bike?

At the moment I have a Fox 36 fork (150 mm of travel) and a Fox DPX2 shock with the BikeYoke mod, that I think rises the back by a few millimeters.

 

[levity]

...do you think it’s really necessary to reduce the fork travel? In your opinion, leaving the original travel (150) makes the handling of the bike worse than before? What about lowering (maybe a couple of spacers) the handlebar to recreate the original biker balance on the bike?

Go ahead and try it at 150mm before changing the travel to see what you think. The BikeYoke will help a little, but I don't think it will be enough (I used a BikeYoke on a previous 6fattie).

As you suggest I tested my Levo at 150mm with the 29x3 wheel and moved two 5mm spacers from below the stem to above it. In some ways I liked this better than the OEM 150mm and 27.5x3 wheel, but the front end just felt too high. Set up like this the bike itself is tilted back too much even though my hands and arms were the same as before, and the front end felt high and light on steep climbs and when turning. Dropping travel to 140mm fixed it, perfect. With the big wheel I don't miss the extra travel at all, in fact it handles bumps and small drops better than the smaller wheel at 150mm.

Fox airshafts are not expensive (~$30 for a Fox 34, ~$40 Fox 36) and are straight forward to swap (~1 hour).