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Post by johnbolton on Sept 6, 2021 18:47:08 GMT 1
Hi Guys, a pals just asked me if Vertex cranks are any good??
I’ve no idea, but on vertex GB’s website they’re pushing Hotrods, if anyone could shed any light on this please..
thanks in advance
John A
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Post by bare on Sept 6, 2021 21:32:40 GMT 1
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Post by jon on Sept 7, 2021 18:35:22 GMT 1
MBD use hotrods cranks, and has one in his bike putting out over 100bhp.
He says they are the best for trueness.
I bought a +4 long rod one from him with high load outer bearings to match the short gudgjn pin height forged pistons I am using. I am yet to use/comment on it. Looks good quality though.
Jon
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Post by johnbolton on Oct 5, 2021 18:11:26 GMT 1
MBD use hotrods cranks, and has one in his bike putting out over 100bhp. He says they are the best for trueness. I bought a +4 long rod one from him with high load outer bearings to match the short gudgjn pin height forged pistons I am using. I am yet to use/comment on it. Looks good quality though. Jon I use Hotrods too in my YPVS and they are pretty bang on true. I have had problems with the 10 ball outer mains though - I’ve got 78bhp and the last one that fell apart lasted 170 miles.. I use Polyamide / brass caged TZ roller bearings now. |
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Post by jon on Oct 5, 2021 18:29:35 GMT 1
MBD use hotrods cranks, and has one in his bike putting out over 100bhp. He says they are the best for trueness. I bought a +4 long rod one from him with high load outer bearings to match the short gudgjn pin height forged pistons I am using. I am yet to use/comment on it. Looks good quality though. Jon I use Hotrods too in my YPVS and they are pretty bang on true. I have had problems with the 10 ball outer mains though - I’ve got 78bhp and the last one that fell apart lasted 170 miles.. I use Polyamide / brass caged TZ roller bearings now. If mine last that little time it’s going back to have them changed. Good news is Martin’s parents are only up the road from me so I get bits next time he’s there. I was told not to use TZ style if I was considering straight cuts. Jon |
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Post by 4l04ever on Oct 5, 2021 22:15:54 GMT 1
I thought the TZ Roller style bearings were only for straight cut gears, as they cannot cope with the side load from helical gears...
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Post by jon on Oct 6, 2021 7:09:58 GMT 1
I thought the TZ Roller style bearings were only for straight cut gears, as they cannot cope with the side load from helical gears... That makes sense to me too, but I’m sure Martin said the other way round? Jon |
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Post by reedpete on Oct 6, 2021 8:46:02 GMT 1
Tz has strait cut primaries and roller bearings. Rollers can’t take any lateral load so no good with helictical gears.
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Post by muttsnuts on Oct 6, 2021 10:22:21 GMT 1
I keep the hotrod cranks in stock, the standard one is £320 inc VAT plus postage, or a 4mm stroker one is £450 inc VAT
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Post by Tobyjugs on Oct 6, 2021 12:09:00 GMT 1
That's good to know Dave, but what are your opinions on the comments above.
You must have more experiance than all of us put together.
In a high output engine i would stay away from steel caged bearings.
I have also seen first hand how strong a ceramic ball bearing can be. Jaw dropping tough.
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Post by muttsnuts on Oct 6, 2021 12:44:09 GMT 1
depends what you mean by high power engines and more importantly what they are being used for
For road use then the hotrod cranks with normal main bearings are fine, got lots of engines out there doing 1000's of miles with no issues that are pushing 70+bhp
For competition use e.g. 1/4 mile/drag racing, track day use then certainly going to 10 ball bearings helps, but then you ideally need to consider C4 or even C5 clearance, rather than the stock C3, but again, how much power and how hard are you riding it - is your budget big enough to afford a strip down every other meeting etc - it won't be the crank you'd need to think about first if that's the case, it would be pistons/rings/bores etc
If running straight cut primaries, then you really need the roller bearing/TZ style main bearings as they will take the high load much better than a standard main bearing - but again how much power and torque are we talking
There are very few engines out there in normal use pushing much more than 90+bhp, my own RS421 pushing 100bhp and used on the road is using a 4mm stroked hotrod crank with C3 clearance 7 ball O ringed main bearings, its done well over 1000 miles with no issues and that's mixed riding including a few track days.
My mito which pushes 109bhp uses a 7mm stroked crank with TZ style bearings (C3 clearance) and thus far has been very reliable (other than a 100mph crash) !
My mates bike pushes 115bhp, that is using a 10mm stroked crank with 10 ball (larger cage) bearings, again C3 and has been very reliable, but the bearings etc have also been treated in a low friction coating.
Going ceramic is a really good idea, but also very expensive and unless you have deep pockets, or are looking at serious power, say 140+bhp, then you'd have to question the benefits, or you are a very fast/hard rider on the track, for road use I'd say ceramics is overkill, but each to their own, I'd love ceramic bearings in all my engines, but I can't afford or justify such expenditure
HTH
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Post by Tobyjugs on Oct 6, 2021 15:13:45 GMT 1
depends what you mean by high power engines and more importantly what they are being used for For road use then the hotrod cranks with normal main bearings are fine, got lots of engines out there doing 1000's of miles with no issues that are pushing 70+bhp For competition use e.g. 1/4 mile/drag racing, track day use then certainly going to 10 ball bearings helps, but then you ideally need to consider C4 or even C5 clearance, rather than the stock C3, but again, how much power and how hard are you riding it - is your budget big enough to afford a strip down every other meeting etc - it won't be the crank you'd need to think about first if that's the case, it would be pistons/rings/bores etc If running straight cut primaries, then you really need the roller bearing/TZ style main bearings as they will take the high load much better than a standard main bearing - but again how much power and torque are we talking There are very few engines out there in normal use pushing much more than 90+bhp, my own RS421 pushing 100bhp and used on the road is using a 4mm stroked hotrod crank with C3 clearance 7 ball O ringed main bearings, its done well over 1000 miles with no issues and that's mixed riding including a few track days. My mito which pushes 109bhp uses a 7mm stroked crank with TZ style bearings (C3 clearance) and thus far has been very reliable (other than a 100mph crash) ! My mates bike pushes 115bhp, that is using a 10mm stroked crank with 10 ball (larger cage) bearings, again C3 and has been very reliable, but the bearings etc have also been treated in a low friction coating. Going ceramic is a really good idea, but also very expensive and unless you have deep pockets, or are looking at serious power, say 140+bhp, then you'd have to question the benefits, or you are a very fast/hard rider on the track, for road use I'd say ceramics is overkill, but each to their own, I'd love ceramic bearings in all my engines, but I can't afford or justify such expenditure HTH Thanks for the detailed answer. |
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