2020 YT Decoy 29 swap to 27.5???

[Jessiejames1108]

I've had my Decoy base since around June and love how fun it makes trail riding and handles the climbs, but I still don't think I have gotten used to the 29er wheels. I sold my 27.5 stumpy to pay for this bike and am sort of regretting the tire size choice. I asked YT what would happen if I put 27.5 wheels on it and all the guy could tell me is that they were designed for 29s and it would void my warranty. While a warranty is important to some I suppose I just wanted to know if the swap would bring with it bodily harm as I descend and try to get as rowdy as the Stumpjumper would before I sold it. Needless to say I got no help so here we are... anybody here try converting their 29 Decoy to 27.5 or even go mullet with it? I looked at the geometry specs between the two models on the YT website but quickly realized I don't know the first thing about that stuff and it didn't help me much. Do a few mm's here and there really make that much of a difference?

 

[TransAmMan]

I am going through the same contemplation with the Capra 29 Shred (still waiting to receive it). You will have some considerations ....

I believe the geometry of the front triangles are identical and the 2 major changes you need to consider would be the rear triangle and the effect of the suspension reduction (150mm front fork 29 vs 170mm mullet)

REAR TRIANGLES

YT seems to make different rear triangles for the Decoys and this is reflected in the chainstay length.

Decoy

Decoy 29 - 458 mm VS the Mullet version 442 = **Difference of 16mm between models

Capra 29 by comparison (for S,M,L models) - I am going through same process

29 - 435 mm VS the 27.5 version 427 = **Difference of 8 mm chainstay

Capra XL,XXL sizes

440 mm on 29 ... 432 on 27.5 = **Difference of 8 mm again.

So long answer, short ... I guess it depends. If you mount a 27.5 wheel to the back of your 29 mullet .. it will have a chainstay that is 16mm longer than the actual mullet design. That is fairly substantial and harder to accept since ALL sizes of Decoys use the same chainstay length (unlike the Capra)

FRONT FORK

Your running a 150 mm front fork on the 29 and the Mullet is a 170. Throwing on a 27.5 rear wheel is going to drop your bottom bracket quite low resulting in a lot of pedal strikes. You could offset (I suppose) by changing the the HIGH BB setting .. but this may mess it up more. Only option may be convert your fork to 170 mm

So there are challenges (more on the Decoy than the Capra). Options

1. Accept the longer chainstay (+18mm) realizing that your weight will be biased a bit more to the rear COMPARED to the actual mullet version, however that is already true anyway with the 29 version (wheelbase will stay the same).

** NOTE: ** If your bike is a SIZE XL or XXL bike, this may be offset by the larger front center. May actually be a OK (albeit 18mm seems big if you compare to the Capra design that only increases the chainstay by 5mm to compensate)

2. Throw on a new rear triangle from the Mullet bike or find somebody to trade you .. trade rear wheel and triangles .. but this wont fix suspension.

3. You may end up with a VERY low BB resulting in pedal strikes. May need to raise front fork to 170mm or use high BB setting (although this would really change the geo) ..or just ride it and accept it. I would question it being WAYY too low however (150 mm fork travel and 145 mm rear VS 170 mm fork and 165 rear on mullet)

4. Sell and buy a mullet

Not really an easy decision to make ... maybe others can chime in ?

My recommendation is to borrow a 27.5 wheel and try it out ... you''ll be the best judge

**I don't want to sound pessimistic , but based on chainstay impacts, fork travel reduction (plus 20 mm less travel out back) this may create a dangerously low BB, you may be better off selling the 29 and just buy a mullet (IMHBO)

 

[Jessiejames1108]

I am going through the same contemplation with the Capra 29 Shred (still waiting to receive it). You will have some considerations ....

I believe the geometry of the front triangles are identical and the 2 major changes you need to consider would be the rear triangle and the effect of the suspension reduction (150mm front fork 29 vs 170mm mullet)

REAR TRIANGLES

YT seems to make different rear triangles for the Decoys and this is reflected in the chainstay length.

Decoy

Decoy 29 - 458 mm VS the Mullet version 442 = **Difference of 16mm between models

Capra 29 by comparison (for S,M,L models) - I am going through same process

29 - 435 mm VS the 27.5 version 427 = **Difference of 8 mm chainstay

Capra XL,XXL sizes

440 mm on 29 ... 432 on 27.5 = **Difference of 8 mm again.

So long answer, short ... I guess it depends. If you mount a 27.5 wheel to the back of your 29 mullet .. it will have a chainstay that is 16mm longer than the actual mullet design. That is fairly substantial and harder to accept since ALL sizes of Decoys use the same chainstay length (unlike the Capra)

FRONT FORK

Your running a 150 mm front fork on the 29 and the Mullet is a 170. Throwing on a 27.5 rear wheel is going to drop your bottom bracket quite low resulting in a lot of pedal strikes. You could offset (I suppose) by changing the the HIGH BB setting .. but this may mess it up more. Only option may be convert your fork to 170 mm

So there are challenges (more on the Decoy than the Capra). Options

1. Accept the longer chainstay (+18mm) realizing that your weight will be biased a bit more to the rear COMPARED to the actual mullet version, however that is already true anyway with the 29 version (wheelbase will stay the same).

** NOTE: ** If your bike is a SIZE XL or XXL bike, this may be offset by the larger front center. May actually be a OK (albeit 18mm seems big if you compare to the Capra design that only increases the chainstay by 5mm to compensate)

2. Throw on a new rear triangle from the Mullet bike or find somebody to trade you .. trade rear wheel and triangles .. but this wont fix suspension.

3. You may end up with a VERY low BB resulting in pedal strikes. May need to raise front fork to 170mm or use high BB setting (although this would really change the geo) ..or just ride it and accept it. I would question it being WAYY too low however (150 mm fork travel and 145 mm rear VS 170 mm fork and 165 rear on mullet)

4. Sell and buy a mullet

Not really an easy decision to make ... maybe others can chime in ?

My recommendation is to borrow a 27.5 wheel and try it out ... you''ll be the best judge

**I don't want to sound pessimistic , but based on chainstay impacts, fork travel reduction (plus 20 mm less travel out back) this may create a dangerously low BB, you may be better off selling the 29 and just buy a mullet (IMHBO)

I am going through the same contemplation with the Capra 29 Shred (still waiting to receive it). You will have some considerations ....

I believe the geometry of the front triangles are identical and the 2 major changes you need to consider would be the rear triangle and the effect of the suspension reduction (150mm front fork 29 vs 170mm mullet)

REAR TRIANGLES

YT seems to make different rear triangles for the Decoys and this is reflected in the chainstay length.

Decoy

Decoy 29 - 458 mm VS the Mullet version 442 = **Difference of 16mm between models

Capra 29 by comparison (for S,M,L models) - I am going through same process

29 - 435 mm VS the 27.5 version 427 = **Difference of 8 mm chainstay

Capra XL,XXL sizes

440 mm on 29 ... 432 on 27.5 = **Difference of 8 mm again.

So long answer, short ... I guess it depends. If you mount a 27.5 wheel to the back of your 29 mullet .. it will have a chainstay that is 16mm longer than the actual mullet design. That is fairly substantial and harder to accept since ALL sizes of Decoys use the same chainstay length (unlike the Capra)

FRONT FORK

Your running a 150 mm front fork on the 29 and the Mullet is a 170. Throwing on a 27.5 rear wheel is going to drop your bottom bracket quite low resulting in a lot of pedal strikes. You could offset (I suppose) by changing the the HIGH BB setting .. but this may mess it up more. Only option may be convert your fork to 170 mm

So there are challenges (more on the Decoy than the Capra). Options

1. Accept the longer chainstay (+18mm) realizing that your weight will be biased a bit more to the rear COMPARED to the actual mullet version, however that is already true anyway with the 29 version (wheelbase will stay the same).

** NOTE: ** If your bike is a SIZE XL or XXL bike, this may be offset by the larger front center. May actually be a OK (albeit 18mm seems big if you compare to the Capra design that only increases the chainstay by 5mm to compensate)

2. Throw on a new rear triangle from the Mullet bike or find somebody to trade you .. trade rear wheel and triangles .. but this wont fix suspension.

3. You may end up with a VERY low BB resulting in pedal strikes. May need to raise front fork to 170mm or use high BB setting (although this would really change the geo) ..or just ride it and accept it. I would question it being WAYY too low however (150 mm fork travel and 145 mm rear VS 170 mm fork and 165 rear on mullet)

4. Sell and buy a mullet

Not really an easy decision to make ... maybe others can chime in ?

My recommendation is to borrow a 27.5 wheel and try it out ... you''ll be the best judge

**I don't want to sound pessimistic , but based on chainstay impacts, fork travel reduction (plus 20 mm less travel out back) this may create a dangerously low BB, you may be better off selling the 29 and just buy a mullet (IMHBO)

I was finally able to talk to a YT service guy over the phone and he pretty much summed up what you said. Changing the wheels to 27.5 would create an extremely low BB and would more than likely cause damage to the frame and motor hence the warranty being voided. Sounds like I am just going to have to spend more time on it and get used to it. The bike is awesome and its held up extremely well to two pretty bad crashes both in rock gardens I just have a hard time getting low over that back wheel and not getting buzzed. Maybe I'll post an add up on Pinkbike and craigslist to see what kind of offers I can get and test the waters. Problem is I would need to sell it for like 5500 to get something else and it only retails for 4300 brand new. Upgrades or not that's a hard sell.

 

[jk-]

The Decoy 29er is based around the wheels why try to change something its not.

 

[Jessiejames1108]

The Decoy 29er is based around the wheels why try to change something its not.

I knew I wanted to get an ebike and this one fit the bill because it was the cheapest one I could find and pretty much what I could afford after selling my ST Stumpjumper. After spending some time on it and a few weekends at the bike park in Truckee I am starting to feel like it may not fit my riding style.

 

[TransAmMan]

Best to abandon idea .. I also ditched my plans of converting the 29 Capra based on the fact I could not alter the chain stay length in the end.


A ahorter chainstay is what gives a 27.5 bike a more “flickable” feel Than a 29’er.

Plus Every time you make a geometry change, it needs to be offset via suspension travel adjustment or fork offset (which was why YT went back to 51mm offset forks when they increased the front travel on the Decoy from 160mm to 170mm)

I have reached the conclusion that if you are going to do a mullet properly, you need to start with a 27.5 bike and use a 29 wheel out front (primarily based on chainstay designed around a wheel size). It’s easier to compensate for BB changes to the front end of a bike (reduce travel or install angleset)
Or just buy a mullet ?

 

[Jessiejames1108]

Best to abandon idea .. I also ditched my plans of converting the 29 Capra based on the fact I could not alter the chain stay length in the end.


A ahorter chainstay is what gives a 27.5 bike a more “flickable” feel Than a 29’er.

Plus Every time you make a geometry change, it needs to be offset via suspension travel adjustment or fork offset (which was why YT went back to 51mm offset forks when they increased the front travel on the Decoy from 160mm to 170mm)

I have reached the conclusion that if you are going to do a mullet properly, you need to start with a 27.5 bike and use a 29 wheel out front (primarily based on chainstay designed around a wheel size). It’s easier to compensate for BB changes to the front end of a bike (reduce travel or install angleset)
Or just buy a mullet ?

Yep, the good thing I guess is I've been wanting to build a bike for some time now.

 

[Craig Anderson]

I've had my Decoy base since around June and love how fun it makes trail riding and handles the climbs, but I still don't think I have gotten used to the 29er wheels. I sold my 27.5 stumpy to pay for this bike and am sort of regretting the tire size choice. I asked YT what would happen if I put 27.5 wheels on it and all the guy could tell me is that they were designed for 29s and it would void my warranty. While a warranty is important to some I suppose I just wanted to know if the swap would bring with it bodily harm as I descend and try to get as rowdy as the Stumpjumper would before I sold it. Needless to say I got no help so here we are... anybody here try converting their 29 Decoy to 27.5 or even go mullet with it? I looked at the geometry specs between the two models on the YT website but quickly realized I don't know the first thing about that stuff and it didn't help me much. Do a few mm's here and there really make that much of a difference?

I have a YT Decoy Base 29 that I have converted to mullet. Can't see why YT will not honor the warranty by changing out the rear wheel. I have replaced the forks to 170mm, installed a 230 x65mm X2 shock. Fitting a 27.5' rear wheel with 2.8 tyre gives you options to run mullet or revert back to 29' wheel. I can run the long rear shock and flip chip in high mode and almost retain the same geometry as the 29er. If you need to claim warranty just reconfigure back to standard.

 

[Jessiejames1108]

I have a YT Decoy Base 29 that I have converted to mullet. Can't see why YT will not honor the warranty by changing out the rear wheel. I have replaced the forks to 170mm, installed a 230 x65mm X2 shock. Fitting a 27.5' rear wheel with 2.8 tyre gives you options to run mullet or revert back to 29' wheel. I can run the long rear shock and flip chip in high mode and almost retain the same geometry as the 29er. If you need to claim warranty just reconfigure back to standard.

Can you throw up some pictures I’d like to see how it looks. How much travel do you get out of the 63.5 X2? The additional travel out of the fork from the 150mm it came with raises the front up a bit right? Do you have any more pedal strikes with that set up than before? I’m very intrigued and curious what it cost you to do all of this? Also how long have you been riding it set up as a mullet?

 

[Craig Anderson]

Can you throw up some pictures I’d like to see how it looks. How much travel do you get out of the 63.5 X2? The additional travel out of the fork from the 150mm it came with raises the front up a bit right? Do you have any more pedal strikes with that set up than before? I’m very intrigued and curious what it cost you to do all of this? Also how long have you been riding it set up as a mullet?

Here are the photos as requested. I haven't ridden it much as a decoy as I'm more 29 inclined coming from a Yeti SB150. The mullet is more nimble around corners and it's beast down hill with the Fox 38 and X2 onboard. But after reinstalling the 29" rear wheel and setting flip chip to high mode to slightly counteract the increase from 150 to 170mm at the front, I feel it's still a very playful bike setup 29 front and rear. I have not measured the rear travel but can't see why it wouldn't be 165mm like the mullet. It has the 230 x65mm X2 fitted. No the pedal strikes are not existent now with the higher travel fork at the front. Climbing is still very good though long travel forks around tight switch backs are hard.

The beauty I can see of having a 29er with the slightly longer chain stay is that at anytime we can change to mullet or revert back to 29".

 

[Jessiejames1108]

Here are the photos as requested. I haven't ridden it much as a decoy as I'm more 29 inclined coming from a Yeti SB150. The mullet is more nimble around corners and it's beast down hill with the Fox 38 and X2 onboard. But after reinstalling the 29" rear wheel and setting flip chip to high mode to slightly counteract the increase from 150 to 170mm at the front, I feel it's still a very playful bike setup 29 front and rear. I have not measured the rear travel but can't see why it wouldn't be 165mm like the mullet. It has the 230 x65mm X2 fitted. No the pedal strikes are not existent now with the higher travel fork at the front. Climbing is still very good though long travel forks around tight switch backs are hard.

The beauty I can see of having a 29er with the slightly longer chain stay is that at anytime we can change to mullet or revert back to 29".

View attachment 43955

View attachment 43956

Wow that looks great! Same color as my bike too the color of the kashima coating looks good on the blue. So after all of that you found yourself going back to 29 huh?

 

[Lowrance]

That blue does look pretty amazing!