The Pump Thread

[ExcelsiorTheFathead]

The thread for all things pumping.

I just broke out my board and pumped around the neighborhood. Feels good.

www.pavedwave.org

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[Keenan]

I pumped a beer keg at our end of season ski school party. I have no video as I was holding a red plastic cup in the other hand.

[Keenan]

More Pumping!

[Puddy Tat]

Been at it for about a month and a bit this season. Ordered a bagful of bushings from Riptide and have been tinkering with those. Running APS bushings all around tall barrels and barrels in the Bennett and then chubbies and cones in the Tracker in the rear.

I'm interested in starting to screw with my wedging angles, maybe increase the rear to deaden that truck. Think I'm at eight degrees now, I'm considering pushing that up to 10-12 degrees and see what happens. I need some longer hardware to play with the wedging.

Currently climbing hills and pumping in flats I'm running close to 12km/h average speed.

Dave

[softbootsurfer]

thanks for starting this thread :) it shows the MOSHUN is alive and well

[slopestar]

This is my primary workout. I love it!

[Puddy Tat]

Well I popped my kingpin cherry this morning about 250m from my house.

This kingpin had about 1000km (~10weeks) on it but was the original grade 8 bolt that came with the Cindrich 15 degree plate. I'd been reading about this happening and was getting a little concerned about this kingpin so I had ordered 15 AN6-24a aircraft bolts from Wick's. They actually arrived last night, but I didn't get home until 10PM. And as I'm busy taking an MBA in the evenings I was thinking I was going to change this on the weekend .

Here's a pic of the broken kingpin, you can see it snapped right where the threading starts.

I'm going to chalk this up to good luck, as I was just warming up and wasn't yet up to speed (not that I'm that quick anyways), I basically heard a schnick sound and felt the front end of the board go loose and I stepped off and jogged it out. When I turned around to look the front end was in two pieces! Anyways fortunately this happened this morning rather than late last night when I was carving hard downhill on bike paths to get to my house in the bottom of the River Valley .

Anyway I've pressed the bolt out and put in one of the aircraft bolts so I'll be good to go again this evening when I get the truck back on. While the aircraft bolts are apparently much stronger I'll be keeping a mileage log on my kingpins from now on and changing them on regular intervals. As well as buying a press to make swapping them easier.

Cheers,

Dave

[slopestar]

I'm running Bennett 5.0 front that has seen extensive wear. I'm going to switch to an inverted kingpin. The ground clearance is ridiculous but I really like the feel. I'm on borrowed time right now as the inside of the hangar has grind marks from the threads on the original kingpin.

[Puddy Tat]

Yeah this was a Bennett 5.0 hanger on a 15 degree Cindrich baseplate. What I found really interesting is the taller bottom bushing (using Riptide tall barrels on Griffin array washers) reached exactly the height of the break, so my hanger was also torquing on the threads directly above the breakpoint. I actually noticed this damage at the start of the season when I installed a Delrin spacer into the Bennett (which is frickin' awesome BTW). :-)

Anyways I'm going to start replacing these aircraft bolts every 1000km (8-10 weeks) or so now as I would hate to have this happen at speed. Also the nice thing about the aircraft bolts is they have a much longer shank, so the hanger isn't torquing back and forth on the bolts threading.

Dave

Edited June 4, 2013 by Puddy Tat
Clarity

[slopestar]

I just spoke to thane @ griffin skates? I'm having a grennet spherical made

[crote123]

Someone's double posting on Pavedwave :)

Broke mine last year:

Original Bennett Kingpin. Broke at a weird place. I was also lucky; wasn't going fast. But another 2km and I would have been into high speed territory

Got AN6-24A from Aircraft Spruce. I should be replacing soon. A friend of mine actually gave me a grade 14.... Not sure how much difference there is.

[Puddy Tat]

Someone's double posting on Pavedwave :)

Shhhhh! I was trying to get as much mileage out of the "Cherry-popping" line as I could ;).

That is a weird place for a break.

Dave

[ExcelsiorTheFathead]

Good stuff. I'd never heard of those Grennett products until now. It's fascinating how these boutique manufacturers appear to fill a niche in what are already niche products. It took me a while to figure out what the heck a Cinnett is. I'm currently running a combination of Venom SHR and Khiro bushings. The SHRs have a really nice pop.

I rode my first 5-mile pump run of the season down my favorite local trail this morning. What a joy to be back on wheels. I would have looped back on the bus to do it again, but I was pretty tired and low on hemoglobin from giving blood a few days ago. I think I'm lucky that I didn't pass out. Between now and Sunday I might have an opportunity to carve and pump on the same day. That would be a minor accomplishment.

[ExcelsiorTheFathead]

Carving in the early morning, pumping in the late morning, then shooting at the range. There's still time to go bowling. For this day to get any better there would have to be some debauchery. Too bad I can't get debauchery on tap.

[Puddy Tat]

LDP keeps me from going bat sh!t crazy during the summer when I can't snowboard.

It feels almost exactly like doing fast cross under carves on an alpine board.

I had a couple of relevations this week I'll post some pics of my board set-up tomorrow and talk about wedging stuff I changed around.

Cheers,

Dave

[slopestar]

I was all set to go hog wild on a grennett front truck but i think a trip to socal skates is in order. im just going to buy a ton of stuff!

[Puddy Tat]

These look interesting. CNC'd trucks specifically designed for LDP and Slalom. They are currently under the last stages of design/testing before release next week. From stuff I've read on Paved Wave and the 'Fish, the front truck is going to be 55 degrees and the rear is 20.

I saw them on his Facebook page (https://www.facebook.com/DontTripSkateboards) yesterday.

He definitely has a spherical bearing in the pivot cup, and either the slalom or the LDP truck also includes a spherical bearing in the hanger.

I'm really interested in ordering a set to try out as soon as he says they are available.

Dave

[Puddy Tat]

After breaking the kingpin, I pressed in a AN6-24a aircraft bolt using an arbor press at work. (You can buy one for your bench at home for about $50 and they make changing kingpins a breeze.) As the inner portion of the roadside bushing was getting chewed up by the threading on the original grade 8 bolt I also replaced it with the same Riptide APS 80a barrel that I was currently using. I suspect using the aircraft bolt will result in far less damage to this bushing as the shank is so much longer on the aircraft bolts.

While I was screwing around replacing the front truck and fiddling with the bushing I decided to play with the wedging on the rear truck. I was wondering if increasing the de-wedge on the rear to make the truck more dead would make me faster, so I increased my rear de-wedge from 9 degrees to 12 degrees. When I put everything back together the board felt great on an initial spin around the block, with it being perhaps a little harder to pump at slow speeds.

The next day I rode into work which is 9.7k (I use a Garmin 610 watch to track my rides). It was incredible. I've never travelled at those speeds while pumping. It was literally like I had changed to a higher gear. My previous best time was about 49mins, with my cruising speeds being 16-17km/h, and an average speed of 11.8 km/h I had hit speeds of 20k if I sprinted but would gas out pretty quickly. That day I made the ride in 46:35 was cruising at 19-20km/h and sprinted at 22km/h. It was amazing! The board feels a little less 'surfy' but it is so much faster.

I'm considering taking a few degrees out of my front end to see if I can push myself up even higher.

As the site only allows the uploading of three images at a time I'm going to divide this post into two separate posts to describe my current set-up .

I'm using a Roe Triton (Stiff), as my board. the board apparently has some vibration damping in it. I can't say if it works or not, but I don't have any issues with my toes going numb on longer 38km rides. I bought a ziplock freezer bag worth of Riptide APS bushings this year to play around with and figure out what I like in duros so I use Riptides everywhere on it. All wedging and dewedging is done with Khiro rail risers.

Board

I'm running a Cinnett 5.0 15 degree as my front truck. That's a Cindrich 15 degree baseplate with a Bennett 5.0 hanger. This is essentially like having a Bennett baseplate pre-wedged by 5 degrees. I'm currently running 10 degrees of wedging in the front truck (15 degrees Bennett truck equivalence). I'm considering reducing this by 3 or 4 degrees to see if I can get faster. The truck sits on a 1/2 solid riser and 1/8" shock riser to ensure I have enough clearance to prevent wheel bite. Bushings are 80a APS barrel roadside and 75a APS tall barrel boardside.

I've put array washers (from Griffin skate) on the top and bottom to help with rebound, and a delrin spacer into the hanger. The delrin spacer makes the hanger pivot much more effectively and prevents the bushings from being extruded through the hanger. Additionally I've polished the pivot point, using a variety of grades of sandpaper to make it as smooth as possible (this takes about 30 mins by hand), and installed a delrin pivot cup (also from Griffin Skate)

I use 75mm 81a Classic BigZigs up front.

Front Wedging

Front Bushings and Array Washers

Edited June 9, 2013 by Puddy Tat

[Puddy Tat]

I'm using a Tracker RT-S 129mm as the rear truck which is currently de-wedged at 12 degrees, and sitting on a 1/2" solid riser and 1/8" shock riser.

I've modified the 'wings' of the hanger by filing them down and polishing the pivot point. I installed a delrin hanger spacer and delrin pivot cup (Griffin Skate again).

I'm currently using an APS 85a Chubby boardside and APS 85a Cone roadside. The installed washers are the smal cup that came with the Tracker (because normal sized washers don't dan't to fit there) and the washer that came with the Chubby. I'm running 77a 3dm Avila's for wheels. I tried the 81a Big Zigs in the back but I couldn't pump without them sliding out so I went with the 77a 3dms. The Avila's have crazy grip while I am pumping but if I shift forward and crank hard into the carve while I push out on my back foot I am able to make them slide out into a check slide to control my speed on moderate hills. On narrow bike paths this almost feels like taking a snowboard down a fall-line descent while jumping the tail back and forth to control speed.

Rear Truck De-Wedging

Rear Truck Bushings

I think I need to press out the rear kingpin and replace it with a longer kingpin. The rear bushings look a little over compressed.

Edited June 9, 2013 by Puddy Tat

[crote123]

Now that you are achieving some nice speeds, it's now time to step it up :)

My advice, go Seismic in the rear. Stiff and dead (near 0deg)... and go for bigger wheels. That's what worked for me, but YMMV. I'm addicted to my eFlys :)

[Puddy Tat]

My advice... Stiff and dead (near 0deg)... and go for bigger wheels. ... I'm addicted to my eFlys

After deadening my rear truck by increasing the de-wedge last week I can see how pushing towards zero degree would make the system faster. I'm going to order some of Don't Trips 20 degree LDP trucks and then I can wedge those to even shallower angles (say 10 or even 5 degrees). Thane at Griffin Skates is also currently building a 0G (zero degree) truck that should be available this summer. Interested in those too. Any comment on what it's like to try and slide a nearly zero degree rear truck into a check slide to kill some speed on hills while carving?

I also get where a larger wheel will give me more speed for the same RPM (effort to get to speed has to be higher) and I'd bet the rotational inertia would allow them to hold their speed even better. Technically for the same RPM what puts me at 20 km/h with a 75mm wheel should put me at ~28.5 km/h with a 107mm wheel. But what are you mounting the eFlys on? If I stuck them under my topmount Triton I think I'd get a nosebleed if I stood on the board? :D I might be able to get away with 83mm or possibly 90mm without jacking myself into the stratosphere. Might be time to invest in a deck with full wheel cut outs?

As I wrote this I started to think of a bunch of questions (stuff like the below)

1. How much more effort is required to pump a board with huge rotating wheels? It would seem to me that at some point gyroscopic stabilization of the wheel must come into play and it would become more difficult to deflect it into turns?

2. Which truck is the driving wheel (which wheels are actually pushing me forwards)? I suspect it is the rear?

3. What would happen if I only oversized the wheels on the rear driving truck (the board would have a forward lean, but weight forward is generally good)? If we raise the tail I'd think this might have a dewedging effect on the front and rear trucks, (both trucks would become more dead?) Maybe we'd get better forward drive?

Hmm I'm starting to sound like my 11 year old daughter, sorry about all the stupid questions. It's interesting to think about how to start to explore this further.

Cheers,

Dave

[crote123]

My Mermaid is about 6.5" off the ground :)

I got used to those big wheels. Yes they are a drag going uphill but I've done 29km without putting a foot down a few weeks back around the F1 track here in MTL (two small climbs). But no, I haven't tried sliding them intentionally :) (I have unintentionally... scary). On flat, they rock, well for me. I've also done a training half-marathon @95% effort in 55mins with them. They roll and roll. But it does take some effort getting up to speed. In my case, eFlys require axle extensions which are hard to come by (running bennett 5" + 30mm extensions as a Bennett 6" without extensions will result in baseplate/riser bite).

Before forking any amount of $$$ into trucks, wheels, etc... make sure that you have your technique down path. Then go nuts on bushings (reflex/riptides/venom SHR stims). You have riptides but try the others too. I also slice the Bennetts bushings to make washers with them. Some people sand down the tall Bennett suhings into an hour shape. Because the wheels are so heavy, I run about 83a/86a replexes on the bennett and I only weigh 150lbs. I also overcompress them too. Same bushings on regular would be too hard. But do expirement with bushings and how tight/loose they are. Then a Seismic in the rear would be the next step. I run purple springs, and I may go harder yet.

I've tried 90mm flys but I didn't like them as much as the eFlys. I also like 83mm Centrax. Some people trim them, removing some width.

Just have fun and be a gearhead, nothing like tinkering to figure things out.

>1. How much more effort is required to pump a board with huge rotating wheels? It would seem to me that at some point gyroscopic stabilization of the wheel must come into play and it would become more difficult to deflect it into turns?

I've gotten used to it so it feels the same. Once in a while, I ride with a friend and we swap boards and I actually like the "feeling" with my board as with his board and small wheels, I feel that I lose momentum quickly.

>2. Which truck is the driving wheel (which wheels are actually pushing me forwards)? I suspect it is the rear?

Depends on the technique, sometimes it's the front, sometimes it's the back.

>3. What would happen if I only oversized the wheels on the rear driving truck (the board would have a forward lean, but weight forward is generally good)? If we raise the tail I'd think this might have a dewedging effect on the front and rear trucks, (both trucks would become more dead?) Maybe we'd get better forward drive?

I've never tried and I'm not an engineer so I can't speculate :) I think massive camber is the way to go but no board exists with that.

bye

[slopestar]

current ride Ehlers drop deck/slant nose 9.5"x40". Minimum modded bennet 5.0 with custom frying pan bonded khiro bushings. Tracker RTS with inverted kingpin and basic wing shaving and hard pivot cup/polished with stock bushings.

love these sector 9 nine balls...

Edited June 11, 2013 by slopestar

[Puddy Tat]

I think massive camber is the way to go but no board exists with that.

I used to like the feeling of carving my dropcarve on hills where the board would de-camber in the turns and then snap back underneath me. It felt alot like the return I would get from an alpine deck. Currently that board is set up for my daughter (who is less than 40% of my weight) so its a little unrideable by me. :-)

Pumping feels more to me like doing fast cross-under carves.

I'll look into larger wheels and further deadening of the rear truck. To much deadness and I'm thinking it might get harder to climb inclines with?

Dave

[Puddy Tat]

Current ride Ehlers drop deck/slant nose 9.5"x40". Minimum modded bennet 5.0 with custom frying pan bonded khiro bushings. Tracker RTS with inverted kingpin and basic wing shaving and hard pivot cup/polished with stock bushings.

love these sector 9 nine balls...

Nice looking ride and nice place to be riding.

Been raining a bit here this week. (Including a tornado warning yesterday:eek:). So between that and having to study for a final this evening I haven't been out much. I've gotten another person into LDP, and found another guy here in Edmonton who is also in to it, so the three of us are going out for a 20k ride on Sunday.

Cheers,

Dave