V20 crank length?

[rx7mark]

Late to the party but add me to the short crank ranks. I’m 6’1” w 34” inseam. Rode/raced 172.5mm on DF for years. Tried the same on my CB (first recumbent) and could barely walk after my first 50 miler due to knee cap pain. Switched to 155 and have never looked back. Now ride 155 on both S40 and V20

Don't forget the thigh to bar clearance advantage that smaller cranks give for taller riders . I am 6'2", but a 45.5 X-seam, so a little longer leg than torso.
On my modified T50, I know not a V, the 155mm cranks I now have really help with the fit. Even with 155 mm my thighs just touch my bar tape. I would not have been able to make the bar to seat to pedal relationship work out as well with a longer crank. I assume the V might be similar.

Mark

 

[Frederik]

Hi, in theory, I would be using best 155 cranks too. But if you're looking for a good price/quality, I recommend a shimano 105 build: the cranks can come at 160 from factory and a Shimano 105 set is really very good for the price.

bike-components.de/de/Shimano/105-Kurbelgarnitur-FC-R7000-Hollowtech-II-p64807/?o=586711344-silky-black-160-0-mm-34-50

Almost no knee pain on my v20, but never tested something longer either . I can have some knee pain on my DF with 170s however.

Best regards,
Frederik

 

[paco1961]

Agreed. The Shimano 105 is an excellent and often overlooked value. The only problem is that it is completely unavailable in 160 length in the US. I have standing order in with about 8 suppliers and have been waiting months. Might try your link. My high school German is a bit rusty but probably good enough to get through the online ordering process. Hopefully they ship internationally. Danke Shoen!

 

[chicorider]

I use Crupi Rhythm cranks. They're meant for BMX bikes, but the chainring tabs happen to be machined to work perfectly with a 110bcd double road ring pairing (I use 36 x 50). The spindle is the 24mm Shimano type, reasonably light weight, and not stupid-expensive. They come in all the short sizes, from 130mm up to 165mm. Mine are 160mm.

 

[paco1961]

Just checked the Crupi site as I sort of remembered looking at them. Website says 165 lb rider weight limit. I don’t think I’ve been under 165 since high school! But since we don’t stand on the pedals and jump tall buildings my guess is that they’d be fine

 

[DavidCH]

I have sram rival crankset... its cut down to 155mm. You can't cut down shimano cranks but can with sram rival. Hope that helps.

 

[paco1961]

Same. Not carbon light but solid and a great price

 

[TransAm]

I have sram rival crankset... its cut down to 155mm. You can't cut down shimano cranks but can with sram rival. Hope that helps.

Are you sure you can cut down SRAM Rival cranks? I got a set of solid aluminum Apex 180mm cut down to 158.5mm by Mark Stonich at bikesmithdesign.com. He said he would not cut down Rival cranks because they are hollow.

 

[LarryOz]

Are you sure you can cut down SRAM Rival cranks? I got a set of solid aluminum Apex 180mm cut down to 158.5mm by Mark Stonich at bikesmithdesign.com. He said he would not cut down Rival cranks because they are hollow.

I have done both. Yes the Rivals do have a hollow section in them and the shorter you to, the larger this section become. From where I am looking at it, as long as the thread of the pedals engaged the threading on both sides of the crank I don't think that there is a big issue with using them.
On the other side of the argument: how much weight are you really saving on having the hollow cranks using Rival? You'll probably save more just by having a shorter crank. I bough the Rival set to shorten just because I could get a set of the Apex at the time.

 

[DavidCH]

Are you sure you can cut down SRAM Rival cranks? I got a set of solid aluminum Apex 180mm cut down to 158.5mm by Mark Stonich at bikesmithdesign.com. He said he would not cut down Rival cranks because they are hollow.

 

[TransAm]

View attachment 10397

What size to start and finish, and did you hit the hollow?

 

[DavidCH]

I got them cut down at an engineering company in the UK: www.highpath.co.uk

My conversation with Patrick
"The Rival range is solid, but it does have rather deep fluting at the back. I can shorten to 150 from 172.5 but the resulting pedal hole is thinner than ideal. If you are happy to have them done at your risk then send them by all means.

We shape the ends on a CNC milling machine to suit the new hole."

So I got them cut down to 155mm. I haven't found them to be a problem.

 

[TransAm]

I got them cut down at an engineering company in the UK: www.highpath.co.uk

My conversation with Patrick
"The Rival range is solid, but it does have rather deep fluting at the back. I can shorten to 150 from 172.5 but the resulting pedal hole is thinner than ideal. If you are happy to have them done at your risk then send them by all means.
.

I don't understand the comment about the flute. My new and old Apex have the flute. My Rival cranks are smooth with parallel faces (and hollow afaik); but they are all a few years old (black with white logo, not white stripe with black logo), so that may have changed?

 

[vosadrian]

Hi All,

New V20 owner here. My V20 has SRAM Rival 165 cranks with 50-34. I come from DF and due to hip issues (trying to open hip angle in aero position on DF) I was running 165 cranks on that and really liked them. I am having no issues with 165 so far on V20, but the 50 big ring is limitting. I am riding some rolling hills that I would pedal down on my DF (52-11) but I just have to roll on the V20 because I can't spin quick enough to make meaningful power at >50kph. Could also be I am not used to spinning quick on MBB yet as I have only just started.

Reading on here I am wondering if a Shimano 105 with 160mm crankset and either 53-39 or 52-36 would be a good choice for me. Does it fir the V20 straight up with the BB it has? Any advice on other options? Could I just stick a spare 52 big ring I have onto the crankset I have?

Cheers!

 

[paco1961]

I am also stuck betwixt and between. Currently running 50/34, 11-36. Need the 34/36 for the steepest hills in my area but spin out at about 32mph on the 50/11. Could really use the 52 the 18 tooth jump from 34 to 52 is too much for most FD. I run 155 Apex cranks on my V and Shimano 105 160 on my S. Don’t notice much difference

 

[3bs]

Wickwerks 53/34 rings, sram 11/36 cassette
All prayers are answered

 

[paco1961]

What FD? Sram Force balks at anything over 16 tooth gap

 

[3bs]

ha!
SRAM force front and rear. No prob.

BUT I went to a rival rear brifter as 2x 10 runs much better with this range

 

[paco1961]

Ha! Back at ya. I also found the 2x10 to work better. Guess it’s back to the shop to play w the rings and FD!

Thanks

 

[Frito Bandito]

Mine came with a Tagra 50/34 front, which was smaller than my TT bike's 172.5mm 52/36. I knew I wasn't going to be able to spin it up enough, so I switched to a 165mm 52/36 (11/25). So far I have maxed the speed out on the V20 at 2kph less than my TT bike under similar conditions (67kph vs 69kph), but I would jump on a 55T front if I could find one locally, especially 165mm or up to 172.5mm. I am not sure if shortening your crank arms or lengthening will help much, but a 52 or 53 will definitely help for top end speed for sure. As you wrote, I was still twitchy at that speed under high power so I might have been able to get a bit more out of it. As for the SRAM/Shimano compatibility, I did a quick search and it seems they will. Worst case scenario is that you have to buy a new BB.

Where I mostly ride has only a few short descents where a 53 or a 55 would shine. But I can imagine they would be a big help in carrying more speed into the rollers or for top speed on the long descents you are riding on.