Escadrille Ecosse Posted January 20 Posted January 20 Meh... So after Simon raised the topic I and being the weight weenie that I am, I decided that I would, at long last, bite the bullet and purchase a pair of alloy front hubs for the Mk1. So a pair of GT6 alloy hubs were duly ordered from Canleys (the car runs GT6 uprights and hubs but with Spitfire brakes coz they're lighter, see) and arrived a couple of days ago. Been faffing about with the bonnet mould (more of that later on that thead) so decided today that I would do some mechanical work and fit the new hubs. Car is on the hoist still so easy access and started on the drivers side. And decided to use the opportunity to fix the leaky trunions while I was at it and the hubs/discs were out of the way. Straightforward job to remove the trunouns from the uprights, knock out the bushes, clean things up and solder up the 'pennies' to the trunion body. Then remove the (good) bearings from first of the old hubs and fit to the new shiny alloy one. My main concern about alloy hubs was that the races have been known to spin in the hub body. Not a probelm here methinks as the hub needed to be well heated (in the outlet from the diesel heater) before they would even look at going in. Then time to fit back on the car. Which is where it all went mammaries up The car has Shack's solid bearing spacers. So these went in before nipping up the hub for a check on end float. Which was enormous. Thinking I had done something I took the spacers out and refitted the hub without them. The castellated nut went past the hole for the split pin before the bearings contacted. Compar and contrast with Triumph's version... Too the hub off and did some measuring against the OEM hub. Basically the seat for the outer bearing race is 4mm inboard from where it should be Side by side it's clear... The outer bearing is the more highly loaded one, particularly when cornering which is not helped by it also being the smaller one. Getting slightly bigger outer bearing is the reason I went with the GT6 hubs in the first place given the huge increase in front end grip over the standard car. Moving the bearing in simply increases the load, in this case about 10%, thereby undoing the benefit of the larger GT6 bearings. So these will not be going on the car. So much for weight saving. Tried phoning Canleys this afternoon but they must have loused for the day so I sent an email with some pics asking if they would give me a call to discuss. I cannot believe no-one has raised this issue before. Although if you arent using solid spacers (Simon?) then wouldn't necessarily notice I suppose.
Nick Jones Posted January 20 Posted January 20 Oh. That’s….. disappointing….. among other things. 4mm is rather a lot! I think you would notice even without the spacers as the split pin hole if left looking somewhat pointless. I take it both are the same?
Escadrille Ecosse Posted January 20 Author Posted January 20 34 minutes ago, Nick Jones said: Oh. That’s….. disappointing….. among other things. 4mm is rather a lot! I think you would notice even without the spacers as the split pin hole if left looking somewhat pointless. I take it both are the same? Disappointing indeed Nick Both unfortunately are the same. The unfitted one is back in its box and I have removed the races and cleaned the other one as best as possible. Just need to wait on Dave P getting back to me hopefully soon so I can decide what I'm going to do.
Escadrille Ecosse Posted January 22 Author Posted January 22 (edited) Got a reply from Canleys yesterday. Ten words and a full stop (including the greeting and signoff) "I will look into this and get back to you." Rather terse but we'll see. Edited January 22 by Escadrille Ecosse
Nick Jones Posted January 22 Posted January 22 Hmm… Been thinking about this and it be occurs to me that it’s just possibly done intentionally to drop the bearing into an area with more meat around it to better withstand the tight fit required for the bearing race?
Escadrille Ecosse Posted January 22 Author Posted January 22 Just now, Nick Jones said: Hmm… Been thinking about this and it be occurs to me that it’s just possibly done intentionally to drop the bearing into an area with more meat around it to better withstand the tight fit required for the bearing race? Hmmm. Meybees, but on the disc brake hubs the bearing race is is still mostly supported by the stud flange. My thought was that is allows a common casting with the sealed bearing mod where you definitely need more hub material for the larger outboard bearing. Either way as of itself it fecks the split pin and increases outboard bearing load. Neither of which are 'optimal'. Also means that my nice solid (and not cheap) bearing spacers are no longer fit for purpose and I'll need to get them modified. At which point they will be useless if I ever go back to the steel hubs. Or a properly dimensional alloy replacement. And at the very least the purchaser should be made aware beforehand. As it stands the cons (including the £240 quid cost, plus postage) outweigh the pros. For me anyway.
Nick Jones Posted January 22 Posted January 22 Yep, no argument from me on any of that. Split pin situation easy enough to sort with a second washer (putting weight back in!), but a bit ghetto and should not be needed. 7 hours ago, Escadrille Ecosse said: I will look into this and get back to you." So he is out there with his ruler wondering how much shit he’s in…. Dunno how many actual manufacturers of these there are. Merlin Motorsport also sell them https://www.merlinmotorsport.co.uk/s/driveline-suspension-and-steering-parts/alloy-hubs-and-bearings/alloy-hubs Also Moss. Not sure about Bastuck
Escadrille Ecosse Posted January 22 Author Posted January 22 (edited) 1 hour ago, Nick Jones said: So he is out there with his ruler wondering how much shit he’s in…. Dunno how many actual manufacturers of these there are. Merlin Motorsport also sell them https://www.merlinmotorsport.co.uk/s/driveline-suspension-and-steering-parts/alloy-hubs-and-bearings/alloy-hubs Also Moss. Not sure about Bastuck Yeah. I wonder that myself. The photo on the Merlin site looks like the hub is machined from billet. The Canley's ones are cast. Meanwhile... I've put it all back together with the steel hubs. I suppose the one real improvement in all this is that the trunions no longer weep oil. Edited January 22 by Escadrille Ecosse 2
Sigma hurricane Posted February 26 Posted February 26 On 1/22/2025 at 8:40 PM, Escadrille Ecosse said: Yeah. I wonder that myself. The photo on the Merlin site looks like the hub is machined from billet. The Canley's ones are cast. Meanwhile... I've put it all back together with the steel hubs. I suppose the one real improvement in all this is that the trunions no longer weep oil. Im guessing the weight saving with alluminium hubs is around 250g-300g per side? Tempted by a set of the billet ones from Merlin, though canley's are meant to be billet these days too?
Nick Jones Posted February 26 Posted February 26 Says billet on their website…… ”All our hubs are CNC'd from 6061 aerospace grade aluminium billet.” Definitely another debating point additional to the dimensional problems!
Sigma hurricane Posted February 27 Posted February 27 19 hours ago, Nick Jones said: Says billet on their website…… ”All our hubs are CNC'd from 6061 aerospace grade aluminium billet.” Definitely another debating point additional to the dimensional problems! Yeh though the photos I have seen off them definitely look more like they have been machined down from an over sized cast blank. The Merlin ones are a different design by the looks of them so at least aren’t just re selling the Canley ones like other websites…
Nick Jones Posted February 27 Posted February 27 Merlin have been selling them as long as I can remember, and that’s quite a while now…..
Sigma hurricane Posted February 27 Posted February 27 Hmm I might pick up a pair to see If it’s any better than Canleys offer then. Combine that and some alloy calipers and it’s 2kg’s a side weight reduction ( or several pints at the pub) Will report back if it suffers from the same issues. 2
Sigma hurricane Posted March 22 Posted March 22 Bit of a delay on doing this as been away as well as being unwell, finally ordered the Merlin hubs so will report back if they are any better. Also ordered one of the last bearing spacers to make that job better too off ebay. 1
Sigma hurricane Posted March 25 Posted March 25 Ok they arrived today which was superfast. First impressions are that they feel super light and well made. Over 1kg per side saving which is a huge plus on unsprung weight. I have compared them to a spare Gt6 hub. (I removed the bearings and races and stubs though a small amount of grease remained. The inportant bearing dimentions are identical so big win there as well as a 1.1kg saving per side. However the bolt holes for the disc are not taped like they on on the cast iron one and the stub holes have no groove marks in (though i guess with it being ally once they are pressed in they will form their own. The centre of the hub also doesnt have the same big void the stock one has. The rear of the hub doesnt have the same external step in however i cant think why that would mater. 1
RogerH Posted March 26 Posted March 26 Hi Siggy like you I wanted to reduce the unsprung weight, but didn't want to phaff around with hubs etc. So I simply removed the springs. Works well until you start moving Roger 1 1
Nick Jones Posted March 26 Posted March 26 20 hours ago, Sigma hurricane said: However the bolt holes for the disc are not tapped like they on on the cast iron one and the stub holes have no groove marks in (though i guess with it being ally once they are pressed in they will form their own. Studs will form their own spline when fitted. Presumably there is a counterbore on the outside for nuts for the disc holding bolts? Seems to be billet from the pics?
Sigma hurricane Posted March 26 Posted March 26 Yep its billet, fairly reasonable pricing given that lumps of ally that big arent cheap plus the complex machining. Yep there is a counter bore on the outside. I was thinking about the issues of the canley one and wonder if its a common casting with the other one they do with larger bearings (same bearing inside and outside sold under a bearing upgrade hub)
Escadrille Ecosse Posted March 26 Author Posted March 26 (edited) 8 hours ago, Sigma hurricane said: I was thinking about the issues of the canley one and wonder if its a common casting with the other one they do with larger bearings (same bearing inside and outside sold under a bearing upgrade hub) Yes. Except that it's not the casting, rather the machining of the bore for the outer bearing that is the issue. Things I like about the Canleys hubs are 1. They're made from a finished casting and not machined from what is in all likelihood a cast (rather than wrought) billet - cast billet stock being significantly cheaper than wrought at the sizes involved here. 2. By casting to the original Triumph pattern the form around the stud seats is better, stronger and more rigid - it's narrower for better support of the flange face but deeper providing plenty of space for the stud seat 2. There are machined slots in the bearing faces as per the originals to allow the races to be tapped out with a punch 3. They come with studs fitted and the holes for the studs are correctly chamfered to take the chamfer of the stud seats (if not using the big M12 flat face studs) The other potential issue with the Merlin hubs is that it looks as if the stud flange is slightly thinner than the steel items which isn't ideal. On the other hand the fact that the threads for the disc bolts are uncut makes fitting of thread inserts simpler. Personally I would always fit inserts into a stressed alloy component as per aerospace practice. Going back to the 'bearing upgrade' thing, I believe it is something originally developed by our Caterham friends as a cheaper (from initial manufacture) solution to bearing location than the solid bearing spacers and shims for the taper roller bearings whilst also allowing for the use of sealed bearings. The pics here show the sealed bearing installation on a Caterham. Note the thick spacer under the hub nut. The upgraded hubs here (Caterham) are of a somewhat different design again and which look rather stronger than the Merlin ones athough from the marks on the disc seat it rather looks as if these are also from cast stock. They also have cutouts for tapping ot the bearings. The original Caterham taper bearing hubs are also clearly cast (rather nicely) For those interested the link to the original thread on Pistonheads is here https://www.pistonheads.com/gassing/topic.asp?h=0&f=47&t=1353089 Update for me. Canleys came back and offered to supply spacers to go under the bearing race but given the time involved and having put everything back together I've kind of lost interest in the whole subject (at least for the time being) and sent them back for a refund which they also offered. Not particularly keen on the other options out there so will in all likelihood stick with the steel originals which function quite adequately. Edited March 26 by Escadrille Ecosse 2
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