NorCal Kayak Anglers

Kayak Fishing Zone => Safety First => Topic started by: eiboh on January 12, 2017, 05:52:31 PM

Title: converted mirage drive
Post by: eiboh on January 12, 2017, 05:52:31 PM
many years back as I was heading out for a quick trip on the salt in Sonoma County. noticed another guy doing the same in bicycle riding shoes and curiosity prompted me to go investigate. he had converted his Mirage Drive pedals to compatible with the shoes and told me it was an easy swap to do it. anyone on this site do this it looked kind of dangerous to me ?   :smt001
Title: Re: converted mirage drive
Post by: Fishcomb on January 12, 2017, 07:46:02 PM
Searching is your friend. Lots of threads about this.

http://www.norcalkayakanglers.com/index.php?topic=48564
Title: Re: converted mirage drive
Post by: NowhereMan on January 13, 2017, 08:12:19 AM
Yes, this topic has been discussed, but I'm curious whether anybody has anything new (or old) to add. On my Hobie, I've experimented with different crank arm lengths and different types of pedals, but never tried clipless. FWIW, here's my current thinking...

1) Slightly longer crank arms are worth considering, although determining the optimal length might require some experimentation. I've got about 33" inseam and usually have the Hobie pedals adjusted to 6 (second longest setting). I've experimented with crank arms ranging from 1/2" to 2" longer than standard, and I've settled on 1" longer (I'm using a GT drive, by the way). I'm definitely not a speedster and don't do 20 miles of pedaling per day, but I do feel like this setup gives me more sustained power for less effort. I haven't tried to quantify the improvement, so I can't be sure how much more efficient it is, but it seems to me that it's significantly more than the switch to GT.

2) I've experimented with various pedals, all non-clipless. This might be sacrilege to some, but I ended up going back to the Hobie platforms (using a custom spindle that's threaded like pedals, so I can easily switch to bike pedals, if I want to). Why the Hobie platforms? Shoes are subject to loss and the thought of pedaling barefoot on standard bike pedals doesn't appeal to me. Even (bike) platform pedals would be hard on your bare feet, and clipless pedals would be murder. I find no discernible advantage to bike pedals over the Hobie platforms, and bike pedals like to rust and collect grit around the spindle. And gritty bike pedals are very hard to clean, since the grit is trapped in grease.

3) If you do decide to experiment with different crank arm lengths, use 6061-T6 aluminum, not 7075. Yes, 7075 is stiffer and stronger, but it's also way more expensive, it's more difficult to work with, and it's subject to corrosion. Charles Atlas himself couldn't break a pair of 6061 cranks in a Hobie, so the extra strength of 7075 is completely pointless, IMHO.

4) And speaking of grease... This is a little bit off-topic, but if you have the GT drive, I'd recommend you get rid of the delrin rollers and replace them all with nylon rollers of the same diameter. With nylon, you don't need any grit-trapping grease, and the drive will be quieter as compared to delrin with grease. The only catch is that nylon expands ever-so-slightly when wet, so you'll want to use one less roller in each case. For example, around the main axle, there are 15 (as I recall off the top of my head...) delrin rollers. Replace those 15 with 14 nylon rollers. This will not introduce any additional slop or wobble. And nylon is extremely durable in this application---after a whole season with this setup, I can detect no wear on the rollers. I'll be doing some maintenance on my mirage drive soon, and I'll post some more info on this in a separate thread.

The bottom line? In my estimation, Hobie platforms are better than pedals. And if you're feeling really ambitious, you might want to experiment with different crank arm lengths.
Title: Re: converted mirage drive
Post by: seabird on January 13, 2017, 11:09:48 AM
anyone on this site do this it looked kind of dangerous to me ?   :smt001
Using clipless pedals wouldn't be any more dangerous than normal pedals; They're easy to remove your foot from if you have practiced once or twice. That said I'm not sure the utility would outweigh the downsides that NowhereMan suggested.

There are combo platform/clipless pedals but none of them are going to be comfortable barefoot. You could use them with normal shoes, however I seriously doubt any of them would do well on a kayak, especially in the salt.
Title: Re: converted mirage drive
Post by: Bushy on January 13, 2017, 11:54:16 AM
Yes, this topic has been discussed, but I'm curious whether anybody has anything new (or old) to add. On my Hobie, I've experimented with different crank arm lengths and different types of pedals, but never tried clipless. FWIW, here's my current thinking...

1) Slightly longer crank arms are worth considering, although determining the optimal length might require some experimentation. I've got about 33" inseam and usually have the Hobie pedals adjusted to 6 (second longest setting). I've experimented with crank arms ranging from 1/2" to 2" longer than standard, and I've settled on 1" longer (I'm using a GT drive, by the way). I'm definitely not a speedster and don't do 20 miles of pedaling per day, but I do feel like this setup gives me more sustained power for less effort. I haven't tried to quantify the improvement, so I can't be sure how much more efficient it is, but it seems to me that it's significantly more than the switch to GT.

2) I've experimented with various pedals, all non-clipless. This might be sacrilege to some, but I ended up going back to the Hobie platforms (using a custom spindle that's threaded like pedals, so I can easily switch to bike pedals, if I want to). Why the Hobie platforms? Shoes are subject to loss and the thought of pedaling barefoot on standard bike pedals doesn't appeal to me. Even (bike) platform pedals would be hard on your bare feet, and clipless pedals would be murder. I find no discernible advantage to bike pedals over the Hobie platforms, and bike pedals like to rust and collect grit around the spindle. And gritty bike pedals are very hard to clean, since the grit is trapped in grease.

3) If you do decide to experiment with different crank arm lengths, use 6061-T6 aluminum, not 7075. Yes, 7075 is stiffer and stronger, but it's also way more expensive, it's more difficult to work with, and it's subject to corrosion. Charles Atlas himself couldn't break a pair of 6061 cranks in a Hobie, so the extra strength of 7075 is completely pointless, IMHO.

4) And speaking of grease... This is a little bit off-topic, but if you have the GT drive, I'd recommend you get rid of the delrin rollers and replace them all with nylon rollers of the same diameter. With nylon, you don't need any grit-trapping grease, and the drive will be quieter as compared to delrin with grease. The only catch is that nylon expands ever-so-slightly when wet, so you'll want to use one less roller in each case. For example, around the main axle, there are 15 (as I recall off the top of my head...) delrin rollers. Replace those 15 with 14 nylon rollers. This will not introduce any additional slop or wobble. And nylon is extremely durable in this application---after a whole season with this setup, I can detect no wear on the rollers. I'll be doing some maintenance on my mirage drive soon, and I'll post some more info on this in a separate thread.

The bottom line? In my estimation, Hobie platforms are better than pedals. And if you're feeling really ambitious, you might want to experiment with different crank arm lengths.



Or, just hold your paddle with two hands.

~Bouché~
Title: Re: converted mirage drive
Post by: NowhereMan on January 13, 2017, 12:37:18 PM

Or, just hold your paddle with two hands.

~Bouché~

That'll never catch on...
Title: Re: converted mirage drive
Post by: michel on July 25, 2017, 11:50:05 AM
I shortened my cranks by about an inch. I needed a new pair after a break at Gimme Shelter and have pretty big legs so prefer a little more resistance.

I didn't want to repeat the experience of paddling an AI a few miles upcurrent so went with 6061 barstock that was 1/4" thicker in one dimension than the 3/4" square tubing that Hobie uses. This puts significantly more metal at the weak point (adjustable pin) though it means you can't use their nice adjusters.

Also wasted a lot of time milling the cranks down. If I did it again I'd drill them out instead to save weight.(http://i.imgur.com/K3zXC5C.jpg)
Title: Re: converted mirage drive
Post by: AlexB on July 25, 2017, 12:57:07 PM
As a guy who has spent a lot of time on a mountain bike, I personally think clipless pedals are a BAD idea on the water. Yes, you can get really good at disengaging them quickly, but anyone who's pushed their limits on a mountain bike knows that sometimes when you crash you end up in a tangled mess, still attached to your bike.

The same could happen on the water, but you could potentially end up hanging upside down under your kayak if it flipped over. Gravity and bouyancy might make it hard to twist your feet just right to release the pedals.

I also know that sand and grit can affect your pedal's release mechanism.


Sent from my iPhone using Tapatalk
Title: Re: converted mirage drive
Post by: NowhereMan on July 25, 2017, 04:19:42 PM
... I personally think clipless pedals are a BAD idea on the water. ...

Agree 110%. I even removed the rubber straps from the Hobie platform pedals (and sawed off the nubs that hold straps, but that was because they can get in the way of the ropes when sailing...).