getting new frame. Geometry question
08-01-10, 11:58 AM
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getting new frame. Geometry question
Hello,
Im riding a 54 cm trek 1000. it has traditional geometry and the top tube is 54cm. I feel like my reach is good already but there is a problem with my headtube height. I have a +17degree stem and 5 cm of spacers. basically my current headtube is only 110 mm tall. I know this is too small.
Im looking at picking up a frame from performance but I cant figure out which size to get. Ive been told I should ride a 56 because I have a 84cm inseam but my reach right now feels ok. The 54 on performance has a top tube of 55cm so it would be slightly larger than what I have right now. My question is, how much larger should my headtube be. the 54 has a headtube length of 148mm. the 57 has a headtube length of 175mm however the top tube would be 3cm longer than what I currently ride.
Suggestions?
Im riding a 54 cm trek 1000. it has traditional geometry and the top tube is 54cm. I feel like my reach is good already but there is a problem with my headtube height. I have a +17degree stem and 5 cm of spacers. basically my current headtube is only 110 mm tall. I know this is too small.
Im looking at picking up a frame from performance but I cant figure out which size to get. Ive been told I should ride a 56 because I have a 84cm inseam but my reach right now feels ok. The 54 on performance has a top tube of 55cm so it would be slightly larger than what I have right now. My question is, how much larger should my headtube be. the 54 has a headtube length of 148mm. the 57 has a headtube length of 175mm however the top tube would be 3cm longer than what I currently ride.
Suggestions?
08-01-10, 12:31 PM
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A typical racing geometry frame will have a headtube that's still too short for you. You should be looking at a endurance or sportive type frame that has a taller than average headtube. I would go no smaller than a 165mm tall headtube. A 165mm headtube + 30mm spacers + -6 degree stem will end up giving you virtually the same positioning as you have right now.
08-01-10, 01:07 PM
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what about the nashbar aluminum frame then? the 56 has a top tube of 54.5 and a head tube of 165. should I go with the 58 with the 185 mm head tube?
thanks for the advice
thanks for the advice
08-01-10, 08:17 PM
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So you are running a -17 stem flipped up? Are your bars the perfect height now or do you need to higher or can you go lower?
You don't want to make frame size/geometry selections base on inseam length. I would go for the smallest frame that allows for proper reach and optimum bar drop without having to add a ton of spacers and/or go with a high rise stem (which is what are running now if in fact you have your -17 flipped up). You should be looking at top tube length, seat tube angle and head tube length.
Using your present bike you should be able to determine the minimum head tube length you need then just make sure that whatever frame you go with has at least that length head tube.
I don't know if your budget allows but check out the specialized bikes I believe some of them have proportionally long head tubes if that is in fact what you need.
You don't want to make frame size/geometry selections base on inseam length. I would go for the smallest frame that allows for proper reach and optimum bar drop without having to add a ton of spacers and/or go with a high rise stem (which is what are running now if in fact you have your -17 flipped up). You should be looking at top tube length, seat tube angle and head tube length.
Using your present bike you should be able to determine the minimum head tube length you need then just make sure that whatever frame you go with has at least that length head tube.
I don't know if your budget allows but check out the specialized bikes I believe some of them have proportionally long head tubes if that is in fact what you need.
Last edited by rich88; 08-01-10 at 08:20 PM.
08-02-10, 06:57 AM
#5
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If you really need 5cm of spacer and a flipped +17 stem that raises the bars about 6cm more, then you have a bigger problem than head tube length. Even the recreational models only have head tubes that are 2-3cm taller than the racing models.
If you really want sound advice, you need to post your actual saddle height, and your desired saddle to bar drop. I would also need to know what type of headset is used on the frame in question. Integrated headsets are only 8-20mm in height, while conventional threadless models are 25-35mm.
If your saddle height is 74cm, for example, all it takes to produce a modest 5cm drop is a total head tube length, with the headset and spacers, of 165mm. Combine that with a +6 degree stem.
If you really want sound advice, you need to post your actual saddle height, and your desired saddle to bar drop. I would also need to know what type of headset is used on the frame in question. Integrated headsets are only 8-20mm in height, while conventional threadless models are 25-35mm.
If your saddle height is 74cm, for example, all it takes to produce a modest 5cm drop is a total head tube length, with the headset and spacers, of 165mm. Combine that with a +6 degree stem.
