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7VRN Frameset; Anyone tried one?

Old 09-26-17, 04:33 PM
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spartanKid
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7VRN Frameset; Anyone tried one?

Has anyone here ridden one or own(ed) one?

Brooks Cycles sells them here: 7VRN Carbon Track Frame - Brooks Cycles
and identical geometry framesets are all over eBay.

The frame geometry seems like it checks all the boxes for more traditional track geo and not a TT bike with track ends, but the 45 mm rake fork worries me. The 74.5 deg HT angle combined with a 45 mm rake fork would give an extremely twitchy 47 mm of trail. Most other track bikes are in the 57-63 mm trail range. Of course an easy solution would be to swap in a shorter rake fork, but one shouldn't have to automatically buy a second fork for a frameset to ride/steer predictably.
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Old 09-26-17, 04:49 PM
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I've ridden one briefly and it seems fine. Nothing stands out as stellar, but there's nothing that's a dealbreaker either. It's very good value for money, I just think the seatstays look ugly AF. I've got a bunch of friends who ride them though, and Jessica Crampton got her national title on one.
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Old 09-26-17, 05:59 PM
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Those frames have a really good reputation and are ridden by some people are very high levels.

The combo of the 45mm fork and the 74.5deg HTA raises my eyebrows, too. But I haven't taken one for a spin.
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Old 09-26-17, 07:31 PM
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Originally Posted by queerpunk View Post
Those frames have a really good reputation and are ridden by some people are very high levels.

The combo of the 45mm fork and the 74.5deg HTA raises my eyebrows, too. But I haven't taken one for a spin.
I have one of these frames, the Chinese/eBay model, not 7vrn. But this frame is marketed all over the place, and the brands that seem to be from the same mold include 7VRN (UK), Ferocity (South Africa), and Comanche (ridden by the Ukraine national team in World Cup events). Pictures below.
My experience with the Chinese/eBay brand has been fine with caveats:
- This is not a light frame. Carbon, yes, but my guess is it's built with cheaper carbon laid on much heavier - the frame set comes in at 1800 grams for the Large. That's heavier than good/basic aluminum 6061 and 7005 frames such as an Aventon Mataro or a Bianchi Super Pista. These frames look something like BT's (at least a few people at the track have asked me if it was), but are not anywhere near the same class. But it seems solid. I'm 6'2" and 205, and while I'm not a superstrong rider (I ride the old-man division), it rides nicely given my bulk. I don't see why I wouldn't use it for some years to come.
- The 74.5 HT/45 rake is an issue. I found that this combo - a 47 trail, as you say - works just fine on good, smooth tracks such as T-Town and Rock Hill, where the transitions are dialed in. At tracks like Dick Lane (and its "famous dip" between turn 3 and 4 that throws you off the line), or at bumpy old Kissena, you really get to see the difference. But I don't think it's twitchy, but rather the opposite, sluggish - if you go off your line, it takes forever to correct back.
- Given that geometry issue, and my concerns about carbon steer tubes bought on eBay, I went ahead and bought a Dolan/Alpina track fork with aluminum steer tube, which has a 30mm rake. IMHO, it nicely corrects all the steering problems on all tracks because the trail then comes in at the standard track spec of 60-ish. I also like that with the alu steer tube, I can change stems without worry - and the Alpina fork (about $150, as I recall) is actually lighter than the all-carbon 45mm fork.
- The seat post can slip. I have found that a combo of lots of paste and careful torque helps. But the situation got better when I finally replaced the bolt that came with the frame with one of a higher-quality steel. It actually helped a lot. I applied blue Loc-tite on that bolt as well, and torque to the very limit.
- I love the chain tensioners. I don't know why all track frames don't come with these now.
- Also, beware the specs as stated. The seat post is super wide, so the top-tube spec of 59.5 C-C in their chart is probably more like 58.5 if it were a 27.2 post. I have a steel frame with a 58.5 TT, and to me, the two frames match up. The next size down, listed as 56, is probably a 55 or so.
So, in the end, a nice bike, bike I doubt a lot better than the many aluminum frames in the same price range. In the end, you get what you pay for, and in that respect, I got a fine bike for such a low price.
Hope that helps! Pictures:
Attached Images
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my bike.jpg (24.2 KB, 213 views)
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Comanche track.jpg (25.7 KB, 215 views)
File Type: jpg
ferocity.jpg (24.6 KB, 212 views)
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7vrn black and white.jpg (24.6 KB, 211 views)

Last edited by TDinBristol; 09-30-17 at 11:18 AM.
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Old 09-26-17, 08:30 PM
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Has anyone actually measured the offset of the fork? From photos of these frames built up I don't see how the stock fork could be 45mm and have a 30mm fork actually work without the tire touching the downtube. I suspect that figure is a typo.
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Old 09-27-17, 05:25 AM
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Originally Posted by spartanKid View Post
To compare, TDinBristol could just hold the stock fork and the replacement Alpina fork side-by-side with the steerer tubes aligned and see where the dropouts sit relative to each other.
I can confirm the original fork had a rake of 45mm and that the Alpina is 30. I measured both forks on the bench as I swapped them out.
I added a picture below of my bike when I first built it up. You'll see that with the original 45mm fork there's a ton of tire clearance, so that was no issue.
Now I'm speaking here of the Chinese unbranded, but if you look at the picture you'll see the design of the L size has the down tube rising up then curving into the head tube. That affords clearance. If you look at smaller sizes of the same frame (green bike below, and the smaller 7VRN and Ferocity in my earlier post), that curve is less present in the M and not present in the S. So tire clearance could become an issue as you get smaller.
But as the more math-savvy posters (Carleton? BitingDuck?) can hopefully confirm, when the difference between the 45mm and 30mm rake is 15mm at the wheel axle, that offset reduces geometrically as it moves up closer to the steer tube. Therefore, where the tire would be closest to the frame is needing maybe 3 or 4mm of wiggle room...
Also, it's worth noting that the geometry is not that unusual these days - the Specialized Langster Pro goes with 74-degree head tube and 45mm rake, and you see lots people on those at the track. I think they make this spec because more buyers are getting these to ride fixed on the road than will ever see the velodrome.
https://www.specialized.com/us/en/la...rameset/106261
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chinese track bike green.jpg (26.2 KB, 202 views)
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Old 09-27-17, 05:55 AM
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I've wondered if the spec sheet has a typo, too, but maybe it's just the fore-aft thickness of the fork that makes it kinda look like it's not 45mm. TD, thanks for the complete post that confirms a lot of my guesses about that frame!

I didn't realize the Comanche was one, too - the paintjob threw me off.
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Old 09-27-17, 03:22 PM
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Originally Posted by spartanKid View Post
What I find the most surprising about the Langster is that they keep the same fork for 3 degree differences in HTA, so that's anywhere from 50 to 68 mm of trail!
That frame was made by the marketing department.
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Old 09-28-17, 08:46 AM
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@TDinBristol, I realize it's size dependent, but do you have stack and reach measurements on that frame?
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Old 09-30-17, 09:11 AM
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Originally Posted by sarals View Post
@TDinBristol, I realize it's size dependent, but do you have stack and reach measurements on that frame?
Sarals,

I may be a bit inexact, but I have reach at 44.5cm and stack at about 55cm.
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Old 09-30-17, 02:55 PM
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Thank you!
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