Increasing tire clearance - is it possible?

[d_douglas]

I am not sure if I am in the correct place here to ask this question, but I have a frame modification question for you. I own a 2008 (I think) vintage Vicious Cycles 29er. It is a very fun bike to ride and I am in love. It doesn't have 'current' geometry for where I live (PNW) and it doesn't have much tire clearance.

I can't do much about the geometry issue, and it is a riot to ride anyways, BUT I am wondering if there is a way to crimp the chainstays and seatstays just a bit in order to increase the clearance of fat tires? For reference, I had a set of 2.2" Trail Kings on there and they were just too tight for comfort. I would estimate that there is 2-3mm clearance to the chainstays with the Conti's, so I switched to some 2.0" skinnies, but the bike was really more fun with the fat tires. Any misalignment of the wheel (through accident or slippage of QR) and the tire would be rubbing on the frame, mostly at the BB shell area, but also up near the seat stay bridge.

Obviously, I would ask a skilled frame builder to do this (I live near to Naked Cycles, Dekerf, Hampsten) but I wanted to get an idea if this is worth investigating or if it will mess up the geometry of the frame/risk damaging the tubes etc. If it would do damage, I would abandon the idea in favour of living with it the way it is, or selling the frame and buying something else that would allow better clearance (and I do have something in mind that I admire)...

Thanks for any advice on this. Photos can be supplied if needed!



DARREN DOUGLAS

[EnginCycles]

I am rather intimate with Carl's bikes and I would not suggest trying to manipulate the tubes in any way. The stays would probably just crack if a dimple of any sort was attempted. Carl was very fond of the 1.95" tire and unfortunately he did not adopt the newer standard of a large tire.

IMO the best approach is to keep the bike as a period correct item and think about a more current bicycle that allows for modern equipment to work.

[BShow]

keep your wheels true and use a bolt on hub (or a more secure QR skewer)... then use the widest tire that you're comfortable using. Also, find the best tire pressure for you and your riding. I'm with you...I have an older steel 29er SS with pretty tight clearance. I'm basically limited to using low profile 2.0's and maaaaybe 2.1's. Matter of fact, I tried a new low profile 2.1 last night and it was too close for comfort. I like the frame a lot but just a couple more mm of clearance would alleviate some headaches. Now it's something I'll consider any time I get a frame.

[d_douglas]

Thanks, Drew. Yes, I think these things were made for racing. I might be able to get a marginally wider tire in there, but not enough to make a big difference. I have nice, high end Schwalbe 2.0" tires, so for the limits of the frame, it is about as good as it gets. It is a fun bike to ride, so I am tempted to just keep it and enjoy its old school characteristics.

Sadly, I don't think I can support two hardtail 29ers in my life, so if I get a new one, this one would have to go. I have a 100mm FS bike to play on and it is fun, but my heart is in only owning a hardtail - and I want it to be capable of wide tires and a longer travel fork - somewhere in between the Vicious and my Rocky Mountain squishy.

cheers,

DARREN DOUGLAS

I am rather intimate with Carl's bikes and I would not suggest trying to manipulate the tubes in any way. The stays would probably just crack if a dimple of any sort was attempted. Carl was very fond of the 1.95" tire and unfortunately he did not adopt the newer standard of a large tire.

IMO the best approach is to keep the bike as a period correct item and think about a more current bicycle that allows for modern equipment to work.