[ziegler]

Hey all,
This is the first of my posts documenting my Cannondale Prophet build. The aim is to create the first "modern geometry" prophet with the original lefty.
A little background first; I got this bike over a year ago after discovering mtb in my junior year of high school. I like the unconventional and unique so I naturally fell in love with the lefty fork and the engineering of the Cannondale of yesteryear. This particular prophet is an XL which has a super long headtube to provide the modern reach numbers I'm after. (crude measurement says 490mm or so).
After some moonlighting on various forums I found this very insightful thread:

Slack head tube angle w/Lefty

I have a Prophet that is converted 650b. My only complaint is I have to run the frame in Xc mode for tire clearance. I've had a few people tell me over the years there is a headset and a different tube you can get for the lefty to slack it some. Can someone link me what I would need?

www.mtbr.com

Fast forward a year of research and searching for a Project 321 clamp-on adapter I finally got hold of one from a lovely gentleman from the east coast. By coincidence, its custom anodizing is close in color to my frame.

With the guidance from the above thread, I ordered the Works 2-degree angleset and waited for the various mail couriers to do their thang.
With both ingredients in my possession, it was finally time to realize my project.

A couple of love taps from a dead blow and the oppressive 1.56” steerer was removed.

It was at this time I realized I ordered the wrong headset. I was meant to get ZS49-EC49 to preserve the original stack and clamp spacing. I got the ZS49-ZS49 by accident. It would take another month for the correct one so I proceeded with this janky setup. (get the right one my setup means the clamps arent entirely where they should be.)

In the Works headset went and I got my first glimpse of the new frontend.

The 780mm bar and 50mm stem bring the cockpit to the modern-day. No 100mm stem for me.

Then it was the standard steerer shortening and star nut install before it was ready for a pedal on the street. Looks pretty good so far for a 15-year-old 26er.

with the correct Works headset that keeps the stack the same, unlike mine which lowers the headtube slightly, the headangle in the "freeride" shock position will 65.5 degrees. With offset shock bushings you could push that another degree slacker.

I have more upgrades and changes on the way. I am building a new heavier duty wheelset with Schwalbe Majic mary's which I will post soon.

 

[ziegler]

I got a set of ethirteen rims and Schwalbe magic mary DH tires on closeout for a steal to replace the perishing kendas and weak stock rims. I got the front one laced up the other day and wow does it look cool. The front of the bike is getting there. I am not a fan of the rear "fire" hub, it doesn't hold adjustment to well but finding a good replacement qr hub for a good price has been tricky.

I took it for its first real mtb ride ever on 1000ft of post-rain pnw goodness. The blue flow trails had turned to choppy tech from the heavy rain, but the new geometry and rubber transformed the bikes performance and my confidence. So far its proving to be a respectable all-mountain bike for its age.

What became clear from the climb to the top though was that the 1x9 drivetrain from the previous owner is dreadful. Combined with my rather lacking fitness it took me twice the time and four times the effort as it should to ascend. Needless to say, I am trying to find a deal on a 1x11 and a 27.2 dropper post. (maybe even drill the seatube for internal routing. )

 

[RS VR6]

Can't believe how long seat tubes used to be. I still have a Pivot Mach 5 from 2010. The seat tube is super long. I don't think I can even get a 100mm dropper in there.

 

[ziegler]

Can't believe how long seat tubes used to be. I still have a Pivot Mach 5 from 2010. The seat tube is super long. I don't think I can even get a 100mm dropper in there.

I think I might be able to get a 120mm if I cut down the seatube a bit. there is extra length above the weld I can cut off If i have to. You might be able to do the same.

 

[Energetik]

This is great! I have a 27.5 converted Prophet with a standard fox 34 150mm fork. It runs around 67 degrees I think. I run it in the xc position and that does fine for trail riding.

Another big upgrade suspension wise was the custom tuned rs monarch that I got done at dirtlabs. As you know I'm sure the regressive curve takes a high compression and low rebound tune. The custom shock made a huge difference.

Cool project you have going here. Nice work!

 

[ziegler]

This is great! I have a 27.5 converted Prophet with a standard fox 34 150mm fork. It runs around 67 degrees I think. I run it in the xc position and that does fine for trail riding.

Another big upgrade suspension wise was the custom tuned rs monarch that I got done at dirtlabs. As you know I'm sure the regressive curve takes a high compression and low rebound tune. The custom shock made a huge difference.

Cool project you have going here. Nice work!

Thank you! Your prophet sounds rad.

I am thinking about getting my rear shock sorted as its a replacement monarch r with the totally wrong tune. (low compression I believe) It tends to blow through travel like its free in contrast to the lefty which is very firm.
Down the line a coil shock might be interesting to match the coil fork, but I've heard that coil shocks are hard to tune for single pivots. But I do like the small bump sensitivity. I am relatively new to the sport and I get killer arm and hand pump.

 

[Energetik]

Yeah a custom tuned air shock might be better. I was told by a dirtlabs. PUSH, MRP, and Avalanche (all tuners or shock manufacturers) that the regressive or falling rate design of this single pivot makes coil shocks a hard go. They tend to be very linear so they'd blow through travel quick or have to be tuned so high compression that it loses its amazing small bump sensitivity. I could be wrong. There are some new progressive springs and spring tuning options out now that might make that work. I know some Prophet MX models had coil but I was told they didn't ride well enough to justify the weight over air. That's second hand from many years ago though.

As for my Prophet I went Shimano xt 1x11 and I'm so happy to never touch a front derailleur ever again. It's well worth it with the right gear combo. For me it's a 32t front with a 42t max in the rear. I can climb most things with that. The rest is just being out of shape.

I went with Race Face stuff for the cockpit and pedals. Brakes are Magura MT5s with MT7 pads. 200mm/180mm rotors. I went with Maxxis dhf/Aggressor tires at 2.3. They work decently well for SE PA. (USA)

 

[ziegler]

Yeah a custom tuned air shock might be better. I was told by a dirtlabs. PUSH, MRP, and Avalanche (all tuners or shock manufacturers) that the regressive or falling rate design of this single pivot makes coil shocks a hard go. They tend to be very linear so they'd blow through travel quick or have to be tuned so high compression that it loses its amazing small bump sensitivity. I could be wrong. There are some new progressive springs and spring tuning options out now that might make that work. I know some Prophet MX models had coil but I was told they didn't ride well enough to justify the weight over air. That's second hand from many years ago though.

As for my Prophet I went Shimano xt 1x11 and I'm so happy to never touch a front derailleur ever again. It's well worth it with the right gear combo. For me it's a 32t front with a 42t max in the rear. I can climb most things with that. The rest is just being out of shape.

I went with Race Face stuff for the cockpit and pedals. Brakes are Magura MT5s with MT7 pads. 200mm/180mm rotors. I went with Maxxis dhf/Aggressor tires at 2.3. They work decently well for SE PA. (USA)

I have heard much the same, but I haven't read much about progressive coils. Something to look into. For the immediate future though I am going to have to stick with the current shock for budgetary reasons.

I cant wait to get a 1x11, the current 1x9 has a 32 chainring and at max a 36 cog. Pretty terrible for here in the PNW.

Do you have any pictures of your build anywhere? Id like to check it out for some insperation.

 

[dietz31684]

Looking really good! I like the lefty. I ditched mine but miss the look. Regarding the 1x11 due to gearing, just drop the size of your front ring, no shame in that! I am set up 1x10 and don't have any issues.

Here is mine, still rocking it as my main ride. Looking to upgrade the 140mm sektor to a pike or 36 and would love to get my rp23 tuned. A new fork would also allow me to try a 27.5 up front. Maybe I'll buy some stuff over the winter. A shorter stem is tempting too but I have my seat rails all the way back and still find myself wanting a little more reach so the 60mm stem will stay for now.

 

[ziegler]

i wonder how small of a chainring it will take to make a 34 tooth cog good for climbing. I might try that for a short term solution.

I am a little jealous that yours is an mx prophet. I think the ultimate prophet would be an XL MX Prophet with the front-end modifications I made on mine along with a 1x11 and all that. that would be rad, but I haven't even seen a picture of an extra large MX frame.

As for a 27.5 wheel up front, I think you should give it a try. I might do the same in the distant future. Everybody I have seen do it has been happy with it.

 

[Energetik]

Sorry for the late reply. I'm having issues posting pics here from my phone so here's a link to my vital bike check:

Cannondale Prophet "Grave Metal"

View Vital MTB member Prophet26's mountain bike check "Cannondale Prophet "Grave Metal"".

www.vitalmtb.com

27.5 is great. It does raise the bb a bit but honestly the geo and bb height are old school yo begin with so I don't really notice. I'd likely go mini mullet (27.5/26) when I go back to my local bike parks. Then I'd drop it in the low setting. I'd be interested to see how that works.

 

[ziegler]

Heres a preview of what I've been cooking up these last weeks...
Should be mounted and documented in a post shortly.

 

[ziegler]

Here is the 1x11 all done. It took much longer than it should have because I was clamping down the shift cable wrong on the derailleur. Simple mistake that took days too diagnose.
The results though were definitely worth the wait.
The big 50 tooth granny gear is awesome, while I am still unfit and the climbs are still extremely tiring, I can now actually turn over the cranks and spin circles properly.

I chose a deore m5100 for its huge capacity, features and shockingly low price. I agree with reviewers that say it's a great value. Just $50 for this modern mech.

I chose a sunrace 11-50 cassette because it was available and importantly to me, the cogs are all steel. I dont care about the weight penalty, I am after durability.

I already bought a pnw Rainier 125mm internal dropper post which will be the next upgrade. (Still struggling with the matching rear wheel). So stay tuned for some frame modifications.

 

[ziegler]

Heres a sneak peak of roughly what the dropper will look like installed. I still need to cut the seatube down about 10mm for more clearance and drill the hole for the cable to come out. but it looks promising.

 

[Energetik]

That looks great! My biggest cog is 42 I think. That's about what was average when I bought my m8000 complete drivetrain. That's one of the few things I've ever bought at brand new retail prices. Almost everything else has been after research or good luck finding crazy deals.

I hope the dropper works out but I personally am not ok modding my frame. It sucks because a lot of the good droppers are internal anymore.


Nice build! Good luck.

 

[ziegler]

Went

That looks great! My biggest cog is 42 I think. That's about what was average when I bought my m8000 complete drivetrain. That's one of the few things I've ever bought at brand new retail prices. Almost everything else has been after research or good luck finding crazy deals.

I tend not to buy anything new if possible for various reasons but I got good deals on these parts new and I am enjoying the worry-free aspect.

One cool additional thing I have noticed with this drivetrain is that the prophet's high swingarm and the derailleurs clutch make the drivetrain silent as a church mouse. There is no chainstay to slap into like on most bikes.

 

[ziegler]

I sent my fork out to Mendon Cyclesmith a few days ago to be rebuilt and upgraded to the tpc damper. There is only so much oil I could pretend wasnt leaking out the bottom. Here's to hoping that it's not all worn out or damaged to the point of my wallet spontaneously combusting.
Only a divine power knows for sure if its ever been serviced since new. I don't have much of an idea the life this bike lived before me besides that i think it originally came from California. Maybe they followed the regular service intervals. Something tells me that didn't happen though, I know I don't.

 

[Energetik]

Mendon is the man for the job. He's the lefty guru as you know. Not a fan of the latest ones apparently.

Otherwise it's not hard to fit a regular fork. I used a mix n match from Cane Creek for the headset and 150mm fox 34 at 539mm a2c. Slightly over the max of 530. The lower shock setting would likely maintain the 65.5° head angle with that. Hopefully your lefty is good. Mendon is the master for those.

 

[ziegler]

Mendon is the man for the job. He's the lefty guru as you know. Not a fan of the latest ones apparently.

I got an email back, and my worries about the fork are over. Just regular service and the upgrade. I can't wait to have it back on the bike and push it to its limits.

For anyone on the fence about having your lefty serviced by Mendon, I can't recommend him enough. His pricing is extremely fair, in fact, a basic service is the same most shops charge for a fox fork. Fantastic considering the premium we normally pay for anything lefty-related. He was understanding about a shipping issue that was my fault and is prompt and friendly in his communication.

 

[Energetik]

I got an email back, and my worries about the fork are over. Just regular service and the upgrade. I can't wait to have it back on the bike and push it to its limits.

For anyone on the fence about having your lefty serviced by Mendon, I can't recommend him enough. His pricing is extremely fair, in fact, a basic service is the same most shops charge for a fox fork. Fantastic considering the premium we normally pay for anything lefty-related. He was understanding about a shipping issue that was my fault and is prompt and friendly in his communication.

I'm glad that's working out for you. He comes highly rated from many others on the forum. He's a member here too.

My own suspension needs the full rebuild front and back. I'm not looking forward to the cost of that. The fox 34 might just go straight to Vorsprung if I can swing it and the RS Monarch needs to go back to dirtlabs who did the original tune. This parts shortage is killing me for replacing drive train wear parts too.

I'm always keen on seeing Prophets get the treatment. I did mine and I'm glad to help anyone out with theirs. Cheers!