[Truckeemtb]

Help: 2019/ 2020 Stumpy sizing help, I am 5'9" and will demo both medium and large...

Looking to buy Stumpy pedal bike. I am 5'9" and have a 2019 Turbo Levo in a Medium and it's tight (a tiny bit small) but works, it does have a slightly different geo than the pedal bikes and wheelbase is longer. The seat is all the way back on the rails and bars rolled forward a little bit. I am looking at a new pedal bike. Either a modified Stumpy Pro (would change out dropper, cranks, bars, cassette etc) or possibly s works pedal bike. Yes, I am going to demo both a medium and large but right now my back is messed up.

Additionally, I only weigh 140 lbs so I have had some struggles with Fox factory 36 and not being able to use full travel even with no tokens and running 42 psi. I feel if I go lower its going to mess up the stroke and pack more in the middle. I do have Vorsprung on Pivot with Fox Factory which helped a little on small bump and keeping it higher in the middle of the stroke. So RockShox Pikes seem to work better for my weight and I end up getting more travel out of a Pike 150 than a Fox 36.

Of course the only Spech build now with RockShox is the new 29 AXS and not sure I am willing to spend the coin for that, it comes with Pike Ultimate. Despite their millions of options I want an xo1 build with a Pike Ultimate so I might build from frame. I am curious if lighter folks are finding the Spech RX tune softer and are using full travel?

I live in Tahoe and have done about 1,000 miles this year starting in Mid May. I do the smaller jump trails but don't hit the big boy send it 30 feet gaps.

That being said I am still curious what other people decided. I am 46 and have been on mtn bikes for 30 years and ride 4 or 5 times a week. I have had a handful of Santa Cruz bikes among other and more recently a Yeti 5c and currently a Pivot 5.5. If I compare Yeti sb130 dimensions a medium Yeti is very similar to a large Stumpy, of course that bike is pretty long and slack My Yeti 5c is now ridden by my wife and also feels a tad small. I have sold the Pivot. I have a bunch of 5'10" friends in a large Spech and I suspect this is largely due to the Spech geo being pretty conservative by today's standards and are messing with stem, bars and seat to get the geo wanted.

If large I would have seat forward and probably a 35mm stem. If medium I would have seat all the way back effectively slacking an already fairly slack seat angle.

PS the Pivot 5.5 was a little small and not super stable at flat out DH speeds but that geo is also in between older geo and more progressive geo.

Any suggestions or thoughts are appreciated.

 

[rushcentrale]

If I were you I'd go large with the seat forward and a shorter stem. I'm 5'8" and I'm on a medium which is fine for me, but I would say I'm the upper limit compared with more progressively geo'd bikes.

IMO Stumpys are bikes you can upsize safely if you're in between the suggested range.

 

[rushcentrale]

Also have you tried burping your seals on the Fox36 with a zip tie?

At 42 PSI, no tokens and not using your travel, it sounds like you have trapped air and/or too much grease in your air chamber.

 

[Truckeemtb]

Yes, tried the zip tie burp, pumped up while equalizing pressure, did fluid in lowers twice and cleaned up the extra grease (there was too much new). Vorsprung helped making it a little softer/ active/ plush off the top and keeping the mid stoke up. Still almost always leave 30 mm or on the table even on the bigger jumps and gaps I do (still not huge) but should be using it all. I do have friends my size that run 33-35 psi but loaded up with tokens but they are boosting much more. I even borrowed a Shock Wiz since I was curious and ended up with the same settings I was at, had to go to faster rebound with the super low pressures. It said less LSC but that all the way off so can't have less than none. I look around at most riders on 36 forks everywhere I go including our local groups with all size and weight riders and notice that most are only using 1/2 to 3/4 travel. My gut tells me these were made for sending it but they now come with most 150-160 trail/enduro bikes.

So I was curious about the Specialized RX tune, I can't find much about what that means if it's softer or different progression or shims etc. I want to use all my travel every ride or two. We have some pretty solid trails in the area and I have ridden the 36 in other places such as Moab, Colorado Lunch Loops, Downiville, Gooseberry etc.

I have only briefly tried the Grip 2 as mine is a Fit 4, it seems a little better but it wasn't setup for me and I didn't want to play with my friends setup on his new Bronson too much.

I will take both sizes out when my back is better, play with different stems and rail position and steer tube spaces and see if I can find a clear path forward. Right now it seems 5'8" Medium, 5'10" large and 5'9" me could perhaps go either way by moving saddle, stack and different stem sizes.

Thanks for the info, keep it coming.