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Re: Question about new wheel rim vs tire size [PedalingHertz] [ In reply to ]
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PedalingHertz wrote:

I'm concerned about crosswinds with too deep a front wheel. It can get VERY windy here (except on Saturdays when I want to go kiteboarding, apparently). I don't want to get pushed around too hard. Is that a legitimate concern for a rider my weight?

Again, I really appreciate everyone's help. I welcome random shout outs to wheels you think would be good. I looked up the HEDs mentioned and like them so far!


Hello fellow Honoluluian! I run a Tarmac SL6 too and the HEDs would not be that good for 28c tires. If you put those tires on that wheel, it'll probably balloon up to 29-30mm wide and that'll violate the 105% rule. At that point, you might as well be running shallower rims because most of that aero gain of a deep wheel will be lost and you're just running a heavier wheelset.

https://blog.silca.cc/...ure-and-aerodynamics

Aero may not be as big of a deal if you're going with 28c tires but more than anything, running a tire that's too wide for the rim will adversely affect cornering/handling. So, if you want to run 28s, match it with some wide internal rim width rims. Your stock ones are actually pretty good with this regard. This shimanos with 17mm internal rim widths would have been pretty bad with 28s.

I run 28c tires, because like you mentioned, Oahu roads suck. Currently using Conti GP5000s, on these set of 50mm deep 25.5 internal wide wheels built by November and they're awesome.

https://novemberbicycles.com/...disc-chris-king-r45d

These kind of rims are the new generation optimized for 28c tires. Others include the Enve 4.5AR, Hunt 48 limitless, HED Vanquish, Light bicycle Falcon Pro WR50 or WR38

I just finished doing a crap ton of research in buying my wheels so it's fresh in my mind.

Handling crosswinds is a skill/practice thing. Went to Makapuu on those windy days last week with 25mph gusts on those 50 deep rims and was blown around but those wheels handled it really well. I'm about 140lbs so it should be even easier for you at 200lbs.
Last edited by: Montster: Aug 11, 19 0:05
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Re: Question about new wheel rim vs tire size [Montster] [ In reply to ]
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That is some very helpful info! And good to see someone else in the area here!

I may be willing to come down in tire size for a race specific wheel (although I am definitely switching to 28s for my stock/commuting/training wheels). Most races are on closed roads, which gets me off of the shoulder and onto the less treacherous part of the road. That said, the ability of a race wheel to accommodate larger tires is a huge plus for me. It just removes a bit of anxiety for shooting down some of the descents. I hit an invisible pothole coming down Manoa Rd a couple weeks ago. I don't know how the bike stayed together, but more cushion would have been a lot better.

Are the Chris King wheels as aerodynamically sound as the HEDs? Or at least close enough not to worry about it?
Last edited by: PedalingHertz: Aug 11, 19 14:17
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Re: Question about new wheel rim vs tire size [PedalingHertz] [ In reply to ]
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PedalingHertz wrote:
That is some very helpful info! And good to see someone else in the area here!

I may be willing to come down in tire size for a race specific wheel (although I am definitely switching to 28s for my stock/commuting/training wheels). Most races are on closed roads, which gets me off of the shoulder and onto the less treacherous part of the road. That said, the ability of a race wheel to accommodate larger tires is a huge plus for me. It just removes a bit of anxiety for shooting down some of the descents. I hit an invisible pothole coming down Manoa Rd a couple weeks ago. I don't know how the bike stayed together, but more cushion would have been a lot better.

Are the Chris King wheels as aerodynamically sound as the HEDs? Or at least close enough not to worry about it?

Those wheels I linked don’t have to come with Chris King hubs. They branded that line of wheels as “All Road 50s”. You can choose a cheaper, more economical hub too and that line of wheels more describes the rim. I would say they’re close enough to HEDs to not worry about it. As far as aero goes, the most important thing is to match the measured tire size with the rim width. The dimensions of the rim matter more than the design. If you want to run wide AND still be reasonably aero, go for something like the All Roads. Alternatively you can see how much it would cost for them to build you that wheel locally. I assume your LBS is The Bike Shop?

Yea, Manoa road is a death trap right now with all the construction. No amount of wheel width would save you if you bomb down it at speed and hit one of the big holes. With your weight you may break the rim. Be careful out there.

If I were you, just go with the 28 tires on the rim you currently have. The stock wheels that come with the Tarmac are really a good bang for the buck because that internal rim width is good enough to run 28s for now. If you still feel like the wheels are lacking, go for the upgrade.
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Re: Question about new wheel rim vs tire size [Montster] [ In reply to ]
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Thanks. I'm going to keep researching the issue. I like that the November wheels are wider but wonder if I really need the 28s on the race set. If not, I may just go with the heds and use 25s. As you say, I def want them on my stock wheels for everyday use. But I don't think I want to race on my stock set with 28s on them due to weight and aero penalty, so I'll wait until I have a dedicated set of race wheels to do that.

With 2 local tri sprints coming up in the next 2 months, I'd like to get the upgrade done relatively soon. If you make your bike faster and don't race it, you didn't really make it faster, did you. :)
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Re: Question about new wheel rim vs tire size [PedalingHertz] [ In reply to ]
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PedalingHertz wrote:
Thanks. I'm going to keep researching the issue. I like that the November wheels are wider but wonder if I really need the 28s on the race set. If not, I may just go with the heds and use 25s. As you say, I def want them on my stock wheels for everyday use. But I don't think I want to race on my stock set with 28s on them due to weight and aero penalty, so I'll wait until I have a dedicated set of race wheels to do that.

With 2 local tri sprints coming up in the next 2 months, I'd like to get the upgrade done relatively soon. If you make your bike faster and don't race it, you didn't really make it faster, did you. :)

If I was you I'd probably get something like HED Jet 4 or 6 plus, fit 25mm GP5000 tyres and see how they feel. A wider rim increases the air volume compared to the same tyre on a narrower rim. So the HED will be more comfortable than the Ultegra wheel with the same tyre. Also the 25 or 28 label on the tyre is not the whole story. For example GP4000 tyres were far bigger than the labelled size on most rims. GP5000 has apparently dialled it back and is much closer to the labelled size. From what I've seen a GP4000 23 is very close to the size of the new GP5000 25.
You'll find inflated sizes of the GP5000 tyres on a 17mm rim at the link below:

https://www.bicyclerollingresistance.com/...omparison#sizeweight
Last edited by: Ai_1: Aug 12, 19 1:20
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Re: Question about new wheel rim vs tire size [PedalingHertz] [ In reply to ]
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PedalingHertz wrote:
Thanks. I'm going to keep researching the issue. I like that the November wheels are wider but wonder if I really need the 28s on the race set. If not, I may just go with the heds and use 25s. As you say, I def want them on my stock wheels for everyday use. But I don't think I want to race on my stock set with 28s on them due to weight and aero penalty, so I'll wait until I have a dedicated set of race wheels to do that.

With 2 local tri sprints coming up in the next 2 months, I'd like to get the upgrade done relatively soon. If you make your bike faster and don't race it, you didn't really make it faster, did you. :)


Honestly, if you’re doing tris on a tarmac, have you optimized everything else like aero helmet and suit? Otherwise, narrower tires and deeper wheels are not your low hanging fruit. Also about the HEDs. You would actually have to run something like 22s or 23s on that front tire, because again, the 105 rule. A 25 labeled tire would balloon up to 27 or 28ish on those wheels and you run into that problem of have a tire too big for the rim. Those wheels are too old for disc brakes and too narrow with only a 25mm external. It’s a really bad deal actually if you plan on running 25s. If you run 22s, then it’s fine. The whole point of disc brakes is to break free from old rim dimensions. Going with an HED is a bit out of date with disc brakes IMO. There are plenty of other rim options from November, light bicycle, roval etc.

edit: If you're going to spend HED Jet plus money, you're better off going with

https://novemberbicycles.com/...riant=28614804570205

or at the higher end,

https://rovalcomponents.com/products/cl-50

I'm sure there are others but there's a common theme here. 21mm internal, 28+ external, 50ish deep. That's modern dimensions for disc brakes and would be excellent for the tarmac disc. You can run the 25c front tire for race day to be maximum aero and 28c for everyday.
Last edited by: Montster: Aug 12, 19 2:01
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