crank identifacation

[shamrockexpress]

Got two black series 3 58/107 cranks.
crank on the left is from Buzz solo moto £120
crank on the right is from a guy who was selling on ebay a few months back.....£90
at a glance they both look identical but here is difference in them .
there doesnt seem any noticable problems this is my findings so my question is any body having any problems with either of these cranks??

side float on the mecur crank is 0.60mm on the ebay its 0.40mm and feels less play up and down.

conrods are different 11.2mm on the mecur as opposed to only 10.25 on the ebay crank.

outside webs mecur is 40.52mm as opposed to 40.48 on the ebay

both cranks are tru no run out at all,
so my analysis is the ebay seems to be a better tighter and better finished crank whilst the mecur has the stronger rod even with that being so it will come down to the quality of the metals and treatment /tampering..........
SO ANYTHING TO BE ADDED TO THE ABOVE WILL BE OF INTEREST.

[philcasino1973]

i bought two off the same lad [was off here or lcgb]
so far used one in an full rebuild with all new bearings and seals and the mb 195 kit
bike runs a dream with no issues whatsoever ...i havent gone into the technical side of things but is good enough for me
regards
phil

[shamrockexpress]

thats a good sign Phil, its just the crank in question will be going into a slightly tuned gt186 so it might have to cope with a bit more power and 8/9000 rpm and as for the other crank it will be a gt200 so only time will tell.
cheers for the response.

[shocky]

I have a mec cank but the rods silver I wonder if the rods signify anything ?

[shamrockexpress]

the webs on both of the above cranks look identical so my guess is someone makes the webs and then different brands/suppliers add the rod of their choice!!!!!!!!!!

[shocky]

the webs on both of the above cranks look identical so my guess is someone makes the webs and then different brands/suppliers add the rod of their choice!!!!!!!!!!

Proporting buy there stuff from tameni who I was told were the only crank web manufacturer in Italy for lambretta cranks everyone else including evergreen, mec , af etc just buy there webs or cranks and rebrand I dont know were mazzucchelli or mdp fit in though ?

[rosscla]

Polished silver rod on the mec is usually described as the race version, may also be 'flowed' ...whatever that means, the other is standard black crank. I think they're all made by Tameni.



Sent from my iPhone using Tapatalk

[shamrockexpress]

So that explains the silver rod !!!!!what about the two different ones pictured other thn the obvious one is thicker than the other.........
Curious to who put together the ebay version with the thinner rod is this the reason they are 30 quid cheaper?

[drunkmunkey6969]

Other way round Rosscla. As far as I understand it, the 'race' version had big end shims in and the 'standard' version did not. Usually this meant the race version had the gold looking rod and the standard version silver.

I used the race version religiously in loads of motors, until a rod snapped in a customers engine and wiped it all out. There then seemed to be a whole batch of them snapping just below the little end on the rod in forum members engines, they were all getting posted on here. After that I stopped using them, not worth the risk.

For 58mm cranks I build SIL webs and 110mm jap rods now. And will be using the Rich Taylor ones when they are available.

If I had to hazard a guess, based on the obvious......i'd say the crank with the thinner which you have might be from the weaker batch, i'd get a jap rod fitted to that instead!

[Shuggie]

the Richard Taylor rods are available just now.........got one a few weeks ago and just about to send it off to get fitted