Recumbent Newbie
- Thread starter torkjunky
- Start date
ReklinedRider
Zen MBB Master
Does anyone do the crank shortening besides Bikesmith Design?
JOSEPHWEISSERT
Zen MBB Master
You can take them to your local tool shop. It can cut and drill your cranks. That's what I did with my trainer bike's cranks. And if your local tool shop doesn't have the right taps, you can get the new holes tapped at your local bike shop, which probably has taps for fixing cranks with screwed up threads. It should be cheap and you can walk in and get it done quickly. No shipping and no waiting. You just have to be specific about where to put the holes, about the angle of the holes, and the size of the holes. It's likely that your local tool shop has never done custom cranks before. But it's not difficult.
The shorter cranks help with knee pain but what other pro's are there and any con's, easier or harder to pedal up hill?
Went on the longest ride so far, 20 miles give or take and seems to be getting better. Was pretty windy, at one point rolled off a hill at 30 mph with a good cross wind and bike felt good.
Went on the longest ride so far, 20 miles give or take and seems to be getting better. Was pretty windy, at one point rolled off a hill at 30 mph with a good cross wind and bike felt good.
JOSEPHWEISSERT
Zen MBB Master
Short cranks feel better in my opinion. The smaller pedal circles feel more natural. But there is no advantage or disadvantage in the gearing because you have more than one gear. But short cranks will shift your highest and lowest gears a little in the bigger gear direction. And it will do it by a factor of the ratio of the distance your feet travel in a circle in either case. If you go from 170 mm cranks to 150 mm, the difference will be 13.3%. So your easiest gear will be 13.3% harder. So will your biggest gear though, which is a bonus on a fast bike. So you should consider getting an easier small gearing by getting a bigger large cog on the cassette. This effect is caused by the work it takes to move you and your bike a given distance compared to the distance your feet travel, which means your feet are doing more work per pedal revolution with short cranks. Which means all your gearing shifts in the harder direction. Which means you should get a bigger big cog on your cassette.
bladderhead
Zen MBB Master
I had 145 cranks for about a week, until the BB fell to bits, when I had to revert to 165. In the end I decided it was my fault, so I am now waiting for the delivery of a new BB of the same type, which I think will last a bit longer. I think, for that week, I found the bike easier to handle. I think that short cranks made high cadence more comfortable.
With the 165 I use a 44t single chainwheel. With the 145 I used a 42t. I never noticed a difference in gearing.
With the 165 I use a 44t single chainwheel. With the 145 I used a 42t. I never noticed a difference in gearing.
My boom is 2" aluminum tube. I used 2" aluminum hose clamps, only thing is they are for a 2" tube with a hose on it so they were to big. I cut a piece of rigid conduit [aluminum] and made a spacer. If you look in the picture you can see the spacer.
Just type 2" aluminum clamp on ebay and you will find them. I just looked and there are some quick release 50mm clamp that might work.
Just type 2" aluminum clamp on ebay and you will find them. I just looked and there are some quick release 50mm clamp that might work.
Attachments
LarryOz
Cruzeum Curator & Sigma Wrangler
Well, I actually did do it (shortened the hollow core) "accidentally". I shortened then to 145. The "hollow" part is less than 1/8" at the point. I have ridden with them and don't really notice an issue, but I would still recommend the Apex solid core. The weight saving is immaterial at this point. You loose more by shortening that you do by having it hollow.
Today I was just starting my ride and felt good so I went full out and could manage 28.3 mph on flat ground. Still working on getting stronger. I had a 172.5 crankset with a 50/34. Was curious so went back home changed the crankset to a 175 53/39 and tried again, best I could do on two different attempts on same stretch of road was 27.7 My knees where feeling it after the test. I ordered taps and going to shorten the cranks to 155 or 150 haven't decided yet.
super slim
Zen MBB Master
Shorten to 150 or 155 and your Knees will LOVE you!!
I by no means have would consider that I have figured out the MBB bike but today I got on my Vision RWD and could not ride it. My brain is all screwed up. I didn't relize how much I was counter steering with the pedel stroke until I got on the RWD and was constantly turning back and forth with every stroke. Was afraid to get on the road so I parked it and got back on the clone.
Robert O
Well-Known Member
I had the same thing happen about 50 miles into my Vendetta experience. I got up on a rainy morning, decided to take the old RWD high racer out for my commute. Got about half a block, wobbling all over and feeling like I was completely disconnected from the bike. Turned around and coasted home, got in the car and drove that day. I've heard from a number of riders that they can flip back and forth mentally after a little practice.
1happyreader
zen/child method
On my Day6 (crank forward) I had to lean forward and put weight on the handlebars, to stop my self from twitching the front wheel.
quickbeam
Well-Known Member
I heard some horror stories, so I was pleased the other day when I got on my son's bike (my old bike actually), and took off feeling stable. About 100 feet later I notice I'm swerving a bit on every stroke. It took me the rest of the block, but with some concentration on not moving my arms I got back to riding pretty smoothly. Never felt nervous, just had a bit of unneeded motion for awhile.
ratz
Wielder of the Rubber Mallet
Just ride no hands when the kid is not looking;
Got crankarms shortened to 150mm, after first ride only 12 miles I noticed that my cadence was higher, I don't have a meter but it was noticable and knees don't have the normal ache after. It feels a little werid but I am sure that feeling will go away. Gonna have to go on a longer ride but so far its a thumbs up.
